How To Wire Tweeters With A Built In Crossover To An Amp

Tweeters – even budget ones – can make a huge difference in your system. However, you may need to know a bit more before getting started. I’d love to help!

In this article, I’ll show you how to wire tweeters with built in crossovers to an amp. I’ve spent hours creating clear & detailed diagrams to help, too.

I’ll cover a lot of topics that really matter:

  • How to wire tweeters with built-in crossovers to an amp
  • Using tweeters with an amp’s built-in crossovers
  • Using your tweeters with a 2-way component speaker crossover
  • Whether or not you can use tweeters with an amp driving subwoofers
Contents

How to wire tweeters with a built in crossover to an amp

how to wire tweeters with built in crossovers to car amp diagram

The great news is that generally, car tweeters with crossovers are fairly easy to connect to amp in your current (or new) mobile audio system.

Note: I’ll use both the words Ohms and its symbol (“Ω”), used often in electronics, when talking about speaker impedance & resistance.

There are a few things to know first:

  • Most of today’s 2 and 4 channel car amp products can handle both a 4 ohm full-range speaker and a 4Ω tweeter connected in parallel at the same time.
  • It’s possible to keep the tweeter’s crossover and use an amp’s built-in crossover later (See related section below for more details).
  • Not only should you never use a tweeter without a crossover, but you also shouldn’t connect a tweeter to subwoofer outputs under normal circumstances. I’ll cover that in more detail later also.
  • You can replace the original tweeter crossover with a better one or use it with a 2-way component speaker crossover if you like.

How to connect tweeters with crossovers to an amp

To connect tweeters with crossovers to an amp, you’ll want use one of the following setups as they’re the most common situations you’ll come across:

  1. Connect them to unused amp channels with a full-range output option: Follow the positive and negative wiring connections on the amp, being sure to match the same speaker polarity at the tweeter (either on the tweeter or marked on the external crossover for those that use an inline one).
  2. “Tapping off” of full-range speakers already connected to the amp: Don’t mix the polarity – for correct sound, be sure connect the tweeter’s positive & negative speaker wiring to the same as the speakers already connected to the amp. To save time, effort, and speaker wire, if it’s convenient you can connect them in parallel at the speakers themselves. You’ll get the same audio signal there as at the amp as long as they’re full-range speakers.
  3. Connect them to unused amp channels: Using a full range RCA output pair from your head unit or use a pair of RCA Y-splitters at the amp to connect the 2nd pair of signal inputs to unused full-range amp channels. You’ll probably need to adjust the amp gain to a good level to match your speakers already in use.

Connecting tweeter wiring

While it’s true that a lot of tweeters come with connectors already on the wire, sometimes it’s just easier (and gives better results) if you use another way to connect the wire. Crimp connectors, for example, give professional results and won’t let you down.

In my experience, some of the connectors (usually slide tab or “spade” type) included with car tweeters are a pain in the behind to deal with. In fact, I rarely use them at all myself.

Keep reading to find out how to connect tweeter speaker wiring with professional results.

Where to install your tweeters

Car tweeter factory installation locations examples

Car tweeters work best when installed where they have a good direction toward your ears. That’s because high-frequency sounds are more directional than bass, for example. As a rule, try to avoid installing them lower in your car or truck. This is one reason you see factory-installed tweeters mounted in vehicle doors or side pillars near the windshield.

It’s not always an option, but when possible it’s best to mount tweeters:

  1. High up near the level of your ears
  2. Pointing towards you

That’s because unlike subwoofers which create huge sound waves that are so big it’s hard to tell where they’re coming from, highs are directional, meaning you’ll get better tweeter performance when the sound is directed towards you and unobstructed.

example of component speakers installed in car door

Example of upgrading factory speakers in a car door with a separate woofer, tweeter, and crossover. Note how the aftermarket tweeter is mounted in the factory bracket, held in with hot glue.

It’s one reason that factory-installed tweeters are placed high in the doors or side windshield pillars from the factory. In fact, high-end home stereo speakers are designed the same way…just that both the tweeter and woofer are placed on the same “plane” or at the same level for best results.

This is also one reason why car component speakers include tweeters designed to be mounted separately – to get the best possible sound by putting them in the best position you can find.

How to connect tweeter wires like a pro installer

Man with sign for how to strip & connect speaker wire properly

For excellent installation quality, I recommend using better connectors when possible. There’s really only a few steps needed and before you know it, you’ll be great at it!

The steps are:

  1. Strip the speaker wire and prepare it for the connector
  2. Insert firmly into the (correct size) crimp connector
  3. Properly and firmly use a crimp tool to permanently connect the wire

Then repeat for the other wires as needed.

How to strip speaker wire

How to strip wire example

To strip speaker wire you can use a number of tools. My recommendation (and preference) is to use an affordable tool called a crimp tool. Most of these not only crimp connectors but can also cut and strip wire.

Stripping speaker wire can touchy at first and take a little bit of practice, but you’ll pick it up quickly after a few tries. The trick is to pinch only the wire’s insulation and not the wire strands themselves.

If you catch the wire inside by squeezing a stripper too hard you’ll likely break the wire and have to start over.

To strip tweeter speaker wire:

  1. Insert the wire in the stripper and close it carefully on the insulation. Use enough force to hold the wire in place and slightly pinch the insulation, but not enough to put force on the wire inside.
  2. Hold the tool & pressure in place firmly so it cannot move.
  3. Pull the wire. The insulation could break off and the exposed wire should remain.

What to know before stripping speaker wire the first time

Some wire types (especially smaller gauges like 20AWG, 24AWG, etc) can be harder to strip without breaking. For your first few tries, practice on some surplus wire that won’t cause you to use up what you need for your tweeter installation.

Image showing ruler next to 1/2 inch stripped wire

I recommend stripping enough to leave about 3/8″ to 1/2″ of bare wire exposed. For crimp connectors, 3/8″ or more should be fine. 

Don’t leave an excessive amount of length because it can stick out of the connector once it’s inserted.

How to use crimp connectors with speaker wire

How to use crimp connectors with wire instruction steps image

Shown: Step by step pictures of how to strip & connect speaker wire using crimp (“butt”) connectors. After stripping the wire, it’s time to use a crimp connector on each one and a tool to crimp them for a long-lasting connection.

Using crimp connectors with speaker wire isn’t very hard – I promise! You’ll get the hang of it after doing a handful of times.

How to crimp speaker wire properly:

  1. Strip the wire leaving 3/8″ to 1/2″ bare wire exposed.
  2. Tightly twist the wire so it can be pushed into the connector properly.
  3. Insert the wire into one end firmly, pushing it into the metal contact inside. Be sure to insert it fully.
  4. Place the connector into the crimp tool in the appropriate position in the tool, near the end of the connector.
  5. Crimp very hard with the tool to make and indentation in the outside of the connector. The internal metal connector should bend inward and make a permanent hold on the wire.
  6. Repeat the same for the other side & speaker wire.
Tip: For best results, once you’re done pull gently on the wire while holding the connector. The wire shouldn’t come out. If it does, you’ve crimped it poorly and will need to do it over again.

What should it look like when you correctly connect speaker wire together?

Closeup example of properly crimped speaker wire

Crimp connectors, also sometimes called butt connectors, are sold in standard colors for the wire gauge sizes they can be used with. Although red is listed as fitting 18 AWG wire, I’ve been using blue butt connectors with 18 AWG speaker wire for years without problems.

You should be able to find a very small package of blue connectors (or an assortment of several sizes) for just a few dollars in general merchandise stores or auto parts stores.

Can you hook up tweeters to the same amp as a subwoofer?

Hooking up tweeters to same amp as subwoofer diagram

Here’s the short answer:

  1. You cannot use tweeters on a monoblock (bass-only) amp or a subwoofer output channel using a low-pass crossover.
  2. You can use tweeters with unused amplifier outputs (channels) that are full-range.

Why can’t you use tweeters on a monoblock sub amp or bass output?

You might not have known it, but nearly all monoblock (single-channel) subwoofer amps are designed only to produce bass. They’re designed just to create a lot of power and drive subwoofers with high volume. There’s no treble (highs) to drive tweeters with at all.

Additionally, using an amplifier’s channel/channels with the built-in low pass crossover means you’re doing the same there as well. For that reason you’ll have just a few options:

  • For multi-channel amps, connect the tweeters to unused full-range amp channels.
  • Connect the tweeters in parallel to the main speakers.

If you only have a single amp for driving the subwoofers and no unused full-range speaker outputs on your amp, there’s no way around it – you’ll have to buy another amp for the tweeters or use your head unit.

Note that head units produce a very small amount of power (about 15W or so per channel) so your tweeters won’t get anywhere near the volume or power your amplified speakers will have.

Can you use the built-in crossovers on an amp with tweeters?

How to use car amp built in crossover with tweeters diagram

Yes, in many cases you can use an amp’s built-in crossovers with your tweeters. In some circumstances, you can even completely replace the tweeter’s crossovers this way!

Additionally, it’s one way to take advantage of your amp’s features and improve the sound.

A few examples are:

  • Using the amp’s 12d/octave crossover improve (or replace) cheaper 6dB/octave crossover some tweeters use.
  • Remove the hardwire tweeter crossover, making installation simpler.
  • Improve tweeter bass blocking without the need for extra parts or work.

How to use tweezers with built-in crossovers with a 2-way crossover

How to use tweeters with built in crossovers with 2-way speaker crossover diagram

I’ve actually run into this situation myself! Let’s say you have some extra tweeters lying around or you’ve got a cool idea for your own 2-way component speaker setup.

Or maybe you’ve got a component speaker system and one of the tweeters is blown, damaged, or broken. What if you could make good use of those extra tweeters or a pair you got a great deal on?

The good news is that in most cases if the tweeter impedance matches that of the 2-way crossover this can work.

However, the most important thing here (the “showstopper” if you will) is that you don’t use the built-in tweeter crossovers. You’ll have to remove and/or bypass those.

What can’t I connect my tweeter crossovers to a 2-way component speaker crossover?

The problem here is that a speaker crossover is designed to connect directly to the speaker “load” (to the speaker impedance, or resistance if you will) directly.

Speaker and tweeter crossovers contain capacitors and inductors. No problem there, but when one crossover is connected to another it changes how they behave. This means (1) the sound will be wrong, and (2) the crossover frequencies will be very wrong.

There’s no way to “fix” that. You’ll have to be sure and remove or bypass a tweeter’s crossover before using it with a speaker crossover it wasn’t originally used with.

More excellent tweeter & speaker articles you can’t miss

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How To Add A Resistor To A Speaker To Change Or Match Impedance

How to add a resistor to a speaker to change impedance featured image

Maybe you’ve got some extra speakers lying around or just want to know how to add a resistor to a speaker to change its impedance. Either way, you’re in luck!

In this article, I’ll show you:

  • How to change (or match) speaker impedances using resistors (with great diagrams to follow!)
  • The disadvantages of using resistors to change the speaker impedance
  • What kind of resistors you’ll need
  • What to do if you can’t find exactly the right resistors (there are some handy ways around that!)
  • Where to buy the right resistors – without going broke, too!
Contents

What kind of resistors should you use for changing speaker impedance?

Audio power resistor examples

Examples of common “power” (high-power) resistors used for audio & speaker impedance needs. These are resistors built to handle the higher power levels put out by an amplifier or stereo.

To work with the higher output of amps and receivers, you’ll need to use power resistors when working with speakers.

A power resistor is just a larger-size resistor that can handle a lot more power & heat than the small ones commonly used on electronic boards. They’re actually fairly inexpensive, too ($5 or so for 2 to 4 in a pack), and are commonly used for custom speaker projects.

For speaker systems, I recommend using one with a power rating of 25 watts or more to be sure. For car stereos (not car amplifiers – those are higher power), you can often get away with around 10W to 15W.

Note: Resistance is usually described in units called Ohms, also commonly shown with the Greek omega “Ω” symbol.

Resistors to avoid

Example of standard electronic axial resistor

Shown here is an “axial” type resistor used for low-power electronics. These types of resistors aren’t suitable for working with speakers, audio, and other high power electrical circuits. Don’t use them for speakers as they can get extremely hot and potentially burn out.

While you might be tempted to try them, it’s important to avoid low-power (small) electronic resistors. These usually are rated for only about 1/8 of a watt to 1/2 watt. They’re simply too small to safely handle the large amount of heat that speakers and amps can dish out.

If you connect these to a high-power audio system they can become extremely hot, possibly causing burns or simply burn out altogether and cause failure (if you’re lucky) or even damage items they’re close to.

How to add a resistor to a speaker to change or match impedance

How to add resistor to speaker to change impedance diagram

You can change speaker impedance with resistors for two situations:

  1. To use a lower impedance speaker than you normally could with an amplifier or stereo.
  2. To use a higher impedance speaker where a lower one is needed (for example: speaker crossover designed only for a certain Ohm rating speaker).

Of the two cases, #2 is a lot less common. However, it’s really helpful when using speakers with crossovers and a few other situations you may run into.

If you’d like to use a higher speaker impedance than required for a stereo or amp, that’s normally not a problem (I’ll cover this in more detail later). I’ll explain 

1. Using resistors to increase the total speaker impedance load

As shown from my diagram above, if you’re planning on using a lower impedance speaker you can add resistors in series in order to bring up the total impedance that the stereo or amp sees. This allows you to safely avoid overheating and burning out the electronics you’re connecting to.

To do so:

  • Connect a resistor with the right resistance (Ohms) value to bring up the speaker impedance as needed, and with at least 1/2 the rated power of the stereo or amp’s power output rating. (Ex.: for a 50W/channel stereo, you’ll pick a power resistor with a rating of 25W or more)
  • Insulate any exposed resistor leads so they can’t short to speaker wire or metal. Always make sure the speaker or resistor wire is fully covered & not exposed.

A resistor connected in series simply adds its resistance to the speaker impedance rating. (Ex.: A 4 ohm resistor plus a 4 ohm speaker = 8 ohms total).

2. Using resistors to decrease the total speaker impedance load

What’s great is that not only can you increase speaker impedance connected to an amp or receiver, but you can also effectively decrease it, too! This isn’t something you’ll run across very often, but there are some situations where it’s really handy to know how to do it:

  • Matching a different impedance speaker to speaker crossovers
  • Temporarily using extra speakers until you can get replacements for the original ones
  • Replacing obsolete speakers with the next best ones you could find, but need to match the impedance
  • Making use of discounted speakers you’ve gotten an excellent price on

In this case, you can decrease the total speaker load seen by connecting resistors in parallel.

