how to guide

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

November 9, 2020

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

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

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

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

Contents

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

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

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

There are a few things to know first:

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

How to connect tweeters with crossovers to an amp

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

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

Connecting tweeter wiring

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

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

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

Where to install your tweeters

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

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

High up near the level of your ears
Pointing towards you

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

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

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

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

How to connect tweeter wires like a pro installer

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

The steps are:

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

Then repeat for the other wires as needed.

How to strip speaker wire

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

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

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

To strip tweeter speaker wire:

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.
Hold the tool & pressure in place firmly so it cannot move.
Pull the wire. The insulation could break off and the exposed wire should remain.

What to know before stripping speaker wire the first time

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

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

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

How to use crimp connectors with speaker wire

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

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

How to crimp speaker wire properly:

Strip the wire leaving 3/8″ to 1/2″ bare wire exposed.
Tightly twist the wire so it can be pushed into the connector properly.
Insert the wire into one end firmly, pushing it into the metal contact inside. Be sure to insert it fully.
Place the connector into the crimp tool in the appropriate position in the tool, near the end of the connector.
Crimp very hard with the tool to make and indentation in the outside of the connector. The internal metal connector should bend inward and make a permanent hold on the wire.
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?

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

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

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

Here’s the short answer:

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

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

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

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

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

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

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

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

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

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

A few examples are:

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

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

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

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

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

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

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

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

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

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

More excellent tweeter & speaker articles you can’t miss

You’re in luck! As it turns out, I’ve more fantastic AND free info about tweeters & speakers for you:

Are you tweeters too loud? Find out here how to reduce tweeter volume with resistors.
Find out here everything you could want to know about tweeters.
Confused about tweeter, midrange, or woofers crossover frequencies? Here are the best crossover frequencies for home and car audio.
What happens if you change your tweeter impedance? Find out what happens if you change the speaker impedance with a crossover.

Got questions?

Freel free to leave a comment below or visit my Contact page (see the menu at the top). I’d be happy to help you the best I can.

Thanks for your time!

How To Install LED Light Strips In A Car

September 17, 2020May 6, 2020

Car LED light strip installation guide featured image

Want to add some amazing style and color to your ride? Not only can you do it yourself, but you can also get great results for less than the price of a pair of speakers!

I’m passionate about helping others so I worked hard to put together this detailed do-it-yourself (DIY) guide to show you how to install LED strip lights in a car.

Want to see what they look like before you spend the time and effort? Be sure to check out my demo video at the end.

Contents

Infographic – Car LED light facts and tips

What are LEDs?

Light-emitting diodes (LEDs) are semiconductor components that produce light. Semiconductors are basic electronic elements made up of silicon and other elements that allow electrons (electrical current) to flow in certain ways. Diodes are “one-way valves” which allow current to flow in only one direction. An interesting property is that they also produce visible light. An anode (positive lead) connects to a positive power supply and the cathode (negative lead) connects to the ground or (-) wire.

Light-emitting diodes (LEDs) are one of the most important components in the electronics world. They’ve been around for decades but in the last 10-15 years or so they have become increasingly useful in our everyday lives. This includes uses in both home and car lighting, too.

LEDs work on the principle of a semiconductor junction. In other words, they contain 2 different materials like silicon and germanium bonded together to form a junction – or bridge – that forms a diode.

Diodes are extremely important to the electronics world as they’re electrical one-way valves, so to speak.

That principle is the basis of microscopic transistors which are what allow microprocessors and many other modern technological miracles to work.

The tiny components like the LED chip (the semiconductor materials themselves) are very sensitive but are sealed in an extremely hard and durable epoxy housing. Wires are bonded to the tiny components for connecting power.

If you’d like to read more about the different types of LEDs check out this page.

How LEDs produce light

Diodes have a special side effect when they pass electricity – they produce light! The color of the light produced depends upon the materials used to make them.

Over the years more and more companies have improved upon them and now produce cheap, great-looking LEDs that can produce light in a variety of colors.

Unlike regular light bulbs, however, LEDs actually work on a low voltage (say around 1.5 volts or so each). This means they must be used with a resistor to limit the amount of current flowing Otherwise they burn out quickly.

Resistors are used with LEDs when powered by car voltage (normally somewhere around 12V).

LEDs vs light bulbs & neon bulb comparison

LEDs have several advantages over incandescent (filament-type) bulbs and neon tubes as well. Here’s a comparison table highlighting some of the pros and cons of the three types.

CRITERIA	LED BULBS	LIGHT BULBS	NEON TUBES
Power use	Low	Moderate/high	Low
Cost	Low	Low/medium	Medium/high
Voltage	Low	Low/as required	High (special power supply)
Durability	Excellent	Poor/moderate	Poor/moderate
Life expectancy	Extremely high (tens of thousands of hours)	Low/medium (hundreds of hours)	Low/medium (hundreds of hours)
"Soft" glow effect	Poor	Fair	Great

As you can see from the table, LEDs have significant advantages in nearly every category that matters. They’re more cost-effective too.

It’s not just because they’re so durable and have an extremely long useful life (in the 10, 000 of hours, typically) but also because they need a lower voltage to work.

One drawback is that they can’t reproduce the “soft glow” neon tubes can, but that’s a minor drawback overall. When done well they still look great!

How do multicolor RGB LEDs work?

Image showing a multicolored red-green-blue (RGB) LED up close. These LEDs are actually a combination of 3 separate red, green, and blue LEDs built together. Today’s multicolored LEDs are very tiny and some are only a few millimeters in size!

Red, green, and blue (RGB) LEDs are made of 3 separate color LED segments combined into one small package.

Just like images displayed by your computer monitor or a phone’s liquid crystal display (LCD) the colors are produced in various brightness levels to form different color combinations.

RGB LEDs have 3 connections: one for each color. By using a specially designed LED controller the 3 colors are driven at different brightness levels and various hues of colors are produced.

Of course, basic red, green, and blue colors can be produced as well. The number of variations in color and brightness you can choose from depends on the ability of the controller used.

How do LED light strips work?

Diagram showing the design and basic operation of car LED light strips. The 12V supply powers the light strip controller which drives each light strip with separate red, green, and blue on/off waveforms. These waveforms are how brightness and color combinations become possible. Resistors are required to limit the amount of current each LED segment can receive.

LED light strips worked by being driven by a special power supply that controls the amount of time (and which color) LEDs switch on and off.

While simple single-color LED strips don’t need a power supply, they’re incapable of having different color combinations and special features like dimming or pulsing with music sounds.

An LED controller makes this possible in more advanced light strips by using very fast switching on/off with separate wiring for each individual RGB color.

LED light strips contain an evenly spaced set of multiple RGB LEDs and resistors wired in parallel. When powered, each color receives a separate on/off signal from the LED driver controller box. This allows a variety of brightness levels and color combinations.

The longer the on time applied to an LED, the brighter it will seem to your eyes. If one color is turned on more than the others that color will appear more prominent. (For example, if blue is turned on more often than red, you’ll see a color mix with more blue in it)

Each light strip connects in parallel with other light strips by design in most light sets.

Choosing a great LED light strip set

Car LED light strip sets like this popular one from Amazon that I've tested are a great deal for the money and offer a lot of options including color-changing, a remote, and pulsing with your music.

Getting a good LED light set is definitely important. There are so many sold today it can become a headache when shopping!

Although you can buy a simple single-color light strip set for around $10 (like this one here) I recommended spending just a few dollars more.

My advice is to look for one with the following features:

Good buyer reviews and happy users
Fairly installer-friendly
Offers multi-color modes
Music mode to change with sound
Color rotation modes (gradient, fast, etc)
Brightness control

You don’t need to spend a lot – say $30 or less. Here’s a great example of a light strip set that does all this and more for a great price.

Instructions included with Chinese products like these can be hard to understand, so be ready for that!

Supplies, tools, and your shopping list

It’s really smart to make a list of what you’ll need before getting started. It only takes a few minutes and can really help you be better ready for the specifics of installing in your vehicle!

I recommend making a basic list of what you can expect to need before you begin installing LED lights in your vehicle.

Tools:

Multimeter (for measuring voltage) – preferred over a test light
Crimp tool for crimp connectors
Screwdrivers and etc (as needed for your vehicle)
Wire-cutting pliers or pliers with a wire-cutting feature

I highly recommend getting an inexpensive but good multimeter (left) like this best-selling budget model from Amazon and a wire crimp tool and wire crimp connectors (right) before starting your installation. You’ll get professional results and it will go much more easily, too!

Supplies:

Wire (“zip”) ties (usually sold in a bag of 100 or more), 6″ length or similar
Wire crimp connectors (small assortment)
Roll of electrical tape
Good quality fast-drying glue
Fuse tap adapters (if wiring from fusebox)

If you’re mounting the light strips to flat (or other material) surfaces, I really recommend using a great glue like this fantastic Gorilla super glue gel that’s easy to work with. For making your installation wiring neat or mounting lights to wires or other nearby objects, definitely pick up some small wire ties like these.

While it might not seem important now, I strongly recommend picking up a pack of wire ties. They’re incredibly useful for keeping wires held together and nice and neat.

They’re also very handy for mounting light strips to metal braces or nearby wiring (and other objects) underneath your dashboard and seats.

Installing LED lighting in your car: getting started

You’ll need to do just a few major steps to get your LED lights installed. The good news is that in most cases it’s not that hard! It does take a little while to do it right, but it’s well worth it!

You’ll need to plan to do the following:

Wire the controller (or lights directly) to a power source of +12V and ground
Mount the light strips securely
Test and verify operation

In most cases, you don’t need to run any wiring to the battery. LED lights use only a relatively small amount of power so in most vehicles they can be connected to the factory stereo or cigarette lighter socket wiring.

There are also a few more sources I’ll mention later.

How to wire 12V LED lights in a car

Many sets include a cigarette lighter plug with an on/off switch. While using the cigarette socket to power a set is an easy option, it’s not the best or neatest way. However, for temporary use it’s ok.

While LED car interior light sets often include a cigarette socket power plug, that’s not the best option. Ideally, you’ll want to hardwire them to turn off with the ignition switch just like the car stereo.

LED light strip wiring diagram

In order to power the set you’ll need to hardwire it to an accessory wire to get a +12V supply that switches on or off with the ignition.

You can normally find a wire that works for this in one of several places:

Behind the car stereo (usually the first option)
At the cigarette lighter socket wiring
At the fusebox in the vehicle interior

How do I find a +12V accessory (“ACC”) wire?

1. Look up your vehicle’s wiring colors

I recommend looking for wiring color codes for your vehicle at The12volt.com. In most cases, you’ll find the colors and diagrams for your car or truck’s wiring.

