How To Set Crossover Frequencies For Your Car Audio System

How to set crossover frequency for car audio system featured image

Crossovers are awesome for getting better sound from even cheap speakers. But what are crossovers, how are they helpful, and what are the best crossover settings for car audio?

In this article I’ll show you how to set crossover frequencies for your car audio system along with some other helpful info:

  • How crossovers work and why they make a big difference
  • The best car audio crossover frequency settings (table is provided)
  • Diagrams to show you how to set your car amp crossovers

…and much more, too. There’s a lot to cover so let’s get started!

Contents

What does a crossover do? Crossover frequency, slopes, and more explained

Crossovers and crossover frequencies explained diagram

People tend to talk about crossovers as if they totally “block” sounds you don’t want to go to your speakers. While they sort-of do, in reality, crossovers are filters that greatly reduce the amount of unwanted sound frequencies sent to speakers.

How are crossovers helpful for speakers?

Crossovers are very important for car audio as they help us deal with the poor enclosures they’re used in along with the weaknesses that small speakers have. Some of the most common speaker sizes installed from the factory or sold for aftermarket use like 3.5″, 4″, and 5.25″ sizes can be terrible for playing bass, resulting in bad sound and ugly distortion.

To make matters worse, speakers in cars, trucks, and even boats are often mounted in areas where it’s impossible to get great sound because they leak air and don’t form a good enclosure to deliver sound properly unlike home stereo speaker cabinets. That means they leak air badly and can “bottom out” easily if driven hard with bass sounds, for example.

One reason why crossovers are so helpful there is that we can use them to block terrible-sounding audio frequencies that ordinarily would cause these problems and others, too.

Understanding crossover basics

Car audio crossover examples

When we think about musical signals we don’t always realize the important things going on behind the scenes. In fact, you’ll almost never find a good-sounding speaker system that isn’t using one or more types of crossovers; that’s how important they are for great sound.

A crossover (audio crossover) is an electrical or electronic component circuit made up of parts that react to certain frequencies and designed to eliminate unwanted ranges of sound from reaching speakers.

Crossovers allow a desired range of sound to pass unaltered and effectively block ranges of sound past a limit called the cutoff frequency.

A crossover circuit can be used for only one single speaker channel or combined with another to separate and direct sound the best speakers suited to produce it. In car audio, the most common speaker crossovers are used in 2-way coaxial and component speakers.

Simple speaker crossovers can also be added inline with speakers to block lower-end bass as well.

What are the 3 types of crossovers in car audio?

There are 3 types of crossovers:

  1. Active (electronic) crossovers – work in the signal path (line-level signals)
  2. Passive (speaker) crossovers – work in the amplified speaker path after an amplifier
  3. Digital (software) crossovers – they work with sound in the digital music domain

1. Active (electronic) crossovers

Illustrated diagram of an electronic (active) crossover example

An example of an external (add-on) electronic (active) 2-way crossover. These are basically the same as the electronic crossovers built into many amps you can buy today. Some offer a few more options, but unlike years gone by, they’re less and less important these days. Most amps today include what you’ll need already.

Active crossovers use electrical components such as transistor-based chips called op-amps (operational amplifiers) to behave the same way as their much bigger and much less efficient speaker crossover counterparts.

They offer a lot of benefits (especially their compact size) and can be designed to allow you to choose between using no crossover, a high-pass, or a low-pass easily. Unlike passive crossovers, they do require power to work and change the signal, hence the name “active.”

Active crossovers work with a line-level (RCA) signal either before an amp’s RCA inputs (in add-on external crossovers you can buy) or inside the amp. The signal output of an electronic crossover has to be amplified, unlike speaker (passive) crossovers that you connect between an amp and speakers.

2. Passive (speaker) crossovers

Image showing speaker crossover examples and resistor, capacitor, and inductors

“Passive” crossovers are those that use inductor and capacitors, without a power source, to filter out sounds you don’t want to reach speakers. They’re usually used for smaller speakers like with tweeters, 2-way coaxial speakers, and component speaker systems because they’re relatively affordable in those situations.

Passive speakers aren’t used to block midrange and treble (“highs”) from subwoofers because the size of the inductors needed would be really big – and expensive, too! They’re also much less efficient than electronic ones in that case.

That’s one reason the built-in low-pass subwoofer crossovers in amps are so great.

3. Digital (software-based) crossovers

In dash car stereo with equalizer shown

Software-based equalizers and crossovers use advanced software routines to alter sound in the “digital domain.” That means they can alter the sound (or filter it, as crossovers do) by working only with the digital musical signal. This makes them more complicated but saves spaces & money since it reduces size & the electronics required.

This type is implemented in the software code of home theater receivers, car stereo head units, or digital audio processors. Software-based crossovers usually work by implementing math-based functions that alter the signal output based on its frequency.

It’s a really complicated topic, but the basic concepts aren’t hard to understand. By using special formulas, not only different types of crossovers but also equalizers can be implemented and operate on the musical signal when its represented as a binary digital number.

This is a cost and space-saving feature as there are few, if any, parts needed to make it work. However, it usually takes more specialized microprocessors or digital signal processor (DSP) chips to do so.

What are good crossover frequencies for car audio?

Crossover audio range chart diagram

Within the range of sound your ears can hear, for most cases crossover frequencies typically fall into a small range you’ll likely use for tweeters (high-pass), full range speakers (high-pass), and subwoofers (low-pass).

The truth is, there’s not a “perfect” set of crossover frequencies that work for every speaker in every vehicle. That’s basically impossible because nearly everyone is using different speakers, a different setup, and so on.

However, here are some of the most common frequencies that work well in many cases. 

Recommended crossover frequency table

Speaker/System TypeCrossover Freq. & TypeNotes
Subwoofers 70-80 Hz (low pass)

Good low-pass frequency range for subwoofer bass & blocking midrange sounds. Best for pure, clear bass sound that "hits."

Car main (full range) speakers 56-60Hz (high pass)

Blocks low-end bass that causes distortion or speakers to "bottom out." Great compromise between full-range sound and midrange bass capability.

Tweeters or 2-way speakers 3-3.5KHz (high pass, or high/low-pass)

Most 2-way or 1-way (tweeter) crossovers use a frequency near this as most tweeters can't handle sounds below this range. Same for woofers above this range.

Midrange/woofer 1K-3.5KHz (low pass)

Woofers and many midrange speakers do not perform well above this general range. They're poor for treble and a tweeter should be added.

3-way system 500Hz & 3.5KHz (Woofer/tweeter crossover points)

Similar to 2-way systems the upper freq. would be the same. Midrange drivers in a 3-way system often do not perform well below 500Hz or 250Hz in many cases.

How to set the crossover frequency for speakers on your amp

How to set crossover frequency on car amp diagram

How to set high pass filter options on your amp (for main speakers)

Most people typically use a car amplifier for one of a few basic systems:

  1. Driving front and rear full range speakers, no subwoofer
  2. Driving front and rear full range speakers plus a subwoofer
  3. Driving a subwoofer

For cases #1 and 2, if your amplifier has a built-in crossover option you can use the high pass crossover to block low end bass that small speakers simply can’t produce well, if at all. The end result is that you’ll be able to drive your main speakers with more volume and lower distortion.

We only want to block that certain range of bass that subwoofers can handle. We don’t want to block bass found in the lower end of midrange like from the vocals in music (for example, around 100-120Hz or so). 60 to 70Hz or so are pretty common crossover frequencies that usually work well.

Adjusting an amp’s high pass crossover

For amplifiers with adjustable crossovers, use the following steps:

  • Turn off equalizer or bass boost functions
  • Set the front channel or front and rear (if using both) crossover switches to “HP” or however they’re labeled for the high pass function.
  • Adjust the crossover frequency control to the lowest setting (this is usually around 50Hz for most amps).
  • Using a small screwdriver, turn it up slightly – about 1/8 of a turn. This should be around the 60-70Hz range.
Note: Not all amplifiers offer an adjustable control. Some (especially ultra-compact models) use fixed frequencies and switches only. In that case, try using the switch position closest to the 60-70Hz high pass frequency range.

How to set subwoofer crossover frequency options

Similarly, do the following to adjust the subwoofer frequency & crossover:

  • Turn off equalizer or bass boost functions
  • Set the crossover switch to “LP” or however it’s labeled for the low pass
  • Adjust the crossover frequency control to the lowest setting (this is usually around 50Hz for most amps).
  • Using a small screwdriver, turn it up slightly – about 1/8 of a turn. This should be around the 70Hz range
  • Adjust as needed: if you’re not happy with the low-end range (the range of bass sound produced), don’t be afraid to adjust the frequency control a bit.
TIP: With decent power and a good speaker enclosure properly matched to the sub, you should have clean, pure bass at this point.

However, I’ve seen many cases where a subwoofer installed in the wrong type of subwoofer enclosure produces bland, poor sound. A crossover can’t fix that problem.

What crossover slope do I need? Does it make a difference?

What crossover slope do you need image of man thinking

In some cases, you’ll be able to choose from a number of crossover slopes (the steepness of the cutoff) on your amplifier or other components. As I mentioned earlier, the slope how effective a crossover is at allowing fewer unwanted sounds to reach your speakers, with higher numbers being more effective.

And as I mentioned ealier, -12dB per octave (“-12dB/octave”) is very common in car audio. While it may seem like the rule of “more is better” applies here, the truth is that most of the time a 12dB or 18dB/octave crossover slope is all you’ll need.

Why do some electronics offer more crossover slopes?

Some amps, head units, and digital processors/equalizers for car audio offer more crossover options for people who want advanced control – especially if you’re working on a high-end sound system. For example, when bi-amping speakers (using an electronic crossover and separate amp channels for the tweeter, the midrange speaker, and so on), you can take advantage of each speaker’s natural behavior and get super-detailed control over the signals you send to them.

That’s a much more advanced topic and worth its own article, by the way.

However here are the basic rules for crossover slopes that will work for 90% of people:

  • A 12/dB setting is good and will do the job in most cases for subwoofers (low-pass) and full-range speakers (high-pass).
  • However, 18dB/octave can be better for some subwoofers depending on your particular subwoofer, the enclosure, and how your vehicle alters the sound. In that case, experiment using the -18dB setting and see how it sounds.
  • 6dB/octave is a bit poor and will allow sounds to pass that can “muddy” the sound and just isn’t good enough for bass speakers. I don’t recommend that in most cases.

Most of the time, the main goal is to have the same cutoff at the same frequency. The goal, in perfect conditions, is that the speakers match up just right so there’s not much overlap in their sound as well as no gaps in the sound.

However, it’s definitely a lot harder in the real world. In my experience, however, 12dB/octave works well and is effective enough to make a big difference in how your system sounds.

More great speaker and crossover info to see

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How To Hook Up A Car Stereo To AC Power – You CAN Do It!

How to hook up a car stereo to AC power featured image

Want to use your car stereo at home? Great news – it’s actually not that hard…if you know what you’ll need.

In this article, I’ll show you how to hook up a car stereo to AC power along with:

  • What you need to know first
  • Clear & easy-to-follow wiring diagrams
  • What kind of AC power adapters or supplies you can use
  • How to wire a computer power supply to a car radio

…and more! There’s no reason to wait so let’s get started.

Contents

First things first: can you hook up a car stereo to a house outlet?

Can you hook up a car stereo to a house outlet image

The quick answer is yes, with the right power supply, you can hook up a car stereo to a house outlet with 120V or even 220V power. You cannot, however, directly connect a car stereo to an outlet.

However, you’ll need to know just a few things to make sure you don’t have any headaches or potentially destroy your car stereo.

Is a car radio AC or DC?

Car radios use direct current (DC) voltage to power their electronics while home electronics use alternating current (AC) with a much higher voltage. In fact, car radios can work down to somewhere around 11 volts DC, with 12V to 14.4V being typical when a vehicle’s engine is running.

The reason car radios use DC power is because automobiles use a DC battery to start and power the engine. While the motor is running an alternator generates AC power that’s changed to DC in order to charge the battery. Batteries store DC power, not AC.

What voltage do home outlets use?

Home AC outlets supply around 120V (volts, or “V”) AC if you’re in the United States and some other countries. Others I’ve been to are even higher at 220V AC. It’s extremely dangerous to try and connect a DC device to AC power – in fact, it can even explode or catch on fire.

What you need is a power supply to safely reduce the high voltage of a home AC outlet to a lower DC voltage that a car stereo can use.

How many amps does a car stereo draw?

The good news is that unlike car amplifiers, a car stereo draws only a few amps. Typical car stereos (depending on the design, features, etc) draw about 2 to 5 amps or so at full power.

I’ve seen some units that have a 10 amp fuse, but that doesn’t mean they use quite that much current. Fuses come in certain sizes so that’s the next closest one the manufacturer needed to use.

Although car stereo manufacturers may advertise them with high power ratings like “50W peak per channel”, in reality, the average car stereo can only put out about 15 to 18 watts RMS per channel.

That’s because they have to work with a +12V supply which limits the power they can deliver.

What is the 12V accessory wire on a car stereo?

Example of car stereo wiring harness power colors, labeled

Car stereos have 3 power wires that have to be connected in order to work:

  1. Ground/negative, “GND”
  2. +12V power/radio memory backup “BATT”
  3. Accessory on, “ACC”

For 99% of car stereo, the 12V accessory wire is a red-colored signal wire that triggers the electronics to switch on. They’re normally connected to a vehicle’s ignition switch accessory wire to turn on and off with the switch. 

It’s necessary to connect this to power on a car stereo. When power is removed from the radio’s accessory wire it turns off and goes into a low power mode.

What can I use to power a car stereo at home?

Car stereo AC-DC power supply examples image

The good news is that 12V power supplies are available if you look in the right place – and one that’s right for hooking up a car stereo to AC power shouldn’t cost much. You just need to know what to look for.

The good news is that it’s usually not hard to find the right kind of supply to power a car stereo at home. You’ll need one with 2 main things:

  • The right voltage: 12V to 13.8V
  • The right current (amps) rating: about 2 to 2.5A for most car stereos and towards 5A for some units that draw more
Tip: 12V supplies will work fine and are also the most common kind. 13.8V AC-DC supplies are used sometimes for powering CB radios and other equipment, so they’ll work fine but aren’t necessary. Don’t go out of your way to use those.

12V supplies are usually a lot more affordable anyway.

You can pick up an AC-DC supply from a variety of places: Amazon, your local electronics store, and you can even use an old PC computer supply (also called an “ATX” supply) you’ve got lying around. I’ll cover that in more detail later.