To do so, it’s basically the same as connecting resistors in series but the main difference is that you’ll wire it in parallel:

  • Calculate the resistor value you need, in Ohms (this is usually the same as the speaker: for example, to have a crossover see a 4Ω with an 8Ω speaker, you can connect an 8Ω resistor in parallel
  • Add resistor to speaker wire & speaker: Connect the resistor to the positive and negative terminals of the speaker (you can do this using speaker wire – there’s no need to do it right at the speaker if that’s a problem)
  • Insulate & fully cover any exposed speaker wire or resistor leads so they can’t cause a short-circuit to nearby wiring or metal

Resistance in parallel is a little bit more complicated

How to calculate resistance impedance in parallel example diagram

Resistance in parallel is a little bit more complicated to figure out as far as the math is concerned. However, don’t worry! It’s actually fairly easy once you understand how it all works.

Resistance in parallel adds using this formula: R_total = 1 / [ (1/R1) + (1/R2) ]

However, for resistance/impedance in parallel, if the values are all the same you can just divide by how many there are.

What are the drawbacks of using resistors for changing speaker impedance loads?

How power is divided between speakers and resistors diagram

Diagram showing an example of how power is divided up when using resistors to change speaker impedance seen by an amplifier or radio.

One thing to be aware of that it’s not a perfect solution – there are drawbacks.

One of these is that when you add a resistor in series with a speaker, the power delivered is split between the two. The second one is that you can’t get the same maximum volume from your amp or radio as you could using only the correctly matched speaker impedance.

For example, let’s say you want to use a 4 ohm speaker with an 8 ohm minimum 100W/channel home receiver. Adding a 4 ohm resistor in series will bring the total resistance (speaker load, in Ohms) up to the safe level of 8Ω.

However, having a series resistor connected to the speaker means that each one gets only 1/2 of the total power delivered. That means when using a resistor to compensate for the wrong speaker Ohms value, you’ll always lose some power across it. That’s regardless of connecting before or after the speaker – that doesn’t matter.

Overall power available is reduced for parallel resistors, also

Similarly, when using resistors in parallel with a speaker to bring down the impedance the amp or stereo sees, they share power as well. For example, using an 8Ω resistor in parallel with an 8Ω speaker will give 4 ohms total. However, with a 50 watt per channel amp, the power is still divided between them, leaving a maximum of 25W to the speaker.

That’s because they share the amount of electrical current the amp can produce. It’s no longer fully available for only a single resistance (a single speaker).

Using resistors can sometimes slightly affect the sound

Speakers aren’t exactly like resistors – this means in some areas their impedance changes with the sound frequencies they’re playing. This is due to inductance and how the voice coil is affected by an alternating current (AC) musical signal.

This being the case, adding a resistor can slightly alter the sound as it can cause a speaker to behave slightly differently across the range of sound. However, for the most part, this isn’t normally a big issue.

Just be aware that if you notice a difference that may be why.

What if you can’t find exactly the right resistors?

Example of power resistors in retail store on display hooks

Shopping for the right value & power rating of resistors can be a pain! That’s especially true when you can’t find the right values or if they’re out of stock

Here are a few tips for getting the right value resistors if you’re having problems finding what you need:

  • You can use multiple resistors that add up the right value.
  • They don’t have to be the perfect Ohms value – close is usually fine. For example, if you couldn’t find a 4Ω resistor, a 4.2Ω would be fine (as long as it’s ok for handling the power across it).
  • You can use two resistors in parallel to get a lower value: for example, if you need an 8Ω one, you can use two 16Ω resistors in parallel to get 8Ω.

In my experience, not every electronic parts store carries what you need. You may need to get creative if you can’t find what you want.

Some of the most common Ohm rating resistors are values like 1Ω, 2Ω, 5Ω, 10Ω, and so forth which you can use to get fairly close to the value you need.

Example of miscellaneous power resistors different values in package on floor

You can use multiple value power resistors with speakers to change their impedance. To do so, you can mix and match as needed to get the right overall value.

Where to buy resistors for changing speaker impedance load

Power resistors aren’t something you’ll find everywhere. A few places I’ve found them available are at:

  • Fry’s Electronics (may be going out of business, however, so be aware).
  • Parts Express – great supplier of many types of audio & speaker parts including resistors.
  • Amazon, eBay, and other online sellers of miscellaneous parts.

That’s if you’re the USA, of course. For other countries, you’ll need to search a bit if you don’t already have a good source.

How much do power resistors for use with speakers cost?

Power resistors should be affordable. For example, I’ve paid as little as $1.99 for a pair and often have gotten sets of 2 or 4 for about $5 or so. This is for resistors with up to 25 watts power handing, in fact.

More excellent articles to read

Check out these other articles I’ve put together! There’s a ton of great info just waiting for you.

There’s even more waiting, too! Check out all of my how-to & informational guides here.

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How Does Increasing Speaker Impedance Affect dB Volume & Power Output?

How does increasing speaker impedance affect dB output featured image

Does changing speaker impedance make a difference in the volume (decibels, or dB) you’ll get? And what about power – how does that change?

I’d love to help clear all of this up! In this article I’ll cover:

  • What impedance is all about
  • How the dB output (volume) changes if you increase speaker impedance
  • Car and home stereo power & volume differences related to speaker impedance

…and lots of other great info. Read on to learn more!

Contents

What is speaker impedance?

What is speaker impedance diagram

Speaker impedance, measured in Ohms, is the voice coil total resistance to the flow of electric current as it operates with a musical signal.

Any time you can a voltage delivering current flowing through wire you need some amount of resistance to limit how much can flow. Likewise, an amp or stereo needs at least some speaker resistance (a speaker load, if you will) to limit how much electrical current the radio or amp tries to supply.

Unlike straight wire that goes from point “a” to point “b” when you hook up power, the voice coil’s wire winding forms a loop that has an electrical property called inductance. Inductance is a bit different from resistance as it has resistance depending on the frequency of the alternating current (AC) flowing in it.

This is called inductive reactance.

Speaker impedance changes with music frequencies – somewhat

For car speakers, this means that the real impedance (the total resistance) actually changes a little bit as music plays! However, the good news is that we can still give speakers an Ohms rating (speaker impedance rating) as it’s always within a certain range like 2 ohms, 4 ohms, and so on.

When we talk about the impedance of a speaker, most of the time people are referring to the category (general range) of the speaker as used to match home or car stereo amplifiers.

In the electrical world, Ohms are sometimes represented by the Greek symbol Omega, or “Ω.”

How does speaker impedance work?

how does speaker impedance work diagram

As I mentioned earlier, a speaker’s impedance is made up of it’s resistance and inductive reactance due to the coil of wire that makes up the voice coil.

Impedance can’t be measured fully with a direct current (DC) test meter. For example:

  • If you use a digital multimeter set to read resistance in Ohms, you’ll measure only the DC resistance of the wire.
  • If you had the right equipment and could apply an AC signal you’d see an additional amount of resistance also.

Adding both of these together would give the actual “impedance” total. Like wise, the same things happen when an musical signal is driving a speaker to make sound: the amp or stereo will “see” a speaker load that’s the sum of both.

Resistance and inductive reactance math explained

Unlike standard resistance, you can’t simply add inductive reactance to it. To compute the total speaker impedance, you’d add them together by finding the square root of the sum of the squares, sometimes called the “trigonometric sum.”

Note: For the sake up general discussion, we don’t need to know the exact speaker impedance when matching speakers, talking about dB output & power, and so on.

I’m offering this as additional info to help your understanding of where it all comes from.

How does increasing speaker impedance affect power? 

Speaker impedance vs power & Ohms law diagram

As you can see from the diagram I’ve provided above, increasing a speaker’s impedance doesn’t just affect volume (which I’ll cover in more detail below) but power, too. In fact, it can make a big difference in how much power you’ve got on tap with your home or car stereo or amplifier.

That’s because of Ohm’s Law and how power works:

  • Home & car stereos and amps have a certain amount of voltage they can produce to deliver power to speakers.
  • According to Ohm’s Law, if you change the resistance (speaker impedance, in this case), the power developed changes accordingly.
  • Amps and radios have an upper limit to how much voltage they can put out, so the maximum output doesn’t change if you increase the speaker impedance. It’s a fixed limit.
  • Therefore: if you increase a speaker’s impedance, less power will be developed using the same stereo or amp.

Increasing speaker impedance vs power in watts comparison graph

In this example graph, you can see how much power a 4 ohm speaker will develop with the same amplifier as an 8 ohm speaker. The 4 ohm will not only develop 2x the power of the 8 ohm speaker, but the 8 ohm one will never get the full power available from the amp.

That’s important in some cases and less important in others. For example, for home stereos where you don’t need a huge amount of power, you can use 16 ohm speakers in place of 8 ohm ones without noticing that much of a difference.

However, it’s a different case when we talk about car audio as they often need a lot more power to produce great sound or volume in a vehicle – especially with subwoofers for heavy bass. In that case, switching from 4 ohm to 8 ohm speakers means you’ll have 1/2 the power available that you used to.

That’s a big difference!

Does speaker impedance affect volume? 

Increasing speaker impedance vs dB volume output comparison graph

Diagram showing an example graph comparing the dB output volume of an 8 ohm speaker at the same level as a 4 ohm speaker. A 4 ohm speaker will produce a few more decibels of volume at a lower output level of a radio or amp. When the amp is at its maximum output (maximum output voltage), the 4 ohm speaker will have a much higher dB output than the 8 ohm at the same level.

In the graph above, you can see what happens when we use an 8 ohm speaker in the place of a 4 ohm speaker connected to the same amplifier. It might seem confusing at first, but what the graph is showing is:

  • The dB output of the 4 ohm speaker at its 1 watt output and higher. [This is a lower output voltage on the radio or amp than for an 8 ohm speaker]
  • The dB output for an 8 ohm speaker at those same amp levels.
What this helps show is that when you increase the speaker impedance on a stereo or amplifier designed for a lower speaker impedance, the decibel output (dB, volume) will be lower throughout the full power range.

It can also be a lot less than the correct impedance at the maximum output.

You’ll have to increase the output of the radio or amp to get the same dB volume output for the higher impedance speaker.

This means that:

  • For a higher impedance speaker, the overall volume will be a few dB lower typically, depending on the particulars of that speaker.
  • You’ll never get the full capacity out of the stereo or amplifier as you would with a lower impedance speaker like it’s designed for.

For car subwoofers, for example, that’s a big deal. For every doubling of power to a speaker, you’ll get 3dB more volume, not double the volume. 4x the power is 6dB, and so on.

Our ears work in a way such that about 10dB is considered a big difference, which takes about 10x the power. When doubling the speaker impedance, as you can see from the graphs above, you’ll “run out of steam” well before reaching the maximum power your amp could put out like it would with the correct (lower) impedance speaker.

For home or car stereos with lower power output (most car stereos are limited to about 14-15W or so) that’s quite a difference.

What happens if I use a higher impedance speaker on a crossover?

Crossover shift due to speaker impedance change explained diagram

What is crossover shift?

Speaker crossovers are designed using predetermined values for the capacitors and inductors they use as filters. When a speaker manufacturer design speaker crossovers, it’s always based on the speaker impedance they’re designed to be used with.

Crossovers behave differently when the speaker load (Ohms load they see) changes. Because of this, when you change the speaker impedance you change the crossover frequency and the sound. The crossover frequency will change – typically a lot.

In other words, changing the speaker impedance will shift the crossover frequency. You may notice several problems after doing this:

  • A “harsh” sound from woofers or midrange speakers. Tweeters may sound distorted and being to “break up” the sound at volume.
  • A “thin”, weak quality to the music.
  • Gaps in the sound ranges you should be hearing.

Speaker crossovers should only be used with the speaker impedance they’re designed for or they won’t sound right.

For example, using a 16 ohm speaker with an 8 Ohm home speaker crossover won’t work correctly. It’ll sound poor and won’t work as designed. You can definitely expect to be disappointed with the sound.

Don’t forget that if your speakers aren’t of the same impedance, the higher one won’t be at the same output level as the correct one, meaning they’re not properly matched.

Do I need to match tweeter and woofer impedances for 2-way speakers?

Do I need to match speaker impedance in 2-way systems? Image man thinking

I don’t recommend mixing speaker impedances in 2-way or 3-way speakers because they won’t have the same volume level once you turn up the volume. That means the sound won’t be right and you’ll be left having to deal with some sound frequencies being poor after a certain point.

As you can see from the graphs I provided earlier, as the power increases the higher impedance speaker will always fall short of the also correctly matched speaker.

In 2-way speaker systems, that an even bigger problem because very often tweeters already have a higher volume output than their woofer or midrange counterparts. To make matters worse, most 2-way speakers have at least crossover they depend on.

This means in many cases changing the speaker Ohm load will also change the crossover behavior and affect the sound negatively.

I’ve seen some speakers systems where one speaker (typically the tweeter) has a different Ohms rating than the others, but in that case the designers take that into account.

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What Will A 2, 4, or 8 Ohm Impedance Speaker Measure For DC Resistance?

What will a 2 4 8 ohm impedance speaker measure DC resistance featured image

Speakers a little bit of a curious thing: they’re called 4 or 8 ohm impedance and so on, but most don’t actually measure that amount of resistance in Ohms when you check them!

Why is that, and what should you measure when checking the DC resistance for most speaker impedances ( 2, 4, and 8 ohm)?

I’ll explain everything in detail and provide a handy chart of some DC measurements you can expect.

Contents

What will a 2, 4, or 8 Ohm impedance speaker measure for DC resistance?

Speaker impedance label and ohm meter examples

In the real world an 8 ohm speaker will have a resistance measurement less than its 8 ohm rating. That’s normal and is because the DC resistance and the total resistance, called the impedance, are not the same. DC resistance is always less than the total speaker impedance as you’ll see later.

You can find the typical DC Ohms measurement range for many speaker common speaker impedances here. To use this chart, just find the impedance rating you’re interested in (1st column) and look at the Ohms measurement range in the 2nd column.

Speaker impedance DC resistance/Ohms range chart

Speaker impedance DC resistance
2 ohms 1.2-2 ohms
4 ohm 3.1-4.0 ohms
8 ohm 5.7-8 ohms
6 ohms 4.0-6 ohms
1 ohm* 0.5-1.0 ohms
16 ohms* 12-16 ohms

*(1 ohm speakers are unusual but can be found in some car stereo products such as Bose premium amplified systems. 16 ohm speakers may sometimes be used for home or other speaker systems but you won’t run across them very often, either.)

The speaker DC resistance chart listed here covers a wide range of speakers. These can vary quite a bit between different models and different sizes of speakers, even from the same manufacturer. Don’t be surprised if your 8 ohm home speaker measures around 6 ohms for example.

What is speaker impedance? Impedance vs resistance explained

What is speaker impedance diagram

A speaker’s impedance is the total resistance to the flow of electrical current when it’s connected to an amplifier or stereo. It’s a combination of the direct current (DC) resistance AND the portion of resistance due to magnetic fields created when an alternating current (AC) musical signal is applied.

Both resistance and impedance are measured in Ohms so the end result is a total value in Ohms also.