If that doesn’t work out, it’s ok. We’ll fall back on plan #2.

2. Test wiring until you find a suitable wire

For this step, you’ll want to use a digital test meter (as I mentioned earlier). The main reason is that in modern vehicles not all wiring is 12V. Some now have signal lines or other wiring with voltages below +12V.

Caution! A simple test light can’t show you the real wiring voltage and can cause potential problems with the vehicle. Using a test light can lead to using a lower-voltage wire by accident which can cause your LED lights to fail or never work right.

You can try removing the radio and, with the ignition in the ACC position, check wiring until you find +12V wires. Then test again with the ignition off to decide which are suitable.

3. Tap off of the fusebox

A vehicle’s fusebox containing a power source for the radio – and your LED set – is usually in one of a few places. (Above) Under a panel in the dash itself or (below) in the lower driver’s side of near the brake pedal. The owner’s manual normally has labels for the fuses.

Additionally, another option is connecting to a power source at the fusebox. They’re typically found at the left side of the dashboard, either near the lower left-hand side of the interior or under a panel in the dashboard itself.

You can use the vehicle’s owner’s manual to show you which fuse is for what purpose. Most vehicles have one for the radio supply that you can tap power from.

Fusebox wiring adapters make it pretty easy to tap off of a power circuit for installing LED lights. You plug them in place of the original fuse and then connect the power wire.

If tapping off of the fuse box consider picking up a fuse wiring adapter. They can make it so simple!

If you don’t have an owner’s manual you can use a test meter to check fuse power with the ignition on and off until you find a suitable one. Then use a fuse tap adapter or other connection to attach the LED power wire.

Here are some great ones which will make installation much easier.

Connecting the wiring

Once you’ve found a suitable source for power, you’ll need to:

Connect the LED power wire
Ground the negative power wire

Here’s a helpful diagram with some ideas clearly explained.

Mounting your LED light strips

As many light sets (like the one I’m using here) have the light strips permanently attached to the control box, wire length is limited. However, there should be enough for most typical installations.

I measured about 48″ (122 cm) and 58″ (147 cm) for the front and rear lengths on mine. That’s about 4 ft (1.22 m) and 5.6 ft (1.7 m) in length for each front and rear pair.

Interior light strip locations

Diagram showing typical locations for the LED light strips in a car interior. Great locations are under the dashboard for the front 2 and either on the front or rear of the seats. Use the light strips with longer length cables in most cases.

Ideally, you’ll install your light strips (assuming you have 4, which most sets do) here:

Left & right front: under the dashboard, facing down
Left & right rear: under/on the front or rear edges of the front seats

Be sure to have them facing the areas you want the light glow to appear on.

You can also test them temporarily using some good quality tape to hold them in place before installing them permanently.

Locating the controller

The LED light set controller (for those having a remote control and/or sound sensor) needs to be accessible from the remote and should be placed where it can sense sound properly. Install it on one side of the dashboard center console where it’s hidden a bit. Most likely the driver’s side is best (as shown in the diagram above).

LED controllers that offer a remote control usually use an infrared receiver (IR) type of sensor. These need a direct line-of-site to the sensor in the control box.

Additionally, models (like the one shown here) have a sound sensor internally, too. In both cases, you’ll need to place the control box where it’s not totally covered and where the remote can work with it. Normally I suggest the driver’s side, hidden slightly underneath the dashboard.

Installing the light strips and cables (and why adhesive strips may be a bad choice)

The diagram above shows 2 great ways to install the LED light strips in your vehicle. I no longer recommend self-adhesive strips, even included on the light strips. After being exposed to heat in a car’s interior they often fail.

While LED light strips typically include a self-adhesive tape on the back of the strips, it’s often not reliable. The reason is that the adhesive fails after multiple sessions of heat exposure, vibration, and being kicked by feet in a vehicle.

For that reason I recommend the two methods I mentioned earlier:

Use a high-quality glue for attaching to under-dash plastic panels
Use wire ties to fasten light strips to vehicle wiring bundles or dashboard brackets

Using a high-quality gel super glue like Gorilla Glue is a great idea. Although it may sound permanent, you’ll only need a few small drops (about 4 to 5) for each light strip. The glue dries quickly but gel glue is easy to work with and quite strong.

Be sure to clean any surfaces beforehand with alcohol and a cloth, an alcohol pad, or a good surface cleaner. Silicon and other protective products like Armor All leave a residue that prevents glue from adhering well.

Additionally, wire ties are easy to use and allow for a lot of creative installation ideas. Nearly any nearby object or hole can be used to support a light strip.

Attaching light strips to seats

Similarly, after attaching the light strips underneath the dash, you can do the same for the seats as well.

If you’d like to avoid using a permanent glue, you can also consider using genuine Velcro. Generic velcro tends to have poor quality adhesive and won’t last long.

Where possible, try using wire ties on the seat frame if available. Wire ties are very strong yet can be cut and removed later without any permanent damage.

Spice up your system! LED amp rack lighting example

Want to add some extra style and class to your system? One great idea is to use LED light strips, facing your amps, to create a cool soft light glow that looks sharp. Pictured above: My custom car amp rack I built.

In the photo above you can see my custom car amp rack with backlighting inside. LED light strips are great for your own low-cost custom amp rack too!

Just add them around your amps (for as many sides as you like or make sense for your system) with them facing the amps. It’ll add a beautiful look that you’ll be proud to show off.

In fact, you can use a simple relay connected to the remote wire & power from the amp +12V & ground terminals so they’ll come on automatically with your system.

Final notes and demo video

Car Interior LED Light Set Demo

Watch this video on YouTube

An example of the kit installed in a Toyota sedan. The results are great!

Adding LED lights to your vehicle’s interior is a very cool project you can do yourself! The results are great and one of the most cost-effective ways to really spice up your ride.

As I mentioned before, a good LED light strip set won’t break the bank. In fact this multi-color car LED light strip kit I picked up from Amazon is under $20. It’s easy to install, too.

Additional reading

Speaking of taking your ride to the next level…got an amp yet? If it’s time for an upgrade, have a look at my list of the best 4 channel amps for sound quality.

Got questions, suggestions, or ideas? Feel free to comment below or send me a message.

How To Hook Up A 4 Channel Amp To Front And Rear Speakers

October 28, 2020May 2, 2019

How to hook up 4 channel amp to front and rear speakers

Adding a 4 channel amp is a great idea. I’ve enjoyed powerful, crystal-clear sound in my vehicles for years using my own 4 channel amps.

But how do you hook them up?

In this guide I’ll show you how to hook up a 4 channel amp to front and rear speakers. After installing hundreds of amps in vehicles just like yours I’ll share with you the fundamental tips you need for great results.

And hey – don’t worry…in most cases you can do it yourself and get professional results on a budget!

Contents

Infographic – How to hook up a 4 channel amp (tips and general guide)

Basics first

If you’re reading this there’s a good chance you’re not familiar with installing an amp, connecting wiring, and other details related to hooking up a 4 channel amp in a vehicle.

Not everyone has installed car stereo equipment before so I’m going to be as thorough as possible and avoid making any assumptions about how much you know.

What is a 4 channel amp?

Today’s 4 channel amps offer newer technology, better sound, and more compact size than in the old days. An excellent example is the Alpine MRV-F300 50W x 4 model. It uses Class D technology to run extremely cool and yet it’s small enough to fit under a car or truck seat. Very nice!

What a 4 channel car amplifier is may seem obvious at first but there’s a bit more to know Additionally, there are some interesting (and good) ways they differ from 2-channel amps.

In fact, there are actually a few benefits you’ll get using one 4 channel amp instead of 2 stereo ones to power your front and rear speakers.

A 4 channel amplifier is a stereo amplifier with 2 more channels built in to boost (amplify) weak input signals to a higher voltage signal. This drives speaker voice coils to move the speaker cone and produce sound.

4 channel amplifiers add more channels into a more compact and efficient design than separate amplifiers would have.

Additionally, they offer more flexibility, as most can be configured for “bridged” operation which can give more power when you don’t need all 4 channels.

What is “bridging” an amp?

Bridged mode capability is a special design feature in which a “push-pull” set up is created: one channel (normally used for the left speaker) produces a signal that’s the opposite of the second channel (normally used for the right speaker).

This causes the speaker to receive a voltage audio waveform that is the difference between the two channels – resulting in more available power to speakers.

Essentially, bridged mode is a flexible way to get more power if you’re not driving 4 speakers. It means 2 channels are sharing the workload of one speaker between them and therefore and drive it with more power.

2 channel vs 4 channel amp diagram

A 4 channel car amp is basically an expanded version of a 2-channel amp. However, because they’re built together and not 2 separate 2-channel amps, they’re more compact. This saves installation space and makes it easier too. Additionally, most can be bridged to use 2 channels (or 3, depending on your needs) so you’re not restricted to using them with only 4 speakers.

The benefits of using an amp to drive speakers

Whether you have a factory stereo or a great aftermarket (non-factory) one, adding an amplifier is one of the best decisions you can make.

In-dash stereos are very limited in how much power they can produce. They can’t drive speakers with the same clarity and low distortion as a good amplifier can.

The maximum volume you’ll be able to get from your speakers will be pretty low, too.

There’s simply no way around it – most in-dash stereos are limited to about 15W-18W RMS of power for each speaker channel. That’s because they’re running directly from the +12V supply. Amplifiers are unique in that they take the +12V electrical supply and boost it to a higher voltage.

When a signal is boosted and sent out to your car’s speakers the voltage is much higher and the speaker can receive much more power.

That’s why tiny amplifiers are rarely worth bothering with – if there’s no special power supply inside, it’s simply not capable of producing much power.

Getting great sound

Powering speakers from an amp makes a big difference, and I’ve enjoyed excellent sound for years this way.

When an amplifier drives your vehicle’s speakers it’s often not even pushed to its limits. The sound produced at the speaker has lower distortion, doesn’t “bottom out” when heavy bass is played, and you can get a lot more volume, too!

Additionally, using an amplifier with built-in high-pass crossovers means you can block out lower-end bass that causes your speakers to distort and attempt to play music tones they’re not suited for.

The result is cleaner sound, less distortion, and great volume – you can crank your music even higher!

Just imagine driving down the road with the windows open and finally being able to blast the music you love. I’m confident you’ll love it as much as I do.

Things to know before you start

It only takes a few minutes to make a list of the parts, wire, tools, and other bits and pieces you’ll need. Planning ahead can mean the difference between getting your system going without major problems or having a frustrating time – or complete failure! I always get organized and get my items together before I start a job.

Planning ahead is very important. You don’t want to run out of wire or discover you don’t have the rights parts, for example. That will mean you can’t finish your project.

