How to Connect 4 Speakers to a 2 Channel Amplifier?

Introduction

If you have a 2 channel amplifier but don’t know how to connect your 4 speakers with that 2 channel amplifier. Generally, 2 channel amplifier means there are 2 sets of positive and negative terminals. So, two speakers can easily be connected with a two channel amplifier. But what if you have 4 speakers and a 2 channel amplifier? Nothing to be disappointed here, you can connect 4 speakers to a two channel amplifier by bridging the speakers in different ways.

The parallel and series connection of the speakers will help you to match the total speakers impedance with the amplifier’s impedance. As long as the total impedance is less than the amplifier’s impedance and the wattage rating is below there is no risk of damaging the speakers by bridging them. So let’s find out how to connect 3 speakers to a 2 channel amplifier.

What Should You Understand When Connecting Speakers to An Amplifier ?

It’s not all about connecting speakers with an amplifier in different ways, you must know and understand a few terms to safeguard your speakers and amplifier. Here, we’ll let you know about those terms before showing the 2 channel amplifier wiring diagram and the process.

Impedance Matching

As you are here to know how to connect 4 speakers to a 2 channel amplifier, here you must match the amplifier’s nominal impedance rating with the combined impedance of the speakers. For example, if the nominal impedance rating of the 2 channel amplifier is 8 ohm, for each channel you can’t connect speakers with combined impedance of less than 8 ohm. Either  the connected  speakers and amplifier must have similar impedance or the speakers combined impedance must be more than amplifier’s 8 ohm impedance.

So anything lower than 8 ohm may overload the amplifier. As a result, the amplifier will have overheating issues, distortion and ultimately it will damage the amplifier.

Wattage Matching

Every amplifier provides the wattage rating in the specifications. If you have a 700 watt 2 channel amplifier, it means each channel can provide 350 watt for speakers. Now sometimes we match the impedance for combined speakers and amplifiers, but don’t see the wattage. it ‘s not right. For a 350 watt channel of an amplifier, if you connect two speakers, the sum of their wattage should not exceed 350 watt. Otherwise both speaker and amplifier will be damaged.

Series and Parallel Connections

For connecting multiple speakers on a single channel, the total impedance depends on whether the speakers are connected in series or parallel connection. You’ll get a detailed idea about series and parallel connection in the detailed procedures, but in short series connection adds the impedances and parallel connection decreases the total impedances.

 Wiring speakers in Series Connection

Suppose your amplifier has 2 channels and its impedance rating is 8 ohm. You have 4 speakers to connect and each of them has a 4 ohm rating. So let’s see how to connect 4 4 ohm speakers on 2 channel amp.

In series connection, the positive terminal of one speaker connects with the negative terminal of the other speaker. So first you must decide which channel you will connect with front speakers and which channel for rear speakers. We recommend one channel for front speakers and another channel for rear speakers.

• Connect the positive terminal of amplifier’s channel 1 to the positive terminal of speaker (A).
• Now connect the negative terminal of the Speaker (A) to the positive terminal of the Speaker (B)
• Finally, connect the negative terminal of the speaker (B) to the negative terminal of the amplifier’s channel 1.
• Repeat the process for speaker (C) and (D) connecting with channel 2.
• Now, as the amplifier ohm rating is 8 ohm, the speakers combined ohm should not go less than 8 ohm for each channel. Calculate the total impedance of speaker (A) and (B). As they are connected in series and both are 4 ohm, you will find the combined impedance of speaker (A) and (B) is 8 ohm which is equal to the amplifier’s impedance rating. So no risk here.
• Same thing happens for speakers (C) and (D). their combined total impedance is equal to the amplifier’s impedance rating.

Note: suppose,  the total wattage of the amplifier is 700, for two channels you must divide the total wattage with 2. So it’s 350 wattage for each channel, so your speakers total watt should not exceed 350 wattage.

Wiring Speakers in Parallel Connection

Suppose your amplifier impedance rating is 4 ohm both channels and all of the 4 speakers have 8 ohm impedances. Now, if you connect 2 speakers in series with a channel, the combined impedance will be 16 ohm for 2 speakers, way more than the amplifier’s impedance rating of 4 ohm. As a result, the current flow will be lower in the speakers and their volume won’t satisfy you. And it will create some kinda distortion too.

That’s why for wiring 4, 8 ohm speakers to a 2 channel amp (4 ohm impedance rating), we recommend parallel connection.

• Make a connection from the positive terminal of the amp’s channel 1 to the positive terminal of the speaker (A). wire the negative connection from the Channel 1 negative terminal to the negative terminal of the speaker (A).
• Now connect the positive terminal of both speakers (A) and (B) and the negative terminal of them together.
• So this way, both Speakers (A) and (B) are connected in parallel with Channel 1.
• Same way, connect the speakers (C) and (D) to channel 2.
• Now, as the amplifier ohm rating is 4 ohm, the speakers combined ohm should not go less than 4 ohm or way more than 4 ohm for each channel. Calculate the total impedance of speaker (A) and (B). as they are connected in parallel connection and both are 8 ohm, you will find the combined impedance of speaker (A) and (B) is

For two 8-ohm speakers in parallel:

1 / (1/8 + 1/8) = 1 / (2/8) = 4 ohms

• Even the speakers (C) and (D) will have the same combined impedance of 4 ohm which is absolutely alright for a 4 ohm impedance rated 2 channel amplifier.

Note: don’t forget the wattage issue and following parallel connection, you can even solve the problem of how to wire 4 speakers to 2 ohm amplifiers.

Using a Selector Switch

Selector switch helps to distribute the impedance of the speaker properly according to the impedance rating of the amplifier. You will have a selector switch for specific impedance. Like there are selector switches that provide 8 ohm impedance output so if your amplifier’s impedance rating is 8 ohm you can have that selector switch. Also some selector switches can provide different impedance output, so you can have front speakers sound littles less powerful and rear ones sound more.

• First, sonnet the all positive and negative terminals of the speakers and then connect them to the two speakers with one selector switch and connect the other 2 speakers with the other selector switch.
• Then connect both the selector switch with the positive terminal of the 2 different channels of the amplifier. Here the selector switch works as a connector between amplifier and speakers and maintains proper impedance flow without giving you the hassle of doing parallel or series connection.

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FAQ

Can I run 4 speakers on a 2 channel amplifier?

– Yeah it is possible to connect 4 speakers with a 2 channel amplifier by series or parallel connection. But for both occasions you must maintain the total impedance of the speakers around the rated impedance of the amplifier.

How to connect 4 speakers to a 4 channel amp?

– Connecting 4 speakers to a 4 channel amp is a regular task. All you have to do is connect the positive and negative terminal of the speakers to the positive and negative terminal of one of the channels. Just try to connect speakers that have almost the same impedance of the amplifier.

Conclusion

Connecting 4 speakers to a  two channel amplifier is not a tough thing to do, even if you can connect more than 4 speakers on the two channel amplifier. Only things you must notice are the balance of impedance and wattage between amplifier and speakers. If you have 2 channel amp  3 speakers and 1 sub, you can connect them in the same ways we’ve described here. But our recommendation is to connect 3 speakers to a channel and keep a dedicated channel for the subwoofer. Because for generating lower frequency, subwoofers always require more power than speakers and they must sound loud to keep the sound balance between speakers and subwoofers.