For example, when measuring a speaker’s resistance with a test meter or Ohm meter, the meter puts out DC voltage and measures DC resistance. If you had some fancier test equipment and a lab to put out an AC signal, you’d also see that a speaker develops more resistance based on the frequency applied to it.

Speaker impedance, measured in Ohms, is the voice coil’s total resistance to the flow of electric current as it operates with a musical signal, not just the DC resistance of the wire it’s made of.

Speaker impedance vs resistance explained

how does speaker impedance work diagram

As I mentioned, speakers use a voice coil that’s a long length of wire spun into a tightly wound coil by high-precision machines at the speaker factory.

When you play music and drive a speaker with power, magnetic fields are created as current flows through the coil. These fields create an opposition (resistance, called reactance in this case) to the current flowing through it. This is a very common property of wire coils and is also used to create electric motors, spark plug coils for engines, stun guns, and much more.

The coil has a property called inductance that affects how strong the magnetic fields are. Inductive reactance is different from resistance as it changes as the frequency changes, unlike DC resistance.

This kind of “resistance” is called inductive reactance.

Resistance measurements (Ohms) are sometimes shown by using the Greek symbol Omega: “Ω”

Where the total speaker impedance comes from

How to calculate speaker impedance diagram

The mathematical formulas for calculating speaker voice coil inductive reactance at a given frequency and total speaker impedance. It’s a bit complicated, but not too bad once you understand it!

Unfortunately, impedance/inductive reactance is a bit complicated to deal with mathematically. Because of how inductance works and the physics involved, the total speaker impedance (resistance + inductive reactance) isn’t as simple as just adding together the resistance and the inductive reactance.

Instead, speaker impedance is found from the square root of the sum of the squares of the coil’s wire resistance and the inductive reactance.

Inductive reactance is represented as “Xl”, pronounced “X sub L” and is measured in Ohms just like resistance. Inductance is measured using a unit called the “Henrie” and is shown as an “H.” “uH” means microHenries (1/100,000 of a Henrie), mH” represents milliHendries (1/1,000) of a Henrie), and so on.

Inductors are extremely useful for audio – especially for speaker crossovers. In that case, they’re a critical component for high- or low-pass crossovers and are chosen based on their inductance.

How to measure speaker impedance with a test meter correctly

How to measure speaker impedance with an Ohm meter example

In this picture, you can see an example of how to measure speaker impedance using an Ohm meter or any standard test meter set to measure resistance in Ohms. To do so, set it to one of the lowest ranges (0-10 Ohms, 0-20 Ohms, etc) or the auto-range setting if available. Touch the test probe leads firmly against clean, bare metal on the speaker terminals with at least one speaker wire removed to avoid a false measurement.

To measure the impedance of a speaker you’ll need a multimeter or a dedicated resistance meter.

Do the following:

  1. Switch on the meter and set it to measure Ohms on the lowest range. This is often the x1 range, 0-10 Ohms, 0-20 Ohms, or auto-range setting.
  2. IMPORTANT!Disconnect one or both speaker wires from the speaker to avoid a false reading due to other resistance that may be connected to it. If other things are connected they can cause false readings and give you the wrong idea.
  3. Hold the probes firmly against the speaker terminals on a clean, bare metal spot. The meter should quickly settle to a reading. The meter will show the DC resistance of the voice coil wire.
  4. Use the measured value to determine the closest approximate speaker impedance (see my chart above if you like)
  5. For speakers inside a cabinet or enclosure such 2-way speakers, crossovers may be in use and these can interfere with this reading with a few exceptions. However, in many cases, you still measure the resistance of a woofer fairly well. (I still recommend disconnecting at least one wire before taking a measurement.)

Remember that you won’t measure exactly 4 ohms for a 4 ohm speaker or 8 ohms for an 8 ohm speaker, for example. The DC measurement is almost always 30% lower than the impedance rating on the speaker’s package or label.

Selecting the correct test meter resistance (Ohm) range for speakers

Image showing examples of test meter resistance setting for measuring speaker impedance

It’s important to use the correct Ohms range on your meter when measuring speaker impedance. That’s because the wrong setting may display nothing useful or mistakenly give you the idea that the speaker is blown or even an incorrect reading.

If you’re not sure, check the test meter’s manual. Many modern digital meters often have an auto setting that will automatically adjust for the Ohm measurement it detects and will change the range and decimal place automatically for you. Other meters require you to select the correct range manually.

As a general rule, use the lowest range that includes 0-10 ohms (or similar) then go up if necessary.

That should almost never happen, but in the case of a poor connection, a blown (or almost blown) speaker, stuff can happen and you could get a reading that’s not really the speaker’s normal DC resistance.

In my experience, however, that’s not something you’ll run across often, if at all.

What happens if my speaker impedance is too low or too high?

4 ohm vs 8 ohm speaker power comparison graph

This is a graph showing how a higher impedance speaker makes less power than the correct speaker that should match an amp or stereo. For example, using an 8 ohm speaker in the place of a 4 ohm one means you’ll get 1/2 the power and as a result, you’ll never be able to the same volume or performance that you paid for with your system.

Using a speaker that’s not matched to the stereo or amplifier it’s rated for can have relatively minor – or even terrible results depending on what you’re dealing with:

  • Using a higher impedance speaker won’t damage equipment. The result will be lower power developed and therefore lower possible volume. You may also introduce problems with speaker crossovers, however.
  • Using a lower than specified impedance speaker will cause radios or amps to suffer extreme heat and even permanent damage because the current output will be much more than what it’s designed for.

As an example, if you were to use 8 ohm speakers in the place of 4 ohm car stereo speakers you wouldn’t hurt anything because less current will be output and it wouldn’t overheat. The problem will be (although it will play fine, otherwise) is that the total power available will be 1/2 that of a 4 ohm speaker.

What happens if using a higher or lower speaker impedance diagram

However, there’s a huge problem if you use a lower impedance speaker that’s matched to the amp, home stereo, or etc. The end result will be that it’ll being to overheat and can potentially suffer permanent damage and stop producing sound.

That’s because using a lower speaker impedance causes the radio or amp to attempt to put out twice as much (or more!) current than it’s designed for.

If you’re lucky the radio, home stereo, or amplifier will shut off to protect itself. Unfortunately over the years more often than not I’ve seen amps or radios burn out their output stages because of a short-circuit or the wrong impedance speakers being connected.

Why do lower impedance speakers cause an amp or radio to burn out?

The high-power transistors used in home or car audio devices can only handle a certain amount of electrical current (amps) or heat. When forced to handle more than their safe limit they become incredibly hot and start to break down. Before long they’ll stop working altogether as the semiconductor components are destroyed.

Caution! Never wire speakers in a way that gives a total speaker load lower than the radio or amp is rated for. Also, don’t guess about the correct speaker impedance – check first. Don’t risk it as it’ll be an expensive lesson it what not to do!

What happens if I use a different impedance speaker on a crossover?

Crossover shift due to speaker impedance change explained diagram

Diagram showing what happens when you change the speaker Ohm load connected to a crossover: crossover shift occurs. This means because it was designed for a different speaker impedance, the frequency at which it works changes.

As I mentioned earlier, speaker crossovers are based on parts (capacitors and inductors) that work as filters according to the speaker load they’re connected to. Because of this, when you change the speaker impedance you change the crossover frequency and the sound.

You may notice several problems after doing this:

  • A “harsh” sound from woofers or midrange speakers. Tweeters may sound distorted and being to “break up” the sound at volume.
  • A “thin”, weak quality to the music.
  • Gaps in the sound ranges you should be hearing.

Speaker crossovers can only be used with the speaker impedance they’re designed for or they won’t sound the same.

For example, using an 8 Ohm home speaker crossover with a 4 Ohm car speaker won’t work correctly. That’s because the part values were chosen for one impedance only. When you change that, it dramatically changes the crossover frequency!

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Why Is It Bad If Speaker Impedance Is Too Low? Your Question Answered

Why is it bad if speaker impedance is too low featured image

It can be confusing when we talk about impedance, Ohms, and all that with regards to car or home audio speakers. Yeah, most people are familiar with speakers, Ohm ratings and more…but what does it really mean?

Exactly why is it bad if speaker impedance is too low? That’s what I’ll answer here and clear up once and for all.

In this article, I’ll cover everything you need to know:

  • What exactly is speaker impedance?
  • Two big reasons why a low speaker impedance can be bad…and why it matters
  • Why you can use higher impedance speakers but not lower ones (and what to expect)

There’s a lot to cover so let’s jump right in!

Contents

What does impedance mean for speakers? Speaker Ohms explained

Illustrated diagram of a woofer speaker and its parts (3D exploded view)

An illustrated view of the parts that make up a speaker including the voice coil. The voice coil is a tightly-wound, long length of wire that has a certain amount of resistance from the electrical conductor used. It creates magnetic fields that drive the speaker cone forward and back, creating sound as it moves air.

In the world of electricity and electronics, we need a few things to do useful work:

  • A power source with voltage to move electrical current through a resistor, motor, etc to do something useful. A home or car amplifier or radio provides this.
  • Electrical conductors (speaker wire) to create a path for that current to flow
  • Some level of resistance to limit how much current can flow (too much current causes things to burn out, get hot, etc)

By that same token, just like other electrical devices, speakers are like little motors that use electricity flowing to turn motion (the cone) into sound we can here – that’s basically all speakers are!

What does speaker impedance mean?

What is speaker impedance diagram

Speaker impedance, measured in units of resistance called Ohms, is the total amount of resistance a speaker has to the flow of electricity. 

Speaker impedance comes from two things:

  1. The resistance of the long winding of wire that makes up the voice coil
  2. A special property created when wire is wound into a coil called inductance

Just like you can’t have a short circuit across a battery, an amp or stereo needs some amount of speaker resistance to limit how much electrical current the radio or amp tries to supply.

Speaker voice coils use a very long length of wire that’s tightly wound into the voice coil necessary to produce magnetic fields to create motion of the cone. Because of this length, there’s always a certain amount of resistance that is part of what makes up speaker impedance.

The resistance of a given speaker is almost always a few units of resistance, measured in Ohms.

What does inductance mean? Why it matters in speakers

Example of an inductor

Inductors are very useful electrical parts that take advantage of inductance. Inductance is a property of electrons flowing through a wire loop and the magnetic fields that build up because of it. Similarly, speakers have inductance due to their voice coils, although a small amount.

Coils of wire have an interesting side effect that happens unlike straight sections of wire. The voice coil’s wire winding forms a loop that has an electrical property called inductance.

Inductance is different from resistance as it changes as the frequency changes; resistance stays the same. This is called inductive reactance, which is just a more complicated resistance to the flow of electrical current.

For speakers, this matters because it means that the total resistance is made up of the two things I mentioned: wire resistance and inductive reactance. The name used to describe this total is impedance.

For speakers, this means that impedance (the total resistance) changes slightly as music plays because of the changing sound frequencies. However, the good news is that we can still categorize speakers according to an Ohms rating since it’s always pretty close.

When we talk about the impedance of a speaker, most of the time people are referring to the range of the speaker assigned to categories like 2 ohms, 4 ohms, 8 ohms, and so on. This is how we match speakers to a car or home amplifier, radio, and so on.

In the electrical world, resistance units measured in Ohms can be written as the Greek symbol Omega, or “Ω.”

How does speaker impedance work?

how does speaker impedance work diagram

When a musical signal (made up of alternating current) is applied to a speaker it generates magnetic fields as current flows through the tightly wound wire coil. Interestingly enough, a coil of wire develops magnetic fields that resist the flow of the current (resistance, also called reactance in this case).

Similarly, many other electrical components like motors deal with the same electrical resistance as alternating current (AC) is applied.

How the math works (yeah, it’s a little complicated!)

How to calculate speaker impedance diagram

Because of how inductance works and the physics involved, the speaker “impedance” (total resistance) isn’t the sum of the resistance and the inductive reactance. Instead it’s the “algebraic” sum, meaning it’s the square root of the sum of the squares. You may remember this kind of math from trigonometry class.

Speaker impedance isn’t as simple as just adding the measured DC resistance of the coil wire and the inductive reactance for a given frequency.

Instead, speaker impedance is found from the algebraic sum of the coil’s wire resistance and inductive reactance. You can find this by squaring each and then taking the square root of the two numbers added together.

Inductive reactance is commonly written as “Xl”, pronounced “X sub L” and is measured in units of Ohms just like resistance. Inductance is measured using a unit called the “Henrie” and commonly noted with an “H”: “uH” for microHenries, “mH” for milliHendries, and so on.

There’s also a corresponding value for capacitors called capacitive reactance (Xc) but that doesn’t usually apply for speaker voice coils. It’s very important for speaker crossovers, however.

Why is it bad if speaker impedance is too low?

What happens if using a higher or lower speaker impedance diagram

Just like any other device connected to an electrical power source, the speaker impedance will determine how much or how little current a home or car receiver, amplifier, etc will produce. The speaker impedance also affects how some speaker components such as speaker crossovers behave too.

What happens if speaker impedance is too low?

You can connect a higher speaker impedance in most cases without any problems (at least not major ones). A radio, home or car amplifier, etc will still produce sound and run at normal or low temperatures. That’s because a speaker with a higher impedance than expected will reduce how much electrical current the audio source tries to produce.

As a side effect, you’ll get sound but with much lower power output than you would with the correct speaker load. Car stereos or amps, for example, have to work with lower voltages than home stereos so they need a lower impedance 4 ohm speaker typically to produce more power.

Home stereos, on the other hand, have higher voltage available and can use a higher speaker impedance (8 ohms, typically).

Illustrated image of Rockville marine audio amplifier guts & internal view

Internal view of an amplifier. When connected to a speaker impedance load that’s too low, the amp will begin to get very hot and this can burn out the output transistors as they can’t handle the heat caused by trying to supply excessive current to a lower speaker load.

However, using a lower speaker impedance is bad because it causes the radio or amp to attempt to put out twice as much (or more!) current than it’s designed for. Your home or car stereo will get very hot quickly and if you’re lucky will go into a self-protect mode and shut itself off.

However, in my experience, it’s pretty common for the output stage electronics to burn out when connected to a lower speaker load than they should be. The high-power transistors in a home or car amplifier or stereo are only rated for a certain amount of heat & electrical current.

When they’re forced to try and handle an amount outside that range they become super hot and start to break down permanently. It doesn’t take long before the damage is permanent and they no longer produce sound.

Caution! Never wire speakers in a way that gives a total speaker load lower than the radio or amp is rated for. Also, don’t guess about the correct speaker impedance – check first.

I’ve seen cases where someone’s “friend who’s smart” has as a way to “get more power” but caused a stereo or amp to try to and put out more power than it was designed for. The end result was a burned-out amplifier.

Why does speaker impedance matter for crossovers?

Examples of 2 way crossovers and diagram

Speaker crossovers work to separate the sound sent to certain speakers for improved sound, reducing distortion, and to give you more control over how they’re used. For example, they block bass that tweeters can’t produce and highs that a woofer can’t produce well. However, they’re designed for a specific speaker impedance. Changing the speaker impedance affects the sound.