Can you use a wall adapter for a car stereo?

AC-DC wall outlet adapter example with barrel connector

While you can use a wall adapter to power a car radio with decent results, most are pretty poor and can’t supply many amps and only a little bit of power. You’ll also need to cut the wiring which in some cases can be a little tricky since it’s sometimes very small wire.

Technically, you can use a wall outlet AC-DC 12V adapter, but I don’t recommend it. 

They’re pretty limited in power output and the amperage they can provide (many are less than 1A rated). They’re designed to do things like charge devices or supply low-power devices.

They also don’t have good reserve power and when you start cranking up your car radio the voltage may begin to sag (drop out) and it won’t work well along with the sound breaking up & distorting. You’ll need to find one with enough current (say 2 to 2.5 amps or more if possible) and cut the wiring since most come with a connector attached.

Caution! When using a AC/DC wall adapter, be careful because for some it can be hard to tell which wire is positive and which is negative. 

Always be 100% sure before connecting a radio to avoid a reverse polarity condition as that can damage electronics!

What to know about computer power supplies

Computer power supply 12V current rating examples

PC power supplies are also called “ATX” supplies and can provide lots of current from their 12V wiring. You can see their amps rating on the label like in these examples above.

Computer power supplies are fairly common and are usually priced pretty well (especially used). You won’t need a high-power one.

In fact, even a standard low-end 150W PC power supply will work great for a car stereo! Nearly all of them have more current output than you need.

The drawback, however, is that PC power supplies require a certain (but easy to do) wiring connection in order to turn on. That’s because they’re normally connected to a PC motherboard that provides a control signal for them to work.

Fortunately, there’s an easy workaround you can use that makes them great for a home car stereo system power source.  See my detailed diagram for that further below. 

How do you hook up a power supply to a car radio?

How to wire a car stereo to power & speakers at home diagram

Connecting radio power and ground

To connect a car radio to a power supply you’ll need to do the following:

  • Ground: Connect the radio’s ground wire (black wire) to the (-) power supply output
  • Main power: Connect the radio’s +12V battery wire (usually the yellow wire) to the (+) power supply output
  • Turning the radio on: You can do this by hardwiring the radio’s accessory wire (usually red) to the +12V battery wire or you can use a switch in between.

If you hardwire the accessory wire to the yellow wire (battery power), you can turn the car stereo off with the power supply on/off control. However, while that’s very easy, it comes with a price.

Removing power from the 12V battery wire means the unit will lose its radio tuner settings, audio settings, and any other adjustments you’ve made. Optionally, using a switch to connect the accessory wire as an on/off control is a good idea. Leave the power supply on in this case.

Another way is to simply turn the radio on/off using the power button and leave the power supply on. In either case, when turned off the radio will go into a low-power mode draw less than 0.5 amps when shut off.

Connecting the speaker wiring

Car stereos usually use standard wire colors for speaker connections:

  • White = Front left +, White/black = front left –
  • Gray = Front right +, Gray/black = front right –
  • Green = Left rear +, Green/black = left rear –
  • Violet = Right rear +, Violet/black = right rear –

Just like power wiring colors, not all brands follow these standard colors so always check first!

Remember that car stereos can’t handle a speaker impedance (Ohms speaker load) below 4 ohms. You can, however, use 8 ohm home stereos speakers although you’ll only have 1/2 the rated output power available. I’ll explain that further below.

Never connect 2 ohm speakers for example or wire speaker outputs together as the radio can become hot and permanently damaged. Car stereos aren’t designed to be bridged like a car amp.

How to wire a computer power supply to a car stereo

How to wire a computer power supply to a car stereo diagram

Using an ATX (desktop computer) power supply for a car stereo isn’t hard – in fact, you only need a few steps:

  • Power connections: Cut a +12V wire (yellow) and a ground (black) wire from the main connector. Strip the insulation to leave about 3/8″ to 1/2″ bare wire. Use a crimp connector, solder, or another connector type to join the power supply’s +12V output (yellow) to the radio’s +12V battery wire (yellow). Do the same for the ground wires (black).
  • Supply on control: PC supplies don’t turn on even if the on/off switch on the case is used. A PC motherboard uses a control signal to the “supply on” wire pin. To do the same, you’ll need to find, cut, and jumper this control signal wire to a ground wire either directly or with an on/off switch if you like [See diagram above]
  • Radio accessory wire: Connect the radio’s accessory/on wire (red) to the +12V power wire from the supply either directly or you can use an on/off switch if you like.

Once you’ve connected the +12V and ground wiring to the radio, connect the “supply on” wire shown above to another ground wire as shown. The supply should start and your car radio should turn on. 

As I mentioned earlier, switching off the power supply will cause the radio to lose its “memory” (settings, last station you played, etc) so you may find it easier to use an on/off switch on the accessory wire or turn the radio on & off using the power button.

Don’t forget that a radio uses only a tiny bit of power when turned off so you can leave your power supply running if you like.

How to connect car stereo wires together properly

You’ve got several options for how to connect car stereos wires together properly. I’ll cover a few here. These are:

  1. Using the twist-and-tape method (not something I recommend, but it works “in a pinch”)
  2. Using connectors such as crimp (“butt”) connectors or wire nuts
  3. Soldering the wires together

I’ll cover each in detail.

1. Connecting wire using the twist-and-tape method

Example of speaker wire extended by twisting and wrapping with tape

Although it’s easy to do and cheap (especially if you don’t have many tools around), it’s the least reliable way to connect speaker or car stereo wires together. In my experience, the tape can come off later or the twisted wire may work its way loose at some point.

It’s as easy to do as:

  1. Strip about 1/2 inch insulation from the end of each wire
  2. Twist the bare wire together as tightly as possible, wrapping around each other to help hold them together
  3. Tear off some electrical tape and tightly wind it around the exposed wire and also the wire insulation

2. Connecting wire using crimp connectors

How to use crimp connectors with wire instruction steps image

This is one of the most reliable ways to connect wire and one I’ve used for years for car stereo installations. You’ll need one or more tools to strip your wire and crimp the connectors.

Here’s how:

  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 press the connector down hard, holding the wire inside permanently.
  6. Repeat the same for the other side & you other wires as needed.

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.

Image showing example crimp tool and crimp connectorsExamples of a wire crimping & stripping tool and crimp (“butt”) connectors. Blue is one of the most common and works well with 18AWG wire.

When shopping for crimp connectors you’ll notice they’re available in different colors for different gauges of wire. In most cases, the blue ones are fine for car speaker & radio wiring use. You can also pick up an affordable set that includes the crimp tool and connectors as well.

3. Connecting wire by soldering

Image showing steps for how to solder speaker wire

This is hands-down the most reliable way to extend & splice wires as when done properly soldered wire is extremely strong and is permanent.

How to solder car stereo wires

  1. Cut & strip the wire (at least 1/2″ length of bare wire is needed).
  2. Hold up both ends to form an “X” shape with the wire facing opposite directions.
  3. Hold both ends and tightly twist each end around the other until they’re completely wrapped over each other.
  4. After the soldering iron is hot, apply heat to the wire with the tip. Once heated (after a few seconds usually), apply solder enough so that it has flowed fully through the wire.
  5. Rotate the wire to the other side and apply the solder until all of the wire is fully saturated with solder.
  6. Allow the wire to cool for a few moments.
  7. Tear 2 short pieces of electrical tape. Starting at the insulation and at an angle, tightly wrap the tape until it is fully covered.

It’s important to fully cover the wire once you’re done. That’s to prevent adjacent wires from touching each other and causing a short circuit that can permanently damage the radio’s output stages.

How long does soldering speaker wire properly take?

All in all, you’ll need about 30 minutes to solder a full set of car radio power & speaker wires or a bit less if you’re only connecting the power side.

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How To Wire A Computer Power Supply To A Car Amp

How to wire a computer power supply to a car amp featured image

There’s more than one way to power a car amp in your home. Even so, computer power supplies are easy to find and make a great option – if you know how.

In my detailed guide, I’ll show you how to wire a computer power supply to a car amp. I’ve also put together some great diagrams, tips, and more to help you enjoy your music with less hassle and fewer headaches.

Contents

Can a computer power supply run a car amp? What to know

Can a computer power supply run a car amp man thinking question

Yes, it’s possible to use a PC computer power supply for powering a car amp. 

There are a few things you’ll need to know though. For example, unless you’ve got a higher-power model supply you won’t be able to drive speakers with the same power you could when installed in a car.

Do you need to hook up the remote wire on your car amp?

Yes, a car amp won’t work without a +12V signal on the remote wire terminal. The amp’s internal power supply is controlled by this wire and acts as a shutoff control. Likewise, you’ll want to either turn the power supply on & off as I’ll show you or use the remote wire as a shut off in order to keep the amp from drawing power when not in use.

Computer power supplies also have a particular control wire you’ll need to connect in order to switch the supply on as I’ll show you.

Computer power supply current (amps) & power limits

Computer power supply 12V current rating examples

Examples of the current output (amps) for a typical 200W supply and a higher-power 700W supply. The current output will limit how much power you can get from a car amp.

Computer power supplies are available in a wide range of power output options, with 1500-200 watts being very common but others as large as 700W or more can be found (although they cost a bit more). This is important to know because the current limit of a power supply will limit how much power your car amp can produce.

That means you need to be aware that for higher-power amps you can’t expect to drive speakers with the full power output it’s rated at. The good news that unlike in cars, speakers used in your home use less power for the same volume because vehicle interiors are poor for sound and require more power for good results.

How to power a car amp with a computer power supply (diagram and details)

How to wire a computer power supply to a car amp diagram

Using an ATX (desktop computer) power supply for a car amp isn’t hard – in fact, you only need a few steps:

  • Power connections: Cut the +12V wires (yellow) and the same number of ground (black) wires. Strip the insulation to leave about 3/8″ to 1/2″ bare wire. Twist them together tightly or use a crimp connector (ring terminal, spade terminal, etc) and connect to the amp’s power & ground terminals, being sure not to leave any stray wire strands sticking out to cause a short-circuit.
  • Supply on control: PC supplies don’t turn on even if the on/off switch on the case is used. A PC motherboard uses a control signal to the “supply on” wire pin. To do the same, you’ll need to find, cut, and jumper this control signal wire to a ground wire either directly or with an on/off switch if you like [See diagram]
  • Amp remote wire: There are several great ways to do this and I’ll cover them below.

Once you’ve connected the +12V and ground wiring then ground the “supply on” wire the supply should start up and your car amplifier should power on. There are some cases where you could have a problem, however.

NOTE: If you’re using a high amount of current be sure to use all or nearly all of the yellow +12V wires to connect to the amp. Just like with a car amp installation, you need enough wire conductors to supply higher current without losing voltage from insufficient wiring.

A note about some amps

Larger, very high power car amplifiers can sometimes draw a short current “spike” when they’re first connected to a power source after being disconnected. That’s because they contain large capacitors that, when first connected to power, momentarily draw a huge number of amps.

When this happens it’s possible it could trip the self-protect mode in your power supply. If that happens you can try starting the supply and then wait before turning on the remote wire. You can also leave the supply running when the remote wire is disconnected so the amp’s capacitors don’t discharge when the amp is turned off.

It’s possible you may need a more robust power supply if it happens but it’s not a problem most people should run across.

Remote wire options & examples

How to connect remote wire on car amp used in home diagram

The car amp “remote” terminal uses a low-current +12V input to start its power supply & related circuits. You’ve got a few different options you can use:

  1. Jumper wire:  When connecting the power and ground 12V connections, you can use a small jumper wire from the +12V battery terminal to the remote it so it’s on any time the amp has power. 18AWG or smaller wire is fine (you don’t need a large gauge wire).
  2. Jumper wire + switch: The same as #1 but to control it yourself you can add a simple inline switch on the remote wire. This is helpful if your power supply doesn’t have an on/off switch or you’d rather leave it running.
  3. Home stereo use – RCA converter with remote lead: If you’re connecting the amp to speaker outputs on your home stereo you can use a line level converter with a remote wire output. This will turn the amp on and off automatically with the stereo’s output.

If you’re using a toggle switch on the remote wire you can leave the AC/DC power supply plugged in. When the amp’s remote wire is off (disconnected) the amp will shut off and it won’t drain power.

Using a line level converter with remote wire output

Example of line level converter with remote wire output Axxess AX-ADCT2

An example line-level converter with remote wire output. You’ll need to connect these to 12V power and ground for the internal electronics to work. When the speaker level inputs detect a signal the remote wire output will produce +12V and turn on your amplifier. When the speaker signal is lost it will switch it off automatically.

Connecting a laptop, tablet, or smartphone to the amp for audio

Diagram for how to connect audio signal to a car amp used in your home

What’s great is how many options you have for getting an audio signal to your amp’s inputs. In fact, nearly any analog (non-digital) jack can be used from almost any device. Smartphones, tablets, and laptops can be used either by their headphone jack or via Bluetooth.

Just be aware that not all headphone or audio out jacks are created the same –  some work well and have good sound & volume while others can have low volume and “meh” sound quality. However, the good news that generally speaking they’ll work well and I’ve used this approach several times with no complaints.

Connecting your smartphone or tablet via Bluetooth

You also use an affordably-priced Bluetooth receiver for around $25 from places like Amazon. They offer a direct line output jack or RCA jacks to go into a home receiver and a car amp just as easily.

Be sure to get a decent brand as the generic/no-name brand models tend to have sound quality problems and can produce odd noises between music tracks playing on your phone, for example.

What if I have a laptop with no headphone jack?

Example of a USB to headphone audio adapter

You can use a cheap USB to stereo 3.5mm adapter to get a headphone sized jack to connect an audio signal to your amp. They’re really affordable (under $10 in some cases!) and are a good option if your laptop’s headphone jack is broken or none is available.

If you’re like many people and want to enjoy music, movies, or more from your laptop there’s a problem if you don’t have a line-out or headphone jack – or if it’s just not working. A great option is to use a USB audio adapter as it’ll provide a 3.5mm jack you can connect to your amp’s RCA inputs.

I’ve found some for under $10 available with both the older USB-A and the new USB-C connection as well.