It’s even worse when you have to drive around town searching for items or you’re not able to do anything after the stores close. Believe me, I’ve been there, and it’s terrible!

Notes about wire, tools, and a few other things

When it comes to installations, always plan to have more, rather than not enough, wire. This goes for speaker wire as well as RCA cables.

The amplifier kits I recommend have the right length for your amp installation, but speaker wire & RCA cables are another matter in this case.

What length and size speaker wire do I need?

There’s no need to spend an excessive amount of money on speaker wire. 18 gauge is enough for many installations, but 16 gauge is a great choice too if the price is right. A great example is this AmazonBasics 100 foot roll. I recommend a 100 foot roll for many installations with a 4 channel amp (see why below).

Here’s an estimate of the worst-case scenario for the length of speaker wire required. I’ll use the example of installing an amp using speaker-level inputs, with the following typical installation:

Amp is located in the trunk
Speaker level signal connections near the radio (center console)

Let’s use roughly a 15′ length of distance from the radio to the amp. That’s a good estimate in my experience.

So we have:

Wire from the radio to amp (signal wire): 4 channels x 15′ = 60 feet
Wire from the amp to speaker wiring near radio: 4 channels x 15′ = 60 feet

Total estimated wire required: 120 feet.

That means you need 2 100 ft rolls of wire. Or at the least, 1 100 ft roll and 1 50 ft roll. If you’re planning to use a line-level adapter, expect to pick up a 100′ roll.

If your installation is using RCA jacks, expect a 100 ft roll also (4 channels x 15′ length estimate for the speaker wire from the amp).

What about RCA cables?

If you’re installing a 4 channel amplifier and using RCA cable connections, you’ll need to buy a 2nd pair along with your amp wiring kit, as most only include a 2-channel cable.

For most installations, I recommend 18′ length cables. That’s usually long enough for most vehicles and you should usually have enough length to hide the cables inside the interior and under the rear seat, etc.

There’s no reason to spend an excessive amount of money. Just pick up some good quality, well-made cables. Even a pair like these value-priced ones will be fine in most cases.

Tools you’ll need.

Crimp tools are great for installing your amp and speaker wiring with professional results. If you’re doing your own installation, you can get by with an inexpensive tool like this Pros'Kit crimp tool. Crimp connectors are sold separately in many automotive parts stores or general stores and are very affordable.

I recommend a few tools. If you shop carefully, you can avoid getting ripped off on tool prices. When connecting speaker wiring to factory wiring, it’s easier to use crimp connectors than solder.

Never simply twist the wire together and wrap it in electrical tape. Always use a reliable connection.

During warm weather, electrical tape adhesive can fail and the tape can come off of the wire. This exposes it to possible short circuits and potential damage to your radio or amp.

If you have access to a cordless drill, that’s fantastic! They’re great for drilling holes in the vehicle’s metal for mounting your amplifier or connecting the ground wire to bare metal.

I also recommend the following:

Wire cutters (some crimp tools have this built-in)
Roll of quality electrical tape
Wire ties (“zip ties”), 6″ length, bag of 100
A digital test meter for voltage measurement

A test meter is often incredibly helpful when installing an amplifier. However, you don’t need to spend much money! A basic but good budget model like this one at Amazon will work great.

I recommend getting an affordable but good digital test meter to find a switched +12V wire for getting a remote-on signal to the amp.

They’re also extremely helpful when troubleshooting power problems when something isn’t working.

Get your installation shopping list together

Here’s a general but pretty accurate list of what you’ll need for connecting a 4 channel amp to front and rear speakers.

Installation types 1 or 2: Factory radio or no RCA connections

4 channel amplifier with speaker level inputs or amp and line-level adapter
120 feet or more speaker wire, 18 gauge or larger
Amp wiring kit
Crimp tool and butt (wire crimp) connectors (25 or more at least)
Cutting pliers
Electrical tape
Wire ties, 6″, bag of 100
Test meter

Installation type 3: RCA connections

4 channel amplifier with speaker level inputs or amp and line-level adapter
100 feet roll speaker wire, 18 gauge or larger
Amp wiring kit
Additional RCA cables, 18′ minimum
Crimp tool and butt (wire crimp) connectors (25 or more at least)
Cutting pliers
Electrical tape
Wire ties, 6″, bag of 100
Test meter

Be sure to plan well and estimate the amount of speaker wire you’ll need. For the amp installation itself, I strongly recommend using a pre-made amp wiring kit like you’ll find here in my amp kit buyer’s guide.

You’ll also need to get a 2nd pair of RCA cables. I recommend 18 ft length or more. Don’t spend too much money, but do get decent quality ones.

How to get a signal to your amp

Image of an aftermarket (non-factory) stereo showing the RCA jacks and speaker output wiring. Either one can be used for getting a signal to an amp, but RCA jacks offer a better option. They’re normally lower distortion and allow using plug-in RCA cables. If those aren’t available, either an amp with speaker-level inputs or a line level (speaker level) adapter can be used.

In order to install a 4 channel amp and drive all 4 speakers, in many cases, the biggest obstacle is getting a signal to the amp. Once that’s done, the rest is usually a standard amp installation.

There are 3 basic ways to get a signal to your 4 channel amplifier:

Connect speaker outputs to your amp’s speaker level inputs
Connect a line-level adapter to the radio then use RCA cables to the amp
Connect your radio to the amp using RCA cables directly

NOTE: I won’t be covering factory sound systems that are “premium” and have a factory amplifier. Those such as Bose, JBL, and Mark Levinson, often found in luxury vehicles or special-edition models, are much more complex and harder to deal with.

In that case, my advice is to speak with a good installation shop first and do your research.

If you feel that factory amplified systems should be here as well, send me a message or comment and let me know

In a few cases, adapters are available to connect an amp to a factory amplified system’s audio wiring, but it’s often difficult or there are obstacles you won’t find until you get started.

One of the reasons why is that factory amplified systems often have non-standard wiring connections for the audio path and are prone to bad noise problems if you connect an amplifier without the proper adapter or wiring.

Which type of connection do I need?

If you have a radio with RCA jacks, skip on down to the next section.

However, if you have a stereo with no RCA jacks (which is always the case for factory-installed stereos) you’ll have to buy one of the following:

A “line level” converter
An amplifier with speaker-level (“high level”) inputs

1. Line level converters

Line-level converters like this PAC LP7-4 4-channel model are designed to take speaker-outputs from a stereo with no RCA jacks and adapt them to RCA jacks. Using this, you can run RCA cables to your amplifier.

Line level converters are designed to allow connecting to an amplifier’s RCA inputs by converting speaker outputs from a stereo to a low-level signal an amp can use.

It’s very important to buy a quality, well-designed line-level adapter to avoid noise, poor sound quality, and other problems. Don’t get the cheapest – instead, get a name brand model you can rely on (like the one above).

2. Speaker level inputs

Amplifiers with high-level (speaker-level) inputs like this one allow connecting to speaker wiring for a signal source. This avoids having to buy a separate adapter.

Speaker level inputs are common on many 4 channel amplifiers. These amps contain electronics that scale down speaker wiring signals to a lower signal safe for the amplifier’s input circuitry.

They’re simple to connect: normally it’s just a matter of connecting both positive (+) and negative (-) wiring for each speaker channel on a small wiring harness included. This then plugs into the speaker level input connector.

A typical speaker-level input harness for a 4 channel amp. The wires are color-coded to make installation easier. White = left front, gray = right front, green = left rear, and purple = right rear.

While it can save money (you won’t need a line-level adapter in this case) I often recommend that people consider buying a line-level converter anyway.

This allows an easier upgrade for your stereo later, which is very common for people to do. Using the line-level converter now will allow you to run RCA cables to your 4 channel amp to be used later if you buy a better stereo (which will include RCA jacks, almost always).

3. RCA jack (line-level) connections

RCA jacks offer a clean, lower-noise connection than speaker-level adapters do, but honestly, it’s not noticeable to the average person. RCA cables (line-level connections) are the preferred way to connect a signal to your amp if you have that option.

RCA jacks on the rear of a Pioneer head unit. This is the ideal way to connect your amplifier’s signal inputs, if available. For a 4 channel amplifier, you’ll need 2 stereo RCA cables to do so. White represents the left channel white red represents the right. These are standard colors for audio outputs for both car and home stereo.

If your stereo has RCA jacks, then congratulations. Things just got a bit easier – and potentially better sounding, too!

You’ll need 2 stereo RCA male-to-male cables (4 audio channels total) to run from the radio to your 4 channel amp. That’s 4 signal channels: left & right front and left & right rear.

4 channel amp signal connection diagram

Here’s a helpful diagram showing the most common connections you’ll need to make one of the 3 most common cases I mentioned earlier:

Connecting to your amp’s speaker level inputs
Using a line-level converter
Connecting your amp to the radio’s RCA jacks

You can also click here to view the .pdf document for print or download.

Connecting and running signal wiring

Speaker-level connections

As mentioned above and as shown in the diagrams, if you’re using speaker-level outputs to get a signal from the radio, you’ll need to connect wire. Ideally, you’ll do so near close to the radio, then run the wire together as a bundle.

You can bundle speaker wire together with wire ties to keep it neat and make the installation easier.

Estimate the length of speaker wire you need to reach the amp (or line level converter) for each audio channel. To do so, run a length of wire from the radio to where the amp will be installed, then allow a little extra and enough length to run around curves and interior parts.

Cut 7 more lengths of wire, for a total of 8:

4 channels (4 pairs of wire) going to the amp’s speaker level inputs
4 channels from the amp to the radio’s factory speaker wiring

I recommend connecting to speaker-level outputs using crimp connectors and a crimp tool for a reliable, solid connection. Blue connectors are normally the right size for 18-16 gauge wire.

Factory stereo color codes

If you have a factory stereo, you’ll need to find the wiring colors for the speaker wiring.

A great resource for that is The12Volt.com, where you’ll find wiring diagrams for your vehicle and color codes listed.

Making connections

After removing the radio you’ll find connectors like this for the factory stereo wiring harness. You’ll need to separate the speaker wires, cut them, and attach wiring to run to the amp.

Remove the radio and disconnect the factory wiring plugs or aftermarket radio’s wiring harness.

Cut the speaker wires, leaving enough length to move the wire and to have enough length to connect to the wire freely.

Strip a small part on both the stereo’s speaker wire and your amp speaker wiring. If using a line-level adapter, connect to the stereo’s speaker output side. Then connect the 4 pairs of wire to the speaker wiring in the harness.