Speaker crossovers are amazingly helpful for getting better sound with speakers. Even the cheapest, most basic capacitor connected inline with a tweeter working as a high-pass filter makes a big difference in the sound.

The result is cleaner sound and avoiding possibly damaging it when bass sounds are played.

The catch is that because of how crossover components (capacitors and inductors) behave, they’re designed for specific speaker loads and can’t be used with other Ohm loads without affecting the sound output.

Crossover shift when using different impedance speakers

Crossover shift due to speaker impedance change explained diagram

When you change the speaker impedance connected to a speaker crossover it can significantly shift the crossover’s cutoff frequency. As a general rule:

  • Halving the speaker impedance (ex.: 8ohms to 4 ohms) doubles the frequency
  • Doubling the  speaker impedance (ex: 8 ohms to 16 ohms) halves the frequency

That’s bad because it allows the speakers to be sent a sound range they’re not suited for. In the case of tweeters, bass & midrange are bad because they can’t produce it properly. Similarly, many woofers can’t produce high frequency sounds well.

The end result in either case is poor sound that’s a lot worse sounding that it should be. If you change the speaker Ohms load you’ll have to replace the speaker crossover as you’ll need different parts values for it to work the same.

Is 8 or 4 ohm better? Is higher or lower impedance better for speakers?

What is better 4 ohm 2 ohm 8 ohm speakers

8, 4, and 2 ohm speakers aren’t necessarily “better” than one another. The correct answer is that it depends on the application and what stereo or amplifier is being used. The best impedance is the one that matches an amplifier or stereo’s impedance spec correctly.

By industry tradition, 8 ohms are used for home and some theater speakers. 4 ohm speakers are generally used for car and marine audio, with some 2 ohm models also (usually subwoofers).

For example:

  • 8 ohm speakers are used in home stereo systems and require 1/2 the current of a 4 ohm speaker. That means they can use smaller speaker wire as they can take advantage of home electrical systems that have a high voltage supply for driving speaker amplifiers.
  • 4 ohm speakers are used because car stereos and amplifiers (particularly car head units) can’t make large amounts of power in speakers as they have a very low 12V power supply. Reducing the speaker impedance from 8 to 4 means we can double the power for the same output voltage.

As a matter of fact, car stereos can only put out about a small 15-18 watts RMS per channel, despite the exaggerated peak power ratings you may see in advertisements. That’s because they only have about 12 volts to work with and have to divide that in half in order to produce AC waves that drive a speaker.

Car amplifiers are able to deliver huge amounts of power to 4 and 2 ohm speakers. They use an internal “inverter” power supply that steps up the +12V supply to higher voltages. This way they’re able to supply much more power to 2 or 4 ohm speakers than would be possible otherwise.

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What Is Car Speaker Impedance? Speaker Impedance And Ohms Explained

What is car speaker impedance featured image

Impedance is kind of a “scientific” sounding word, right? At first glance it’s fairly confusing and you might not know how much – if at all – it matters for hooking up speakers.

But what is car speaker impedance? As it turns out, it’s really important and can have some serious consequences on your vehicle’s sound, your car amplifier, and more. Let’s dig in!

Contents

What does speaker impedance mean?

What is speaker impedance diagram

Speaker impedance, measured in Ohms, is the voice coil total resistance to the flow of electric current as it operates with a musical signal.

Just like you can’t have a short circuit across a battery, an amp or stereo needs some amount of speaker load impedance to limit how much electrical current the radio or amp tries to supply.

Unlike straight wire that goes from point “a” to point “b” when you hook up power, the voice coil’s wire winding forms a loop that has an electrical property called inductance. Inductance is a bit different from resistance as it changes as the frequency changes. This is called inductive reactance.

For car speakers, this means that the real impedance (the total resistance) actually changes a little bit as music plays! However, the good news is that we can still categorize car speakers according to an Ohms rating since it’s always pretty close.

When we talk about the impedance of a speaker, most of the time people are referring to the category (general range) of the speaker as used to match home or car stereo amplifiers.

In the electrical world, Ohms are sometimes represented by the Greek symbol Omega, or “Ω.”

How does speaker impedance work?

how does speaker impedance work diagram

When a musical signal (made up of alternating current) is applied to a speaker it generates magnetic fields as current flows through the tightly wound wire coil. Interestingly enough, a coil of wire develops magnetic fields that resist the flow of the current (resistance, also called reactance in this case).

Similarly, many other electrical components like motors deal with the same electrical resistance as alternating current (AC) is applied.

How to calculate the total impedance (if you like!)

How to calculate speaker impedance diagram

Because of how inductance works and the physics involved, the speaker “impedance” (total resistance) isn’t the sum of the resistance and the inductive reactance. Instead it’s the “algebraic” sum, meaning it’s the square root of the sum of the squares. You may remember this kind of math from trigonometry class.

Speaker impedance isn’t as simple as just adding the measured DC resistance of the coil wire and the inductive reactance for a given frequency.

Instead, speaker impedance is found from the algebraic sum of the coil’s wire resistance and inductive reactance. You can find this by squaring each and then taking the square root of the two numbers added together.

Inductive reactance is commonly written as “Xl”, pronounced “X sub L” and is measured in units of Ohms just like resistance. Inductance is measured using a unit called the “Henrie” and commonly noted with an “H”: “uH” for microHenries, “mH” for milliHendries, and so on.

There’s also a corresponding value for capacitors called capacitive reactance (Xc) but that doesn’t usually apply for speaker voice coils.

How to tell the impedance of a car speaker

Car speaker impedance example

There are a few different ways to tell what a car speaker’s impedance is – even if it’s missing the label or it’s not printed on it anywhere.

Here’s what you need to know:

  • A speaker’s impedance is usually listed on the speaker magnet, packaging, and/or box and specifications. Unfortunately, it’s not always the case as some manufacturers might not have printed it on the speaker.
  • If the Ohm rating (impedance) is not available on the speaker, you can measure the impedance of a speaker using a test meter set to the Ohms (resistance) function. This will give the resistance of the voice coil which will let you determine the speaker’s impedance range/category such as 2 ohms, 4 ohms, 8 ohms, etc.
  • Unlike when a speaker is playing, measuring resistance with test meter won’t give you the total impedance – just the DC resistance of the speaker coil. However, that’s all you need to figure out the Ohms rating of your car speaker.

Long story short, if your speaker doesn’t have the impedance listed anywhere or you can’t find the manufacturer’s specs, the best thing to do is to measure it.

That’s the best way as you can be 100% sure of what you’re dealing with – especially if you need to match the impedance to an amplifier, car stereo, or crossover.

How to measure the impedance of a car speaker

How to measure speaker impedance with an Ohm meter example

It’s easy to measure car speaker impedance using a test meter set to read resistance (Ohms). Once you get a reading you can tell what Ohms rating your speaker is.

To measure the impedance of a car speaker you’ll need a multimeter (test meter with multiple functions) or a dedicated Ohm (resistance) meter. Digital multimeters are inexpensive and easy to find these days so I recommend using one of those.

  1. Turn on the meter and set it to measure resistance (Ohms) on the lowest range. This is usually the x1 range, 0-10, 0-20, or auto range setting.
  2. Disconnect one or both speaker wires from the speaker to avoid a false reading due to other resistance that may be connected to it.
  3. Hold the probes tightly against the speaker terminals on a clean, bare metal spot. The meter should quickly settle to a reading. The meter will show the resistance of the voice coil inside the speaker.
  4. Use the meter reading to determine the closest approximate speaker impedance (see my chart below for help).
  5. For speakers inside a box or enclosure there may be a crossover connected elsewhere which can interfere with your reading, so be sure to disconnect at least one speaker wire if possible. Subwoofers are usually fine to measure while installed in a subwoofer box.

As I mentioned above, the goal here isn’t to try and measure the perfect impedance rating.

Remember that you won’t measure exactly 4 ohms, 8 ohms, etc. You’ll measure an Ohms value that’s close to that and will help you tell the actual Ohms/impedance range of your speaker.

Note: Speakers like tweeters with a capacitor  crossover connected to them will act as an open circuit and will interfere with your measurement.

See my notes below on how to deal with that.

How to set your test meter for measuring car speakers

Image showing examples of test meter resistance setting for measuring speaker impedance

Shown are some example test meter resistance range settings to use for typical test meters.

As I mentioned earlier, it’s important to use the correct resistance range on your meter when measuring speaker impedance. that’s because the wrong setting may display nothing or give you the wrong idea that perhaps the speaker is blown when it isn’t.

If you’re not sure, check the test meter’s manual. Many modern digital meters often have an auto setting that will automatically adjust for the Ohm measurement it detects and will display the reading & decimal places accordingly. Other meters require you to select the correct range manually.

As a general rule, use the lowest range that includes 0-10 ohms (or similar).

Once you’ve got your measurement, use my speaker impedance chart to find the next closest speaker impedance value listed.

Measuring speaker impedance for tweeters & after crossovers

Diagram showing where to measure speaker impedance of tweeters with crossover

Tweeters often are supplied with a high-pass crossover in the form of a capacitor. To get a correct reading you’ll need to disconnect it or measure around it. Be sure to disconnect the tweeter from an amp or head unit!

Measuring the speaker impedance where crossovers are in place is a problem. That’s because capacitors, which are commonly on tweeters as a high-pass filter, appear to behave like an open circuit when measuring resistance as the capacitor charges.

You’ll want to measure around the capacitor if used or disconnect one capacitor lead or one tweeter wire. 

For 2-way speakers, there may or may not be a crossover used on the woofer. Often there’s an inductor in series with it. The good news is that directly reading resistance across a speaker and an inductor doesn’t make much difference – inductors have a tiny resistance value.

In fact, they’re usually in milliOhms (thousandths of an Ohm) which is almost nothing. However, as a general rule, it’s best to disconnect speakers from their crossovers before measuring Ohms.

Car speaker measured Ohms to impedance chart

Measured Ohms* Speaker impedance rating
3.1-4.0 ohms 4 ohm
6.0-8 ohms 8 ohm
1.2-2 ohms 2 ohms
4.0-6 ohms 6 ohms
0.5-1.0 ohms 1 ohm**
12-16 ohms 16 ohms**

To use this chart, take the speaker resistance measurement you got from your test meter reading and use it to compare to the measurements here. Your car speaker should fall into one of the common ranges you see above.

*This is an approximate range and should cover nearly all speakers but may vary slightly.

**1 ohm is rare but can be found in some car stereo products such as Bose premium amplified systems. 16 ohm speakers may sometimes be used for home or guitar amp systems, but aren’t very common.

Can I hook up 8 ohm speakers to a 4 ohm amplifier or radio?

4 ohm vs 8 ohm speaker power comparison graph

This graph shows what happens when you use an 8 ohm speaker in the place of a 4 ohm one. The 8 ohm speaker will work – however, it comes with a price. Since the 8 ohm speaker isn’t matched to the 4 ohm amp, it can only receive up to 1/2 the power output (and a lower volume) than a 4 ohm speaker would.

Using a speaker that’s not properly matched to an amplifier or car stereo can have minor – or major – consequences. 

Using an 8 ohm speaker in place of a 4 ohm won’t hurt anything. However, it can only develop 1/2 the power output of a 4 ohm speaker meaning lower volume. It also won’t work properly with speaker crossovers since it will shift the cutoff frequency.

For example, if you were to use some home stereo 8 ohm speakers or subwoofer instead of 4 ohm speakers, you’d notice the volume would be lower than when using 4 ohm ones. That’s because a speaker needs more and more power output to increase the volume more and more.

Car amplifiers & car head units don’t have much supply voltage to work with unlike home stereo receivers and amps. That means they need a lower impedance speaker to develop the same amount of power by letting more current flow.

I also don’t recommend mixing 8 and 4 ohm car speakers because they won’t have the same volume level once you turn up the volume. That means the sound won’t be right and you’ll be left having to deal with some sound frequencies being poor after a certain point.

What is better: 8 ohm or 4 ohm speakers? Are 2 ohm or 4 ohm speakers better?

What is better 4 ohm 2 ohm 8 ohm speakers

8, 4, and 2 ohm speakers aren’t necessarily “better” than one another. The correct answer is that it depends on the application and what stereo or amplifier is being used. The best impedance is the one that matches an amplifier or stereo’s impedance spec correctly.

Traditionally 8 ohms are used for home and some theater speakers. 4 ohm speakers are generally used for car use, with some 2 ohm models used at times (usually subwoofers).

For example:

  • 8 ohm speakers are used in home stereo systems and require 1/2 the current of a 4 ohm speaker. That means they can use smaller speaker wire as they can take advantage of home electrical systems that have a high voltage supply for driving speaker amplifiers.
  • 4 ohm speakers are used because car stereos and amplifiers (particularly car head units) can’t make large amounts of power in speakers as they have a very low 12V power supply. Reducing the speaker impedance from 8 to 4 means we can double the power for the same output voltage.

In fact, car stereos can only put out about a measly 15-18 watts RMS per channel, despite the exaggerated peak power ratings you may see in advertisements. That’s because they can only work with a 12V supply to develop power across a speaker.

Car amplifiers are able to deliver huge amounts of power to 4 and 2 ohm speakers by using an internal power supply that generates higher voltages for amplifying the speaker signal. Without that, it wouldn’t be possible to drive car speakers with tons of power to get boomy bass like many people enjoy.

When are 2 and 1 ohm speakers used?

Image of a Bose factory installed car amplifier

Factory-installed amps sometimes use 2 or 1 ohm speakers to develop more power without spending the money on amplifier designs using an improved power source.

2 and even 1 ohm (yes, 1 ohm!) car audio speakers are rarely used except for car subwoofers and some special cases for main speakers. Some factory-installed premium amplified car audio systems use lower impedance speakers to “cheat” using a “real” amplifier and save money.

That’s because they use the 2 or 1 ohm speaker to develop more power at each speaker without having to supply an amplifier with an internal power supply as is normally done. While it does technically work, it’s not a substitute for simply using a proper amplifier. 

They introduce other problems, like not being compatible with standard 4 ohm speakers when it’s time to upgrade or replace faulty ones. They also still can’t produce as much power as a decent aftermarket amp can with 4 ohm speakers, meaning you’ll still end up needing to replace them.

Speaker impedance matching

Example of matching speaker impedance to an amplifier

In order to get the most enjoyment (and power) for your dollar – along with avoiding damaging audio electronics – it’s important to match the speaker impedance (impedance load the amp sees at its output).

Here are some simple reasons to help you understand what happens when you don’t:

  • Using a speaker properly matched to the amplifier or radio’s minimum Ohms rating allows it to deliver the maximum output power it’s designed for.
  • Using a higher than specified speaker impedance will work. However, the speaker won’t be able to develop the full power that you paid for. As I mentioned earlier, a speaker needs more power to produce more volume, meaning you’ll lose volume because of this.
  • Using a lower than specified impedance speaker will cause an amp or stereo to run hot and can permanently damage the output transistors. Don’t do it!