How to connect a car amp to a home stereo

How to connect a car amp to a home stereo diagram

You can also connect your car amp to your home stereo if you like. There are 3 ways to do it:

  1. Home stereo with no RCA output jacks + car amp with speaker level inputs: It’s fairly common for home stereo amps and receivers not to have RCA jacks available to connect to. If your amp has built-in speaker level inputs these can be connected to either an unused pair of speaker terminals or alongside speaker terminals in use.
  2. Home stereo with no RCA output jacks + car amp with no speaker inputs: You’ll have no choice but to use a line level converter in this case. These are car stereo adapters that you connect to speaker wiring or speaker terminals. This will drop the signal down to a level compatible with the amp’s RCA inputs.
  3. Home stereo with full range RCA output jacks + car amp: This is the easiest way but not all home stereos have full-range RCA output jacks. Some only have subwoofer RCA output jacks which are bass-only outputs. Full-range RCA output jacks can be connected directly to the car amp’s RCA inputs.

Image showing examples of line level RCA converters

Line level connectors will let you connect a car amp with no speaker inputs to any home stereo. You can connect these to unused speaker terminals on the receiver or amp as well as in parallel with home speakers already in use.

Dealing with ground loop hum (noise)

Example of an RCA ground loop isolator

You can use a ground loop isolator to break the ground conductor in RCA cables but still carry the audio signal. Since the ground connection can carry the noisy signal that gets amplified this often eliminates ground loop noise.

One thing you might not count on running into is noise. Ground loop noise, which appears as a very annoying 60Hz “hum”, is somewhat common for home stereo equipment. Unfortunately, despite car amps being designed to eliminate it, it can still happen.

One thing you can do is to try using a small gauge wire and connect it between the grounds or metal casing of the car amp, the RCA cables, and the power supply. If the noise disappears you can connect the wire to those points as a solution.

Alternatively, a ground loop isolator can often get rid of it. Connected inline with the RCA cables, they work by physically disconnecting the RCA cable’s ground connection while still sending the audio signal. They’re not expensive, but it’s a good idea to shop carefully as the “el-cheapo” units don’t always carry the entire audio range well and can cause a loss of sound quality you can notice.

Additional reading and helpful guides

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How To Connect & Power A Car Amp In Your Home + Diagrams

How to power a car amp in your home featured image

It might seem puzzling at first, but it’s actually not that hard to connect and power a car amp in your home.

In this detailed guide I’ll show you how along with detailed diagrams anyone can understand.

Here’s what you’ll learn:

  • Car amp power supplies: what voltage & current ratings you need
  • How to wire a computer power supply to an amp
  • How to connect a car amp to a home stereo, smartphone or tablet, or Bluetooth
  • Additional tips to make it easier & offer more options
Contents

First facts: Can I use a car amplifier in my house?

Can I use a car amplifier in my house man thinking image

Yes, it’s possible to use a car amplifier in your house. You can also connect a car amp to any home stereo, your smartphone, and more as an audio source.

There is a catch, though. Because car amps use a different power source than home stereos the biggest problem is getting them the power they need. Not only that, but they use a remote-on wire to turn the amp on & off to avoid draining a car battery – meaning that needs to be dealt with too.

Here’s a list of what we’ll need to cover:

  • Signal inputs: Not all home stereos have RCA line-level jacks, so if you’d like to connect an amp to your home stereo it may require a workaround I’ll show you. You can also connect a car amp to nearly any smartphone or external Bluetooth receiver.
  • Power source: Unlike home stereos powered by an alternating current (AC) electrical outlet, car amps work from a +12V direct current (DC) supply. You’ll need a +12V AC-DC power supply with enough current to run the amp. Not just any AC/DC 12V adapter will do – I’ll cover this below.
  • Turning the amp on/off (remote wire): Home stereos or other audio devices don’t have a remote wire output to switch your amp on and off. However, there are some easy ways to deal with this, too.

You also need to know that:

  • Unless you have all the parts already, you may need to spend a little bit of money to get what you need & get it working. The good news is that most of it is affordable and you can even make use of some power supplies like a computer DC supply you may left over.
  • Retail stores are pretty bad about not having the parts you may need, so you might want to plan ahead and order parts online. You can find many affordably priced parts on Amazon, eBay, and from electronic part suppliers.

Choosing a power supply for car amp use

Example of how to estimate car amp current used

You can estimate how much electrical current (amperage, “amps”) your amp will draw based on its maximum power given in watts RMS. However, the truth is that’s only if you need a lot of power. For casual listening you can get by with a lot less.

Basically, there are 2 ways to go about choosing a power supply for a car amp:

  1. Getting a “good enough” power supply if you’re not driving the amp hard (fine for casual listening)
  2. Estimating the amp’s current draw based on its power rating (useful for when you want serious amp power)

Of these, #1 makes it a lot simpler. You may be able to use a DC supply you’ve already got handy or a leftover computer power supply (sometimes called an ATX power supply).

What voltage does a car amp need?

Car amps normally work off of a range of voltages, not just 12 volts, although that’s used as a general reference. In fact, as a vehicle’s engine runs the alternator charges the battery and the voltage can range from near 12V to about 14.4V. 

For home use, choose a power supply with a DC output from 12V to 13.8V, with 12V being perfectly fine to use. When shopping most of the higher-current supplies you’ll see are 12V anyhow.

At around 11V or so car amps and other car stereo equipment may shut off so it’s important to have enough voltage available.

What size power supply do I need?

Car amp DC power supply examples

Powering a car amp in home requires a power supply with a decent amp rating. Standard wall adapters won’t work as they’re very weak (0.5 to 1A, usually). You can find bigger power supplies like a 5 amp model for under $15 if you shop smart. Desktop computer ATX power supplies are cheap, easy to find, and range in power ratings up to 500W or even more.

Quick tip: Computer power supplies can offer 15 amps or even more current output making them a great solution. They’re available in a variety of power ratings such as 150W to 500W or more.  A good ATX power supply will have enough power output for the average person.

Option #1: Getting a “good enough” power supply for casual listening

When not driving an amp & speakers hard, I recommend at least a 2.5A supply for small amps (under 50W/channel). For 4 channels, I’d get a 5A or bigger. If you’d like to have more power, consider getting 15A or above.

You can find a 5A supply for under $15-$20 if you shop around. 10A and 15A supplies are fairly popular so they’re usually under $30-$35 dollars or so. When it comes to much bigger supplies that will let you drive a subwoofer with heavy bass things tend to get expensive. Very high current power supplies are around $100 and above for 30 amps or more.

However, one of the best options is to use a desktop computer power supply (“ATX” power supply) as they’re easy to find and have pretty good power output.

Option #2: Estimating amp current needed for higher power use

If you’re planning to use a car amp to drive speakers hard you’ll need a lot of amperage which you can estimate pretty closely We also need to take into account wasted power to come up with a final number. (All amps waste some power as heat and draw some additional current for that reason)

  • Class D car amplifiers are more efficient and therefore waste less power (and draw less current) than standard class A/B amps.
  • If you’re not sure what class your amp is, it’s probably class A/B. Class D amps normally say so on the amp itself, the box, or sales info. Class A/B types have been so popular for years that it’s a pretty safe assumption.

You can estimate amp current based on the maximum RMS power of the amp. Don’t use “peak” or “maximum” watt power ratings as these are misleading. We need to use the continuous power (RMS) the amp really delivers.

As class D car amps are around 85% efficient and A/B amps are around 65% or so efficient we can use that to estimate the total current an amp would need.

Class D amp example:

Estimate amps used by a 50W RMS x 4 amp:

  1. 4 x 50W = 200W total. (200W/12V) = 16.7A.
  2. Take into account power waste: 16.7A/.85 = 19.6A
Class A/B amp example:

Estimate current used by a 150W RMS x 2 amp:

  1. 2 x 150W = 300W total. (300W/12V) = 25A.
  2. Take into account power waste: 25A/.65 = 38.4A

As you see, to run a car amp at full power you’ll need a pretty big power supply! However, most people don’t so it’s usually a lot less hassle (and less money) to use one of the other supplies I showed examples of.

How to wire a computer power supply to a car amp

How to wire a computer power supply to a car amp diagram

Using an ATX (desktop computer) power supply for a car amp isn’t hard usually. It’s a matter of a few steps:

  • Power connections: Cut several ground wires (black) and +12V wires (yellow) and strip them for about 3/8″ to 1/2″ bare wire. Twist them together tightly or use a crimp connector (ring terminal, spade terminal, etc) and connect to the amp’s power & ground terminals.
  • Supply on control: PC supplies don’t automatically come on even if the side switch is on. Normally a mother board uses a control signal to the “supply on” wire pin. As shown in the diagram above, you’ll need to jumper the wire by cutting it, stripping it, and either connecting to a ground wire permanently or you can use a toggle switch.
  • Amp remote on: As there are several good options for this, I’ll cover this in more detail below. 

Once you’ve connect the supply on wire to a ground wire the power supply should start and your car amp should work. Note that in some cases, it is possible to have a problem.

Huge, high-power car amplifiers can sometimes have a short current “spike” they draw when first connected to power. In some cases, this can trip the self-protect mode in power supplies. If that happens you can try starting the supply first and then give the remote wire power after a moment.

It’s possible you may need a more robust power supply if that happens as well. This shouldn’t be an issue most of the time, though.

Remote wire options for turning the car amp on

How to connect remote wire on car amp used in home diagram

A car amp’s remote-on input uses a low-current +12V signal that starts its internal power circuitry. There are several good ways to do this:

  1. Jumper the remote on terminal:  When wiring the power and ground 12V connections, you can use a small jumper wire from the +12V terminal to the remote terminal so it’s on any time the amp has power. 18AWG or smaller wire is fine.
  2. Jumper wire + switch: Basically the same, but you can also use a simple inline switch on the remote wire to turn it on/off yourself.
  3. Home stereo use – RCA converter with remote lead: If you’re connecting an amp to speaker outputs you can use a line level converter with a built-in remote wire output. They’ll automatically turn the amp on or off with an input signal present.

If you’re using a toggle switch on the remote wire you can leave the AC/DC power supply plugged in. When the amp’s remote wire is off (disconnected) the amp will shut off and won’t drain power.

RCA adapters with remote wire output

Example of line level converter with remote wire output Axxess AX-ADCT2

Example of a line-level converter with a remote wire output feature. When the speaker level inputs have a signal and it creates a +12V remote on signal. When no signal is detected, the remote wire will go to zero volts and turn the amplifier off. Unlike a regular converter, these need +12V and ground connections to work.

How to connect a home stereo, smartphone, or other audio sources to an amp

What’s great is how many options you have for getting an audio signal to your amp’s inputs. In fact, nearly any analog (non-digital) jack can be used from almost any device. I’ll cover some of the main ones here:

  • Smartphones, tablets, and laptops can be used either by their headphone jack or via Bluetooth (see below)
  • Any home stereo receiver or amp can be used – even vintage ones!

How to connect a smartphone or other device to a car amp (diagram & options)

Diagram for how to connect audio signal to a car amp used in your home

Be aware that headphone jacks can be a good or bad audio source depending on your particular device. Even though they’re usually not quite as good as RCA outputs/AUX output jacks, I’ve had pretty good experiences doing using this with brand name smartphones or tablets.

In fact, I use this method to test a car amp at home.

You also use an affordably-priced Bluetooth receiver for around $25 from places like Amazon. They offer a direct line output jack or RCA jacks for this very reason.

Be sure to get a decent brand as the generic/no-name brand models tend to have sound quality problems and can produce odd noises between music tracks playing on your phone, for example.

How to connect a car amp to a home stereo (diagram & options)

How to connect a car amp to a home stereo diagram

The way you connect your car amp depends on both your home stereo and your car amp’s features. You’ll end up with one of 3 situations:

  1. Home stereo with no RCA output jacks + car amp with speaker level inputs: It’s actually fairly common for home stereos and home theater receivers to have no full-range RCA audio-out jacks. In this case, if your car amp has speaker level inputs built-in these can be connected to an unused pair of speaker terminals or alongside speaker terminals in use. The amp’s speaker level inputs will scale down the speaker signal to a much lower signal the amp needs.
  2. Home stereo with no RCA output jacks + car amp with RCA jacks only: In this case, you’ll have no choice but to use a line level converter used for car audio. Just like in #1 above, these are connected just like speakers to speaker terminals alone or alongside connected speakers.
  3. Home stereo with full range RCA output jacks + car amp: This is the easiest way by far. Unforunatley, not that many home stereos have full-range RCA output jacks. Some only have subwoofer RCA output jacks which are bass-only outputs. Full-range RCA output jacks can be connected directly to the car amp’s RCA inputs, but subwoofer RCA jacks won’t work for full-range music since they only pass bass.

What is a line level (RCA) converter and how do they work?

Image showing examples of line level RCA converters

Shown here are two good examples of speaker level converters: a 2 channel model and a 4 channel model. Both take a higher voltage speaker level signal and reduce it greatly to a low voltage suitable for the amp’s input section.

Line level converters (also called RCA speaker level adapters) are small adapters that reduce the higher-voltage signals from speaker outputs to a much lower voltage (“line level”) used by a car amp’s RCA jack inputs. They can be connected directly to a ratio, amp, or at a speaker and provide RCA jack connections.

They’re really useful because they make it possible to connect an amplifier to a signal source that you otherwise can’t.

What to do if you have ground loop noise (humming)

Example of an RCA ground loop isolator

A ground loop isolator you can use to “break” (isolate, disconnect) an amp’s RCA ground connections from that of an audio source to eliminate the electrical path that causes ground loop noise.

Sadly, noise can be a BIG headache when it comes to car amps despite them being designed to prevent it. The same is true that home stereos, too: anything that carries a signal and has a ground connection can create a “ground loop” that gets picked up by the amp and then turned into a very annoying noise you easily hear.

What causes ground loop noise?

Ground loop noise happens when there’s a slightly different potential (a slight difference in voltage) between the ground connections in an amp, stereo, and other components. Despite everything you try, sometimes it’s nearly impossible to eliminate.

In that case, you can try a simple RCA cable ground loop isolator which often solves it. Note that you shouldn’t try to get the cheapest you find because they can negatively affect sound quality.

You can find a good one for $10-$25 or above depending on the brand and features.

Related helpful articles

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Just reach out via my Contact page or leave a comment/question below. Thanks for reading!

How To Connect A Car Amp To A Home Stereo (With Diagrams)

How to connect a car amp to home stereo featured image

Using a car amp…at home? It’s not such a crazy idea after all! While it’s true that it’s not super easy, it’s really not all that hard and you can do it.

In this article, I’ll explain how to connect a car amp to a home stereo with clear diagrams anyone can understand. I’ll also show you all the little things you need to know before you try so you avoid disappointment & headaches.