Insert the stripped wire (about 1/4″ of bare wire) into the connectors and crimp them carefully using a crimp tool if you have one. Alternately, you can twist together wire, solder it, and carefully wrap it with electrical tape or use heat shrink tubing for insulation.

If using speaker level inputs on your amp, also connect 4 pairs of wire to the output of the stereo.

To make a neater, more professional installation, bundle the speaker wiring similar to this using wire (“zip”) ties. I recommend using 6″ ties which often are sold in packs of 100.

Once all wiring is connected, bundle it up using wire ties or, optionally, a little bit of electrical tape wrapped around. In both cases spacing out wire ties or tape about every 1″ or 1.5″ along the length of the wire works well.

Connecting RCA cables

Connecting RCA cables to an aftermarket (non-original) stereo for running to an amplifier.

If you’re using a line-level converter or have a stereo with RCA jacks, connect all 4 cables plugs to the front and rear outputs.

RCA cables are sometimes marked with left and right symbols (“L” and “R”). In some cases, white, clear, or some lighter color can be used to represent the left channel.

Connect the cables consistently so you’ll be able to recognize which one is which. If the front and rear RCA cables are the same, you might want to mark front and rear using some masking tape and a marker or pen.

Connect the remote-on amp wire

Don’t forget the remote wire! Amp wiring kits include a small wire that’s used to connect the amp so that it switches on and off with the accessory position of the ignition switch.

Locate a +12V wire that has power when the ignition is switched to “ACC” or similar but turns off with the key. You may also have good luck finding an existing wire color from vehicle wiring diagrams I mentioned earlier or from a Google search.

I recommend checking the wiring even if you have already located it online, just to be sure.

Before re-installing the radio connect this wire and run it alongside the speaker wiring.

How to connect a 2 ch. car stereo to a 4 channel amp

You can connect a head unit car stereo with only 2 channels (left and right) to a 4 channel amp easily. Ordinarily, all you need is 2 RCA Y adapter cables. The head unit’s left channel RCA jack should be connected to the left front and left rear amp inputs. Likewise for the right channel. If using speaker level inputs on the amp, use the connections shown above. NOTE: Use only ONE of the two connections above! Never connect both types at the same time! Speaker-level outputs will damage RCA connections.

If your head unit (car stereo) only has 2 RCA jacks or two pairs of speaker outputs, that’s not a problem.

As shown in the above diagram, you can connect 2 channels to a 4 channel amp using either the speaker level inputs wired in parallel or by using simple RCA adapter cables.

All you need is a decent pair (a total of 2) female to male RCA “Y” adapters like these low-cost ones from Amazon.

The sound quality will be exactly the same. Today’s amps are designed in such a way that there’s no harm in using a Y adapter to connect the amp. The amplifier will receive exactly the same signal, with the same quality, in the front channels as well as the rear.

The only drawback is there won’t be a front to rear fader control like with head units with 4 channels of outputs.

After connecting the stereo to the amp, you’ll need to adjust the rear gain to set the volume level for the rear speakers as needed for the proper volume depending on the stereo’s signal strength.

Installing the amp

An amp wiring kit like this one will make installing your 4 channel amp much easier. A good-quality one like this Belva 8-gauge complete kit includes not just wiring but much more. You’ll also need to pick up a 2nd pair of RCA cables (if using them) and enough speaker wire.

Your amplifier needs a good solid metal connection to ground and you’ll need to run the positive battery wire to the engine compartment. Your amp wiring kit will also include a fuse holder that should be installed near the battery as well (most kits include instructions, by the way).

You’ll also need to connect the amp’s speaker outputs to the wire you ran from the radio.

As it also applies to 4 channels amps, for the amplifier installation you can follow my guides here:

Here’s a basic diagram as well to help:

Setting up your amp

Once installed, you should set up your amp’s gain levels and crossovers for the best sound. In this image, you can see the adjustable crossovers for both front and rear channels. Turn on the high-pass crossovers and adjust to a setting close to 50-60Hz, to allow good bass for music but block low-end bass that distorts.

Once installed, you’ll need to set up your amp’s gain levels and crossovers, if available. Most sold today have that. (See my recommendations at the end for some great models)

Gain control is the amount of signal amplification the amplifier performs. Ideally, with a good input signal, it can be kept low to reduce any hiss or noise that can appear when it’s turned up high.

Here’s a great rule of thumb for how to adjust the gain for this type of system:

Turn down gain controls on the amp
Turn the stereo’s volume to 2/3 of maximum
Slowly raise the gain controls until the volume is enough

When finished you should have enough volume available from the stereo but noise should be minimal. You’ll still need to tweak it a bit if the volume is too high or too low.

Setting the crossover

As I mentioned at the beginning of this guide, using high-pass crossovers will allow more volume with less distortion and will help protect the speakers from heavy bass.

For both front and rear channels turn on the high-pass feature and, if an adjustable dial is available, set it near 50 to 60Hz. Some models don’t offer an adjustable frequency for the cutoff but are likely preset to a good level.

Test and tweak

Once installed, test and tweak your amplifier as needed. A great way to mount your 4 channel amp is by using a board mounted to the car, covered with speaker box carpet or other material.

Play some music you’re very familiar with and adjust things like bass, treble, and the fader as needed. Using music you’re very familiar with (of high quality) means you’ll be able to notice any problems with the sound fairly easily.

If you don’t already have one, you might consider later upgrading to a head unit with built-in equalizer (EQ) functions to help tailor the sound.

Summary and recommended products

Hopefully you’ve found this post useful. Hooking up a 4 channel amp to your front and rear speakers takes some work and time, but it’s a great way to get sound you’ll love.

Considering buying an amplifier? You can find some great 4 channel amps (including the Alpine MRV-F300 pictured here) in my 4 channel amp buyer’s guide.

You’ll also need a good amp wiring kit – I’ve got a good amp kit buyer’s guide here.

If you find anything missing or have suggestions, just leave a comment below or send me a message!

10 Great Reasons Why You Should Install Your Own Car Stereo System

September 16, 2020February 11, 2019

10 Great Reasons Why You Should Install Your Own Car Stereo featured image

Way back in the day before I ever worked in the car audio field as a professional, I tinkered with audio in the used cars I owned over the years. Like a lot of people, I struggled trying to figure out how to do things.

Along the way, I learned some hard lessons. It turned out I also learned a number of reasons why you should install your own car stereo system.

As time went on I realized how much I benefited from completing all kinds of great car audio installations on my own rather than paying someone else.

Installing your own car stereo equipment is really beneficial and I’ve written a solid list of reasons why. Read on to find out why!

1. You learn to be self-sufficient

The first 2 vehicles I owned – in which I had to figure out how to install car stereos – a 1976 Toyota Corolla (left) and later a 1985 Toyota Corolla SR5 (right). It wasn’t easy and I was nearly broke at the time! I somehow had to figure out how to get things done on my own – which I did, enhancing my resourcefulness and knowledge in the process!

I had a hard time growing up. I didn’t have much money and I couldn’t count on my dad to help and guide me through basic mechanical things.

I’ve always been a mechanically inclined tinkerer at heart, but I had to learn how to use tools and fix things all on my own. The same goes for all my technical projects and repairs and projects up to now including car audio.

For me, the first cars I owned were a real challenge. When you’re poor and don’t have the money to pay someone else, you live by the old saying, “Necessity is the mother of invention.” I didn’t have any choice – I had to try and I learned to be resourceful.

Building skills for a lifetime

By taking things apart in my cars with a few basic hand tools like screwdrivers, pliers, and metric sockets, I learned some great skills. I became able to take a car dash apart and put it back together.

As I removed the original stereo and tried to fit a new one into place (bear in mind – there were no kits I could buy to do so easily!) I had no choice but to come up with some kind of solution if I wanted it to work. I wanted to listen to better music so badly and was motivated to keep trying. It was a hard struggle and times and there were times when I failed…but I learned so much and I don’t regret it.

By trying to do it myself, I learned new skills and had the experience I could fall back on next time – I learned to be self-sufficient.

That same approach became valuable over and over in many areas of life, too.

2. You save money

Money is a precious commodity especially when you’re a young and broke part-time student, for example. What little money you have restricts the things you get to enjoy in life. Be smart and save money when you can – installing your own car stereo system is a FANTASTIC way to save cash and get the great sound you couldn’t afford otherwise.

Whether you’re well-off or not, you should consider doing things by yourself to save some money. Why? Allow me to explain more.

In many cases, car stereo shops charge a lot. But they charge not only for labor costs, (which is usually fairly reasonable, depending on the shop and where you live) but especially on parts and accessories.

You’re almost always to going to pay a lot, and believe me, I’ve seen people overpay because they thought they had no choice but to do so.

In reality, the necessary equipment, parts, and information are readily available to you! If you research properly, you can save yourself A LOT of money and avoid being scammed into paying more than you’re supposed to.

You have plenty of options – you simply need to learn how to exercise them properly.

When we’re young, money is hard to come by unless you’re lucky to be born into the right environment. Most of us struggle financially when we’re young, and there are some adults who are still struggling today.

In my experience, unless you are dealing with more difficult installations (like remote start systems, car alarms, etc) you’ll end up wasting a lot of money paying not just for labor but also the parts an installation shop will say you “need” but will mark up a lot – by as much as 40-100%!

3. Your research skills will significantly improve

One of the first principles you’ll learn is that finding good, reliable information takes time. The internet is much better than it used to be but it’s still very much like a junkyard in many ways. Also, you’ll “learn how to learn” – that is, you’ll begin to better understand how you can learn more by seeking out information, learning to cut out what isn’t valuable, and making the best decision possible.

When you install your own car stereo systems, you’ll often start at “square one.” That is, you’ll have to figure out on your own what you need to buy, how to install it, and which electronics are the best buys.

A person who has very little knowledge about the subject is often overwhelmed with information or can feel like it’s too difficult to accomplish by themselves. But the truth is that everyone starts somewhere.

No one is born knowing everything!

Understanding what to look for in reviews

When you decide to install your own car stereo system you’ll realize soon that you need to scour the internet for reviews, information, and opinions from other people who have contributed feedback.

Unfortunately, a lot of it is junk and is biased, being written by people who are emotionally driven and have an axe to grind.

However, plenty of others post genuinely helpful and honest opinions about what they bought, how well it works, and how hard it was to install. That’s what you have to seek out.

As you go along, you’ll soon discover a few patterns emerge when trying to find information. You’re actually doing a form of research!

What you’ll learn

By attempting to install your own car stereo system, you learn to:

Seek out general information about the car stereo product you think you need
Look for more specific information to decide if it’s worth the price
Look at general opinions and reviews – until you’re convinced you want to buy the product

As you go through all these, you’ll soon discover that you’ve become more efficient at finding useful information. After looking up specifications, buyer reviews, and more details about several car stereos and amplifiers – you’ll have developed a new, personalized method of approaching research.