While in some cases an amplifier might be able to shut itself off before it becomes damaged when a lower speaker impedance is used, don’t ever assume it will. Sometimes the damage still happens and you’ve just ruined an amp.

Most car stereos don’t have any type of overheating or high-current self-protection circuitry built-in so they’re likely to have their output stages destroyed.

Subwoofer impedance options

It’s a little bit different when we’re talking about car audio subwoofers, but the same rules hold true. Since a subwoofer channel on an amp usually has a lot power output on tap it’s not always an issue when using say a 4 ohm sub vs a 2 ohm sub with a 2 ohm min. amp.

However, as a general rule, it’s best to match the subwoofer impedance to get the power you’re paying for.

More great speaker articles

There’s lots more to learn!  Check out my other great articles you’ll love:

Something on your mind? Feel free to leave a comment or question below.

Component Vs Coaxial Speakers: Differences, Pros/Cons, And Which Is Best

component vs coaxial speakers featured image

Getting better car or home speakers can make a huge difference in the music you enjoy. Everybody has certain wants, needs, and of course, a budget.

On that subject, it’s helpful to understand component vs coaxial speaker differences why they matter before you go shopping. Not just the differences, but also:

  • Pros and cons of coaxial and component speakers
  • What type of sound coaxial and component speakers put out
  • Which one is best for you, and if there’s really a “better” choice
  • Installation difficulty

I’ll also help you better understand which is a better choice for you. Let’s get started!

Contents

What is the difference between coaxial and component speakers?

Component vs coaxial speaker comparison

What are coaxial speakers?

What are coaxial speakers diagram & parts labeled

Coaxial car speakers are basically a 2-way speaker system built together: the tweeter, woofer, and a simple crossover are assembled into one piece. They’re designed to replace older & lower-quality speakers by fitting in the same hole for easy installation. They provide better sound than a single cone speaker and allow more price options along with easier installation choices.

Coaxial speakers are a 2-way speaker design with a tweeter, woofer, and a simple crossover built into a single speaker assembly. Most provide a woofer cone with a separate tweeter for good full-range sound quality and frequency coverage, unlike basic single-cone speakers.

You can think of coaxial speakers as a compromise between single cone speakers (the cheapest type of speaker, with poor sound quality) and a more advanced component speaker system. They’re very popular as they offer good sound quality but don’t cost as much as more expensive speaker options like component speakers.

Coaxial speakers have some great advantages:

  • Easy sound upgrade: they’re a drop-in replacement for older factory-installed & bad sounding single cone speakers.
  • There’s a wide range of performance & price options for buyers: different levels of tweeter quality, crossover design, cone materials, higher power ratings, and so on.
  • They give somewhat similar performance to separate 2-way component car speakers – but without the need for a separate speaker crossover you have to install, too.
  • They’re easy to find and very popular – in fact, they’re the most popular car speaker upgrade and it’s really easy to find them when shopping.
  • Affordability: good coaxial car speakers can be found for around $25 and up. Very good quality coaxials are only about $50-$65 or so.
  • Coaxial speakers can immediately fix the poor frequency response many people have with their older speakers.

Coaxial vs standard/single cone speakers

Standard vs coaxial speakers comparison image with frequency response graphs

Coaxial speakers provide much better sound than standard low-end single cone speakers – even those with a whizzer cone added to supposedly improve the sound. Coaxial speakers are a type of 2-way design where the job of producing sound is split between them for best results. This way a full range of sound can be produced.

The thing is that plain ‘ole car speakers like you’ll find in many vehicles and home stereo systems are terrible! They’re well-known for bad sound and have been one of the single biggest complaints of my car stereo installation customers for years.

But why? As you can see in my picture above, they’re bad sounding because only have a single speaker (woofer/midrange) isn’t good enough. There’s a big range of sound they can’t produce well – if at all.

The truth is that single cone speakers simply can’t produce great sounding music like coaxial models do. Coaxial speakers make up the difference by using a tweeter to take care of the upped end of the musical sound range, filling in what other speakers can’t produce.

2-way vs 3-way coaxial speakers

2-way vs 3-way coaxial speaker examples image

3-way coaxial speakers are simply an extension of 2-way models with an additional small speaker (usually another tweeter or type of mid range) added for extra sound performance. 

It’s important to understand that just because they might look better doesn’t mean they sound better than a very good 2-way model. Some definitely do have improved sound production, however.

For example, some 3-way full range speakers add a tiny piezo type tweeter than can exceed the upper-frequency limit of standard tweeters, allowing for enhanced sound. Really good models offer not just a higher range of sound frequencies but a nearly flat sound response which is ideal.

The main thing to take away is that a quality and well-designed 2-way speaker can give great sound and most of the time is your best value for the dollar. Don’t spend the time, effort, and money chasing after 3-way speakers due to thinking they’re better just because of the added speaker.

Like many other things, it comes down to the quality and the design details. I recommend shopping primarily for a good quality 2-way coaxial speaker set.

What are component speakers?

What are component speakers diagram

Component speakers are a speaker system in which separately mounted speakers and a more advanced crossover are designed to provide advanced sound quality. They’re the next level above coaxial speakers and offer better performance than coaxials can provide.

Components speakers, which are made up of a separately mounted woofer, tweeter, and crossover, are a more advanced speaker system that provides better sound quality than coaxial speakers.

One reason for this is that component speakers often use better dome tweeter and woofer materials along with a more advanced (and better) speaker crossover. They may also include features such as a tweeter volume reduction option, tweeter fusing to protect against overload, and additional wiring configurations.

Some are even designed to allow assembling them together so they resemble coaxial speakers for easier installation.

Unlike coaxial speakers, component speakers offer:

  • Better frequency response and sound accuracy overall – even entry-level component speaker sets can have really great sound quality!
  • Tweeters with a more rigid and high-performance design: silk, aluminum, ceramic, or other special dome materials are common.
  • More power handling – often 75 watts RMS, 100 watts RMS, or more.
  • -12dB per octave crossover slopes (or greater) versus the standard -6dB/octave crossover used on coaxial tweeters.
  • Better crossover component quality.
  • Better speaker connector terminals and installation accessories.
  • The ability to mount the tweeters at a line-of-sight listening angle and height for better stereo imaging during music playback.

That being said, it’s important to understand that the installation process is harder than for coaxial speakers and can require custom fabrication for the tweeter mounts. Also, you’ll need to mount the crossovers as well, ideally away from moisture, and relatively close to where the speakers are mounted.

They’re also a bit more costly, too, as many component speaker sets cost around 1.5x to several times more than coaxials of the same size.

I’ve been a longtime user of component speakers and love them. Hands down, I can confidently say that a good (not even the most expensive model!) set of them can sound fantastic when used properly and powered by an amplifier.

Coaxial vs component speaker crossover differences

Component vs coaxial speaker crossovers diagram

Shown here is a diagram comparing coaxial vs component speaker crossovers. Coaxial speakers normally use a simple high-pass crossover only for the tweeter to block bass and none for the woofer. The result is overall good sound, but with room for improvement. Component speakers, however, use a more advanced crossover design that filters unwanted sound frequencies from reaching the woofer or tweeter. The result is less distortion, more accurate sound, and a better listening experience.

As I mentioned before, component speakers use more advanced crossovers than coaxials. They use 2 stages of filtering vs the single stage used with coaxials. This means more effective filtering of bass and midrange sound from the tweeter and more high-range sound is blocked from the woofer.

Most coaxials use a single cheap capacitor connected to the tweeter mounted and nothing for the woofer. Instead, they use a lower-cost design that relies on the fact that most woofers “roll off” (gradually stop producing) higher frequencies naturally.

Although it gets the job done and it works, there’s still room for improvement and the sound quality is compromised.

Component speaker crossovers use a better design

Component speakers, by comparison, use an external crossover with a designed for the specific speakers used and are made using better quality capacitors and inductors. They’re much more effective at preventing unwanted sound frequencies from reaching the speakers that aren’t suited for them.

The end result is much better clarity & lower distortion, allowing you to better hear the music as it was intended to be heard.

Even better, some component speaker crossovers include a tweeter volume control option. This is helpful if the tweeter seems too harsh sounding to you. Some also include tweeter overload circuit protection to avoid burning them out during high power delivery.

Wiring component speakers and coaxial speakers

Component vs coaxial speaker wiring diagram

Both types of speakers are fairly easy to wire – aside from the additional wire & labor needed for mounting component speakers properly.

Here’s a simple breakdown of the wiring connections needed:

  • Coaxial speakers: wired from the head unit or amplifier positive wire and negative wire to the same terminals on the speaker, same as factory-installed speakers. (Note that when replacing some factory-installed “premium” speaker systems, you may need to run new speaker wire to bypass the troublesome original wiring).
  • Components: 
  • Connected from the head unit or amplifier’s speaker outputs to the INPUTS of the speaker crossover.
  • Connect the tweeter output of the crossover to the tweeter’s positive and negative terminals.
  • Connect the woofer output from the crossover to the woofer’s positive and negative terminals.

example of component speakers installed in car door

Shown here is a typical component speaker installation: the woofer, tweeter, and crossover are mounted inside a car door. This is a pretty common installation and gives excellent sound, although it takes more time & money to complete.

Note: While it’s not required, I highly recommend using an amplifier with component speakers for the best results and maximum sound quality. (More about that further below)

Which is better, coaxial or component speakers?

Coaxial or component speakers image

The best way for me to answer this question depends on what the definition of “better” means to you. After all, you’re the best judge of what you like, right?

The simplest answer is that component speakers are the best in terms of sound quality, power handling, tweeter & woofer technology options, and installation creativity.

However, that’s not what everyone needs – not everyone cares about super-crisp sound, more power handling, or better speaker crossovers. Perhaps the best thing for me to do is to simplify it with a short comparison below.

There are several differences between coaxial speakers and component speakers you should know:

  • Coaxial speakers fit the entire 2-way speaker system into a single speaker assembly. Most component speaker systems (aside from a few rare designs) are separate and everything has to be mounted individually.
  • Coaxial speakers, in order to keep costs down and fit into a small space, have some compromises. A basic -6dB/octave crossover for the tweeter and many use a lower-cost tweeter material. Component speakers, however, have better crossovers (-12dB/octave minimum, usually) and better tweeter materials like silk, aluminum, or others.
  • Coaxial speakers tend to have lower power ratings while component speakers tend to have higher power rating limits. Coaxials tend to range around say 35W-65W RMS or so while components typically are available in 65W-100W RMS or higher options.
  • Coaxial speakers are simple to install while component speakers are harder and take more time & effort.
  • Component speakers, because of their design, offer better sound quality and clarity than coaxial speakers. Coaxials are good, but many are average (however, still much better than standard single-cone speakers).

It’s a lot easier to find coaxial speakers when shopping than it is to find component speakers. Coaxial speakers, as I mentioned earlier, are a lot more popular and because of it, many stores have them in stock.

Even your local department store, auto parts store, and “mom and pop” electronics stores probably has some in the car audio section.

Coaxial speakers are great for budget sound!

As far as price is concerned, prices for component speakers start at about the same price as a very good pair of coaxial speakers. You’ll pay less for coaxial speakers and have more options to choose from depending on what you can afford.

For example, I installed quite a few average quality coaxial speakers in cars, trucks, and even boats over the years. They’re good enough for many people yet still within reach of what they could afford when you add in the cost of installation.

Most of the time you can expect to pay somewhere around $45 for good coaxials and about $75-$100 for a good component set.

Should I get component or coaxial speakers?

Here’s a comparison to help you decide if you’re unsure.

You should get coaxial speakers if:

  • You don’t have a lot to spend or just need something that’s good enough to sound ok – not “high end” sound
  • You want an easy way to replace your old speakers
  • You’re not planning to amplify your speakers and will use a standard stereo
  • You don’t want to do the extra work or running extra wire needed for component speakers
  • You don’t have the time, tools, or money to spare on a custom installation

You should get component speakers if:

  • Sound quality is your what you’re mainly after
  • Want to use speakers with more advanced materials (especially for the tweeters)
  • You prefer speaker crossovers with a steeper cutoff and/or tweeter volume reduction option
  • Will be doing a custom home, car stereo, or marine speaker installation with higher-end electronics
  • You want improved stereo imaging for music playback and critical listening with high-fidelity recordings
  • You would like to drive your speakers with an amplifier for extra power and clarity

The good news is that there are some component speaker systems that can be used a lot like component speakers, making them easier to install. You’ll save a lot of work & hassle in the process.

As I noted above, component speakers should be driven with an amplifier for the best results. You simply won’t get great sound from them using a low-power stereo unit.

Coaxial style component speaker set example

An example of a component speaker set (in this case by speaker company MB Quart) that can be put together to work like a coaxial speaker for easier installation and using less space.

Do I need an amp for component or coaxial speakers?

Image of a car amplifiers installed with component and coaxial speakers

It would be a bit misleading to say you “need” an amp for your speakers. The better thing for me to say is that there are some great advantages you’ll get by using an amplifier to drive component or coaxial speakers.

Here’s a list of reasons why amplifying your speakers is a good idea:

  • Lower distortion & cleaner sound
  • The ability to block power-robbing & distorting low-end bass by using a crossover
  • Lots of power available for much more volume
  • A lot more flexibility for system set up

For example, most car stereo units, despite the misleading advertising they have, output only about 15-18 watts RMS per channel at the most.

And that’s not clean, great-sounding power, either. They’ll start to distort badly and sound poorly when pushed to their maximum output.

You’ll be fine for every day listening to your speakers at a moderate to moderately high volume with a good car stereo head unit. However, using an amp can take your audio system to the next level.

How does an amp make speakers sound?

Using an amplifier (even a decent one, not a high-end unit) can make a big difference in how your car audio system sounds. Amplifiers will provide several sound options you can’t get from a head unit – even the expensive ones!

Here’s a list of what an amplifier can offer:

  • Built-in high pass crossovers to block distorting and power-robbing low end bass your speakers can’t handle
  • Higher signal-to-noise (SNR) ratio, giving better clarity than a head unit can provide
  • Much better listening volume & power left over, without the high distortion you get when you crank up a head unit
  • More installation options and bass boost

I’ve been powering my component speakers with amplifiers for years and it’s like a night and day difference in sound quality! It’s a bit more work, but well worth it and I’ve had readers report exactly the same too.

I recommend using a decent quality amplifier with 50 watts RMS per channel or higher for best results.

More great speaker and sound articles

Don’t leave just yet – check out my other excellent articles!

Why Do 6×9 Speakers Look Different? A 6×9″ Speaker Facts Guide

Why do 6x9 speakers look different featured image

At first glance, it may seem like there’ no real reason for 6×9″ speakers to have their unusual shape. But as you’ll learn, there are some good reasons for them. Not only that, but they have some advantages you might find interesting!