Contents

First things first: Can a car amplifier be used at home?

Can a car amp be used at home man thinking

The good news is that YES, one way or another, you can definitely connect a car amp to a home stereo.

However, since car amps use a different power source the single biggest challenge is getting enough power to them. They also use a remote-on wire to turn the amp on & off so it doesn’t draw power and kill your battery when installed in a car.

Fortunately, these (and other) problems are fairly easy to deal with. Here’s a list of what you’ll run into when using a car amp at home:

  • Signal inputs: Not all home stereos have RCA line-level jacks, so this may require a workaround to connect to your amp’s audio inputs. Some amps make this pretty easy, however. (This isn’t much of a problem as you’ll see from my diagrams below)
  • Power source: Unlike home stereos that are powered from alternating current (AC), car amps work from a +12V direct current (DC) supply. You’ll need a +12V AC-DC power supply with enough current to run the amp. Not just any AC/DC 12V adapter will do as you’ll see later.
  • Turning the amp on/off: This is actually really easy! You can simply disconnect your DC power supply and let the amp shut off or use a simple switch to turn the amp on and off. I’ll show you how to wire the car amp so it can turn on.

The bad news is that unless you have the parts you need already, you’ll probably have to spend a little bit of money to get it working well.  The good news is that most of what you need can be found and bought new or used but you may need to order some online.

Sadly, retail stores are usually poorly stocked when it comes to power supplies that you can use for a car amp indoors. You’ll have much better luck online at places like Amazon or electronic parts suppliers.

How to use car amp with a home stereo + diagram

How to connect a car amp to a home stereo diagram

The way you’ll connect your car amp depends on both your home stereo and your car amp’s features as I mentioned earlier. You’ll end up with one of 3 situations:

  1. Home stereo with no RCA output jacks + car amp with speaker level inputs: It’s actually fairly common for home stereos and home theater receivers to have no full-range RCA jacks you can connect to the amp. In this case, if you’ve got a car amp with speaker level inputs these can be connected to either an unused pair of speaker terminals or alongside speaker terminals in use. The amp’s speaker level inputs will scale down the speaker inputs to a low signal it can use.
  2. Home stereo with no RCA output jacks + car amp with RCA jack inputs only: In this case, you’ll have no choice but to use a line level converter commonly used for car audio. Just like in #1 above, these are connected just like speakers to unused speaker terminals or alongside an existing speaker set. This will drop the signal down to a very low level that’s used by the amp’s RCA inputs. Note: I strongly recommend getting a decent quality model converter with adjustable outputs for best results.
  3. Home stereo with full range RCA output jacks + car amp: This is the easiest way by far, but not all home stereos have full-range RCA output jacks. Some only have subwoofer RCA output jacks which are bass-only outputs. Full-range RCA output jacks can be connected directly to the car amp’s RCA inputs.

How to connect the remote-on wire on a car amp

How to connect remote wire on car amp used in home diagram

In all cases, you’ll also need to wire the amp with power and a remote-on wire so it can turn on. You can do this one of several ways:

  • Jumper the remote on terminal:  When wiring the power and ground 12V connections, you can use a small jumper wire from the +12V terminal to the remote terminal so it’s on any time the amp has power.
  • Just a jumper wire + switch: Basically the same, but you can also duplicate how a car stereo’s remote on wire works by using a simple inline switch on the remote wire to turn it on/off yourself.

If you’re using a switch you can leave the AC/DC power supply plugged in if you like. When the amp’s remote wire loses its +12V signal, the amp will switch off internally and draw zero power.

Example of line level converter with remote wire output Axxess AX-ADCT2

QUICK TIP: To make things even easier, you can use a line level converter with a built-in remote wire output feature which will automatically turn the amp on or off with the speaker input signal.

Note that these do need a power and ground connection.

What is a line level/RCA converter and how do they work?

Image showing examples of line level RCA converters

Shown here are two quality examples of line level/RCA speaker level converters: a 2 channel RCA output model and a 4 channel RCA output model.

Line level converters (also called RCA speaker level adapters) are small electronic devices that connect to speaker outputs from an amp or receiver and scale down the higher-voltage signal to a low level (“line level”). The outputs are RCA jacks which can then be connected to an amplifier or subwoofer with RCA jacks.

They’re extremely handy in the car stereo world because they make it possible to connect a stereo without RCA outputs to any amplifier or powered subwoofer. We can also use them for home stereos, too.

How much do line level converters cost?

While you can get the el-cheapo ones for under $10, I don’t recommend those. Expect to spend around $15-25 or so for a good one. No need to spend too much these days as there are lots of good values out there.

What voltage & size DC power supply do I need for a car amp?

Example of how to estimate car amp current used

You can get a rough estimate of the maximum amount of electrical current you’ll need for a car amp using its maximum RMS power as shown here. However, if you’re not using an amp to its full capability you can get buy with a smaller (and less expensive) power supply.

What voltage does a car amp need?

Car amplifiers, when installed in a vehicle, work off of a voltage range as the engine runs. Although we say cars & trucks use a 12V supply, in reality, a car amp is designed to work from somewhere around 11V to 14.4V or so as the alternator in your vehicle raises or lowers it’s output while charging the battery.

Therefore you can use a power supply with a DC output similar to this, but I recommend 12V to 13.8V. Most power supplies you can buy are one of these.

What size power supply do I need?

Car amp DC power supply examples

You’ll need a power supply with a decent amperage (A) rating. Regular wall adapters won’t work as they’re very weak (0.5 to 1 amps or so). You can find 5A supplies for under $15 depending on where you shop. Desktop computer “ATX” power supplies are affordable and available in power ranges up to 500W or more. They’re easy to find but need a certain wiring connection in order to turn on.

In order to figure out how big of a DC power supply you need, you might want to calculate roughly the amount of current your amp will draw at full power. Once we know that, we can take into account wasted power that all amps use up and come up with a fairly accurate number.

Just so you know, class D car amplifiers are more efficient and therefore waste less power (and draw less current) than standard class A/B amps.

If you’re not sure what class your amp is, if it’s a class D amp it’s usually stated on the box or the amp itself. Class A/B amps often don’t state it anywhere. (Many new amps are class D so I wanted to take that into account)

Estimating amp current

You can estimate amp current based on the maximum RMS power of the amp. Don’t use “peak” or “maximum” watts as these don’t reflect the actual continuous power a car amp puts out.

As class D car amps are around 85% efficient and A/B amps are around 65% or so efficient we can use that to estimate the total current an amp would need.

Class D amp example:

Estimating the current used by a 50W RMS x 4 amp, all 4 channels used:

  1. 4 x 50W = 200W total. (200W/12V) = 16.7A.
  2. Take into account power waste: 16.7A/.85 = 19.6A
Class A/B amp example:

Estimating the current used by a 150W RMS x 2 amp, both channels used:

  1. 2 x 150W = 300W total. (300W/12V) = 25A.
  2. Take into account power waste: 25A/.65 = 38.4A

As you can see, to run a car amp at full power you’ll need a pretty big power supply! However, the good news is that it’s only if you really want to drive the amp at full capacity. For lower-power, casual listening, we can get by with a smaller (and thankfully, cheaper) power supply.

Realistic power ratings you’ll need

For just listening to music with decent volume, I recommend at least a 2.5A supply for small amps (under 50W/channel). For 4 channels or higher power ones, I’d get a 5 amp or bigger. If you’d like to have more power, consider getting 15A or above.

You can find a 5A supply for under $15-$20 if you shop carefully. 10A and 15A supplies are fairly popular so they’re usually really affordable, too. However, when it comes to much bigger supplies that will let you drive a subwoofer with heavy bass, for example, those can be expensive: $100 and above.

Connecting 2 RCA stereo outputs to a 4 channel amp

Diagram showing a 2 channel car stereo connected to a 4 channel amp

What if you’ve got a 4 channel amp? No problem! You’ll still use the same methods shown earlier but you’ll need to jumper either the speaker level inputs or the RCA inputs using “Y” connections to get a signal to the rear channels too.

Most car amps with front & rear speaker level inputs can be wired to 2 speaker input pairs as shown in the diagram here. When using RCA connections, you can pick up a pair of inexpensive female-to-male Y adapters to split the signal from 2 into 4 connections. (Don’t spend too much on Y adapters as you can use a decent pair of cheap ones just fine)

QUICK TIP: Some car amps have a 2/4 channel input switch built in for this purpose. In that case, setting it to the “2ch” position will supply a signal to all 4 channels. For some amps this only applies to the RCA inputs so be sure to check your owner’s manual.

Can I use 8 ohm speakers with a car amp?

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 car amp, it can only receive up to 1/2 the power output and has a lower maximum volume than a 4 ohm speaker would.

Using 8 ohm home speakers in place of 4 ohm ones with your car amp won’t hurt anything. There’s a catch, however. They’ll only develop 1/2 the power of a 4 ohm speaker meaning lower maximum volume is possible.

For example, if you were to use some home stereo 8 ohm speakers instead of 4 ohm speakers, you’d notice the volume would be a bit 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; also 8 ohm speakers allow only 1/2 the same amount of electrical current to flow vs 4 ohms.

Car amplifiers & car head units don’t have a high voltage supply like home stereos and home amplifiers do. That means they’re designed to use lower impedance (lower resistance) speakers to develop the same amount of power by letting more current flow.

As long as you’re aware of this it’s ok, because they’ll still sound and play fine – you just can’t get the same power and as much volume when you crank it up vs using 4 ohm speakers.

I have a hum (ground loop noise) from the amp. What can I do?

Example of an RCA ground loop isolator

Example of a ground loop isolator you can use to break the ground conductor connection in RCA cables to eliminate ground loop noise.

Unfortunately, noise is a problem with car amps despite them being designed to prevent it. It’s also true that home stereos and amps are known to sometimes create “ground loops” between different electronic components via the RCA cables.

Ground loop noise happens when there’s a slightly different potential (electrical voltage point) between the grounds of an amp, stereo, and other components. Despite everything you try, sometimes it’s nearly impossible to eliminate.

In that case, you can use a ground loop isolator to connect inline in the RCA cables. This usually does the trick. Note that you shouldn’t try to get the cheapest you find because they can negatively affect sound quality.

You can find a good one for $10-$25 or above depending on the brand and features. The good news is that they’re super easy to use: just connect them to the RCA cables and you’re done!

More great articles you’ll love

There’s lots more great stuff to see! Here are some excellent articles that have helped many others, too:

Let me know what you think!

Have questions or comments? Just let me know below! You can also contact me directly here.

How To Hook Up A Car Subwoofer To A Home Stereo (With Diagrams!)

How to hook up a car subwoofer to a home stereo featured image

Thinking about putting that extra car sub to good use? Maybe you’re wondering if it’s possible to hook up a car subwoofer to a home stereo or amplifier at all.

The good news is that yes, in many cases you can use a car sub with a home stereo. However, it’s not as easy as just wiring them up any old way.

I’ll tell you what you need to know and provide some helpful diagrams. Let’s get started.

Contents

Can I hook up a car subwoofer to my home stereo?

Can I hook a car subwoofer to a home stereo? Man thinking image

The quick answer is that it depends. There are several basic things you need to understand first before you try. These are important, too…so don’t be careless or you could damage your home receiver or amplifier.

You can hook up a car subwoofer to a home stereo directly if:

  • You have a subwoofer or more than one subwoofer that can be wired for at least 8 ohms total. This can be two 4 ohm subwoofers or a 4 ohm dual voice coil (DVC) subwoofer.  [See diagrams below for how] 
  • Your home stereo or amp can handle 4 ohm speakers (most can’t so let’s ignore this).
  • Using workarounds: this includes using a small 4-ohm capable amp between the receiver and sub or an inline resistor to bring up the speaker load. (Don’t worry – I’ll share these in detail below)

Even if you have the right car subwoofer(s) your amp needs to have enough power available to drive the subwoofer box. The good news is that for casual listening you don’t need a ton of power like you do for cars and truck use.

The single biggest obstacle is that most home stereos, home theater receivers, and home amplifiers can’t handle the 4 ohm speaker load of many car subwoofers. It’s 2x lower than the 8 Ohm minimum most require. (Some car subwoofers are even 2 ohms, in fact).

Why can’t I use a 4 or 2 ohm car subwoofer with a home stereo?

Diagram showing how to match speaker ohms to a home stereo

You’ll need to be sure to avoid connecting a speaker impedance (Ohms, speaker load) that’s too low to a home stereo amp or receiver. Doing so causes it to try to produce more electrical current than it’s designed for. This causes overheating and potentially permanent damage to your electronics.

Just like car amplifiers & car stereos, home stereos have a minimum speaker load, stated in Ohms, that they’re designed to handle. 

Never try connecting 2 or 4 ohm car subwoofers or speakers to a home stereo – they’re likely to overheat very quickly and suffer possible damage.

Why is matching speaker impedance important?

Matching the speaker load to your home stereo just means matching it up with the best Ohm load that will deliver the power & volume it’s designed to produce. As you can see in my diagram above, if the speaker is over the rated Ohm spec, it will work safely but at the expense of delivering a lot less power and volume than you’d like.

Using the correct Ohm load means you’ll get the rated power – and as you might guess – the maximum volume possible. 

However, using less than the rated Ohm speaker load (whether 1 or more speakers, the total Ohm load the stereo sees) is dangerous and won’t work. Don’t do it!

Tip: In cases where the subwoofer is less than 8 ohms total and/or the receiver or amp doesn’t have enough power don’t give up! There are some work-arounds that can you can use as we’ll see.

Do I need a speaker crossover for a car subwoofer?

Example of a passive subwoofer low pass crossover

Example of an 8-Ohm compatible low-pass speaker crossover for blocking all sounds above a low bass frequency (cutoff frequency). These are used to get “clean” sounding bass from a subwoofer when there’s no crossover already provided.

By the way, there’s another important part you’re likely to need and may not have thought about: using a speaker crossover for clear bass with a car subwoofer. Car subwoofers are normally used with a car amp with a low-pass crossover built in already.

That’s often not the case for home stereos, although some do have a subwoofer RCA output jack for use with an amplifier or powered subwoofer.

Diagram showing a passive subwoofer speaker crossover

The point is that unless you want to hear vocals and other sounds from the car subwoofer, you’ll need to hook up a subwoofer speaker crossover between the stereo & the sub. For clear bass, you’ll need a crossover to block higher-frequency sounds subs can’t play well.

