How to Wire a 4 Channel Amp to 4 Speakers and a Sub: Explained

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In today’s world, building a custom sound system for your car without any prior experience is simpler than you might think. This is thanks to the wealth of information available on the internet and the guide that we’ve put together below! In this article, we’ll walk you through a detailed look at how to wire a 4 channel amp to 4 speakers and a sub

Before we start our guide, we will explain what each component of a car audio setup does, beginning with the speakers. These devices are meant to reproduce the frequency spectrum’s mid and high frequencies. They’re usually present in the form of woofers and speakers, or a combination of both in the same casing.

On the other hand, Subwoofers are specialized speakers solely designed to reproduce the low frequencies of the frequency spectrum. They are optional when you have a normal woofer, but when you add a sub to your car audio setup, the result will be a sound with much more presence in the low range, enhancing the bass.

Finally, the amplifier. As its name implies, it amplifies the line-level signal into one that the speakers can actually read and reproduce. It also delivers power to each component of the system. Whether it can be wired to 4 speakers and a sub or not depends on the design and impedance of the whole system.

Also Read:How Speakers Work

How to Wire a 4 Channel Amp to 4 Speakers and a Sub

Things To Know

Even though the process is fairly simple, there are a few simple terms you must know in order to ensure you connect compatible parts and don’t damage your audio system.

1. Minimum Impedance Rating

If you’ve done a little research about car audio systems in the past before, you’ve certainly come across the term minimum impedance rating. Simply put, the impedance rating refers to how much resistance the amplifier will have to the electrical current when connected to the speakers.

While the subject sounds a little complex, especially for beginners, you just have to keep in mind that your 4-channel amp has a minimum impedance to function properly. If the manual says the minimum impedance rating of the amp is 4 Ohms, then you must connect a speaker that has at least 4 Ohms of impedance to it.

If you, for example, connect a speaker with 2 Ohms of impedance to a 4 Ohm-amp, the result will not be nice, and you will damage both equipment, so pay extra attention to this specification.

2. Wiring Systems

As the name implies, wiring systems relate to how the speakers are connected to the amp. The best wiring system for your setup will depend on things such as the minimum impedance of your amp and speakers.

3. Bridging

Bridging is when two amp channels are combined to give you a higher output power. The voltage, in this case, will double.

4. Power Rating

The power rating of an amp is measured in watts and refers to how much power the equipment can provide to each speaker. This specification must be matched between the amp and the speakers.

5. Parallel Connection

When you connect your speakers in parallel to your amp, the impedance is split between the speakers.

6. Series Connection

When you connect your speakers in series to your amp, the impedance of the speakers will add up.

Should I Wire a 4 Channel Amp to 4 Speakers and a Sub? Pros & Cons

By now, you already know that it is totally possible to wire a 4-channel amp to 4 speakers and a sub, but is it the best solution for your particular use case? Well, since 4 channel amps are traditionally used with 4 speakers or 2 speakers and a sub, you will have to make a few compromises, but the result will still be great.

Below, we will list all of the pros and cons you may find in the process.


  • You will get a better sound without having to spend extra money buying another channel amp.
  • The bass response in your audio system will be much better with a sub than if you were to use 4 speakers only.
  • Depending on your device, the process is very simple.
  • You will have more flexibility in your sound.


  • You won’t be able to use your front-rear fader the way it is intended to be used.
  • If you have a channel amp that doesn’t allow bridging, the process will be a bit more complex and you will have to use resistors.
  • There will be less power available for each speaker.
  • You risk damaging your equipment if you don’t proceed with caution.

What Tools Will I Need for Wiring a 4 Channel Amp to 4 Speakers and a Sub?

Apart from the 4-channel amp, your speakers, and a sub, the list of materials you will need for the steps comes down to wires and resistors, with the latter depending on your particular device.