But why do 6×9 speakers look different? Are they a good choice for your car stereo system?  How do 6x9s compare to other speakers?

Read on and I’ll tell you everything you need to know.

Contents

Why do 6×9 speakers look different?

Example of older car with 6x9 speakers

Why 6×9 speakers?

6×9″ car speakers were originally used to make good use of limited space in vehicles from the factory. This was mainly the deck near the rear window in older vehicles (sometimes called a parcel shelf). In many vehicles – everything from muscle cars to luxury vehicles – there wasn’t much space to fit speakers.

In fact, in a fair amount of cars back in the day, there weren’t any front speakers at all! It wasn’t until further into the 1970s and afterward that adding a decent stereo and better factory speakers became common with vehicle manufacturers.

Back in those days, the car audio speaker sizes we have now weren’t standard so speaker options that would fit were limited.

Their shape offers more sound in a narrower space

As early as the 1960s some cars and other vehicles used 6×9″ car speakers to offer a better sound by using an oval shape. This allowed taking advantage of the longer width (side to side) rather than the shorter back to front panel measurements.

This allows fitting an overall larger speaker cone which wouldn’t be possible otherwise by using a round speaker. Similarly, 4×10 speakers do the same thing but in even more limited rear deck space.

How big are 6×9 speakers?

6x9 speaker size measurements diagram

Example measurements for a typical 6×9″ speaker. The overall measurements vary from manufacturer to manufacturer and can be slightly different for both the outside measurements and the cutout size too.

6×9 inch speakers aren’t standardized in their measurements which means that different brands and models vary a little bit from each other. However, in general, they’re roughly 6.5″ x 9 5/16″ (164mm x 235mm) in size.

The cutout size, in which the speaker basket will fit for top or bottom mounting, is about 5 5/16″ x 9 5/16″ (143mm x 235mm).

One thing that’s important to know is that the depth can be very different. In most cases, 6×9″ speakers with large magnets have a depth of slightly over 3 inches while lower-power and budget models are closer to 2.5″ or 2.75″ or so.

Why 6×9 speakers? 6x9s vs round speakers

Diagram comparing 6x9 speakers vs round speakers

If you compare the area of an ellipse (oval) from a 6×9″ speaker to a similarly sized round speaker, you’ll see that the 6×9 speaker offers much more cone area. (Note: This is a simple comparison – speaker cone area is more complicated to figure out so I’ve used a more basic example).

You might not have realized it, but when it comes to speakers at least, size does matter! It matters a LOT, in fact.

That’s because the larger the surface area of a speaker cone, the more air it can move when in motion. This means for you more volume and especially more bass sound.

What is the difference between 6×8 and 6×9 speakers?

6x8 inch vs 6x9 inch speaker comparison image

6×8 inch speakers are extremely similar to 6×9 speakers and are made for replacing special factory vehicle speakers. They’re just slightly smaller than their counterparts.

6×8 inch speakers are identical to and very close in size to 6×9 inch speakers. They’re simply slightly smaller and look nearly the same.

They’re designed to replace some factory-installed original manufacturer speakers where 6×9″ models won’t fit without modification. They offer a way to get a better-sounding replacement but without the need to modify the car’s speaker openings or use a special adapter.

In fact, in some cases, a 6×9″ speaker can’t fit in the place of a factory 6×8″ speaker due to extremely limited space or not enough clearance for a 6×9″ speaker cone to move freely without touching.

Are 6×9 speakers good for bass?

6x9 vs 8 inch speaker comparison image

6×9″ speakers offer a big advantage over standard round speakers: despite taking up about the same front to back space as say 6″ or 6.5″ speakers, their width is much bigger, giving them a much larger cone for moving air.

This means 6×9″ speakers can produce more bass compared to others.

Yes, they’re better (in many cases – it depends on the speakers being compared) than other speakers for bass. They’re not a substitute, however, for subwoofers and shouldn’t be used for them.

However, in high quality & properly matched speaker enclosures, it’s possible to get great sound with plenty of bass from them. In fact, 6×9″ speakers have a similar cone size to 8″ woofers!

How much bass do I get from 6×9 speakers?

The amount of low-frequency bass sound you can get from 6×9 depends on a lot of things, but you can roughly expect about the same as mid-level 8 inch woofers.

Some of the things that make a big difference are:

  • The speaker box size – many 6×9″ speaker boxes are too small to produce good bass, so they often work best in trunks or larger boxes.
  • The speaker quality & power rating: speakers with stiffer cones and a higher power rating are better for power-hungry bass.
  • The speaker’s frequency response: You’ll need to pick 6x9s that work well for lower bass. Optionally, you can find 6×9 woofers that are designed just for bass or are part of a 2-way speaker set.

What is the frequency range of 6×9 speakers?

6x9 speaker frequency response examples diagram

Shown here are some graphs showing the frequency response for common 6×9″ speakers you’ll find anywhere. Just like any other type of speaker (6.5″, 4″, and so on) the frequency range depends on the speaker’s design & level of performance.

The frequency range of most full-range 6×9 inch speakers is just like any other size: somewhere between 60hz to 20KHz or so depending on the performance of the speaker.

For example, a 1-way speaker has a more limited range and is a poor performer overall. They’re weak in the upper range with higher-pitched sound response dropping off badly somewhere before 16KHz. That means they have lousy higher-frequency sound production and don’t sound very “crisp.”

High-quality 2-way and 3-way 6x9s add one or more tweeters to cover the additional high-frequency range that the woofer can’t produce. These can produce sound in the range of somewhere around 60Hz to 20Khz and even higher.

While 1-way speakers may have an extra cone called a “whizzer” cone attached for better high-frequency sound, they don’t really add much and these types of speakers have disappointing sound quality.

What about the bass range?

6x9s are just like any other car speaker in that they aren’t subwoofers and most can’t produce very deep bass like a subwoofer can. However, 6x9s, as I mentioned earlier, are some of the best speakers for bass for full-range music.

Some can perform to below 60hz and still produce good bass levels. This is especially true for 6×9″ component speaker sets which separate the tweeter and woofer cones with 2-way crossovers for great sound performance.

Do 6.5 speakers sound better than 6×9?

6x9 vs 6.5 inch speaker comparison

There’s not a “one size fits all” answer to this question because there are many factors that affect car speaker sound. To make a long story short, the best answer is that it depends.

To summarize:

  • A high quality 2-way 6.5 in. speaker will sound better than most 1-way or lower quality 6×9 in. speakers.
  • A high quality, 2 or 3-way 6×9 in. speaker that’s well designed will outperform an identical 6.5 in. speaker.
  • If the installation quality or sound system isn’t done right, even a great quality 6×9 in. speaker can sound worse than a 6.5″ speaker that’s installed & used correctly.

Ultimately, assuming all things are equal (proper installation, the same audio source & power, and the same speaker type) a 6×9 inch speaker will outperform an identical 6.5″ speaker. Don’t forget that as I mentioned earlier they’re the best choice for bass compared to a similar round speaker.

Do I need an amp for my 6×9 speakers?

Image of 6x9 speakers and car amplifier

It would be a bit misleading to say you “need” an amp for 6×9 speakers. The better thing for me to say is that there are some great advantages you’ll get by using an amplifier to drive 6x9s.

Here’s a list of reasons why amplifying your speakers is a good idea:

  • Lower distortion & cleaner sound
  • The ability to block power-robbing & distorting low-end bass by using a crossover
  • Lots of power available for much more volume
  • A lot more flexibility for system set up

For example, most car stereo units, despite the misleading advertising they have, can provide only about 15-18 watts RMS per channel at the most.

And that’s not clean, great-sounding power, either. They’ll start to distort badly and sound poorly when pushed to their maximum output.

You’ll be fine for every day listening to your speakers at a moderate to moderately high volume with a good car stereo head unit. However, using an amp can take your audio system to the next level.

How does an amp make 6×9 speakers sound?

Even a decent budget car amplifier can provide some of the cleanest sound you’ll hear with good car speakers. Since most amplifiers these days have an optional crossover feature built-in, you can block the low-end bass that smaller speaker systems can’t handle.

This will prevent distortion and you can get great volume from your 6x9s while still having really clean & crisp sound.

The sound you’ll get with a good amp and proper installation will be very clear. That’s because an amplifier will have a much higher signal to noise (SNR) ratio compared to an in-dash stereo, meaning the audio will be more clear and accurate.

How big of an amp for car 6×9 speakers do you need?

What to look for in amplifier for 6x9s

The good news is that these days it’s pretty easy to get a great deal on an excellent-sounding car amp for 6x9s. While it’s still true that budget brands don’t have the same technology or ultra-high end specs like more expensive brands like Rockford Fosgate or JL Audio, they’re still pretty good if you shop carefully.

When picking a car amp for 6x9s I recommend you use these guidelines:

  • 50 watts RMS or more power per channel. 65W or 75W or more is even better if you get the option. (Don’t go by the peak power rating listed on an amplifier – it’s very misleading)
  • A good signal-to-noise (SNR) ratio of around 90dB or higher. This is an electrical spec for the level of the internal noise signal to the music signal. The higher, the better, with 100dB being excellent. (90dB is still good for most people)
  • High-pass crossovers for blocking lower-end, distorting, and power-robbing bass below 60Hz. I recommend an adjustable crossover, but that’s not important.
  • For factory systems, you’ll save money by buying an amplifier with speaker level (high-level) inputs built-in. You can use RCA line-level adapters if you like also, of course.

How hard you can push coaxial 6×9 speakers with an amp?

Coaxial 6x9s should be treated like other speakers. The amount of power they can take from an amp will be limited by:

  • The RMS power rating of the speaker
  • Whether or not you’re driving them with heavy low-end bass in the music
  • Clipping from the amplifier (hitting the output limit of the amplifier, driving it to clipping)

Ultimately, you’ll get close to, but not all the way, to the RMS power rating for the speakers assuming it’s accurately stated by the manufacturer.

If you really want to drive them hard, you’ll want to (1) use an amplifier capable of more power per channel than the speakers to avoid clipping, and (2) use a high-pass crossover to block low-end bass.

You’ll need to pick good quality speakers with voice coils suited to more power handling if you want to drive them hard without them burning out.

What is a good 6×9 crossover frequency?

The high-pass crossovers in an amp are usually a preset crossover frequency, a 2-3 selectable switch positions, or an adjustable dial. I recommend using a high-pass frequency of around 56Hz to 60Hz or so with 6x9s for most full range car speakers.

This will block the lower end bass they can’t handle and that should be sent to subwoofers, while still allowing the lower-end range of vocal and drums in music to be heard. Of course, if you’re still getting distortion from your speakers it’s a good idea to try increasing the frequency (100Hz or a bit higher are good).

What is a component 6×9 speaker set?

What is a 6x9 component speaker set example diagram

A 6×9 component speaker set uses separate tweeters and woofer along with a speaker crossover for great sound quality. The speaker crossover filters out midrange & bass sound before it can reach the tweeter. Likewise, the woofer receivers only midrange & bass sound frequencies. The result is very low distortion and very clear & enjoyable musical production.

Component speakers use separate tweeters and woofers, along with a speaker crossover, to provide a higher level of sound quality along with lower distortion and improved musical accuracy. They’re similar to 2-way coaxial 6×9 speakers, but without the compromises required in manufacturing those.

Tweeters distort when subjected to midrange or bass sound. Likewise, woofers perform very poorly when driven with higher-frequency sounds. By blocking these from reaching the speakers they’re not suited for, the speaker crossover splits up the incoming musical signal.

The result is some of the best sound possible. There are a few advantages but also some disadvantages when compared to coaxial 6x9s.

Component vs coaxial 6×9 speakers

Here’s a basic comparison chart to help compare the two.

ItemCoaxialComponentCostCheap to medium priceMedium to high priceSound qualityDecent to goodVery good to excellentInstallationEasy/mediumModerate to hardBuying selectionVery goodFairFeatures availableLowGood (depends on the set)

There are a few things to bear in mind when it comes to choosing coaxial vs component 6×9 speakers:

  • It’s much easier to find coaxial speakers in retail stores than component sets. Also, there’s a very wide range of prices so coaxial speakers are great for people on a budget.
  • Component speakers can take some work to install while coaxial speakers are usually pretty easy. 
  • Coaxial speakers have tweeters that are most often a cheap material like Mylar or PEI. They’re ok, but not very good when compared to those included with a component set.

Most coaxials use a single capacitor to the tweeter mounted on top and use none at all for the woofer. Instead, they use a lower-cost design that relies on the fact that most woofers “roll off” (stop producing) higher frequencies naturally. Despite that, some treble will always get through and affect the sound quality a little bit.

Component speakers, on the other hand, have an external crossover with more advanced circuitry that blocks unwanted frequencies to both the tweeter and the woofer. The end result is better speaker performance and sound, higher volume without distortion, and more clarity.

Not only that, but some component speaker crossovers include a built-in setting to reduce the tweeter volume if it’s too bright (too harsh sounding) to you. Some also may include built-in fusing to prevent you from accidentally blowing the tweeters at high volume.

Which is better, coaxial or component 6×9 speakers?

Component vs coaxial 6x9 speakers image

In my opinion, the best way to answer this question depends on what really matters to you and what you need to enjoy your music. After all, you’re the best judge of what you like, right?

The short answer is that component speakers are better in terms of functionality, power handling, dome tweeter and woofer material options, and of course, they sound better.

However, that’s not what everyone needs – not everyone cares about super-crisp sound, more power handling, or better speaker crossovers.

Should I get component or coaxial 6×9 speakers?

Here’s a comparison to help you if you’re having a hard time deciding.

You should get coaxial 6×9 speakers if:

  • You have a tight budget or just need something that’s fairly good and you’re not super-picky
  • ou want an easy sound upgrade over your existing speakers
  • You’re not using an advanced sound system with amplifiers powering the speakers
  • You don’t want to do the extra work or customization needed for installing component speakers
  • You don’t have the time, tools, or money to spare on a custom installation

You should get component 6×9 speakers if:

  • Sound quality is your most important goal
  • Want to use speakers with more advanced materials (especially for the tweeters)
  • You prefer speaker crossovers with a steeper cutoff and/or tweeter volume reduction option
  • Will be doing a custom home, car stereo, or marine speaker installation with higher-end electronics
  • You want improved stereo imaging for music playback and critical listening with high-fidelity recordings
  • You would like to drive your speakers with an amplifier for extra power and clarity

Ultimately, it’s up to you. Additionally, there are some component speaker systems available that can be used a lot like component speakers, making them easier to install. You’ll save a lot of work & hassle in the process.

As I noted above, component speakers should be driven with an amplifier for the best results. You simply won’t get great sound from them using a low-power stereo unit.

More great speaker-related articles you’ll love

Don’t leave just yet! I’ve got more excellent articles to share lots of helpful info about speakers, speaker wire, and more!