If you’re lucky enough to own a receiver or home amp with a low-pass crossover built in you can use that instead.

How to wire a car subwoofer to a home stereo

How to connect a car subwoofer to home stereo diagram

As you can see from my diagram above, I’ve come up with 4 ways to connect a car stereo to your home stereo receiver or amp – but it greatly depends on the specifics. For example, using a 4 ohm car sub is relatively simple, while using a 2 ohm or another type can be more complicated.

Here are the  4 ways you can do this:

  1. Two 4 ohm car subwoofers: This is one of the simplest setups possible. Just connect the subs in series for a total of 8 ohms and connect them to one of the stereo receiver speaker outputs. However, be aware that if there’s no speaker crossover in place or built-in, you’ll get vocals and sounds in the subs that won’t sound good, so a crossover may be needed. (see above)
  2. Single DVC 4 ohm subwoofer: Likewise, a single dual voice coil (DVC) subwoofer with 4 ohm windings can be wired in series to meet the 8 ohm requirement. Just like above, a low-pass (subwoofer) crossover may be needed.
  3. Single 4 ohm subwoofer or receivers without enough power – using a mini amp: You can use an affordable miniature amp to drive a 4 ohm car sub directly, avoiding the needed to lose power like you would in option #4. You can use a mini amp that can drive a 4 ohm or even 2 ohm car sub directly. Some also have a built-in crossover for great sound making them a great choice.
  4. Single 4 ohm subwoofer using a series power resistor: This is the simplest and most affordable option. Using a power resistor (a resistor that’s designed to handle higher power levels) just wire it in series with the sub to get the 8 ohms needed. Power resistors can be found for around $5 more or less. I recommend a 25 watt or higher rating, depending on your stereo’s power output.

Note that while option #4 is the easiest of all, I don’t recommend it because you’ll lose 1/2 or more of the stereo’s power output. That’s because the power is divided between it and the sub. 

Audio power resistor examples

Examples of power resistors you can use for speaker projects including hooking up a sub to a home stereo. These resistors can be found and electronic parts stores and speaker part retailers, or even Amazon or eBay. They’re often priced very affordably (around $5 or so for a pair or pack).

What to do if you can’t get the right Ohms together

Home stereo mini amp example

Example of a small & affordable amplifier that can be used to drive a lower impedance car subwoofer from your home stereo receiver. You can find these with a crossover built-in (as shown here) for under $30.

It’s a bit tricky in some cases – especially when using multiple car subwoofers and/or those like 2 ohm models, for example. A home stereo amp is a great answer to this problem and offers several benefits:

  • Can drive lower impedance subs directly
  • Low cost (often under $30) and very compact size
  • Some include a low pass crossover built in meaning you’ll save a lot of hassle

While I realize you might not want to have to spend money & wait for the stuff to arrive, it’s definitely worth thinking about. Here’s a good example of an inexpensive one I found.

How do you hook up a subwoofer to a receiver without sub output?

Image showing examples of line level RCA converters

Examples of line level converters use you can use to get an RCA low-level signal from a home stereo without subwoofer RCA outputs.

The good news that if you’re planning to use a small amp to power a sub at home but your receiver doesn’t have a subwoofer or other RCA outputs there’s a solution. You can use a line level converter, commonly used for factory-installed car stereos, to create some, then connect to a subwoofer amp.

You’ll want a good quality one with adjustable output level dials to be sure you don’t have problems with the signal level. They’re especially valuable to have as many vintage or older home stereos don’t have subwoofer outputs.

You can connect them just like you would a speaker, either to unused speaker outputs or also connect them alongside speakers already in use.

How many watts do you need for a subwoofer?

Man thinking about how much power for car subwoofer with home stereo

Car subwoofers are very inefficient speakers and are some of the most power-hungry you can find! The good news is that if you’re just looking forward to average listening levels you can get by with less power.

  • For easy listening, low-volume music levels, or sound from movies, you’d want at least 25 watts RMS of power per channel available to drive a subwoofer.
  • For a bit more “punch” that requires extra bass (especially the bass & thuds from DVD or BlueRay video sound) 50W+ would be much better.

If your home receiver is on the weaker side as some budget models are (for example, 15W-20W per channel) you’ll need a small external amp as I mentioned earlier. If you’re planning driving a car subwoofer with high volume and want some serious bass I’d recommend a minimum of 100W RMS and even more if you can afford it.

Bookshelf stereos usually can’t cut it – they’re just not designed to produce much power. However many decent quality home stereo receivers or home theater amps/decoders can do the job ok.

Home stereos vs car amplifiers

On the downside, home stereos don’t produce anywhere near the power of today’s car amps which typically have at least 75W to 100W or more per channel, if not several times that! On the plus side, when using a subwoofer inside your home you don’t have the terrible acoustical losses that you do in a car or truck.

This means when using a car subwoofer inside your home you need less power to hear it well.

Subwoofer sensitivity (efficiency) & volume

Some subwoofers produce more volume for the same amount of power. This is actually a standard specification used to compare speakers and the official name is speaker sensitivity. In other words, the sensitivity of a speaker describes the volume output it produces for a given amount of power, in decibels (dB).

A standard dB reading of 1 watt measured 1 meter (1M) away is used for this measurement in the speaker industry.

When comparing two subwoofers, for example, one might have a sensitivity of 87dB/W while a 2nd one has one of 91dB/W. This means the second produces more sound with less power. Because speakers require a doubling of power to increase another 3dB in volume, that means a more efficient speaker can use 1/2 the power or less than another speaker for the same volume!

That’s something to think about when comparing subs.

Will a sub work without an amp?

can you use a sub without an amplifier question man thinking

This one’s easy to answer, although it’s important to be clear about power & amplifiers. In general terms, no, a sub won’t work ok without an amp.

Hang on a second, though! What does “amp” mean in that case? To be more clear, here’s the long and short of it:

  • A subwoofer, like any other speaker, must be powered by an amplified audio signal with a decent amount of wattage in order to produce sound.
  • To properly drive a subwoofer for it to work well, that’s different; in that case, yes, without question you need an amplifier of sufficient power to drive it well.

That is to say, you can’t hook up a subwoofer to a non-amplified signal output from any stereo or other audio source. You need an amplified speaker output with a fair amount of power in order for it to work ok and sound right.

As I mentioned earlier, for casual listening inside your home you can likely get away with 25 watts for subwoofers with decent efficiency. However, if you want to drive a subwoofer hard and get that real bass “thump”, you’ll need a lot more power: 80-100W or more for a home amplifier.

More great articles about speakers and audio

Don’t miss out – there’s a lot more great reading ahead! Check out some of my other detailed articles:

Got questions or comments? Feel free to leave a comment below!

How To Connect A Subwoofer To An Old Amplifier Or Vintage Receiver

How to connect a subwoofer to old amplifier or vintage receiver featured image

Got a vintage amplifier or receiver? When it comes time to add some great low-end bass you might be scratching your head wondering how – and if – you can add a subwoofer. 

The great news is that there are several ways to connect a subwoofer to an old amplifier or vintage receiver.

Even better, it won’t cost a lot, either! Read on and I’ll share with you 3 ways to connect a subwoofer along with clear subwoofer diagrams anyone can understand.

Contents

Home stereo subwoofers explained

Passive vs active home subwoofers diagram

Comparing passive (non-powered) vs active (powered) home stereo subwoofers. Powered subwoofers have an internal amplifier and one or more signal input options: speaker inputs, RCA input(s), and in some cases, digital audio inputs.

There are two kinds of home stereo subwoofers: powered (“active”) and non-powered (“passive”).

  • Powered subwoofers use a low-signal signal which is boosted greatly using the built-in speaker amplifier, power supply, and crossover. These types are one of the most common and in many cases use an RCA type input jack to connect to the receiver for sound.
  • Passive (non-powered) subwoofers are simply a subwoofer speaker inside the bass enclosure which is directly wired to the speaker terminals or a passive bass crossover inside. These types are less common.

How does a subwoofer work?

An amplifier boosts the low-level input signal in order to drive the subwoofer’s voice coil with sufficient power and move the speaker cone, producing sound. As the cone moves the air inside of a specially designed enclosure (speaker box) deep bass, contained in the musical input signal, is produced.

They’re designed for only low-end bass and not voice or other musical instrument frequencies.

A powered subwoofer includes an amplifier already inside the subwoofer enclosure. It also has a built-in low-pass crossover to block higher sound frequencies in order to produce clear and great-sounding bass only.

For non-powered subwoofers the problem comes when you connect one to an amplifier or receiver’s outputs without a crossover – it sounds terrible!

Old amplifiers and vintage receivers vs new receivers

Unlike older amplifiers, more modern home stereos and especially home theater receivers have a subwoofer output jack (or pair of jacks) dedicated to this bass signal a subwoofer uses to create sound. This is usually from stereo music signals or the subwoofer (“.1”) channel sound in multi-channel surround sound material such as Dolby Digital or DTS.

For example, you may see terms like “5.1” or “2.1” speaker systems or surround sound audio listed for movies. In this case, the first number represents the number of main speakers. The “.1” is used to represent a sound channel limited to only bass for subwoofer use.

Older amplifiers and receivers don’t provide a subwoofer output so we’ll need to connect a subwoofer by other ways.

Powered subwoofer inputs & controls to know

Powered subwoofer example with inputs and controls labeled

Shown is an example of a powered subwoofer’s rear panel with 2 kinds of inputs: speaker inputs and RCA (low level) input jacks. Note that not all subwoofers offer speaker level inputs, meaning if yours doesn’t have them it’s a bit harder to connect the bass signal input.

Powered subwoofers usually have a few different inputs and controls. It always depends on the particular brand and model you buy.

Here’s what you’ll usually find on most:

  • Power input (AC outlet power)
  • On/off switch
  • RCA input jack or a pair of jacks
  • Subwoofer crossover adjustment
  • Subwoofer level adjustment know (the amplifier’s signal boost level)

In most cases, a subwoofer input jack, if you had one on a receiver, is a “mono” (monaural, 2 stereo channels combined into one) signal you connect with a single RCA cable.

Receiver subwoofer output jack example

Shown: What a receiver with a subwoofer output jack looks like as found on many newer receivers. These connect to the RCA input jack on the subwoofer, if present.

Of course, if you’re reading this it’s because you don’t have a receiver with a subwoofer output. In fact, some of the information you’ll find right now on the internet says that you have to buy another subwoofer if you don’t have a receiver with an output jack. That’s simply not true.

Subwoofers with speaker level inputs are great to have for exactly this reason as you can connect them directly to an older amplifier or vintage receiver’s speaker outputs.

Even if you buy (or already own) a subwoofer without speaker level inputs, it’s ok – there’s another way to basically connect it essentially the same way!

Below you’ll find a diagram showing how to connect an old amplifier or receiver without a subwoofer output easily.

Diagram & examples: Connecting a subwoofer to an old amplifier or vintage receiver

Diagram showing how to connect a subwoofer to an old amplifier or vintage receiver

1. Connecting an old amplifier or receiver to a subwoofer with RCA input jacks

Example of a powered subwoofer RCA jacks & RCA Y adapter cable

Left: Example of a powered subwoofer with 2, instead of the typical 1, RCA input jacks. Right: An RCA Y adapter that can be used with a line level converter to connect to a subwoofer with a single RCA input jack.

If you’ve got a subwoofer with 1 or 2 RCA input jacks and no speaker level inputs, here’s a simple and high-quality way to connect it: by using a line level converter.

What is a line level converter and how do they work?

Line level converters (also called RCA speaker level adapters) are small electronic devices that connect to speaker outputs from an amp or receiver and scale down the higher-voltage signal to a low level (“line level”). The outputs are RCA jacks which can then be connected to any amplifier or subwoofer with RCA jacks.

 While you almost never see them used for home stereo systems, they’re extremely handy in the car stereo world because they make it possible to connect a stereo without RCA outputs to any amplifier or powered subwoofer.

Likewise, they can be used for home stereo amps and receivers, too!

Image showing examples of line level RCA converters

Shown here are two examples of line level/RCA speaker level converters: a 2 channel RCA output model and a 4 channel RCA output model.

How much do line level converters cost?

Line level converters vary in price a bit depending on the quality and features, selling around $15-$25 or so in many retail stores and online stores.

How to use a line level converter

To convert speaker level outputs from your amplifier or receiver to RCA jack subwoofer outputs, you’ll connect the provided speaker wire connections (marked by colors and striped) just like you would regular speakers. You then connect RCA cables (or a single cable, depending on your particular one) to your powered subwoofer.

The internal electronics not only scale down the speaker output voltage from a receiver but also help prevent noise from the audio path, too. Most, but not all, speaker level adapters do not need a power source.

If your subwoofer has a single RCA subwoofer input jack, you may want to pick up a “Y” RCA adapter to combine both receiver channels on the output side into a single mono RCA plug.

Subwoofers with 2 (stereo) RCA jack inputs will need a standard stereo male-male RCA cable.

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3. Connecting a subwoofer with speaker level inputs

Example of subwoofer speaker level inputs

A subwoofer with speaker-level inputs is especially easy to connect to your older amplifier or receiver! To do so, just connect to the speaker outputs on the source unit using speaker wire and then to the matching inputs on the subwoofer. You can even power speakers from the amp or receiver at the same time.

If your subwoofer has speaker level inputs built-in you’re in great shape! Just connect them directly to your amplifier or receiver’s speaker outputs, either to unused speaker terminals or at the same time (in parallel) with speakers connected to the receiver.

Just like an off-the-shelf line level RCA converter I mentioned earlier, the subwoofer’s internal electronics will scale down the speaker signals to a much lower line level signal the internal amp can use.

You can still expect very nice sound quality as the signal used is just divided down and isn’t changed. Because speaker level inputs have a very high input impedance (total input resistance), in most cases it won’t hurt to connect them to your receiver or amp at the same speaker wire terminals where speakers are already connected.

To do so, you’ll just connect them in parallel: positive speaker inputs to positive speaker outputs and negative speaker inputs to negative speaker outputs.

Additionally, there’s a low-pass crossover built-in as well to produce great-sounding bass and no unpleasant parts of the music – just pure, low-end bass.

Note: Subwoofers with speaker level inputs and outputs provide a way to easily connect both at the same time. The outputs are internally connected to the input connectors, making it easier to add speakers and the subwoofer to a receiver simultaneously.