Also, when you start looking for wiring & installation information, you’ll start to see what works and what doesn’t. It can sometimes be a slow and boring process, but you gain more knowledge and experience you can store for future use.

The next time you start to look into a similar topic, you’re well-prepared and ready to do even better than before. These days, it’s an extremely practical skillset to have.

Unlike most people who just believe anything a salesman would tell them, you know the facts – you can make a well-informed, educated decision based on what you’ve already learned through experience.

4. You gain skills with tools and become more mechanically inclined

You don’t have to be an “expert” to do research, learn what parts you need, then try using basic tools like pliers and a crimp tool to install a car stereo. Everyone starts somewhere. If you do it yourself, you’ve overcome a huge obstacle and most importantly, your mindset has changed. You no longer think, “I can’t”, but instead, “I can and will!”

Installing the most basic equipment like an amp and subwoofer box may sound easy, but the reality is often VERY different from what people might tell you and what product descriptions imply.

The reason is that in the real world, every installation is different – you’ll have to overcome new obstacles you have to be successful.

For example, installing an amplifier in some cars is easy, as there’s plenty of room in the trunk. In that case you can mount it to the subwoofer box and you’re done. However, in others space is tight and you’ll have to come up with a custom solution.

You also need to know how to use basic hand tools (like a crimp too or an automatic wire stripper) so that you can strip and connect wires along with many other simple tasks useful for car audio installation.

The most basic and necessary of which are removing and installing by using screwdrivers, ratchets, and cordless drills with a clutch.

Getting better at DIY car stereo installation

It’s an essential set of skills that no one can pass up if they want to succeed.

Even better, if you’re able to solve hard problems like mounting an amp in a hard-to-fit area by using basic brackets or car stereo straps, you’ve gained the ability to solve other problems, too.

If you end up running into a difficult installation and have to get parts at the hardware store or maybe get some great metal mounting straps to make custom mounting brackets, then all the better!

The next time your mind you run into a similar challenge you’ll have ideas to fall back on and will search for similar solutions based on what you’ve learned.

It may be difficult at first, but once you succeed you will have learned many skills and lessons that you can use in other areas of your life.

Similar problems that come up later will be easier to deal with because of the experience you’ve gained.

5. You become more creative and a better problem solver

Let’s say you want to install your great brand-new amp in your car trunk, but you can’t find a good place where it’ll fit perfectly. Before you get all dejected and give up, how about trying something creative like mounting it to a board and then to the rear deck? These are the kinds of ideas you develop when you do it on your own.

When installing a car stereo in your own vehicle, one of the first things you realize when you start – and unfortunately learn the hard way – this that it’s often not easy. You have to be creative to find a solution to get things done.

As your project goes along, you’ll have to really think hard and try different things.

For example, to get a stereo to fit your car’s dash or to mount a sweet new amplifier in the trunk with very limited space it will take some good creativity. Those are things I’ve dealt with many times and it’s why I have very good installation skills.

I had to get creative to persevere – and I did! Since this was a side business of mine, I had plenty of opportunities to improve my creativity and solve more problems…which led to even more opportunities because of it.

Taking the first steps of doing it yourself sort-of forces you into a “try or fail” scenario. It’s funny how we don’t realize what we can do or what kind of problems we can solve until we’re forced to.

6. It builds confidence

“Wow! Did you install it yourself? That’s so cool. I can’t imagine how hard that was!” It’s a great feeling of accomplishment. Hey, you did it on your own – you have every right to be proud!

After installing hundreds of car stereos, amplifiers, and security systems (among other things), I can proudly say I’m very confident in my abilities – I can install nearly everything and do it well with professional results.

However, I didn’t start out this way.

It took years of experience, practice, and a lot of learning from my mistakes to build the confidence I have today. Likewise, any job you’ve accomplished – no matter how big or small – will reward you with a little bit of experience that boosts your confidence and self-esteem.

The reward of a job well done

For example, let’s say you bought an amazing new Bluetooth compatible car stereo like this one and after a bit of struggling you finally got it installed and you love it. Ok, sounds great!

Now you feel a bit more secure that you can add an amplifier and subwoofer later. After all, if you can install a great head unit and it looks good, can’t you do a little bit more, too?

And so it goes…when you complete a DIY project, you don’t get only the great feeling of a job well-done. You also earn the ability to believe in yourself and have more confidence in what you can do.

Self confidence is extremely important for what you can accomplish in life and should never be taken for granted.

7. You’re less reliant on others

Like how this looks? So does he. And he didn’t have to pay hundreds of dollars to a shop to do it for him. When you’re willing to take the little steps and figure out how to install a system on your own, you realize how little you actually need to depend on others. It’s an incredibly useful trait in other parts of your life to have.

This is one of my personal favorites and for many reasons.

I grew up surrounded by very few – if any – people I could depend on. For more times than I’d care to recall, life was a struggle. I was forced to learn to rely on myself.

That can be both a blessing and a curse, but if we look at things optimistically, I can say I’ve gained plenty of life skills because of it.

When you can complete your own projects yourself without asking or paying others for help, you’re free from wasting some crazy-high amount of money for a task you could have easily done yourself.

You can do things the way YOU want – with notably better results once you get better at it!

You can do it!

It’s fantastic being able to not have to stress out over how you’ll handle installing something in your car or truck. After having completed 1 or 2 do-it-yourself (DIY) projects on your own, you’ll just sort of “know” what to do next.

You’ll find that you’re able to do so without nearly fainting at the idea like so many people today. So often these days I see examples of people who seem nearly helpless as they’re not resourceful at all.

Don’t underestimate what you can do – there’s an extremely high chance that you’re perfectly capable of building all kinds of stereo systems (or whatever kind of project you dream up) without paying a “pro” to do it for you.

Here’s some food for thought: in many cases the results I saw from other “professionals” weren’t really much better than what the average person could have done themselves!

8. You learn the “your way” rule and to think outside the box

The “your way rule” means thinking outside of the box. Don’t just be ho-hum and think you can’t have a better sound or have YOUR things the way YOU want them to be – you can! Understand that nothing comes just the way you want it so you must be willing to work on it yourself. Most people can’t see things that way.

I have a good lesson in life I’ve learned over time, and it’s this: if you want things done your way want to get the best enjoyment, you’ll have to do it or customize it yourself. Almost nothing in life is perfect for you out of the box.

What does that mean? Essentially it means you need to understand that if you want the best sound, the best custom set-up and, or the coolest looking install, for example, you’ll have to customize yourself.

You will almost never find things in life that are perfect as they are by themselves.

Understanding this means you accept how you’ll have to put in some time, money, and effort to get what you want, but it’s the mindset that’s critical.

Most people just accept what they have and seem to shrug their shoulders – they can’t imagine that things could be made better or could be improved upon.

9. You’re a better planner and organizer

I’d like to think planning for a project goes without saying, but it’s not necessarily something people appreciate until they learned the hard way.

In reality, when you finally decide to begin working on a big project, it often turns out way different than expected. Some parts come up missing, you don’t have enough wire, you can’t find the right tools – and the list just goes on and on.

When you install your own car stereo system, you learn how much time, gas, money, and stress it can save you if you did a better job of planning ahead of time. You can’t possibly plan for everything, but you can definitely improve how things go.

Learning to 1) make a basic plan and 2) be organized and prepared are skills that are very valuable.

A small amount of effort upfront pays off greatly not just in your personal projects but in other areas of your life.

The importance of planning

By installing your own equipment you learn this and will gain another great skill you’ll use elsewhere.

For example, if you’re planning to install an amp and subwoofer, you’ll need to get together:

The amp
The amp wiring (including miscellaneous accessories)
A solution for how to mount it
A general plan for how you’ll route and connect the wiring
The right tools

Yeah, I know. Maybe it does seem ridiculous to point it out, but you’d be surprised at the number of people who don’t prepare for these tasks. I have seen (and learned the hard way) what can go wrong when you don’t plan or prepare well.

Sudden complications can bring your installation to a grinding halt and cost you days of delay and a lot of stress. Who wants to stop in the middle of installing that awesome new car stereo just because they don’t have the right parts or tools? When that happens it feels terrible!

Being organized and making a simple list is definitely smart. Once it’s become more of a habit and less of a chore, you’ll find yourself making checklists for your everyday life, too! You can now provide an accurate estimate of the amount of time a project will take – allowing you to foresee possible problems that might come up.

As a professional, it is expected of me to expect and prepare for certain complications.

10. Most importantly – it feels GREAT and it’s very rewarding!

Man, let me tell you, this is the most awesome feeling in the world – finally getting your project together and seeing and hearing the end result. It’s like a proud and warm feeling inside.

That’s a feeling very few people will ever experience – and it’s a shame. You don’t have to paint the Mona Lisa like Leonardo De Vinci did to get a very rewarding sense of accomplishment.

Even installing a small pair of tweeters does the same. Sure, maybe it’s on a smaller scale, but it still feels great! Driving down the road listening to your favorite music, sipping a drink out of your awesome new mug, and loving it!

Working on your own car audio system and enjoying the results is a fantastic feeling. Listening to & enjoying your favorite music with sound quality than ever before is great.

It’s almost indescribable!

In summary

Based on my own installation experience and personal accomplishments, I’ve listed 10 great reasons why you should install your own car stereo system.

Before giving up and paying someone else to install it for you, consider what I wrote. There’s nothing wrong with trying. Don’t be discouraged if you don’t know where to begin.

You can find lots of step-by-step guides on the internet, just like my post about how to install a car subwoofer and amplifier.

The DIY Car Amp Rack Guide – How To Build Your Own Car Amp Rack In One Day

September 16, 2020April 28, 2018

Making your own DIY car amp rack may seem like something that’s out of reach. Or maybe you don’t know where to begin and you’re worried you’ll have to pay someone else a lot of money to make one.

Here’s an affordable way to build a do it yourself (DIY) car amp rack in one day.

I still use these same car amp rack plans in not just customer vehicles but my own, too! I love how simple but professional looking they are. It’s pretty cool getting compliments on how great and pro-level it looks.

Now you can build your own car amp rack that looks great and is affordable, too!

Contents

Infographic – Basic amp rack how-to guide

Getting your tools & supplies ready – what to know first

Tools you’ll need

You’ll need a number of tools to do the job well:

Phillips screwdriver
Cordless drill + Phillips bit (not essential but highly recommended) or standard electric drill
Pliers – I recommend square-jaw, locking, or other types but needle nose can work, too
Scissors for cutting material + utility razor (optional)
Staple gun (optional)
1/8″ drill bit suitable for metal
Basic tape measure or measuring tape
Something to take notes with
Permanent marker

As you can see you won’t need many tools. That’s part of the reason this approach works well. I’m hoping to help you carry out this with as little money and hassle as possible.

