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How To Wire A 4 Channel Amp: 5-Step Guide For Beginners

Last Updated on: April 10, 2024

Four-channel amplifiers are now a crucial component of stereo systems.


The four-channel amplifier must be chosen carefully if the goal is to have a high-quality sound system in your car’s front and rear speakers.

Don’t worry, this article is not just about how to wire a 4 channel amp.

If you’re unsure about whether to get a four-channel amplifier or a two-channel amplifier, or you may be hesitant to connect a four-channel amplifier to four speakers and a subwoofer, you’re in the right place. 

It is simple to wire, so let’s try it out and see how it goes. 

What A 4-Channel Amp Is

4 channel amp

A 4-channel automobile amplifier’s function may seem clear at first, but there is more to know and they differ from 2-channel amps in several fascinating (and beneficial) ways.

The use of a single 4-channel amp as opposed to two stereo ones to drive your front and rear speakers has a few advantages.

A stereo amplifier having two additional channels built-in to boost (amplify) weak input signals to a higher voltage signal is referred to as a four-channel amplifier. 

To move the speaker cone and generate sound, this drives the speaker’s voice coils.

Compared to individual amplifiers, 4-channel amplifiers integrate more channels into a smaller, more efficient design.

Additionally, they provide extra flexibility because the majority of them may be set up for “bridged” operation, which can provide more power when all four channels are not required.

Modern 4-channel amps are smaller, more technologically advanced, and have better sound than older models. 

The Alpine MRV-F300 50W x 4 model is a great example. It runs incredibly cool thanks to Class D technology and is tiny enough to fit under a vehicle or truck seat. Nicely done!

A Quick Guide On How To Wire A 4-Channel Amp

car amplifier

1. Plan For Success

Establish the sort of system you have and the parts you will require. 

An original stereo? Perhaps a line-level adaptor is required. A third-party stereo? Verify the signal source’s RCA cables are present since they’re the pioneers of the head unit.

Before beginning, make a thorough inventory of the components and add-ons you’ll require. Always account for the necessary connectors, tools, and wire length.

2. Shop For The Tools Needed

Buy premium wire that is true to wire gauge and quality with care. 

A 4x50W RMS amp (or more) with integrated crossovers is what I advise, as well as the amp wiring kit.

Avoid unproven wire brands of wires and amp wiring kits since they are frequently frauds (undersized wire, poor quality).

3. Connect The Speaker Wires

Connect the line-level converter to the speaker wire (preferably behind the head unit) or the speakers themselves for speaker-level outputs. 

You may also tap off the wiring and feed it to the speaker-level inputs of the amplifier. 

Run cords back to the amp inputs for the RCA inputs of the RCA cable. Roll up the wire. Connect the remote-on wire and amp power cable. make sure the amp is grounded properly for clean metal.

4. Set Up Your Sound

Use the amp’s high-pass crossovers to eliminate bass that causes distortion (50-60Hz is good). 

To get adequate loudness while minimizing amp noise or hiss, adjust the gain setting.

Setting the amplifier at the stereo’s maximum volume of 2/3 is a decent rule of thumb. Next, adjust the gain as necessary.

5. Test And Enjoy

Test your system’s sound quality using a well-known, high-quality test track. Adjust gain as necessary. Check for distortion when listening to bass-heavy music on the speakers. 

If necessary, adjust the crossovers, EQ, or bass boost. Enjoy!

Factors To Consider

You must search for the MIR if you want an amplifier to be connected safely and securely to your car’s speakers or audio system. 

MIR, or minimum impedance rating, is the abbreviation. It frequently appears on the amplifier. Therefore, attempt to utilize the minimum speaker load the amplifier can support.

The sound system in your car may experience many electrical risks if you connect a speaker with a high load. So, make sure to use one aligned with the minimum speaker load.

The increased power won’t be able to support the amplifier, which might eventually overheat and explode.

Minimum Load Of Speakers

The sound systems in automobiles are not very sophisticated or robust.

Therefore, the maximum load that a stereo device may have on a channel in a car is 2 ohms. 

In the case of bridged electrical wiring, it can support up to 4 ohms.

Types of Connection

Using speakers, connections can be created in one of two ways:

1. Parallel Connection

Each speaker connected in parallel receives the same amount of voltage from the amplifier. The speakers’ impedance, however, is split across the two speakers.

2. Series Connection

The power generated by the amplifier in this setup is split between the two speakers. The two speakers’ combined impedance is higher, however.

Therefore, you must make both parallel and series connections to a 4-channel amplifier to connect 4 speakers and a subwoofer securely.

Types Of 4 Channel Amp Systems

Three sorts of systems are often included in some car audio installations.

1. System 1

Using two speakers in parallel will result in an impedance of two speakers times two plus one connected subwoofer. You receive 4 ohms at the back-end channels in this. It is a system that is highly suggested for use.

2. System 2

Using 2 speakers in parallel to create an impedance of 2 ohms x 2 + 1 connected subwoofer to create an impedance of 2 or 4 ohms at the other end channels. It is comparatively less frequent.

3. System 3

Using two speakers in parallel will result in a speaker impedance of four ohms per channel plus one connected subwoofer.

Bridging And Its Benefits

bridging amplifiers

In wiring your amplifier, starting with bridging is necessary to ensure quality.

The mono-mode is yet another name for bridging. The amplifier already has this capability. As a result of the connection of two channels, it allows you to use more power. 

Using a single-speaker channel does not make this amplified power enjoyable.

A push-pull situation exists inside the amplifier in this bridge. The entire configuration process is automated. 

The two channels’ signals are in opposition to one another. Right, and left speakers make up the setup’s two channels.

The built-in bridging capability is advantageous for those who enjoy a high-end, metallic bass. 

You may wire powerful speakers and subwoofers in your automobile radio system with the use of bridging such as a mono-sub amp with a car radio system.

Benefits Of Amplifiers

Amplifiers are a significant advancement in the world of audio devices. With the help of this premium amplifier, you may influence the direction of your listening experience. 

In the audio and stereo system, amplifiers are used for the following purposes:

  • You may experience a more pure and clear bass with the aid of amplifiers. In addition to boosting weak signals, amplifiers may also enhance compressed signals.
  • Your listening experience may be fantastic. You may experience immersive listening by connecting the amplifier to four speakers and a subwoofer.

Pro Auto Thought: Now that you already know how to wire your car amp, the next DIY project to do is attaching a good car stereo. Since you’re a newbie, we recommend purchasing budget units that won’t disappoint. Check our selections here — Best Budget Car Stereo.

Watch This!

Frequently Asked Questions

How many speakers can I wire to a 4-channel amp?

For many speakers, many amplifiers can be employed. The amplifier can power up to eight speakers at once. In essence, you might use two-thirds less power than an amp if you plugged the power cord appropriately. It must first confirm that the amplifier is configured properly for the task at hand.

Is a 4-channel amp good for subs?

Yes. Two speakers plus a subwoofer can be powered by a quad-channel amplifier while a four-channel amplifier can be used to power a subwoofer.

How do you hook up a 4-channel amp to a factory radio?

Typically, your amplifier will have speakers and four-channel amplifiers. Any manufacturing system may be connected to it utilizing an amplifier’s speaker output. Reconnect all of the amplifier’s audio outputs to the stereo harness before using the speakers’ original connections to deliver them to the speakers.


We hope that the information provided above has helped you understand how to connect a four-channel amplifier. Since 4-channel amplifiers are more powerful, you must link them. Similar to this, you may put a sub along with 4 speakers in the wiring if you want to give your bass more crispness.

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