How To Wire A 4 Channel Amp To 4 Speakers And A Sub

4 channel amplifier

A 4-channel amplifier gives an excellent audio output for your guitar, but it is restricted to be used with either of four speakers or two – speakers and sub. However, when you use both speakers and a sub together, the audio quality is enhanced exceptionally. To overcome the restriction, we need to get a bit innovative with the wiring and to get it right, you need to know how to wire a 4 channel amp to 4 speakers and a sub.

Wiring of the amp

As mentioned already, you can connect a 4 channel amp with 4 speakers using either series or parallel connection. But the challenge which we get here is along with connecting four speakers we are connecting a subwoofer also. 

To make a secure connection of 4 speakers and a subwoofer to a 4 channel amplifier, you need to make both series and parallel connections. Now let's first learn what is a series connection and parallel connection.

  • In parallel connection, each speaker would get the same voltage from the amp but the impedance of speakers gets divided between two speakers.

  • In series connection, the power that is supplied by the amplifier gets divides between the two speakers but this adds up the impedance of the two speakers.

You might get this question on why you need to use both series and parallel connection here. It is because we are connecting an extra subwoofer along with four speakers which is why we do both types of connection.

As you can see in the above picture, the four speakers are connected to two amp channels via parallel connection and the subwoofer is connected to two amp channels via series connection.

In most cases, parallel connections are preferred as they tend to consume less power than the series connection. Let it explain it clearly here.

In a series connection, the speaker ohm values (4 ohms for each speaker) are added together. In total, you get 8 ohms. So the resistance is high. 

So the problem that comes here is that the power distribution will differ. Like one speaker gets more power and the other one will get less power. This will affect the sound output. 

In a parallel connection, the speaker's ohm values are divided, which means the power distribution is equal. So both the speakers will receive the same amount of power and you can get an equal and balanced sound output.

I hope you understand why parallel connections are mostly preferred. To get high balanced sound output, most commonly people prefer the parallel connections and in this article also, to connect the 4 speakers with two channels, we have used parallel connection.

Note:  If  you are interested in making things from scrap then check how to make a guitar amp from a speaker article to build a custom guitar amp for your needs.

How to wire a four-channel amp to 4 speakers and a sub

Before you start wiring, you must note the minimum impedance rating of the amplifier. The standard minimum impedance for a stereo(parallel) connection must be 2 ohms, and for the mono(series) connection, it must be 4 ohms. So before you start the wiring part, check the minimum impedance of your amplifier because if you tend to wire speakers with lower impedance ratings than the ones given in the amplifier, your system will get damaged.

wiring methods

Below, I have given three different wiring system. Choose the one that is feasible for you. 

  • System 1

    In system 1, you can wire the channels at the front of each channel's terminal and connect them to the two speakers. So this means that you can connect two speakers in parallel combinations. So when wiring is done in this way, you will get an impedance of just 2 ohms per channel. Once this is done, you can wire the subwoofer to the rear channels by connecting the negative end to the amp's right terminal and the positive end to the amp's left terminal.

  • System 2

    In system 2, the same wiring that is done in system 1 is done. You should make the connections by connecting the speakers in parallel combinations. The advantage here is you have several options for a subwoofer, so you can wire a single 4-ohm sub or a dual 4-ohm sub.

  • System 3

    Again, the speaker's connection is given in parallel to get 4 ohms per channel. But one thing that differs from the other two systems is you can attach resistors along with the speakers as it will protect the wiring from unusual hazards. Also, the resistors help in handling the over-heating problems.


With the help of the above-mentioned steps, you can wire a 4-channel Amp to speakers and a subwoofer. Just make sure you take care of the technical specifications and follow the steps correctly to avoid any complications in the setting up and functioning of your audio system.

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