Questions, comments, or suggestions?

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What Are Coaxial Speakers? The Coaxial Speaker Fact Guide

What are coaxial speakers featured image

You’ve got a lot of choices when it comes to speakers. As it turns out, coaxial speakers are hands-down one of the most popular types of speakers in the world. I’ve installed tons of them over the years myself!

But what are coaxial speakers? How are they different from component speakers, 2-way & 3-way systems, and standard speakers? And why are they so popular?

In this article, I’ll explain what they are, their pros and cons, and show you which coaxial speakers are the best type to buy. I’ll also show how they stack up against component speakers.

Contents

What are coaxial speakers?

What are coaxial speakers diagram & parts labeled

Coaxial speakers are a type of 2-way speaker designed to take up less space and to replace single-cone speakers. Unlike standard single-cone speakers, they include a tweeter and a crossover for improved sound. Coaxial speakers provide not only better sound but also more installation options, they save space and are a good compromise between sound quality and price.

What does coaxial speaker mean?

Coaxial speakers are 2-way speakers mounted on the same “axis” – in other words, multiple speakers built together in the same speaker assembly. Most coaxial speakers provide a woofer cone and a separate tweeter with crossover for improved sound quality over that of a standard single cone speaker.

You can think of them as a middle point between lower-end, lower-cost single cone speakers (used by manufacturers to cut cost) and component speakers (more expensive and complex, but with better sound quality). They’re a good compromise between performance, price, and ease of use.

Those are some of the reasons they’re the most popular type of speakers for car stereo systems. That, and the fact that they’re one of the easiest to install and most affordable sound upgrades you can buy.

Coaxial speakers offer several advantages:

  • Easy sound upgrade: they’re a drop-in replacement for existing poor-sounding single cone speakers.
  • More speaker manufacturing options and price ranges for buyers (different levels of tweeter quality, crossover design, cone materials, etc).
  • Somewhat similar performance to separate 2-way component speakers without the need for a bulky separate crossover box.
  • They’re very common – in fact, they’re the most popular car speaker upgrade and they’re easy to find when shopping.
  • Very affordable: good coaxial speakers can be found for around $25 and up per pair depending on the size & quality.
  • Coaxial speakers can fix the poor frequency response (missing sound frequencies) you find with single-cone speakers. You nearly always get a big improvement in sound right away!

8 ohm coaxial ceiling speakers example

Coaxial speakers are more common for car stereo use but aren’t limited to only that. 8 ohm coaxial speakers are available for both home stereos and sound from walls, the outdoors, and ceilings for music broadcast in business or other buildings, too.

Coaxial vs standard single cone speakers

Standard vs coaxial speakers comparison image with frequency response graphs

Coaxial speakers give you better sound performance than lower-end single-cone speakers – even those with a “whizzer” cone added to supposedly improve higher frequency production. They’re able to do so because unlike a standard speaker that can’t produce the full range of sound your ears can hear (and that is present in music), the additional tweeter added makes up for this. The end result is full-range music production with good high-frequency crispness.

Standard (single cone) speakers are notorious for mediocre and even lousy sound quality. That’s because, as you can see from the picture above, they’re pretty poor when it comes to the range of sound they can reproduce. A woofer cone alone can’t normally produce high frequency sounds well, if at all, and that’s a glaring weakness.

Single cone speakers can’t produce a crisp full-range sound as 2-way coaxial speakers can. Coaxial speakers are designed to improve upon standard low-fidelity speakers by producing the missing upper-frequency sound range your ears expect to let you enjoy your music the way it should be heard.

Are coaxial speakers better?

Image of confused man thinking about car speakers

The short answer is yes: coaxial speakers are better than standard speakers. However, they’re not better than most component speakers systems and some 2-way speaker systems. (More about that later)

While some cheaper standard speakers may have a “whizzer” cone added (a small 2nd cone attached to the dust cap for improved treble sound) they’re still disappointing. I’ve yet to hear one that sounded very good.

Coaxial speakers, on the other hand, use at least one additional speaker (usually a tweeter) to make up the difference and produce crisper & better-sounding higher frequencies.

In fact, in all my years of car speaker installation work I can’t recall a single basic speaker that wasn’t good enough to keep instead of replacing it with a coaxial model.

While factory-installed speakers are often very low cost, coaxial speakers – even for a nice sounding pair – aren’t expensive. You can get a great-sounding pair for $25-$30 or so these days and around $20 if you’re on an extreme budget.

As cheap as that is, you can immediately hear the difference versus factory-installed single cone speakers.

What is a 3-way coaxial speaker?

3 way coaxial speaker examples image

3-way coaxial speakers are the same but with an additional speaker added (usually another tweeter). They offer a slightly different design, especially for extended tweeter performance. I’ve seen some (usually lower quality brands) with a fake 3rd speaker for marketing purposes.

3 way coaxial speakers are simply 2-way coaxial speakers with an additional speaker, usually a tweeter, added for extended or enhanced sound production. These aren’t necessarily better than 2-way coaxial speakers but sometimes offer better performance and sound.

For example, 3-way models typically use a very small piezo tweeter that can produce treble sound at higher frequencies or with better quality for certain ranges to supplement the main tweeter. For well-designed models, you can get better sound quality & performance than more basic 2-way models.

However, that doesn’t mean they’re better in general. In fact, a quality and well-designed 2-way coaxial speaker can sound excellent! Like many other things, it comes down to the quality and the design details.

Tip: I recommend spending your time and money for a very good  2-way coaxial speaker. Don’t spend the effort on search for a 3-way coaxial speaker on the assumption that they’re better.

3-way coaxial speakers with a fake tweeter

One strange thing I’ve run across with lower-end brands is that in some cases, speakers sold as 3-way coaxials may actually be 2-way. Some speakers I’ve seen include a fake miniature tweeter, simply a plastic placeholder, to give you the impression they’re more sophisticated than they really are.

If you stick with reputable brands, though, that won’t be a problem.

What is the difference between coaxial and component speakers?

Coaxial vs component speakers

There are several differences between coaxial speakers and component speakers you should know:

  • Coaxial speakers fit the entire 2-way speaker system into a single speaker assembly. Most component speaker systems (aside from a few rare designs) are separate and everything has to be mounted individually.
  • Coaxial speakers, in order to keep costs down and fit into a small space, have some compromises: a basic -6dB/octave crossover for the tweeter and many use a lower-cost tweeter material. Component speakers, however, have better crossovers (-12dB/octave minimum, usually) and better tweeter materials like silk, aluminum, or others.
  • Coaxial speakers tend to have lower power ratings (say 35W-65W RMS) while component speakers tend to have higher power rating limits. (65W-100W RMS or higher).
  • Component speakers, because of their design, offer better sound quality and clarity than coaxial speakers. Coaxials are good, but many are average (however, still much better than standard single-cone speakers).
  • Coaxial speakers are simple to install and use but component speakers aren’t.

I should also add that it’s far easier to find coaxial speakers in a retail store nearby than it is to find component speakers. Coaxial speakers, as I mentioned earlier, are much more popular and because of it, many stores keep them in stock.

Even your local department store, auto parts store, and “mom and pop” electronics stores probably has some on the shelf.

Coaxial speaker vs component speaker crossover comparison

Coaxial vs component speaker crossover comparison diagram

A comparison of the kinds of crossovers used in most coaxial and component speakers. Because they use a more advanced design and more parts, component speakers sound better than coaxials. That’s because they’re able to better block unwanted sound frequencies from going to the wrong speaker.

As I mentioned earlier, component speakers use more advanced crossovers in most cases. They use a higher “order” crossover, meaning that the level at which they cut off unwanted sound frequencies is better (steeper).

For example, most coaxials use a single capacitor to the tweeter mounted on top and use none at all for the woofer. Instead, they use a lower-cost design that relies on the fact that most woofers “roll off” (stop producing) higher frequencies naturally. Despite that, some treble will always get through and affect the sound quality a little bit.

Component speakers, on the other hand, have an external crossover with more advanced circuitry that blocks unwanted frequencies to both the tweeter and the woofer. The end result is better speaker performance and sound, higher volume without distortion, and more clarity.

Not only that, but some component speaker crossovers include a built-in setting to reduce the tweeter volume if it’s too bright (too harsh sounding) to you. Some also may include built-in fusing to prevent you from accidentally blowing the tweeters at high volume.

Coaxial speakers are great for “good enough” budgets

As far as price is concerned, component speakers start at about the same price as a very good pair of coaxial speakers. You’re simply going to pay less for coaxial speakers and have a lot more options to choose from depending on what you can afford.

For example, I installed quite a few “meh” quality coaxial speakers in cars, trucks, and even boats over the years. They’re good enough for many people yet still within reach of what they could afford when you add in the cost of installation.

Which is better, coaxial or component speakers?

Which is better component or coaxial speakers

In my opinion, the best way to answer this question depends on what the definition of “better” means to you. After all, you’re the best judge of what you like, right?

When it comes down to it, component speakers are better in terms of functionality, power handling, tweeter and woofer material options, and of course, they sound better.

However, that’s not what everyone needs – not everyone cares about super-crisp sound, more power handling, or better speaker crossovers. Perhaps the best thing for me to do is to simplify it with a short comparison below.

Should I get component or coaxial speakers?

Here’s a comparison to help you decide if you’re unsure.

You should get coaxial speakers if:

  • You have a tight budget or just need something that’s fairly good and you’re not super-picky
  • You want an easy sound upgrade over your existing speakers
  • You’re not using an advanced sound system with amplifiers powering the speakers
  • You don’t want to do the extra work or customization needed for installing component speakers
  • You don’t have the time, tools, or money to spare on a custom installation

You should get component speakers if:

  • Sound quality is your most important goal
  • Want to use speakers with more advanced materials (especially for the tweeters)
  • You prefer speaker crossovers with a steeper cutoff and/or tweeter volume reduction option
  • Will be doing a custom home, car stereo, or marine speaker installation with higher-end electronics
  • You want improved stereo imaging for music playback and critical listening with high-fidelity recordings
  • You would like to drive your speakers with an amplifier for extra power and clarity

Ultimately, it’s up to you. Additionally, there are some component speaker systems available that can be used a lot like component speakers, making them easier to install. You’ll save a lot of work & hassle in the process.

As I noted above, component speakers should be driven with an amplifier for the best results. You simply won’t get great sound from them using a low-power stereo unit.

Coaxial style component speaker set example

An example of a component speaker set (in this case by speaker company MB Quart) that can be put together to work like a coaxial speaker for easier installation and using less space.

How to pick coaxial speakers

Coaxial speakers to buy examples and comparison image

There are a number of things you should know before shopping for coaxial speakers, many of which depend on your installation needs, sound quality wishes, budget, and car or outdoor vehicle use. And of course, it goes without saying you’ll want to get the correct size if you’re replacing speakers.

Here are some helpful tips I have as both an installer and a sound fanatic:

  • Vehicles with tight speaker room: (And this is important!) Don’t buy replacement speakers with giant and oversized magnets as in many cases the new speakers won’t fit. If the speakers are too large it may hit the interior of the dashboard, enclosure, or other surface and you won’t be able to install it. Slim-mount coaxial speakers are often the answer for very limited installation space.
  • Sound quality: If you’re a sound quality fan or audiophile like I am, you’ll want to avoid coaxials with mylar tweeters. They’re not “bad”, however, better tweeter types like silk dome, aluminum dome, and others sound much better, smoother, and won’t sound harsh. You’ll usually pay a bit more, however. Unfortunately, mylar tweeter coaxials are the most common type.
  • Marine, motorcycle, Jeep, and outdoor vehicle use: You’ll want to avoid standard speakers with a paper cone material or similar as they’re prone to damage from humidity or moisture. Consider plastic cone speakers, especially marine-rate as they’ll last longer and sound good as expected.
  • Brand names are best: There’s nothing wrong per se with buying no-name-brand speakers, however, they have higher defect rates, worse design (and worse sound), and tend to be a bit more difficult to install sometimes.
  • Get the best you can afford: I recommend overlooking $25 etc speakers (unless you’re nearly broke) and instead spend closer to $50 or higher if possible. There’s a big difference in quality and sound. For about $65 you can get some wonderful-sounding coaxial speakers that you’ll love and will last a long time.
  • Check the speaker’s hole dimensions: It’s always a good idea to be sure that the diameter of a speaker will fit. Check the specs and measure the old speaker opening by measuring it before buying replacements.
  • Watch out for coaxials with tweeters poking out too far. In some cases, I’ve seen coaxial speakers with tweeters that extend way too far out vertically. The end result was that I couldn’t install a speaker grill over them. Be sure to check the old speaker versus the new one you’re thinking about buying.

There are so many speakers to choose from that it’s headache-inducing almost! My advice mainly is to avoid mylar dome tweeter speakers if you can find affordable alternatives.

Silk and aluminum dome (or other advanced material) models from brands like Polk, JBL, Kicker, Infinity, Alpine, and similar are excellent.

For budget options, Pioneer, Rockford Fosgate, Alpine, and Kenwood have some good choices, too.

Be careful which speakers you buy if you own a motorcycle, open-back Jeep Wrangler, or other vehicles exposed to outside air and humidity. Speakers that aren’t moisture resistant can begin to absorb moisture and deteriorate over time. Polymer/mica, metal, carbon fiber, and plastic-type cone speakers usually hold up well.

Do you need an amp for coaxial speakers?

Coaxial speaker and car amplifier installation example image

The truth is that you don’t need an amplifier for coaxial speakers. However, you’ll get even better sound, lower distortion, and potentially more enjoyment (and more volume) out of them if you use one.

Car and home receivers have enough power to drive coaxial speakers with fairly good volume and clarity up to a point. Car stereo head units are very limited in their power output – on average, you’ll get a maximum of about 15-18 watts per channel out of one.

To make matters worse, they’ll begin to distort and “bottom out” quickly if you play music with heavy bass. This sounds terrible! Using an amplifier (and its built-in high-pass crossover) can make an amazing difference in volume and clarity.

You’ll be fine for every day listening to coaxial speakers at a moderate to moderately high volume with a good car stereo head unit. If you’d like to add an amplifier, I recommend using one with a minimum of 50W RMS per channel and a high-pass crossover option.

How hard you can push coaxial car speakers with an amp?

Coaxial speakers should be treated like other speakers. The amount of power they can take from an amp will be limited by:

  • The RMS power rating of the speaker
  • Whether or not you’re driving them with heavy low-end bass in the music
  • Clipping from the amplifier (hitting the output limit of the amplifier, driving it to clipping)

Ultimately, you’ll get close to, but not all the way, to the RMS power rating for the speakers assuming it’s accurately stated by the manufacturer.

If you really want to drive them hard, you’ll want to (1) use an amplifier capable of more power per channel than the speakers to avoid clipping, and (2) use a high-pass crossover to block low-end bass.