3. Connecting an amplifier’s speaker outputs to a passive (non-powered) subwoofer

Example of a passive subwoofer low pass crossover

A passive subwoofer low-pass crossover, unlike an electronic crossover, works using capacitors and inductor coils instead of electronic components to filter out the unwanted higher-frequency sound that would otherwise go to the subwoofer. This lets you power the subwoofer with only a lower bass sound similar to how a powered subwoofer works.

Using a passive (non-powered) subwoofer is definitely not as easy as a powered one. The good news is that it can be done, and relatively easily, too. In fact, it you don’t have to worry about going broke, either, although you will need to do a bit of shopping.

To connect your amplifier or receiver to a non-powered subwoofer as is shown in the diagram above, you’ll need to pick up a low pass crossover that you’ll connect between the amp or receiver and the subwoofer.

These will filter out sounds above the crossover frequency and provide only a nice bass sound to it.

How to choose a subwoofer crossover

Speaker crossovers like the one shown are sold both in a single (one speaker) or dual (2-speaker) models depending on the brand & supplier. They also have to be matched correctly to the impedance (Ohms rating) of the sub.

For example, for an 8 ohm subwoofer, you’ll need to use a crossover designed for 8 ohm speakers. Otherwise, the sound filtering is radically different and won’t sound right since the speaker load will change how the crossover filters the sound quite a lot.

Normally you’d choose one with a low-pass frequency of close to 100Hz or close to that. You may need to shop around to do so.

Where to shop for passive subwoofer crossovers

Speaker crossovers are sold where speaker parts & related components are sold as well as marketplaces like Amazon or Parts Express. Other speaker specialty stores where replacement speaker parts are sold may have them, too.

Stereo vs surround sound receiver subwoofer output comparison

Stereo vs surround sound receiver differences diagram

Unlike older or standard stereo receivers, surround sound receivers have a unique output that comes from the surround sound movie or music source. However, in regular stereo listening mode, they act the same as regular receivers.

Just as a side note, one thing to be aware of is that when you connect a subwoofer to an old amplifier or receiver you won’t be able to get the separate dedicated bass sound channel (.1 channel) like you can with a surround sound receiver. 

Those are able to extract the dedicated bass sound from a DVD or other media and route it to the subwoofer output jack. On the other hand, it might not even be a problem.

Did you know? The surround sound receiver “LFE” (low-frequency) output is considered optional – hence the “.1” name. 

Surround sound receivers and amplifiers are designed so that you can play nearly all the sound through the main speakers if needed.

In some cases, for example, some movies and music use the bass channel to really draw you into the experience. Using a receiver without that output means you can’t get the same effect, but that’s only for surround sound mode.

The good news is that in stereo mode, both new and old receivers & amps have very similar subwoofer behavior when connected as you’ve seen here. In other words, you probably won’t really miss it if you’re using an older receiver or amp.

That’s just something to be aware of in case you’ve considered upgrading at some point.

More articles with speakers, speaker wiring, and diagrams to help

I’ve got some other great info to help you learn more and get your system going:

Questions, comments, or etc?

Please feel free to leave a comment or question below – I’d love to help, and it’s appreciated. Note: please provide specific information like brand & model numbers, speaker ohms, and so forth so I can best help you.

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How To Connect A Subwoofer To A Receiver Without A Subwoofer Output

How to connect subwoofer to receiver without subwoofer output featured image

So your receiver doesn’t have a subwoofer output. You’re probably wondering what the heck you can do about it, and you might be worried if you’ll have to spend a lot of money for either a new receiver, subwoofer, or both!

I’ve got great news – there are several simple ways to connect a subwoofer to a receiver without a subwoofer output.

Read on and I’ll show you several options along with easy and clear diagrams to help. There’s no need to throw away your old receiver or break the bank!

Contents

Home stereo subwoofers explained

Passive vs active home subwoofers diagram

Comparison of non-powered (passive) vs powered (active) home stereo subwoofer enclosures.

Home stereo subwoofers are available in two different types: powered (“active”) and non-powered (“passive”).

  • Powered subwoofers use a low-signal signal which is boosted greatly using the built-in speaker amplifier, power supply, and crossover. These types are one of the most common and in many cases use an RCA type input jack to connect to the receiver for sound.
  • Passive (non-powered) subwoofers are simply a subwoofer speaker inside the bass enclosure which is directly wired to the speaker terminals or a passive bass crossover inside. These types are less common.

How a subwoofer produces bass

The subwoofer works by resting inside of an enclosure designed for it and to produce deep bass when playing music limited to low-end bass sounds.

In order to produce clean-sounding bass without vocals or other sounds a subwoofer can’t properly produce, a low-pass crossover is used to allow only bass frequencies to pass & be produced. The problem comes when you try to connect a subwoofer to a signal without a crossover – it sounds terrible!

The subwoofer output jack on a receiver is normally limited to passing bass only, either from stereo music production or from the “.1” subwoofer channel (dedicated subwoofer music content) of a surround sound system.

For example, when you hear references to “5.1” or “2.1” speaker systems or surround sound audio for movies, the first number represents the number of main speakers. The “.1” is used to represent a sound channel limited to only bass for optional subwoofer use.

Powered subwoofer inputs & controls you may (or may not) have

Powered subwoofer example with inputs and controls labeled

Example of a powered subwoofer with 2 types of signal inputs (speaker level and RCA jacks) along with sound controls. Note: Not all subwoofers have speaker level inputs, which makes it a problem connecting them to a receiver without a subwoofer output.

Powered subwoofers usually have several inputs and controls, but it always depends on the brand and model. Here’s an example of what you’ll usually find:

  • Power input (AC outlet power)
  • On/off switch
  • RCA input jack or a pair of jacks
  • Subwoofer crossover adjustment
  • Subwoofer level adjustment know (the amplifier’s boost level)

The subwoofer input jack usually connects to a single mono (monaural, meaning both stereo channels are combined into one) output jack on the receiver.

Receiver subwoofer output jack example

Example of the mono RCA subwoofer output jack found on many home receivers. These connect with a single male to male RCA cable to a powered subwoofer.

Some models also include speaker level inputs, meaning they can be used with any modern or old home stereo receiver without a subwoofer output.

While that’s nice, if yours doesn’t have that feature, ordinarily you’d need to buy a different subwoofer and waste money.

In fact, some of the information you’ll find right now on the internet says that you have to buy another subwoofer if you don’t have a receiver with an output jack. That’s simply not true.

As I mentioned at the beginning of my article there are several ways to work around this problem.

Diagram & examples: Connecting a subwoofer to a receiver without a subwoofer output

Diagram showing how to connect a subwoofer to receiver with no subwoofer output

1. Connecting a receiver to a subwoofer with RCA input jacks

Example of a powered subwoofer RCA jacks & RCA Y adapter cable

Left: Example of a powered subwoofer with 2, instead of the typical 1, RCA input jacks. Right: An RCA Y adapter that can be used with a line level converter to connect to a subwoofer with a single RCA input jack.

For subwoofers with only 1 or more RCA input jacks (no speaker level inputs), a simple way to connect them to a receiver with no subwoofer output is by using a line level converter.

What is a line level converter, and how do they help?

Line level converters are small devices that accept speaker wire connections and scale down the speaker level signal to a low level signal (RCA jack) type output that the subwoofer can accept. They’re extremely handy in the car stereo world because they make it possible to connect a stereo without RCA outputs to any amplifier.

They’re not commonly used for home stereos but still really useful there, too.

Image showing examples of line level RCA converters

Examples of 2 line level converters – both a 2 channel and 4 channel of each. 

How much do line level converters cost?

Line level converters range in price (for a good one) of about $15-$25 each. They’re connected to the speaker leads of a radio, receiver, or amplifier. RCA cables are then connected to the jacks provided. The internal electronics not only scale down the speaker output voltage from a receiver but also help prevent noise from the audio path, too.

If you’re using a subwoofer with a single RCA subwoofer input jack, you may want to pick up a “Y” RCA adapter to combine both receiver channels on the output side into one.

Subwoofers with 2 (stereo) RCA jack inputs, however, will need a standard male-male RCA cable.

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3. Subwoofers with speaker level inputs

Example of subwoofer speaker level inputs

If you own a subwoofer with speaker level inputs you’re in luck! You can connect these directly to your receiver’s speaker outputs, either by themselves (on unused speaker terminals) or at the same time with speakers connected to the receiver.

These subwoofers with this feature contain internal electronics that scale down the speaker signal from the receiver before it reaches the internal amp that powers the sub.

Additionally, there’s a low-pass crossover built in as well to produce great-sounding bass and no unpleasant parts of the music – just pure, low-end bass.

Connect these directly to the receiver just like you would another pair of speakers. 

Note: Subwoofers with speaker level inputs and outputs provide a way to easily connect both at the same time. The outputs are internally connected to the input connectors, making it easier to add speakers and the subwoofer to a receiver simultaneously.

3. Connecting a receiver to a passive (non-powered) subwoofer

Example of a passive subwoofer low pass crossover

Example of a passive subwoofer low-pass crossover. Passive crossovers, unlike electronic crossovers, work using capacitors and inductor coils instead of electronic components.

If you’re wanting to use a non-powered (passive) type of subwoofer, there’s still hope, although it can be a bit harder to find the right parts and set up vs using a powered subwoofer.

To use a non-powered subwoofer, as shown in my diagram above, you’ll use a low-pass subwoofer speaker crossover which is connected between the receiver and the subwoofer enclosure. These filter out higher frequency sounds before they reach the sub to help provide clear & nice-sounding bass only.

How to choose subwoofer crossovers and where to find them

Speaker crossovers such as this are sold both in a single (one speaker) or dual (2-speaker) model, depending on the brand & supplier. They also have to be matched correctly to the impedance (Ohms rating) of the sub.

For example, subwoofer crossovers designed for 8 ohm speakers must be used only with those. Otherwise, the sound filtering is radically different and won’t sound as expected since the speaker load will react differently with the design.

Normally you’d choose one with a low-pass frequency of close to 100Hz or in that range. Speaker crossovers are sold where speaker parts & related components are sold as well as marketplaces like Amazon or Parts Express.

Stereo vs surround sound receiver subwoofer output differences

Stereo vs surround sound receiver differences diagram

Unlike older or standard stereo receivers, surround sound receivers have a unique output that comes from the surround sound movie or music source. However, in regular stereo listening mode, they act the same as regular receivers.

One thing to bear in mind is that when connecting a subwoofer to a receiver without a subwoofer output, you can’t get a separate “.1” bass channel as you can with surround sound receivers.

On the other hand, it may not even be an issue. In fact, the surround sound receiver “LFE” (low-frequency) output is considered optional – hence the “.1” name. There is a drawback, though: for some movies, especially action or other types, the bass channel can be very enjoyable.

Using a receiver without that output means you can’t get the same effect, but that’s only for surround sound mode. The good news is that in stereo mode, both new and old receivers have very similar subwoofer behavior when connected as you’ve seen here.

Just something to be aware of if you’ve ever considered upgrading later.

More helpful speaker info & diagrams

I’ve got lots more information to help you get your sound system going:

Got questions or comments?

Feel free to leave a question or comment below if I can offer help. (Please be specific with information when referring to speakers, receivers, amplifiers, or other parts so I can help you the best I can)

You can also reach me directly at my Contact page. Thanks!

How To Connect Speaker Wire – A Detailed Guide For Everyone

How to connect speaker wire featured image

Welcome! In my very detailed speaker wire guide I’ll show you how to connect speaker wire with great results. You don’t have to be a tech person to do it – it’s easy to do it yourself (and save money too) once you know how.

I’d love to share what I’ve learned from years of audio installation experience to help you get your system up and going!

In this guide I’ll show you:

  • How to connect speaker wire to car or home speakers and car/home amplifiers & stereos
  • Extending speaker wire (splicing and connecting to other wire)
  • Using banana plugs for speaker wire
  • Clear and detailed speaker wire diagrams
Contents

Which speaker wire is positive? Which is negative?

Which speaker wire is positive diagram with examples

The most common kinds of positive wire markings are shown here as examples. 99% of the time, figuring out which wire is positive is really easy once you know what to look for.

The good news is that once you know what to look for, 99% of the time it’s very easy to tell which speaker wire is positive and which is negative.

How do I check if a speaker wire is positive or negative?

Here’s a list of the most common ways to tell which is the positive wire:

  1. A printed line or series of dashes/lines is on the positive wire
  2. One wire’s insulation is red or a different color than the negative wire (most often red is used)
  3. One wire has a copper color and one has a silver finish
  4. The positive wire may have small positive (“+”) symbols and/or wire gauge info printed on it
  5. An imprint or molded stripe is made in the positive wire’s insulation

Of the 5 kinds, imprints can occasionally be a little bit harder to notice so sometimes you need to look very closely under good lighting. Also, positive wires that use a “+” print can be a little hard to read sometimes, too.

How to connect speaker wire together (extending speaker wire)

Let’s start off by covering one of the most important topics: how to connect speaker wire together to extend for more length.

Below you’ll find a simple diagram showing you how to splice & extend speaker wire using two of the best ways available.

How to splice & extend speaker wire diagram

How to connect speaker wire together diagram

You’ll only need a few tools to do it. Between the two ways, using solder is extremely reliable but takes more hassle time. Crimp connectors, however, give great results in only minutes and this is what I use for most of my professional car & home audio jobs.

1. How to connect speaker wire together with crimp connectors

How to splice and extend speaker wire with crimp connectors section image

Using crimp connectors is one of my favorite ways to connect speaker wire (or power wire, too) as a professional installer. It’s fairly fast and gives professional results with very little hassle or work.

I recommend this way of connecting wire to nearly everyone.

Here are a few reasons why:

  • When done properly, it’s very reliable and the wire won’t come apart
  • Easy to do – only takes a few minutes
  • Not affected by temperature changes & time both at home, on a boat, or for car audio
  • Crimp tools & connectors are widely available and are affordable

There are only a few steps needed: cutting the wire (if needed), stripping the wire, and attaching & crimping the connectors.

A. How to cut speaker wire

Image showing examples of how to cut wire

Examples of some of the best ways to cut speaker wire using tools or a pair of utility scissors. Cutting wire is easy with the correct tools. Many tools like wire strippers or crimpers also have a cutting feature built-in.

Cutting speaker wire (or power wire) normally isn’t hard but you definitely need the right tool. The reason why is that common tools like regular scissors can’t cut wire properly and can even become damaged.