1. Amp Wiring Kit

If you’re doing this for the first time, you probably don’t have the necessary wires lying around in your home. In this case, we recommend buying an amp wiring kit. Here are some of the best options on the market:

– InstallGear 4 Gauge Complete Amp Kit Amplifier Installation Wiring Wire

InstallGear 4 Gauge Amp Kit - Amp Kit with Amplifier Installation Wiring True Spec and Soft Touch Wire - 4 Gauge Wire - Amp Wiring Kit 4 Gauge - Sub Wiring Kit - Amp Wire Kit

Check Price on Amazon

This amp wiring kit from InstallGear comes with 4 gauge wires and all of the tools you will need to connect your amp to your speakers, including some extras. For a price as low as $27.99, it is worth getting one, in our opinion, since it will save you a lot of time in the process.

This Kit Includes:

  • 17ft Red Soft Touch 4 Gauge CCA Power Cable
  • 3ft Black Soft Touch 4 Gauge CCA Ground Cable
  • 17ft Soft Touch 2-Channel RCA Cable
  • 17ft Soft Touch CCA Speaker Wire
  • ANL Fuse Holder with 100A Fuse

2. Optional: Resistors

Depending on your system, you will need to install resistors on your connections. This is the case if you have, for example, a 4-channel amp that is rated for 4 Ohms stereo. In that case, the process will be a bit more complex, but the use of resistors is needed in order to keep the speakers’ impedance at 4 Ohms.

If you’re unsure whether you will need the component, we recommend taking a look at the steps below since we explain the 3 different most popular wiring systems.

Also Read:- Best Equalizer Settings for Car

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Connecting a 4 Channel Amplifier to 4 Speakers and a Subwoofer – Step by Step

Below, we will explain step by step how to wire a 4-channel amp to 4 speakers and a sub. Make sure to follow each step carefully and decide which is the best configuration for your particular use case.

Step 1: Make Sure your Amp and Speakers are Compatible Before Proceeding

If your speakers don’t have any label stating their resistance, you must use a multimeter to find out. The process is easily done by holding the multimeter probes at your speaker’s terminals. The result will be in Ohms.

If you don’t have a multimeter, you can always check your speaker’s manual or look up on the internet for information.

Step 2: Define your Wiring System and Wire the Components Together

There are many wiring systems you can create depending on your setup, but for this article’s sake, we will cover the 3 most basic ones that are guaranteed to work.

Each wiring system will attend channel amps and speakers with different configurations, as you will learn below.

– System 1 – 2 Ohms Stereo & 4 Ohms Bridged Channel Amp

In this system, you must wire 2 speakers on each front channel (L & R). Then, you can create a bridge connection for the sub by wiring its negative on the right, and it’s positive on the left.

This system is useful if you have a channel amp rated for 2 Ohms stereo and 4 Ohms bridged.

– System 2 – 2 Ohms Stereo & 2 Ohms Bridged Channel Amp

In this system, the procedure is similar for the front channel: you can wire 2 speakers to each channel (L & R). However, if your amp has a 2 Ohms bridged configuration, you have more possibilities: you can use either a single 4 Ohms sub or a pair of them, for example.

This system is the best if you have a channel amp rated for 2 Ohms stereo and 2 Ohms Bridged.

– System 3 – 4 Ohms Stereo Channel Amp

This system is a little bit more complex. Basically, you need to install power resistors of 4 Ohms in order to maintain this resistance. These resistors are installed between the positive wiring on each of the speakers. The sub is wired bridged as usual on the back channel.

This is the best system if you have a channel amp that is rated for a minimum load of 4 Ohms.

– Which Wiring System is the Best?

There’s no short answer to this question. As you can see, the best system will depend on your channel amp’s configuration, so you must pay attention to the device’s minimum impedance rating and how much power it can take.

If your channel amp allows, the easiest and most effective system for most cases is system 1 since you won’t have to install any kind of resistors, and is a simple solution for most people looking to wire a 4-channel amp to 4 speakers and a sub.

Step 3: Test the System

With everything in place, you can test the system. Make sure everything is connected properly before turning your channel amp to avoid any problems.