If you can, borrow any tools you don’t have from others to save money and time.

For many basic items you can get great deals at stores like Harbor Freight Tools, Wal-Mart, or even the Dollar Tree $1 store. If you shop carefully things like pliers can be found for around $2 a pair.

A staple gun can be bought when you go shopping for the materials you need, but it’s completely optional. They can drive strong staples into wood unlike a standard stapler and they’re great for stapling fabric securely. You can pick up a staple gun for close to $15 or so.

Will I need a power saw?

Fortunately, most likely you won’t need a saw. In the sections that follow you’ll need to shop for wood, but if your city has a Home Depot or Lowe’s hardware store, the great news is that they offer free wood cutting when you buy wood! And that’s also that much less work you have to do, too.

Parts to pick up before installation time

Metal mounting brackets (straps)

Car stereo metal mounting straps are fantastic for installation and will make building & installing an amp rack much easier. You can buy them finished in black, which I highly recommend, or with the standard metal finish. 9″ straps are fine in most cases, and you can buy a 5 pack or similar to save money. You’ll need at least 4 straps if using these.

One item I highly recommend is excellent metal mounting straps like these Metra BS9BK. They’re FANTASTIC for many types of car audio installations and are used very often by professional installers.

They’re strong enough for mounting an amp rack securely but are flexible enough to bend into odd shapes for more challenging installations.

I’ve used these for years to install almost anything in places you would think were impossible to put a sound system in!

It may or may not be possible to find some at your local stereo shop or electronics store that carries car stereo accessories, so you really need to check beforehand. Expect to pay $10 or less including shipping, although some can be found for around $7-8 for 2-4 straps.

Note: Another option is to use standard metal brackets like “mending plates” that are stocked at local hardware stores. I’ll explain more about the pros and cons of those later.

Speaker carpet vs. fabric

Black automotive-grade speaker carpet (left) is great looking and durable. There’s no backing on it so it can be stretched and cut easily. However, you may have to order it, and it may cost more than regular fabrics like black felt (right) that you can find locally.

To finish your amp rack you’ll also need a good-looking & durable material to cover it with.

Backless automotive carpet (often call speaker box carpet) tends to be very durable and offers a great look. Colors like charcoal, dark gray, or mixed black colors are often available.

Otherwise, I recommend buying a good black fabric like felt. You can expect to spend $10 or so in that case, as it’s usually sold in 1 or 1/2 yards (1 yard = 36″). You may also find a different soft black cloth on sale while you’re there.

Suitable fabric can be bought often for a discount price locally from arts & crafts stores like Joann, Michael’s, and sometimes Wal-Mart.

Measuring installation space

Get basic measurements for the best place you find for installing an amp rack in your vehicle. Think in terms of fitting a large rectangle there, even if you don’t think a flat amp rack can be mounted on some areas that are curved or stick out. Don’t stress if there’s not a perfectly flat area available – that’s actually very common! We’ll cover dealing with curved or unusual surfaces later.

Begin by using your tape measure to find out how much space you have in your trunk (or cargo area, depending on your vehicle) where you can install a rectangular board.

The measurements don’t have to be super-exact but a close estimate of how much space you have available horizontally and from top to bottom. For example, measure from several inches below the rear deck of your trunk to about 1″ to the base of the trunk near the interior carpet or trim.

That should give you a good estimate of what to work with. Be sure to save in your notes the measurements you took.

Don’t forget the weight

As an assembled amp rack will be heavy so you need to be sure to measure the available space as if the assembled rack is resting on its bottom in the vehicle. T

Check for good places to mount the amp rack brackets

While you’re measuring, look for good places where you can fasten your mounting brackets when the amp rack is installed in the car.

Look for a section of the car’s metal body where:

It’s safe to drill a hole without damaging anything underneath (always check!)
The metal is sufficiently thick & strong enough.

In most vehicles, the sheet metal in the rear is the same thickness throughout, so that’s usually not a problem.

Planning your amp rack setup

Planning your amp rack setup: place your amps on your floor and use your tape measure to estimate how much room your amps will need for clearance with wiring & cables installed. Also allow some spacing beside the amplifiers (the top and bottom of the amp rack).

Put your amplifiers on the floor and line them up as you’d like them to be placed on your amp rack. Place them next to each other with enough space so that there’s enough clearance to connect power wire, speaker wire, and RCA cables as needed.

If you’re tight on space you may need to consider using 90-degree bends for the wiring and right-angle adapters for the RCA connections.

When you’ve got the amplifiers lined up with enough space, measure a rectangle with enough clearance before and after the ends of the amps and a little extra clearance from the top to bottom.

Keep enough space!

Don’t make the amp rack spacing too small – you don’t want it right up against the sides of the amplifiers.

You’ll want to allow 2″ space or more at the sides of the amps if your installation measurements earlier will allow for it.

Write down the measurements in your notes as you did earlier.

Your shopping list and tips

You’ll be able to buy nearly everything you’ll need in only a few trips, but planning ahead as much as possible will save money and keep the problems to a minimum.

Give yourself enough time during the day for running around town and dealing with traffic to get what you need. Start shopping early in the day or the before if you’d like to build & install your amp rack the same day.

I hate being stressed out and running into problems right in the middle of a project or installation, so take my advice and try to get what you need the day before if you can.

Be organized and write down or print out what you need before you go. Don’t be sloppy and cost yourself extra time, gas, and stress.

Materials list

Hardware:

With your notes, head out to your local hardware store for the following:

Spray adhesive
Metal brackets (if not using metal car stereo straps)
#8 Phillips head machine screws, 4-pack or similar
#8 washers, small package
#8 machine screw nuts
3/8″ pan head Phillips screws
3/8″ length self-tapping screws
Wooden board

3M Super 77 is a great spray adhesive. There are lower-cost adhesives available but in my experience, I’ve had problems with the adhesive being weak and the fabric can come off by itself. Super 77 usually costs close to $10.

I recommend this one for car audio projects. It provides a strong adhesive and it’s reliable unlike cheaper brands that fail or aren’t very strong. You do have to be careful to not get it on you or nearby objects when using it, however. You can 3M Super 77 Multipurpose Permanent Spray Adhesive Glue, Paper, Cardboard, Fabric, Plastic,...

Choosing a wooden board

You’ll need a wooden board like this to build your amp rack. In the building materials section of your hardware store you’ll find wooden boards that are about 1/2″ or so thick and usually come in lengths of 4 ft. or longer. Pine is the cheapest but is more prone to warping and is weaker than others, but it’s suitable if you’re on a budget. It’s not suitable for installations exposed to a lot of humidity or moisture.

Using the measurements you wrote down from planning your amp rack, buy a wooden board that’s the same or close width to what you measured. To save costs buy one with length closes to your length measurements for what you need.

Quick tip: To save time and hassle, try buying your supplies at Home Depot or Lowe’s if you have one nearby. They offer free wood cutting to customers in the building supply section, so you’ll be able to tell them the length you need and they’ll do it for you.

More about metal brackets

Mending plates and other metal brackets are sold in pairs or 4 packs for smaller sizes and individually or in pairs for the larger sizes.

As I mentioned earlier, if you’re not able to use (or buy) car stereo metal installation straps you might be able to get but with hardware store brackets.

Right-angle brackets and “mending plate” (flat) brackets are also helpful for assembling and installing your amp rack.

Unlike metal car stereo straps, mending plates are nearly impossible to bend. They’re very strong but the drawback is that they’re fixed in length and not suitable for curved or more difficult installation needs.

You can usually find them sold in packs of 2, 4, or 8 for a few dollars.

Fasteners

Self-tapping screws (left) make mounting brackets fast and easy if you have a cordless drill as they simultaneous drill a hole then screw into metal quickly. Regular pan-head screws (right) will work well for mounting your amps to the amp rack. Use #8 machine screws (below) and nuts with washers to fasten your mounting brackets to the rack securely. They’re better suited for this than using only pan head screws.

Machine screws work with nuts and washers. They’re great for attaching brackets to your amp rack board, for example. They come in packs with standard sizes. I normally use #8 machine screws for many projects.

Fabric/covering material

If you’re going to get fabric locally instead of ordering it, arts & crafts stores are where I’ve often found discounted black material I could use for building amp racks.

Ideally, try to get a material with a dark color that’s durable and stretchy. I recommend a strong felt material or similar basic fabric.

Be sure to ask the cashier or attendant for suggestions about what you’re planning to build. Honestly, sometimes they’re helpful and other times they’re fairly clueless when it comes to good suggestions, but at least if something is on sale they’ll normally let you know.

If you’re planning to buy fabric instead of backless speaker box carpet, try checking the clearance tables while you’re shopping. I’ve often gotten fabrics at a MUCH lower price by doing this. There’s a good chance you’ll find a deal! Black fabric is very common and should be easy to find.

Remember that fabric is normally sold in units of 1 yard (36″ in length) or 1/2 yard (18″ length) in many craft stores.

You’ll need to do just a bit of math to figure out how much you need. Try not to get exactly the same length as your measurements.

I strongly recommend you have a bit extra if it’s your first time working on a project involving fabric and a spray adhesive. Typically I use about 2 yards of material and have a small amount left over when I’m done.

The height is nearly always much more than I need.

Making your amp rack – covering the board

After having your board cut to the length you need and planned for its time to put the finishing touch on it and assemble the amp rack.

Now that the board is a length that will fit into the installation space you have and that will allow enough space for your amp wiring & cables its time to cover it and make it look nice.

Find a good place to work where glue overspray won’t get on surrounding things indoors.

Place your board on the fabric and trim it to a good size, allowing several inches past the board of extra fabric on each side. I recommend allowing at least 6″ or so, which you’ll trim as needed.

Follow the rest of the steps in the diagram below.

Spray adhesive is very hard, if not impossible, to remove from your clothes and other materials so be very careful when using it. Use light, consistent spraying strokes. You don’t need to use a tremendous amount, but it does help to spray some on both the wood surface as well as the fabric you want to glue.

Using adhesive on both surfaces gives an even stronger bond. After spraying, waiting about 15-30 seconds and lightly touch the glue to see if it is tacky.

If so, tightly pull the fabric over and onto the wood area you sprayed. Then rub the fabric firmly with your palm for a few moments to make sure there’s good adhesion.

The fabric, no matter how well you tried to trim it, will likely overlap each other a lot. If you have a utility knife with a sharp blade that makes trimming a bit easier than using scissors.