What to set the high pass filter to on coaxial speakers

Coaxial speaker amplifier high pass crossover setting example

For better sound and volume, you’ll want to use the high-pass crossover built into your car amp. I recommend about 56 to 60Hz as a good compromise between blocking low-end bass that causes distortion and still allowing music to pass.

For coaxial speakers, I recommend setting your amplifier’s high-pass crossover somewhere between 56 to 60Hz or close to it. That’s enough to let the lower end of musical frequencies pass but still block distortion-causing bass that should be sent to subwoofers.

It doesn’t have to be exact. If your amplifier has an adjustable crossover frequency dial, it’s near impossible to get it exactly right, so don’t worry about that. Get it close to that based on the labels on the dial.

Basically, anywhere under 80Hz or so is fine, but based on my experience I recommend it’s a bit lower. Whatever works best for your ears is good too, of course.

Bass that’s very hard on small speakers is located below 60Hz so preventing it from getting to them is the most important thing.

More helpful speaker info, diagrams, and ideas to read

Check out my other articles as I’m sure you’ll find something useful!

Questions, comments, or suggestions?

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How To Tell The Impedance Of A Speaker And Understanding Speaker Ohms

How to tell the impedance of a speaker featured image

We take for granted how certain stereos and amplifiers need  2, 4, or 8 ohm speakers to work right. But what is speaker impedance?

And how can you tell the impedance of a speaker if it’s not on the speaker or you can’t find it?

Great news – it’s not that hard! In this helpful article, I’ll explain how speaker impedance works, how you can measure speaker impedance (Ohms), and much more.

There’s also a handy speaker Ohms chart to help you identify what impedance your speaker is to know for sure.

Contents

How to tell the impedance of a speaker

Let’s cover the main ideas before going into more detail as I cover each topic more.

How to find a speaker's impedance
  • If the Ohm rating (impedance) is not available on the speaker, you must measure the impedance of a speaker using a test meter set to the Ohms (resistance) function. This will give the resistance of the voice coil which will let you determine the speaker’s impedance category. (see below for more detail)
  • A speaker’s impedance is usually listed on the speaker magnet, packaging, and/or box and specifications. This is not always the case, however, as it depends on the manufacturer and model.
  • The total impedance changes with frequency as speakers don’t act like resistors but instead have inductance which opposes the flow of current as the audio signal frequency increases. You can calculate impedance based on the formulas included here. Note: you won’t need this just to determine the general impedance range of your speakers.

Long story short, if your speaker doesn’t have the impedance listed anywhere or you can’t find the manufacturer’s specs, the best thing to do is to measure it. That way you can be 100% certain and avoid problems with your stereo, amplifier, and crossovers.

You definitely don’t want to use a speaker with lower impedance than expected as it’s possible to damage your stereo or amplifier permanently!

What is speaker impedance? (Speaker Ohm ratings explained)

What is speaker impedance diagram

Speaker impedance, measured in Ohms, is the voice coil’s total resistance to the flow of electric current as it operates with a musical signal.

Unlike standard electrical conductors, the voice coil’s wire winding forms a loop that has an electrical property called inductance. Inductance is different from resistance as it changes as the frequency changes. This is called inductive reactance.

How does speaker impedance work?

Magnetic fields are created as current flows through the tightly wound wire coil. These fields have an opposition (resistance, also called reactance) to the current flowing through the coil wire. (Similarly, many other electrical components like motors have this too).

Because of how inductance works and the physics involved, the speaker “impedance” (total resistance) isn’t a simple addition of the resistance and the inductive reactance together.

Instead, speaker impedance is found from the algebraic sum (the square root of the sum of the squares) of the coil’s wire resistance and the inductive reactance.

Inductive reactance is commonly written as “Xl”, pronounced “X sub L” and is measured in units of Ohms just like resistance. Inductance is measured using a unit called the “Henrie” and commonly noted with an “H”: “uH” for microHenries, “mH” for milliHendries, and so on.

How to calculate speaker impedance

How to calculate speaker impedance diagram

If you’re a math person, you can see here how speaker impedance is calculated. As I mentioned, it’s the geometric sum of the resistance in the voice copper wire winding and the inductive reactance at a given frequency.

The most important thing to understand about speaker impedance is:

  • The speaker impedance is always equal to or greater than the voice coil wire resistance. You can measure this with an Ohm meter.
  • The impedance number on a speaker is a general guideline for compatibility, not exactly what the speaker measures.
  • The impedance changes slightly (goes up) as the frequency being played increases.

In fact, if you were to use a test meter to measure the Ohms (impedance) of the voice coil on a speaker, you’d find a reading of about 3.2-3.6 ohms or so for a 4 ohm speaker and 6 ohms or higher for an 8 ohm speaker.

Example of calculating speaker impedance

Let’s take an example. We’ll use an example speaker and real-world specifications then do the math.

Calculating speaker impedance example parameters used

Example parameters to use from a real speaker for the voice coil’s resistance (Re) and the winding’s inductance (Le).

Example of calculating the speaker impedance using 1kHz as the frequency:

  1. Calculate the inductive reactance. Use the formula given earlier Xl = 2*Pi*Le*frequency: 2*3.14159*.000028*1,000 = 0.1759 Ohms (Ω)
  2. Find the total impedance (represented by “Z”). Find the root of the sum of the squares of both Re and Xl: Z = ( (3.0)^2 + (0.1759)^2)^-1 = 3.005 Ohms (Ω)

Therefore, for our example speaker, the total impedance at 1kHz is 3.005 Ω, only a tiny bit higher than the voice coil’s own resistance.

This is because (1) most speakers have a very small amount of inductance, and (2) speakers work in the audio range and no higher than 20kHz, meaning the inductive reactance will be limited.

Speaker impedance due to the resonant frequency

That’s not to say that speakers never have a high impedance. In fact, at their resonant frequency where they behave differently, the impedance can be HUGE! In fact, as high as 50 ohms. However, that’s a separate topic.

(Note: as you see from the example speaker’s specs, the parameter “Fs” tells us the resonant frequency of 84.8Hz is where that happens for this particular speaker)

How to measure speaker impedance

How to measure speaker impedance with an Ohm meter example

In this picture, you can see an example of how to measure speaker impedance using an Ohm meter or any standard test meter set to measure resistance in Ohms. To do so, set it to the lowest range that measures units of 1, 0-10, 0-20, or auto-ranging and the meter will measure it accordingly. Hold the test probe leads firmly against clean metal on the speaker terminals with speaker wire removed.

To measure the impedance of a speaker you’ll need a multimeter (test meter with multiple functions) or a dedicated Ohm (resistance) meter.

Use the following steps:

  1. Switch on the meter and set it to measure Ohms on the lowest range. This is often the x1 range, 0-10, 0-20, or auto-ranging setting.
  2. Disconnect one or both speaker wires from the speaker to avoid a false reading due to other resistance that may be connected to it.
  3. Hold the probes firmly against the speaker terminals on a clean, bare metal spot. The meter should quickly settle to a reading. The meter will show the resistance of the voice coil inside the speaker.
  4. Use the measured value to determine the closest approximate speaker impedance (see my chart below for help).
  5. For speakers inside a cabinet or enclosure such 2-way speakers, crossovers may be in use and these can interfere with this reading with a few exceptions. However, in many cases, you still measure the resistance of a woofer fairly well.

The important thing to bear in mind is that you won’t measure exactly 4 ohms, 8 ohms, etc. Speakers are given an impedance rating for stereo purposes that are approximate – or close to – what you’ll measure with a test meter.

Note: Speakers like tweeters with a capacitor connected inline with them will act as an open circuit and will interfere with your measurement.

See my notes below for how to measure those correctly.

Selecting the correct resistance (Ohm) range for speakers

Image showing examples of test meter resistance setting for measuring speaker impedance

Shown are some example test meter resistance range settings to use for typical test meters.

As I mentioned earlier, it’s important to use the correct resistance range on your meter when measuring speaker impedance. That’s because the wrong setting may display nothing or give you the wrong idea that perhaps the speaker is blown when it isn’t.

If you’re not sure, check the test meter’s manual. Many modern digital meters often have an auto setting that will automatically adjust for the Ohm measurement it detects and will display the reading & decimal places accordingly. Other meters require you to select the correct range manually.

As a general rule, use the lowest range that includes 0-10 ohms (or similar) then go up if necessary.

That should almost never happen – but in the case of a poor connection, blown (or almost blown) speaker, strange things can happen and you might get a reading that’s far outside the speaker’s normal impedance.

In my experience, however, that’s very rare.

Once you’ve got your measurement, use my speaker impedance chart to find the next closest speaker impedance value listed.

How to measure speaker impedance when there is a crossover

Diagram showing where to measure speaker impedance of tweeters with crossover

Tweeters are one of the most common types of speakers with a crossover. To measure speaker impedance on them, you’ll need to place the test meter’s probes around the capacitor crossover. Otherwise, the reading will be an open circuit or far too high.

Measuring speaker impedance where crossovers are used is a bit of a problem. That’s because capacitors, which are commonly on tweeters as a high-pass filter, act as an open circuit when measuring resistance.

Obviously, that’s a problem as you’ll never get a correct reading if you use the test leads on the speaker wiring.

To avoid this, you’ll want to measure around the capacitor, if used, which is normally on the positive speaker terminal. You should be able to then get a correct reading.

For 2-way speakers, in many cases, no crossover is used on the woofer. In some cases, there’s an inductor in series with it. The good news is that directly reading resistance across a speaker and an inductor doesn’t make much difference – inductors have a tiny resistance value. In fact, they’re usually in milliOhms (thousandths of an Ohm) which is almost nothing.

Diagram showing where to measure speaker impedance with crossover use

For 2-way crossovers, the same applies, too. Following the diagram above, your main concern is avoiding measuring across capacitors.

Speaker impedance example chart (use with speaker measurements)

Speaker impedance label and ohm meter examples

An 8 ohm speaker, in the real world, will have a resistance measurement less than its 8 ohm rating. That’s normal and is due to how the speaker is made. Speakers do not have exact impedance values but instead will fall into a general range close to their rating. You can use that range to identify their impedance if you don’t know it.

To use this chart, take the speaker resistance measurement you got from the instructions earlier and use it to compare to the measurements here. You’ll see your speaker should fall into of the commonly sold speaker impedance standards.

Speaker impedance measurement chart

Speaker measurement range* Speaker impedance rating
3.1-4.0 ohms 4 ohm
6.0-8 ohms 8 ohm
1.2-2 ohms 2 ohms
4.0-6 ohms 6 ohms
0.5-1.0 ohms 1 ohm**
12-16 ohms 16 ohms**

*(This is an approximate range and should cover nearly all speakers but may vary slightly)
**(1 ohm is rare but can be found in some car stereo products such as Bose premium amplified systems. 16 ohm speakers may sometimes be used for home or other speaker systems, but aren’t very common)

What happens if my speaker impedance is too low or too high?

4 ohm vs 8 ohm speaker power comparison graph

This graph shows what happens when a higher impedance speaker is used with an amplifier or stereo rated for a lower impedance speaker. As this example shows, using an 8 ohm speaker in the place of 4 ohm ones means it will develop 1/2 the power and consequently, lower volume than a 4 ohm speaker.

Using a speaker that’s not matched to the stereo or amplifier it’s rated for can have relatively minor – or even horrible – results depending on which case we’re talking about:

  • Using a higher impedance speaker won’t damage equipment. The result will be lower power developed and therefore lower possible volume. You may also introduce problems with speaker crossovers, however.
  • Using a lower than specified impedance speaker will cause radios or amps to suffer extreme heat and even permanent damage because the current output will be much more than what it’s designed for.

For example, if you were to use 8 ohm speakers in the place of 4 ohm car stereo speakers you won’t damage anything, as less current will flow to the speaker. The problem will be (although it will play fine, otherwise) is that the total power available will be 1/2 that of a 4 ohm speaker.

Ohm’s Law and speaker power

Car amplifier power output formulas image

A radio or amplifier is designed to output a certain voltage level for a given volume and so higher impedance speakers won’t have the same power available at the same volume level. That’s because the power to a speaker depends on the voltage available.

By the electrical formulas called Ohm’s Law, P (power, in Watts) = Voltage^2/R (speaker Ohms)

For a low volume (2V output from an amplifier) a 4 ohm speaker would have 1W of power available. An 8 ohm speaker, however, would have only 1/2W. That means for the same amplifier or radio volume, higher impedance speakers can’t produce the same volume.

How does speaker impedance affect sound?

Using the wrong speaker impedance can affect the sound in a few ways:

  • If you mix and match 4 ohm tweeters with 8 ohm woofers, for example, they’ll be mismatched and at some point won’t sound right as the power increases because their volume levels won’t be the same.
  • Using the wrong speaker impedance with speaker crossovers can have a very big impact on the crossover frequency (it will be shift a lot) and will dramatically affect the sound output. Your speakers won’t sound right, can have a lot more distortion, and will generally be much less pleasant to listen to.

What happens to a car stereo if a speaker has a lower impedance than the stereo is rated for?

Using a lower impedance speaker than your stereo or amplifier is rated for is a terrible idea and should never be done! That’s because it’s not designed to handle the excessive amount of current it will have to supply thanks to the decreased resistance of the lower speaker impedance.

If you’re lucky the unit will go into “protect mode” in which it shuts off until the condition is removed and it’s safe to operate. However, from my experience, many electronics become extremely hot and can burn out their output transistors meaning they’re permanently damaged.

Don’t risk it! Always check the minimum Ohm rating of your equipment and be sure to follow it. Never assume the amp, radio, or receiver, etc, will be able to protect itself from damage.

Speaker impedance and crossovers – yes, it’s important!

2 way speaker system and crossover diagram

Crossovers are designed for a specific speaker impedance. Changing the speaker impedance means you’re changing how they function and shifts the crossover frequency, giving worse sound and potentially adding distortion that wasn’t there before.

When using speaker crossovers, it’s really important to understand that you can’t change the speaker load (speaker impedance they see connected) as the results won’t be good.

Changing a 4 ohm speaker to an 8 ohm one, or vice versa, will have a huge impact on the sound because the crossover cutoff frequency will change greatly since it depends critically on the speaker load used.

As a general rule:

  • Doubling the speaker impedance will halve (decrease) the crossover frequency.
  • Halving the speaker impedance will double (raise) the frequency cutoff.

For tweeters, increasing the tweeter impedance means you’ll be allowing in more bass & midrange, leading to poor sound since tweeters can’t produce those ranges. For woofers, that means introducing poor-sounding midrange or treble that they’re not suitable for.

In both cases, just remember that the crossover frequency changes inversely proportional to the speaker load you’ve increased or decreased.

Note: When reducing tweeter volume, using an L-pad or properly designed L-pad resistor network will properly maintain the speaker load the crossover sees so it won’t affect the sound.

More great speaker-related articles you’ll love

Check out my other articles as I’m sure you’ll find something useful!

Questions, comments, or suggestions?

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