There are some great tools that are very affordable that will cut wire very well and make extending speaker wire much easier:

  • Cutting pliers
  • Automatic wire strippers with a cutter section
  • Needle nose pliers with cutting section
  • Crimper/stripper tool with cutting feature
  • Utility scissors – works ok for smaller gauges, not larger

Of the 5 listed here, I recommend and use wire cutting pliers as they’re capable of cutting a wide range of wire sizes. For typical speaker wire like 18 gauge, the wire cutting feature on many other tools works fine.

Ultimately, though, it’s a lot more convenient to have an “all-in-one” tool like a crimp tool if you’re only doing light work occasionally.

Speaker wire cutting tips

To cut wire, just insert the wire and slightly close the tool until the wire is securely held in place & can’t move. Then squeeze very firmly. The wire should “snap” lightly and will be cut.

While you can get by with utility scissors (don’t use standard scissors used for paper or fabrics!) you’ll have to insert the wire right at the inside of the blades and cut very carefully.

Scissors aren’t a good choice and the wire can even get jammed inside.

B. How to strip speaker wire

How to strip wire example

To strip speaker wire you can use a number of tools. I recommend standard wire a standard low-priced wire stripper/crimper (shown above) or similar.

Stripping speaker wire can be a little bit tricky, but it’s a skill you’ll pick up quickly after a few tries. The main 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 off of the wire strands.

To strip 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

Certain types of wire (especially smaller gauges like 20AWG, 24AWG, etc can be harder to strip without breaking. For your first few times, practice on some surplus wire that won’t hurt your speaker wire length needs.

Once the wire is stripped you’re ready to connect it & splice using crimp connectors.

Image showing ruler next to 1/2 inch stripped wire

I recommend stripping enough wire to leave about 3/8″ to 1/2″ wire exposed.  For soldering, you’ll need a minimum of 1/2″ to be able to twist the wire together.

For crimp connectors, 3/8″ or more should be fine.

C. How to use crimp connectors with speaker wire

How to use crimp connectors with wire instruction steps image

Once you’ve prepared your speaker wire by stripping it, it’s time to use a crimp connector on each wire and a tool to crimp them for a reliable connection.

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

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 press the connector down hard, holding the wire inside permanently.
  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.

Wire crimp connector examples with wire gauges labeled

Examples of “butt” (crimp) connectors are shown here. They’re sold based on the wire gauge they can be used with.

I recommend trying that as since the internal opening is a bit bigger you can be sure they’ll fit with various types of speaker wire. That’s because speaker wire manufacturers sometimes have different internal wire conductor sizes.

2. Connecting speaker wire together by soldering

Image showing steps for how to solder speaker wire

This is hands-down the most reliable way to extend & splice speaker as when done properly soldered wire is extremely strong and is permanent.

How to solder speaker wire

To begin, follow the wire cutting & stripping steps from the first section (using crimp connectors).

Follow these steps:

  1. Cut & strip the speaker wire (at least 1/2″ length of bare wire is needed).
  2. Hold up both ends to form an “X” shape with the wire facing opposite directions.
  3. Hold both ends and tightly twist each end around the other until they’re completely wrapped over each other.
  4. After the soldering iron is hot, apply heat to the wire with the tip. Once heated (after a few seconds usually), apply solder enough so that it has flowed fully through the wire.
  5. Rotate the wire to the other side and apply the solder until all of the wire is fully saturated with solder.
  6. Allow the wire to cool for a few moments.
  7. Tear 2 short pieces of electrical tape. Starting at the insulation and at an angle, tightly wrap the tape until it is fully covered.

It’s important to fully cover the wire once you’re done. That’s to prevent the wire from touching each other and causing a short circuit that can permanently damage the output components in an amplifier or stereo.

How long does soldering speaker wire properly take?

All in all, you’ll need about 10-15 minutes to do this work with a soldering iron vs about 1-3 minutes with crimp connectors.

Example of soldering iron and accessories needed to solder wire

Parts cost for soldering speaker wire

A soldering iron can be bought for about $7-$10. You’ll also need some electrical wire and solder, too. For best results, I recommend at least a 25W soldering iron to get the wire hot enough for the solder to flow well.

I would say you can expect to spend about $10 total if you shop carefully if you don’t already own a soldering iron.

How to connect speaker wire to a receiver or home amplifier

Image showing examples of home stereo receiver speaker terminals

In most cases, a home stereo receiver or amplifier allows connecting speaker wire using the binding posts and/or banana plug jacks.

How to connect speaker wire to receivers or amplifier with binding posts

How to connect speaker wire to receiver or home amp with binding posts diagram

You can easily connect speaker wire to most amplifiers or receivers pretty easily. Here’s how:

  1. Loosen the binding post twist tops enough to expose the wire hole.
  2. Strip the speaker wire to about 3/8″ to 1/2″ length bare wire. Twist the wire tightly by hand to keep the wire strands together.
  3. Insert the wires one at a time up to (but not including) the insulation. Twist the tops down and onto the wire firmly to hold it in place.

How to connect speaker wire to receivers or amplifier with banana plugs

How to connect speaker wire to receiver or home amp with banana plugs diagram

Even though they require a bit more work than just using bare wire, banana plugs offer extra convenience once they’re in place. You can quickly disconnect or reconnect you speakers any time since they simply plug into the jacks.

Note that banana plugs come in 2 main types: those with a side-mounted set screw and those with a top “tension screw” and either a top-located hole and/or side hole.

Side hole types are basically a binding post style.

Here are the steps for connecting to a receiver with banana plugs:

  1. Loosen the set screw or tension screw as provided but don’t remove it fully. If you’re inserting wire through the center hole you can remove it if you like.
  2. Strip the speaker wire using a wire stripper tool or similar for the best results. Leave roughly 1/2″ of bare wire.
  3. [Side hole type] Fold the wire under the insulation. [Center hole type] Twist the wire tightly and thread the wire through the screw’s center hole.
  4. [Side hole type] Insert the wire into the opening carefully, making sure it fits under the screw. [Center hole type] Shape the wire into a half-circle, with the wire tilting horizontally away from the insulation.
  5. Tighten the tension screw carefully. [Center hole type] Push the wire into the bottom of the plug.
  6. [Center hole type] Tighten the tension screw down onto the wire.
  7. Holding the wire and the plug, pull gently to be sure the connection is good and the wire won’t slip out.
  8. Push the banana plugs into the jacks firmly. (Note: It’s not unusual for banana plugs to stick out of the jack slightly – they’re not always flush with the top of the jack when inserted).

How to connect speaker wire to banana plugs

Image showing examples of banana plug speaker wire connector types

Shown: Examples of some of the most common banana plug speaker wire connectors you’ll find for sale today. Most fall into one of 2 basic categories: those that use a set screw or those that have a binding post style. I’ll explain the differences as we go.

When shopping (and especially depending on where you shop) you’ll find several different styles of banana plug connectors that work for speaker wire. However, nearly all work basically the same and fall under one of 2 categories:

  1. Set screw type: these have a set screw that is loosened to allow inserting the speaker wire and then tightened to hold it in place inside a metal barrel.
  2. Binding post style: These are very similar to a binding post type wire terminal. A large threaded screw is used to hold the wire in place and often wire is routed underneath the large screw through a central hole and/or a side hole.

The most important thing to know is how to use them with smaller wire as some of the most common wire gauges (like 18AWG wire) don’t fit correctly inside them if not done right. The wire could come out if not connected properly.

Despite some of these banana plugs being more expensive than others, nearly all work very well so there’s no reason to pay too much. You can find a good deal from online retailers, while local stores can be a bit expensive.

1. How to use speaker wire with set screw banana plugs

Image with instructions for how to connect speaker wire to banana plugs with set screws

Adding banana plugs to speaker wire isn’t hard, but there’s a thing or two that can cause problems if you’re not aware of them ahead of time. Specifically, the internal wire barrel (connector) is too big for most commonly used speaker wire gauges.

Note: banana plugs usually have very small screws so you’ll need to be sure you have a miniature screwdriver to use with them.

Here are the steps you’ll need to follow:

  1. Loosen the set screw, but don’t remove it fully. Just enough that the screw is mostly out of the way of the internal wire opening. For connectors with metal shells, you’ll need to remove them first in many cases. (Note: some connectors may have 2 screws)
  2. Strip the speaker wire using a wire stripper tool or similar for the best results. Leave roughly 1/2″ of bare wire.
  3. (Important) Twist the wire tightly then fold it under itself or under the insulation. This will help the wire to better fit inside for a good firm hold with the set screw.
  4. Insert the wire into the connector carefully, making sure it fits under the screw. Tighten the screw or screws firmly but do not over-tighten. For plugs with a metal shell, re-install it over the plug.
  5. Holding the wire and the plug, pull gently to be sure the connection is good and the wire won’t slip out.

That’s it, you’re done! Despite not fitting inside the plugs perfectly,  you can use 18AWG and other sizes of speaker wire reliably and without pulling your hair out in frustration!

2. How to use speaker wire with binding post type banana plugs

Image with instructions for how to connect speaker wire to banana plugs with binding post style

Binding post style banana plugs aren’t hard to use, but you’ll need to carefully use the wire in a way that it’s held in place under the “tension screw” (large central threaded screw). Otherwise it’s possible for the wire to slip out when pulled.

Some banana plugs (like the one shown above) may have a side hole in addition to a center hole through the main screw. You can use either one, but I prefer not to use the side hole unless I have very large gauge speaker wire.

Here are the steps you’ll need to follow:

  1. Loosen the set screw or set screw as provided. For side opening use, don’t remove it fully. If you’re inserting wire through the center hole you can remove it if you like.
  2. Strip the speaker wire using a wire stripper tool or similar for the best results. Leave roughly 1/2″ of bare wire.
  3. [Side hole type] Fold the wire under the insulation. [Center hole type] Twist the wire tightly and thread the wire through the screw’s center hole.
  4. [Side hole type] Insert the wire into the opening carefully, making sure it fits under the screw. [Center hole type] Shape the wire into a half-circle, with the wire tilting horizontally away from the insulation.
  5. Tighten the tension screw carefully. [Center hole type] Push the wire into the bottom of the plug.
  6. [Center hole type] Tighten the tension screw down onto the wire.
  7. Holding the wire and the plug, pull gently to be sure the connection is good and the wire won’t slip out.

You’re done! Binding posts banana plugs should only take a handful of seconds to add to the speaker wire.

How to connect speaker wire to spring clip terminals

Image showing how to connect speaker wire to spring clip terminals

Spring clip terminals are one of the simplest and most common types of speaker wire terminals and they’re found nearly everywhere: speaker boxes, amplifiers, stereos, and more. 

To  them, use the following steps:

  1. Strip the wire and leave about 1/2″ of bare wire on each end. Twist the wire tightly.
  2. With a finger or thumb, push each spring clip one at a time and insert the wire into the hole (insert enough to fit well into the opening).
  3. Release the spring clip to hold the wire in place. Repeat for each wire needed.
  4. When done, pull gently on each wire to make sure they’re in place and held properly.

How to connect speaker wire to car or home speakers

There’s normally no difference in how you connect speaker wire to home and car speakers. In fact, they’re exactly the same aside from being 4 or 8 ohms for their impedance (resistance) ratings.

As you can see from the instructional steps image below, there are 2 ways to get great results and only a few steps for each: using quick disconnect crimp terminals & a crimp tool or using a soldering iron and solder.

Solder vs crimp terminals for connecting speaker wire

While soldering gives a high quality and permanent connection, it takes more time & effort. It’s also more hassle to use a soldering iron as it needs a power source & extension cord – especially if you’re working in your car.

I recommend using quick-disconnect terminals as they can give an excellent & reliable connection while still being easy to use and removable later. One thing you should know is that speaker wire connection tabs on car or home speakers aren’t standardized in their sizes. It’s extremely important to check before you get started.

One speaker brand & model may use two .187″ or .250″ tabs for example while others may use both a .250″ and a .110″.

For car speakers, the tabs are most often a .250″ or .187″ slide tabs and one .110″.

Tip: The larger tab is used for the positive wire in cases where they’re different sizes.

Image showing common speaker wire quick disconnect terminal sizes

Shown here are the most common speaker & speaker wire quick disconnect crimp terminal sizes. Of the 4 shown, .110″ & .250″ are some of the most common for car and home speakers.

Instructions for connecting speaker wire to car and home speakers

Image showing how to connect speaker wire to car and home speakers instructions

How to connect speaker wire to car or home speakers using crimp terminals (quick disconnects):

  1. Strip the speaker wire (about 3/8″ to 1/2″ is fine) and twist the ends tightly to keep the strands in place.
  2. Get the correct sized quick disconnect crimp terminals needed. If unsure what size, measure the speaker wire tabs with a ruler. You’ll also need a crimp tool as well.
  3. Insert the wire into each terminal and crimp firmly until the crimp connector locks onto the wire and holds it firmly. You can crimp 2 times if you like.
  4. Hold the speaker and carefully slide the crimp terminals onto each tab. Be sure not to use too much force as the tabs can get bent if they’re pushed too hard. (If the connectors are too tight, try carefully prying them open a bit with a miniature flathead screwdriver or other thin, flat tool)
  5. When done, make sure the terminals are nice and tight to be sure they can’t come off over time due to vibration.

How to connect speaker wire to car or home speakers by soldering:

  1. Strip the speaker wire (about 3/8″ to 1/2″ is fine) and twist the ends tightly to keep the strands in place.
  2. Shape the wire ends into a curved hook style.
  3. Insert the wire into the small holes in the speaker wire tabs.
  4. Apply heat with a hot soldering iron to both the wire and the speaker wire tab. After a few moments, begin applying solder until it flows and covers the hole, wire, and tab near the speaker wire.
  5. Allow to cool briefly and repeat for the other wire.

Never use a “twist and tape” approach to connecting speaker wire. That’s a poor connection that causes oxidation, power loss, and can even come off over time.

It’s possible for a poor connection to become free and then short-circuit to the other speaker wire, causing permanent damage to the amplifier or stereo.

How to connect a subwoofer with speaker wire

Subwoofer speaker wire terminal examples

Subwoofers usually have one of two types of speaker wire terminals: spring-loaded binding posts or quick disconnect (slide connector) tabs.

Of the two, the spring-loaded terminals are super easy to use, while the quick-disconnect tabs can be a bit trickier. Additionally, the tabs don’t always come in the same sizes for both.

For subwoofers, the tabs are most often two .250″ slide tabs or one .250″ and one .187″ or one .110″ like are used with smaller speakers.