Otherwise, slightly pull up edges where needed, cut with the scissors, and place it back into place.

You may need to reuse the adhesive spray on some parts. It’s a bit tough to do in small sections but by quickly and gently tapping the spray nozzle you should eventually get the hang of it.

Putting it all together

Now that you have the board covered it’s time to assemble it.

Drill a 1/8″ (or close) hole in each corner and mount a bracket/strap to each hole using a #8 machine screw + washer on the top (amp) side and on the backside use a washer and nut.

Tighten securely using pliers while keeping the machine screw from turning by holding a screwdriver.

Once all the mounting brackets are in place and facing the direction you need them to be, place the amps on the board and mount them using the measurements for spacing you wrote down earlier.

Be sure to leave enough length for the mounting brackets to reach the mounting points in your vehicle that you found during the first steps.

Excess bracket length can remain hidden behind the amp rack for less hassle when installing and for a neater appearance.

Installation – Mounting your rack

Ok, it’s time for the “fun” part! Carefully put your assembled amp rack in the vehicle and begin the “fitting” process.

If you’re mounting it vertically, put as much of the weight at bottom of the vehicle and begin seeing how your brackets will fit to try to get the brackets parallel to sheet metal for mounting.

If you’re using bendable metal straps as I recommended, bend those such that they will allow the amp rack to rest on the straps when in the car.

When that’s done, hold the amp rack in place and begin doing the same for the top. Keep using trial and error until you have a pretty good way for the amp rack to rest securely in the vehicle and to have enough attachment points for the mounting brackets.

Once that’s finished, begin trying to use your cordless drill to drive the self-tapping screws through the brackets and into the body.

I highly recommend using washers on the screws to fit well over the bracket’s hole and keep the fit very tight. This is especially important in a moving vehicle as they vibrate quite a bit and screws may loosen over time.

If you’re having difficulty doing this step while holding the amp rack in place, then use a permanent marker to mark the bracket holes where you’d like to use the screw, remove the amp rack, then drill the screw holes alone.

Then you can return to place the amplifier rack and more easily fasten the screws either with the cordless drill & bit or with a screwdriver.

Taking your amp rack to the next level…on the cheap!

Want something truly unique? You can use an LED light kit (often below $20) to add accent lighting to your cool amp rack. It’s pretty simple to do and will really get compliments from anyone who sees it.

A fantastic idea is adding accent lighting to your sweet-looking new car amp rack.

Using an awesome low-cost LED lighting kit like this one under $20 mounted above the amp rack in order to glow down on them will give an incredible look and really make it shine.

I’ve done this several times (including putting an acrylic clear window in front) and people gave me lots of compliments!

Neon and LED lighting systems are lightweight so you should be able to install them using only zip ties. Overall, it’s usually very easy and it can be done on a budget if you shop carefully.

Wiring is simple as many kits can be powered by +12V directly and wired to a relay to switch on and off with your car stereo using the remote-on wire.

DIY car amp rack plans cost estimate

Here’s a good estimate of what you can expect to pay for all materials (not counting tools) depending on where you shop. Don’t forget to check your amplifier packages for screws you can use, as some include a 4-piece set.

Item Est.	Cost
Wood	$10.00
Fasteners	6.50
Metal straps	9.50
Fabric	12.00
Spray glue	9.75
TOTAL:	$47.75

Additional info

Take my guide and give it a try! It feels awesome when you get it all together and see how great it looks. Your friends and other people you meet will give you compliments and that’s a fantastic feeling, believe me.

Thinking about adding LED lighting? Be sure to check out my detailed car interior LED light kit installation guide.

If you’re still deciding what to do about buying amps and you’re on a budget, have a look at my great budget amplifier guide here.

How To Bridge An Amp – Info, Guide, and Diagrams

September 16, 2020November 18, 2017

Image showing a car amp during installation

Bridging an amplifier can seem like a strange and almost “magical” concept. If you need help figuring out how to bridge an amp, you’re in the right place!

Let me help you understand what bridging is, why it matters, and how to bridge your amp.

It’s easy to make mistakes and – unfortunately – you can permanently damage your amplifier and even your speakers. Don’t worry though as I’ll cover what you need to know before that happens.

Contents

What is car amp bridging?

A 4 channel car amplifier bridged to 2 channels. This is a very common wiring use of a 4 channel amp for situations in which you’d like more power available and don’t need 4 separate amplifier channels.

Bridging is a special feature in car amplifiers which lets you get the maximum amount of power they can produce by using a built-in channel-sharing design.

It means using 2 amplifier channels working together to drive a speaker or a set of speakers with by using the power that normally is split between 2 separate amplifier channels.

It’s actually a pretty cool subject, and very useful! For example, I have owned many car amplifiers and normally used 4 or 5-channel amplifiers. I used 2 channels, in bridged mode to drive a single subwoofer or a pair of subwoofers in the trunk.

This meant having more power available at my disposal and more flexibility even if I changed my speaker setup later.

How does an amp make more power when bridged?

Internal view of a car amplifier. The output sections have one channel per pair designed to provide the bridging option when needed. In normal use with 1 speaker per channel, you won’t notice a difference as they’re wired normally and have separate audio signals.

This is actually a very cool and fascinating subject. If we do the math, we’ll discover something very interesting!

How about we take a real-life example and I’ll show you exactly how this works?

Example #1

A 2 x 50 watts/channel amplifier is connected to two 4 ohm speakers. With some math, we would find out that our little example amplifier puts out 14.14 volts when it reaches 50W into a 4 ohm speaker.

We can find the power using this formula: Power (W) = (Volts x Volts) / Ohms, or P = V^2 / R.

So (14.14)^2/4 = 50W for each amplifier channel.

Example #2

We connect the same 2 x 50 watts/channel amplifier in bridged mode across one 4 ohm subwoofer.

The voltage available across amp’s bridged channels working together in a push-pull fashion is:

Total voltage: 2 x 14.14V = 28.28V

Power across the 4 ohm subwoofer: V x V / R = (28.28)*(28.28) / 4 = 800 / 4 = 400W in bridged mode. (Assuming the amp is designed to support that much power output)

So by bridging the amplifier in this example, we can get close to 400W – yes 4 TIMES – the normal available power when in bridged mode, depending on the connected speaker.

Note: It’s important to remember that we’re assuming a few things, like that our amplifier is rated to provide that much power.

Not all amps can deliver that much – it depends on their limitations and how they’re designed.

Also, note that in this mode each channel is handling several times the electrical current it had to before. Therefore it will draw more power from the car battery.

How do car amps make this possible?

The reason this is possible is that today’s car amps have a design in which one of each 2 audio channels is actually inverted (you can also say 180 degrees out of phase) but is normally connected at the output in a non-inverted fashion.

You’re normally not aware of this as it has no effect on the end user.

This means that in bridge mode the bridge connection is made so that the amp channels have a difference of the available voltage at each output. This voltage difference is twice that of one channel alone.

Connecting to a bridgeable amplifier – how to bridge an amplifier

Bridgeable amplifiers normally have the terminals labelled accordingly. In that case, bridging is easy to do as long as you observe speaker impedance (Ohm rating) warnings from the manufacturer

The good news is that many car amplifiers sold today can be bridged. Note that some (especially smaller, lower-cost products) may not have the feature built in so it’s very important check before buying one.

Never assume you can bridge an amp.

To bridge the amp, connect the subwoofer or bridged speaker positive (+) terminal to the positive amplifier bridged terminal label, and the speaker negative (-) terminal to the negative bridged amplifier terminal also.

Use good speakers & reliable connections

It’s important to use a good reliable connection for speakers. Car and trucks are subject to vibration and lots of movement, so a poor connection can cause problems over time.

Since bridging means that much more power is now available to you speakers (more often than not this is used for subwoofers) it’s best to use a quality speaker wire and make secure, tight connections on both ends.

Before doing so, verify that you have met the required minimum impedance (speaker load, in Ohms) as specified on your amplifier or its instruction manual.

For today’s car amplifiers this is a minimum of 2 ohms when bridged, usually. Some do support less or need 4 ohms but for best results and to make sure you are setting up your system to the best of your requirements it pays to be sure.

Quick Tip: some older model amps and a few modern amplifiers have a “bridge mode” switch that must be used or may require only one RCA audio connection is made. Always make sure you’ve checked!

Don’t forget the crossover

As long as you have the correct speaker impedance in use (see my additional info below) you should be ready to use your bridged amplifier! Note: it may be necessary to set the built-in low-pass crossover also, if available. I’ll cover more about that below too.

Note! You must be sure your amplifier can handle a bridged connection. Not all amplifiers are designed to do so, and most home stereo receivers and home theater amplifiers cannot support a bridged connection.

ALWAYS VERIFY BEFORE ATTEMPTING TO BRIDGE AN AMPLIFIER!

See my additional information below if your amplifier doesn’t support this by design

Understanding the minimum speaker load (Ohm rating)

Shown: An example of measuring the speaker impedance (total resistance) in Ohms for a speaker’s voice coil.

Your amplifier should state in the owner’s manual the minimum required “impedance” (the resistance load a speaker has) for use. This includes both for normal stereo usage as well as a rating for bridge mode too.

If you cannot find the documentation anywhere a good rule of thumb for car amplifiers is to use 4 ohms.

Often you’ll see the phrase “stable to 2 ohms” or something similar to describe what the amplifier can handle.

Here are the basic rules for correctly connecting speakers in bridged mode:

You can connect a SINGLE speaker of the required minimum impedance or higher
You can connect MULTIPLE speakers if the total adds up to the required minimum impedance or more (see diagram)
Dual-voice coil speakers can be used if they can be wired to give the correct amount

Bridging examples

For an amp that requires a 4 ohm load minimum when bridged use:

One 4 ohm subwoofer
TWO 8 ohm subwoofers wired in parallel ( 8 / 2 = 4)
ONE dual 8 ohm voice coil subwoofer wired in parallel (gives 4 ohms)
TWO 2 ohm woofers connected in series (2 + 2 = 4 ohms)

For an amp that requires a 2 ohm load minimum when bridged use:

One 2 ohm subwoofer
TWO 4 ohm subwoofers wired in parallel ( 4 / 2 = 2)
ONE dual 4 ohm voice coil subwoofer wired in parallel (gives 2 ohms)
FOUR 8 ohm woofer wired in parallel (8 / 4 = 2)

Amp bridging wiring diagram

Here’s a diagram showing the most common wiring setups most people will use for typical amplifiers.

(Click to enlarge or click here to get the Adobe .pdf file you can download and print)

Quick tip: For most systems, if using 2 speakers, connect them in parallel to ensure each receives the maximum amplifier power vs. connecting the same speakers in parallel.

