How to Wire Two Amps without a Distribution Block (Full Guide)

It is always challenging to wire an aftermarket amp to your car’s audio system. Adding a second amp boosts your car audio and improves your experience. Besides, the process can get fairly complex when you are thinking about wiring two amps. However, one of the most commonly asked questions is how to wire two amps without a distribution block.

If you don’t intend to use a distribution block but want to wire two amps, the process isn’t that hard. All you need is extra planning with a few preparations. You have to make sure that the power wires fall in line with the power receptacles. Apart from that, they should have the same polarity.

Keep in mind that you can use connect multiple amps to one power source if the signal is too strong to accommodate multiple amps. This post is all about how to hook up two amps without using a distribution block. Let’s get started.

How to Wire Two Amps without a Distribution Block

Why Do You Need to Install Two Amps In Your Car?

If you want to improve the overall sound quality of your car audio, one of the most common ways to do so is to install two amplifiers. As a result, it allows you to connect another one or two speakers. Next, you have to fine-tune the settings and you are good to go.

In short, you can have the best sound quality than previous. However, installing two amps in your car needs appropriate tools. Also, you need a little bit of understanding when it comes to considering certain factors and options available at hand. As such, you don’t risk damaging your car’s audio system.

So, how to hook up two amps? Connecting two amps in your car can be easy if the wiring is done the right way. When you install two amplifiers in your car, it involves connecting one to the speakers while wiring the other one to the subwoofer.

Moreover, there are a few factors to consider such as amplifier classes, power requirements, and impedance of the speakers. If you have a normal sound system in your car, you don’t need two amps. A single amp has enough power for your speakers and produces impressive sound.

But installing two amps makes a great difference if you have a high-quality audio system with multiple speakers. When you have two amps installed, it gives you the option to connect specific speakers to the dedicated amplifier.

You can fine-tune your car audio and have better control. Besides, if you have an efficient subwoofer that needs a significant amount of power, installing a second amplifier improves its performance.

Wiring Two Amps Without Using a Distribution Block

The two most effective ways to wire two amplifiers are active crossovers and selector switches. And, you can do that even without using the distribution block.

1. Active Crossovers

When it comes to differentiating sound frequencies, active crossovers are helpful. Here is how they do.

  • Low frequencies flow to the subwoofer
  • High frequencies to the tweeters
  • Midrange frequencies flow to the speakers

All you need to do is connect one amp to the speakers with the highest frequency. Whereas, connecting the other one to the speakers with the lowest frequency. Follow the below-mentioned steps to connect the amps.

  • Locate the output of the head unit. Connect it to the active crossover’s input. Keep in your mind that you should connect the head unit’s R with the active crossover’s R Now, do the same thing with the L channels as well.
  • Find out the high output signal of the crossover. Next, pair it to the amplifier that you choose to connect the tweeters.
  • After that, find out the low signal output of the crossover. Pair it with the amplifier that you choose to connect the speaker with the lowest frequency.
  • The final step involves testing how the amps are working. Therefore, play some great music while adjusting the control knob of your car music system.

2. Selector Switch

The other method that you can consider when wiring two amps are by using a selector switch. Otherwise called a connector switch, a selector switch helps to pair two amplifiers without many hurdles.

These are helpful when you need to connect two amplifiers to one or more speakers. Because you won’t use the two amplifiers at the same time, you should buy a selector switch. Follow the steps to connect the two amplifiers with a selector switch.

  • Start by going to the back panel of the head unit. Find out the connectors that say output and input. Use the output ones to pair with the speakers. On the other hand, use the input ones to pair two or even more amps together.
  • Try to locate the wire that is reserved for the speaker. Also, make sure that it comes from the amplifier. Connect the wire to the A’ switch input. You have to repeat the same step for the L and R

Remember that the R’ output should match the R’ input. In case you make the connection otherwise, you risk damaging both your speakers and amps.

  • When you are done with the first amp, you need to connect the other amp. Start by finding out the wire of the second amplifier output that’s reserved for the speaker. Pair it with the B’ switch input.
  • After that, you have to locate the speaker wire of the switch and pair it with the speaker input. Let’s assume that there are two speakers in your car. In that case, you have to choose the wire from the switch’s output and connect it to the second speaker’s input.
  • Now, both the speakers and amplifiers are connected and ready to use. You can use the connector switch and choose the amplifier that you need to use at the moment.

Keep in mind to choose a connector switch that makes you switch from one amplifier to the other one without much effort. As such, you eliminate any kind of risks associated with damaging the amplifiers.

Can You Hook Up Two Amplifiers Using One Pre-Out?

If you want to use two amplifiers at the same time, installing preamp outputs can give you the best results. You have a good-quality RCA wire cable. Here is how to connect two amplifiers with a single pre-out.

  • Find the preamp output on the head unit or receiver. It will be labeled as re-Out’.
  • Get the RCA cable as speaker wire from the R pre-out and connect it to the first amp’s R input. Also, you can utilize the L pre-out.
  • Do the same for the second amplifier.
  • Connect the amps to the speakers and test the quality of the sound.


If you want to know how to hook up two amps without a distribution block, don’t forget a few important things. Make sure that the amp-hour rating of your car can handle the power required by the two amps.

You have to use Y-adapters or RCA splitters to connect both amplifiers to the head unit’s preamp output. When you follow these steps, you can wire two amps without any kind of issues. If you want to enjoy high-quality sound even when you increase the volume, use the active crossover method.

Going for another amp supplements your primary speakers while improving the sound quality. Installing two amps allows you to fine-tune your car audio settings. Listening to different kinds of music becomes a soothing experience.