Also Read:- Subwoofers With High-Level Inputs (Reviews)

Extra: Will I Need a Crossover when Wiring a 4 Channel Amp to 4 Speakers and a Sub?

Most modern 4-channel amps feature a built-in crossover which you can use in this case in order to achieve a better sound so that you won’t need one in most cases. A crossover divides the audio signal based on the frequency spectrum and sends them to each corresponding device on your audio system.

For example, we want the sub to produce low frequencies only, so the crossover will be responsible for applying a low pass filter (usually at 80Hz) on the audio signal that gets sent to the driver.

On the other hand, the speakers will be responsible for reproducing frequencies in the middle and at the higher end of the frequency spectrum. The crossover will, in that case, apply a high-pass filter to the audio signal sent to the drivers.

Check out our article on ‘How to Wire Two Dual 4 Ohm Subs Down to 2 Ohms?’

Frequently Asked Questions

1. Can I Run 4 Speakers and a Sub on a 4 Channel Amp?

Yes. Even though 4 channel amps are traditionally meant to be used with 4 speakers only or 2 speakers and a sub, this is totally possible as we’ve seen in the article.

2. Can I Connect 4 Speakers and My Subwoofer to a 2 Channel Amplifier?

It is not possible to connect 4 speakers and a subwoofer to a 2 channel amplifier; however, you can still connect 4 speakers to it, depending on its minimum impedance rating. The process is very similar to the one we depicted in our article when we talked about system 1. Still, you must ensure that your 2-channel amplifier is compatible with your 4 speakers.

3. How Many Speakers Can You Run on a 4 Channel Amp?

With a 4-channel amp, you can run a total of 8 speakers or 4 speakers and a sub, as we discussed in the article.

4. How Do You Wire a 4-Channel Amp to 6 Speakers?

You can connect 6 speakers to a 4-channel amp just fine. The simplest way to do this is to connect 2 speakers on 1 channel and the remaining 4 on 2 channels. As always, make sure that your amp is compatible with your speaker set.

5. How Many Channels Do I Need for 4 Speakers and a Sub?

You will need an amp that has at least 4 channels. For example, the methods depicted in the article won’t work with a 2-channel amp.

6. Can You Run a Sub and Speakers Out of the Same Amp?

It depends on whether you have an active or passive sub. You won’t need an amp solely for the subwoofer if you have an active sub. However, if you have a passive device, you might need an extra amplifier. This will depend on how much power your channel amp can provide.

7. Can I Connect 4 Speakers and My Subwoofer to a 2 Channel Amplifier?

Connecting 4 speakers and a sub to a 2-channel amplifier is not the best solution since, while it may end up working, most 2-channel amps can only provide so much power. With 4 speakers and a sub connected in series or parallel, the power will be split between all of the devices, and the result won’t be that great with a 2-channel amplifier.

8. How Many RCA Cables Will I Need for my 4 Channel Amp?

For a 4-channel amp, you will only need two RCA cables, each for each side’s channel.

To Top


As you can see, connecting a 4 channel amp to 4 speakers and a sub isn’t a complex task in itself. The crucial thing to keep in mind is that you should ensure your amp is compatible with your speakers and sub before proceeding.

As discussed in the article, the most important specification is the minimum impedance rating of your amp compared to your speakers. If you have a 4-channel amp with a minimum impedance rating of 2 Ohms, for example, you should only use speakers that have an impedance of 2 Ohms or more to avoid any risk of damaging your devices.

Another thing that you must look up in your amplifier’s manual is the instructions for bridging. Different amps have different bridging wiring instructions so there’s no universal answer on how it should be done.

Last but not least, keep in mind that this guide is only for wiring a 4-channel amp to 4 speakers and a sub. If your setup is any different than this (a 2-channel amp and 4 speakers, for example), we recommend looking up the exact instructions on how to proceed in your particular case.

We hope this article was helpful. Be sure to research extensively before trying the steps we discussed and feel free to contact us if you have any questions!