Image showing common speaker wire quick disconnect terminal sizes

Shown here are the most common speaker & speaker wire quick disconnect crimp terminal sizes. Of the 4 shown, .110″ & .250″ are some of the most common for small speakers. .250″ is very common for subwoofers.

How to connect speaker wire to subwoofers (how-to image)

Image showing how to connect speaker wire to subwoofers step by step

There are only a few steps you’ll need to do for connecting speaker wire to subwoofers.

Steps for connecting speaker wire to binding post terminals on subwoofers:

  1. Strip the speaker wire to about 3/8″ to 1/2″ length bare wire. Twist the wire tightly by hand to keep the wire strands together.
  2. Push one of the terminals to open the hole. Insert the bare wire up to the insulation.
  3. Release the terminal and the wire will be held in place.
  4. Repeat for the 2nd or additional terminals.

Steps for connecting speaker wire to quick-disconnect terminals on subwoofers:

  1. Get the correct sized quick disconnect crimp terminals needed. If unsure what size, measure the subwoofer wire tabs with a ruler. You’ll also need a crimp tool as well.
  2. Strip the speaker wire (about 3/8″ to 1/2″ is fine) and twist the ends tightly to keep the strands in place
  3. Insert the wire into each terminal and crimp firmly until the crimp connector locks onto the wire and holds it firmly. You can crimp 2 times if you like.
  4. Hold the subwoofer and carefully slide the crimp terminals onto each tab. Be sure not to use too much force as the tabs can get bent if you’re forcing them. (If the connectors are too tight, try carefully prying them with a miniature flathead screwdriver or other thin, flat tool)

You’re done! When done properly, crimp terminals should not be able to move and the wire should be nice and tight, with no looseness to come apart over time.

Note: While you can use solder & a soldering iron to attach the speaker wire to the wire tabs, generally I recommend you use crimp terminals instead as it makes it much easier should you need to remove or replace subwoofers later.

Additional reading + if you have questions

I’ve got some other great information related to speakers, wiring, and more!

Have questions, ideas, or feedback? Feel free to leave a comment below or contact me directly.

I look forward to your suggestions for how I can make my article more helpful to everyone.

How To Reduce Tweeter Volume – Everything You Need To Know!

How to reduce tweeter volume featured image

Trying to get those tweeters under control? It can be a frustrating mess full of complicated math and wasted time & money.

Not to worry, though! I’ve designed & built my own tweeter volume circuits many times and I’ll show you how too.

In this article, I’ll show you how to reduce tweeter volume with clear info and easy-to-follow steps.

Here’s what I’ll cover:

  • How tweeter attenuation works & what options you have
  • How to properly reduce tweeter volume without affecting speaker crossover operation & sound
  • Tweeter resistor volume diagrams & resistor value table – no math needed!
  • Choosing the right resistor types, power ratings, and values
Contents

What is tweeter attenuation?

What is tweeter attentuation diagram

Diagram showing how tweeter attenuation (tweeter volume reduction) works to bring the tweeter volume down to a level better matching other speakers like midrange speakers. A tweeter resistor network, sometimes called an L-pad, can be used to reduce the volume & power a tweeter receives.

Tweeter attenuation is the reduction of voltage & power to a tweeter to decrease its volume output. This is usually done with a resistor network with values chosen to match the expected load of a stereo, amplifier, or speaker crossover.

Tweeter resistor volume reduction circuit diagram

In this simple example, we use a single series resistor to drop the voltage seen by a tweeter. Once we figure out the resistor value needed for a given volume reduction in decibels (dB), we can add it in series to reduce the power and consequently the power the tweeter receives. This causes the volume to be lower.

For speaker systems, tweeters often are more efficient (have a higher decibel output) than other speakers. In this case, there’s a mismatch often described as being “too bright.” For example, tweeters that are mismatched to midrange or woofer full-range speakers may seem very harsh & the music will sound unnatural.

Because tweeters are smaller and work slightly differently than larger speakers like midrange or woofers, it’s not unusual for them to be too “bright” sounding.

Speaker sensitivity explained

Speakers are usually given an efficiency rating by the manufacturer which is described in decibels (dB) of volume at 1 watt of power for comparison purposes.

For example, a midrange speaker may typically be about 87dB/W while it’s not unusual to see a tweeter with 92dB/W efficiency. That’s a difference of 5 dB, and enough that your ears can hear the difference.

This means the treble frequencies (upper range of sound frequencies) in music can be overbearing and annoying, causing listener fatigue – not just sounding bad!

To correct this, we can use a tweeter attenuation circuit with resistors to reduce the decibel output of the tweeters, matching them to the other speakers and improving the sound.

To calculate speaker power, you can use the formula (Volts x Volts)/(Speaker Ohms), or (V)^2/Rspeaker as I’ve done above.

This is from Ohm’s Law for power, voltage, and resistance.

Can’t you just use an equalizer or treble setting?

EQ and treble adjustment examples diagram

Tweeter output can be really hard to adjust with some equalizers and nearly impossible to correct with most treble levels in amps or stereos. For that reason, a better way is to use a tweeter attenuation solution.

To make matters worse, while a good equalizer (EQ) can help by letting you reduce tweeter volume across its output range, many treble controls in car or home stereos can only adjust a very limited range of sound and won’t fix the entire range of tweeter volume.

Not only that but if there’s a really big difference in sound levels between the speakers, the EQ or treble control might not have enough adjustment anyway and you’ll never get it quite right.

Good equalizers aren’t cheap and they take time to set up properly

While it’s true that a very good 31 band equalizer gives you a lot of adjustment range, not many have those handy and they can be expensive to buy. It also takes a lot of time to adjust a complex equalizer.

You’ll also need a lot of time & effort for trial and error if you’re really adjusting your sound the right way. Some people use a calibrated microphone & measurement software to tune a sound system for best results – and none of that is cheap.

It’s much easier to just reduce the tweeter volume across its entire sound range instead.

Series resistors vs L-pads for tweeter volume

Series vs L pad tweeter resistor networks explained diagrams

Resistor diagrams shown: Total resistance values for 8 & 4 ohm car & home stereos with a -3dB tweeter attenuation example. Series resistors are more simple but can’t be used in as many applications, while L-pad (series-parallel) networks work in any situation.

It’s easy enough to use a single resistor in series with a car or home audio tweeter for getting your tweeter volume levels under control. The problem is that without using an L-pad circuit, your amplifier or stereo will see a different value of speaker load for the tweeter side.

That’s not a problem if you’re directly driving a speaker with no inline speaker crossover, as there’s nothing to be affected by a higher speaker impedance (Ohms load). The problem comes when you add a speaker crossover – and that’s almost always the case when using tweeters and 2-way speaker systems.

Speaker crossovers are designed to work with a fixed speaker resistance. Change that, and you’ll mess up the crossover frequencies and the sound, too. Not what we want at all!

L-pads let you keep your sound AND control your tweeters

But how can we add resistors to drop tweeter volume but still keep the crossover working right? The answer is using an L-pad resistor network.

L-pad resistor networks are preferred over just using a series resistor because the total speaker impedance (Ohms) will be the same as what the amplifier, stereo, or crossover expects to sees. These networks use a series and parallel resistor design that add up to a total resistance that’s the same as the tweeter.

They’re a bit more complicated, though. You have to do more advanced math & algebra to figure out the resistors needed based on the decibel amount you’d like to reduce the tweeter by. For example, an L-pad resistor calculator like this can let you do it if you don’t mind the complicated stuff.

Keep reading, however, as I’ll show you an easier way.

Using an L-pad for tweeter volume

What is a tweeter L-pad explained diagram

And L-pad is a ready-made part that lets you easily reduce tweeter volume. With it you can tailor the tweeter level to your liking instead of using fixed decibel levels like with a resistor network.

L-pads are an affordable and really simple way to reduce tweeter volume. An adjustable speaker L-pad is simply an adjustable resistor network version like the fixed value ones I’ll explain later.

Unlike fixed resistors, they’re designed to let you adjust the tweeter level over a range as they use potentiometers which are simply adjustable resistors. As the output is adjusted the total resistance (impedance, as it’s called for speakers) that the stereo or amplifiers see are kept the same. That’s nearly always 8 ohms.

That way if you’re using speaker crossovers, which are designed for a specific speaker Ohms load, the sound won’t be affected – only the volume. As you decrease the tweeter volume output the internal resistance is increased and less voltage reaches the tweeter, causing the volume to drop.

Things to know before buying an L-pad

Some models are single-channel and you’ll need one for each tweeter while stereo models let you control 2 tweeters at once. They’re also available in different power ratings as well. 

However, while they’re a great solution, L-pads are nearly always only available for 8 ohm home stereo tweeters, not 4 ohm car tweeters.

How to wire a tweeter L pad

How to wire a tweeter L-pad diagram

Tweeter L-pads are almost always connected the same way but always double-check your instructions & labels if provided. To connect a tweeter to an L-pad you’ll do the following:

  • Connect the tweeter positive wire to the L-pad tweeter output (+) terminal
  • Connect the tweeter negative wire to the L-pad common ground (-) terminal
  • Connect the amp/crossover positive output to the L-pad positive input terminal
  • Connect the L-pad ground terminal to the negative amp or crossover terminal

The reason why it’s nearly always connected the same way is that most L-pads are designed the same. The details (like wiring pins or terminals) may be a little different, but normally that’s the only difference.

Some models require soldering while others offer a screw terminal that makes the work easier. In either case, always be sure to use an L-pad that has enough power rating for the speaker or tweeter you’re using it with.

A good rule of thumb is to pick one with at least 1/2 of the power ratings (Watts) of the tweeter you’re using. Always use the RMS power rating, not the “peak” or “maximum” as those are misleading and not what you need.

How to reduce tweeter volume with resistors (steps & diagram)

How to make a tweeter L-pad diagram instructions

It’s pretty easy to reduce tweeter volume with resistors. To do so, use the instructions in the diagram I’ve provided above. There are only a few steps you’ll need:

  1. Find the resistors you need based on the tweeter impedance (Ohms) and the tweeter volume, in decibels, you want to decrease. Use my provided chart (easy) to look up the series & parallel or calculate them yourself (much harder!)
  2. Buy power resistors needed. Resistors can be combined using different values in order to help you make the best of limited options. I recommend using 25W minimum resistors, although you can get by with 15W each if you’re using multiple resistors.
  3. Connect the resistors using a reliable connection as shown in the diagram. I recommend using crimp connectors or solder. To prevent short circuits, wrap exposed resistor leads with electrical or use heat shrink tubing.

How big of a resistor do you need with a tweeter?

Audio power resistor examples

Examples of power resistors that work fine for tweeter attenuation use. You’ll usually find the wire-wound type but also sometimes the metal chassis form, too. Both work great and can handle much more power than standard electronic use resistors.

Tweeters need resistors with sufficient power ratings in order to handle the heat they’ll build up since they reduce volume by “blocking” (reducing) power sent to the tweeter.

As a general rule, if using a single resistor for the series or parallel part of an L-pad circuit, use one at least 1/2 the power rating of the tweeter or power output of your amp you plan to use. For average use, a 25W resistor works well.

If you’re combining resistors in order to get the resistance you need, you could also use 15W rated parts. Those are commonly found when shopping too. 

Example of standard electronic axial resistor

Standard resistors like this are used for electronics and aren’t ok for using with tweeters. They’re not available in power rating styles that can handle audio power levels. Most are only 1/8W to 1/2W at most.

Don’t use standard electronics resistors, however, as they’re not designed to handle the power seen from an amplifier for speaker systems. It’s possible for them to burn up due to the extreme heat they can build up.

Which wire does the resistor go to on a tweeter?

Resistors aren’t polarized – either wire (lead) can go towards the tweeter, so don’t worry. That’s different from components like diodes and LEDs which have a single direction of current flow and have to be wired a specific way.

Where to buy the parts + keeping costs low

Image showing online retailer selection of audio resistors

There are some great places to buy audio resistors online if you’re located in the United States. If you’re not, you should still be able to find suppliers of electronic components including audio power resistors. You’ll get the best deal and keep a budget spending limit if you shop carefully.

Unfortunately, the days of being able to go down to your local Radio Shack and buy parts are long gone, at least for most of us here in the USA. To make matters worse, Fry’s Electronics, an electronics retailer, seems to be in terrible business condition and closing stores, in fact.

(Note that you might be able to find enough resistors at Fry’s or another local retailer if you’re lucky). 

Normally, however, unless it’s urgent I buy muy tweeter resistors and resistors for building speaker crossovers from one of a few places:

  • PartsExpress.com – A great company with a nice selection of affordable parts, speakers, audio electronics, and much more. Recommended! (I’ve bought tweeter resistors there several times)
  • Ebay – Not always great, but for typical resistor values it’s possible to get a good deal on a multi-pack set of resistors from a USA supplier.
  • Amazon.com – Ok, depending on the supplier. Power resistors at Amazon are affordable and some but not all are USA-based sellers.

In all cases, I would recommend starting with PartsExpress.com’s resistor selection here.

One of my UK readers mentioned he found some for his project from BlueAran.co.uk.

How much do tweeter resistors cost?

You can expect to pay anywhere from around $.80 each to about $1 each when priced affordably, or around $4-$5 for a pair or for 4 in some cases.

25W resistors do cost slightly more than their lower power counterparts, but not by too much. Usually, though, they’re either sold in singles or pairs while it can be easier to find smaller power rated ones in sets of 4 or 5.

Where to use tweeter volume resistors with crossovers

Where to use tweeter resistors with crossovers diagram

When using a resistor network to reduce tweeter volume & crossovers are used, it’s super-important to use them in the right place.

As I mentioned earlier, it’s very important to use tweeter resistor networks (L-pads) in the right place.

Crossovers are designed to work based off of the speaker load connected to them, and because of this, changing that amount can have a big impact on how they work (and how your speakers sound, too).

For example, if you’re using a car speaker crossover designed for 4 ohm speakers and insert a single resistor (let’s say a 4 ohm, for example) to reduce tweeter volume, the crossover frequency will change radically. It would go up 2x as high in fact in this example.

L-pads & L-pad resistor networks take this into account and create the same resistance so the crossover can work as expected. However, it’s also important to use it properly.

Remember that you should always use an L-pad or resistor network between the speaker crossover and the tweeter.

Additional reading + if you have questions

Want to learn more about speaker topics? Here are some other great articles I’ve created to help:

Have questions about tweeters and reducing their volume? Feel free to leave a comment below or send me a message.