Setting the crossovers on a bridged amp

Close up of a modern typical car amp with built-in crossover features. This allows high-pass, full-range, or low-pass use with adjustable sound range controls in this case.

For most bridged amp situations where the amp is connected to a subwoofer or set of subwoofers, this is what I recommend:

Set the crossover switch to low-pass filter (LPF) or similar on your amplifier
Adjust the LPF dial, if available, to the maximum level
Play music contain bass you’d normally listen to
Begin turning the LPF dial down until almost no voice or upper-range music is heard (note: for reference, a good rule of thumb is 80 Hz or lower in case you’re able to know the actual cut off frequency of your amp)
Adjust the gain if more higher-volume power is needed when the volume dial of your stereo is turned up

Can you bridge an amp without bridging built in?

Amplifiers without the feature built in are unfortunately difficult to bridge, but it can be done. Several solutions exist:

Build your own bridging module (read more here)
Find a bridging module (these are likely very old and hard to find, but may be possible on eBay)
Use an electronic crossover with adjustable phase (0-180 degree control) for each channel and set 1 of the 2 to be 180 degrees out of phase

Unfortunately, unless you’re a hobbyist and are good with electronics (and have the right tools and parts), ideas #1 & #2 aren’t very practical.

It’s much easier to buy an older electronic crossover or an inexpensive crossover that has a bridging or mono feature provided.

Tri-mode capable amplifiers

Example of wiring speakers with a tri-mode capable amplifier.

Amps that have a “tri-mode” or “tri-bridgeable” feature are the same as other bridgeable amplifiers but can also be in bridged mode and wired to 2 speakers at the same time. This makes it possible to keep a regular stereo pair of speakers connected while the amp is bridged and connected to a woofer or other speaker.

This is normally not used by most people, however, it does have some benefits as well as drawbacks.

Pro: This allows a 2-channel amp to connect to 3 or more speakers
Con: for woofer use on the bridged output, an external passive crossover is needed – these are often large, heavy, and expensive for low-frequency speakers like subwoofers

Summary

Bridging your amp should be a fun, easy, and enjoyable way to get more power for your money. It’s a nice way to get system flexibility as well.

When it comes to amplifiers it’s important to have a good, solid wiring connection. Make your installation easy – check out this great post with the top recommended amp wiring kits for your money.

Questions, comments, or suggestions? I’d love to hear from you! Let me know in the comments below or you can reach me here.

The Speaker Wiring Diagram And Connection Guide – The Basics You Need To Know

September 16, 2020November 18, 2017

Image of home and car speakers to be connected

We all enjoy music and speakers make that possible – but it’s confusing if you’re not sure how to connect them the right way.

In this post, you’ll find clear and detailed speaker wiring diagrams that to help (and that you can print out if you like, too!).

I’ll go into detail about the right and wrong way to wire speakers and connect them properly to your stereo or amplifier. It’s actually pretty simple once you learn the basics.

Contents

Printable speaker wiring diagram

Click on the image to enlarge it or click here for the Adobe .pdf version you can download and print.

Speaker basics and speaker wiring explained

1. What is speaker impedance? (the “Ohms” rating)

Speakers, much like other electromechanical devices, all have an electrical resistance to the flow of electrical current, much like a standard resistor, a light bulb, or many common items you’re familiar with.

The difference is how they behave when music is present when they’re connected to a musical amplifier of some sort.

The resistance value comes from a long coil of wire inside each speaker called a voice coil. A voice coil is a coil of wire that, when placed inside a magnetic field, makes the speaker move and produce sound when driven by an amplifier.

Speakers contain a long wound loop of wire called a voice coil. Loops of wire have a property called inductance which affects a speaker’s resistance value depending on the frequency (sound range) being played.

As they have electrical properties that include inductance and capacitance, their “total resistance” can actually change with the music slightly. Because of this, there’s some extra math needed to figure out the total resistance.

The word used to describe this is called impedance.

Speaker impedance is just a more advanced way of finding the total resistance, and by tradition is measured in units called “Ohms.”

The good news is that you don’t have to worry too much about the details – it doesn’t matter for basic speaker use, and long as you understand the basic rules you’ll be fine!

2. Stereo and amplifier minimum impedance ratings

All amplifiers of any type – where it’s a car stereo amplifier, home stereo receiver, home theater amplifier, and so on, have a minimum Ohms (impedance) rating. It’s important that you pay attention and don’t exceed the minimum speaker impedance rating.

This is because as the impedance is lowered, the electrical current increases and the stereo has to do more work. This increases the amount of stress and heat it has to handle.

If your stereo is labeled by the manufacturer as being “8 ohm speaker compatible” or similar, that means connecting lower impedance speakers can cause excessive heat and possible damage very quickly.

For example, connecting a 4 ohm speaker to an amplifier that is labeled as working with 8 ohm speakers would mean it would have to produce double the electrical current to the speaker!

Image of the rear of a home stereo receiver/amplifier. The recommended speaker impedance ratings are usually listed above the speaker wire posts. A home stereo, for example, may often list 6-16 ohms as being ok for use.

Also, attempting to wire two 8 ohm speakers in parallel to an 8 ohm stereo would have the same effect. (Two 8 ohm speakers in parallel is equal to 4 ohms total that the amp will see)

I’ve seen many attempts by people who had friends who claimed they could “boost the power” or “get more power” by some claimed trick, but it doesn’t work. They ended up with a burned-out amplifier.

An amplifier can only handle so much heat and stress before it fails, so be sure to observe these rules. Be sure you wire speakers to meet the minimum Ohm rating you need.

Remember: don’t use a speaker impedance below the rating given by the manufacturer. Overheating or permanent damage can result. I’ve seen it happen!

3. What is speaker polarity?

Speakers are different than other devices in that they work using alternating current (AC) instead of direct current (DC). This is good news! It means you can’t harm your speakers in most cases by having the positive (“+”) and negative (“-“) wiring reversed.

Unfortunately, it gets just a little bit more complicated when we use more than 1 speaker.

Speak polarity and why you should match speaker connections

As I mentioned, speakers work by moving a cone back and forth in order to produce sound. If you wire 2 speakers in a stereo with different polarities (for example, one has positive and negative wired as labeled, and the 2nd speaker has the opposite) an interesting thing occurs: they’re out of phase and some sound cancels out.

The result is a strange and poor sounding stereo. In most cases, you’ll notice a lack of bass sound and it won’t sound pleasing to the ear as expected.

When speakers are wired the opposite of each other sound waves cancel out. When wired the same, sound waves add together for more sound.

Speakers that are wired differently sound poor because much of the sound is canceled out. Basically, it’s simply because sound waves from one speaker are moving in the opposite direction of the other speaker – and if they’re close to the same time and frequency range, often they cancel out.

This is why when 2 woofers are placed in a box and are wired in parallel but with opposite connections to each other, they are “out of phase” and have almost no bass! It’s because they are doing the opposite work rather than working together to produce more sound.

While one is moving up, the other is moving the opposite direction, and so on.

So the most important thing here to remember is to wire speakers consistently the same way as each other.

4. Wiring 2-way and 3-way speakers

2-way speakers, such as home stereo or car audio component speakers, are those which come as a pre-designed speaker set and use a crossover. The job of a crossover (also called a passive crossover, because it use basic capacitors and inductors rather than electronics) is to restrict the music production each speaker tries to produce.

For example, tweeters can’t reproduce bass frequencies (and can in fact be damaged by them) so a 2-way speaker crossover is used to prevent this. Similarly, a woofer can’t produce high pitch sounds well and is prevented from doing so.

Unlike standard separate speakers, 2-way and 3-way speakers that have a crossover can only be used in parallel and not in series.

This is because unlike separate speakers with no crossovers, in this case, many sounds will be filtered out. What this means is that little to no sound would be produced if another 2-way speaker is connected in series.

Therefore if you have a home stereo or car stereo in which 2-way speakers are used, you’ll have to add more 2-way speakers (if the total impedance can be supported by the amplifier) or add more amplifier channels for more sound.

5. Doubling the number of speakers or amount of power does not double the volume

In some cases, more speakers can be added to increase the amount of volume you can get or to place speakers in more rooms, more locations in your vehicle, and so on. You also may have wondered what would happen if you bought an amplifier with twice the power of your present one.

There’s one important thing to understand, however: having 2 or 3 speakers instead of one does not double or triple the sound. It increases a few decibels (dB) for each speaker added.

Doubling the power does not double the volume either.

This is because of how the human ear works and the physics of sound, along with how speakers work and how much volume they can produce for a given amount of power.

Generally speaking, the human ear will hear a very small amount of volume increase for each doubling of acoustic power: about 3 decibels (dB). For most people, the small amount of volume increase you notice when turning up a volume knob 1 notch is somewhere around 3dB.

Example volume produced by a typical speaker at different power levels:

1W = 89 dB
2W = 92 dB
4W = 95 dB
8W = 98 dB
16W = 101 dB
32W = 104 dB
64W = 107 dB
128W = 110 dB

So as you can see, doubling the amount of power you can drive a speaker at does not mean you’ll double the volume. It increases it a very small amount (as far as your ears are concerned).

You can also see from above that really cranking the volume takes a lot of power!

How to get more volume from speakers

The best ways to get more volume in most cases are:

Use more efficient speakers (speakers that produce a higher dB volume at 1W of power – higher is better)
Add more speakers if you have an amplifier that can support it
Use higher-power rated speakers and a larger power amplifier if a lot more volume is your goal

Most people need an amplifier that can produce enough volume to fill a room or vehicle and turn up the volume from time to time. I like to use 50W or higher per channel as a good rule of thumb when buying an amplifier.

How to read speaker positive and negative labels (+ and -)

Home stereo and car speakers normally often use a red or plus sign “+” to indicate the polarity for the speaker wiring terminals which you connect your wiring to.

Here are a few things to know there as well:

In some cases, a black dot or a red or black stripe is used to mark the positive terminal
If a speaker has terminals of 2 different sizes, the larger of the 2 is normally the positive one
For speakers with wire already attached, typically the brass or golden-colored wire is the positive one
For speakers with wire attached but the same colored wires, most have some small printing on the positive wire – be sure to check closely

Summary

Here I’ve provided you with a speaker diagram showing basic connections, I explained several important things you need to know about speakers and speaker wiring. Hopefully I’ve given you more understanding about how to connect speakers and get the most enjoyment out of your system.

Have questions, comments, or suggestions? Be sure to leave a comment below or send me a message.

Confused about tweeters? Here’s a helpful guide explaining what tweeters are and what they’re used for.

Interested in bridging your car amp? Find out how to bridge a car amp in this post.