How to Hook Up 2 Amps With 1 Power Wire (5 Steps)

Wiring an amplifier in your car audio system is already tricky. Things get more complicated when you intend to use two or multiple amps. 

So how to hook up 2 amplifiers with 1 power wire? It will take extra effort to work. Moreover, you must plan your project well to avoid potential problems. 

But don’t worry because we are here to help you. This article will show you the best ways to nail it. Let’s read on to discover! 

How To Hook Up 2 Amps With 1 Power Wire?

Since there are two amps, you have to handle more tasks. We will break the whole process into five steps so you can follow them easier. 

Let’s go straight in and walk through every step to properly install two or multiple amplifiers on a single power cable. Please note that the process might be dangerous if you are not cautious when working with your vehicle’s electronic systems.

You need to unplug your vehicle’s battery completely. You will be using it to run your amplifiers, so preventing potential disasters is vital.

Now that you are ready to start. Let’s talk about how to use a single power wire to power two amps.

Step 1: Run the power wire

You can install separate cables for each amp or use one cable to feed the two amps. We recommend the latter due to its elegant configuration. 

Choose a thick cable so it can handle the extra electrical current demand from your two amps. The amps won’t work efficiently or deliver their rated power otherwise.

Using a power distribution block is the best and most organized approach to connecting two amps to one power cable. This device offers a convenient and economical way to distribute the electrical circuit from one input source to multiple devices. 

In addition to saving you the trouble of running numerous power cables through the firewall, a distribution block will enable a clean installation.

The power distribution block can eliminate the hassle of wiring multiple cables. Moreover, you will have a clean installation. You can also fuse it when your amplifiers lack built-in fuses. 

You need a power distribution block for this step

Step 2: Run the ground wire

Employ a ground distribution block to hook up your amp’s grounds to a connecting point instead of wiring each separately. Then you can avoid ground loop problems and interference in your installation.

Attach each of the amps to the ground distribution block, and connect it to a sanded subframe or chassis. It would be about eighteen inches from the amp’s position.

The ground wire for your amplifiers must be exactly the same size as the power wire. Furthermore, the cable running from the ground distribution block to the ground position must be as long as the cable that runs from the distribution block to the battery. Then, you will have a proper and smooth current flow. 

Step 3: Add the remote cable

There is a blue wire on the back side of the head unit, and it’s a remote turn-on wire. It tells the amp to work whenever the head unit is on. Without this signal, your amplifier can’t turn on. 

Unfortunately, sometimes the remote turn-on signal may need to be stronger to activate multiple amps. To solve this problem, you need a relay, which is an electromagnetic switch. It uses an electric current to start a bigger one by converting small stimuli into larger currents. 

You need to connect the relay straight from the batter or the fuse box. The two methods enable your amps to turn on while successfully isolating the head unit’s remote turn-on signal from them, thus preventing any problems with current overflow. 

Avoid using a single remote turn-on wire to power multiple amplifiers. If you draw too much electricity through the remote lead on the head unit, you may kill it.  

Work with the remote wire behind the head unit

Step 4: Connect your amps to the head unit 

Connect the amplifiers to the head unit’s preamp outputs at this point. In this case, having a head unit with multiple preamp outputs would be excellent because it would simplify connecting your amp.

As an alternative, your amps might also allow pass-through. It implies that you can link one of the amplifier wirings to another before connecting it to the head unit. This feature is beneficial if your head unit doesn’t support multiple preamp outputs. 

What happens if your head unit only has one preamp output or your amplifiers don’t have pass-through features? A Y adapter is what you’ll need for the head unit. 

RCA adapters allow you to join two devices with a single connector. You need a Y adapter with one-male to two-female sets.

While the female part can connect to your amplifiers, the male part will plug into the head unit. Furthermore, make sure you buy a sturdy adaptor with strong power wires.

You need adapters for connecting the amps to the head unit

Step 5: Connect speaker wires to the amps  

Once you have connected the amps to the system, you can access both amps by wiring your speakers to one of them. 

Check the speaker polarity carefully, then match it with the amplifier. Remember to connect the positive terminal of your speaker to the equivalent terminal on the amplifier and proceed with the negative terminal. 

You can connect the amp without speakers if you also link a subwoofer to it. Once more, terminals must match.

Regarding the wiring, the gauge used for the speakers is one to two steps shorter than the one you use for the subwoofer. The right size will depend on the power of your subwoofer and speakers. 

Check the sound system after you complete it

Tutorial Video Of Wiring Two Amps Together 

You can install multiple amps in a car audio setup using one power wire if you correctly wire the devices. But make sure your car’s electrical system can handle it. 

If you install too many amps, they will consume too much power. Hence, you might want to think about upgrading the existing electrical system.

A multi-channel amplifier for the main speakers and a secondary mono-channel amplifier for your subwoofer is the popular reason to connect multiple amps. The steps we have shared in the previous section will help you achieve them. 

This video will give you a visual explanation of connecting multiple amplifiers using one amp power wire:

Diagram Of Wiring Two Amps In A Car Audio System

Before starting your project, you must plan the circuit carefully. So when there is any problem, you can quickly identify the source. 

This diagram will give you a quick rundown of the two-amp system you will install using one power wire:

Diagram of wiring two amps in a car audio system

Here are simple steps to set up everything in place:

  • Use a power distribution block to connect two amps to a single power cable. This device helps deliver the electrical current from one source to multiple devices. 
  • Employ a ground block to hook up the amp’s ground to a connecting point so you can avoid ground loops. 
  • Attach each of your amps to a ground block, and connect it to a ground chassis. 
  • Now, connect the remote turn-on wire. You need a relay to each turn-on lead. It would be best to get power from the head unit.
  • Wire your amps to the speakers by running the speaker wires to the amps.


You can connect multiple amplifiers using one power wire. This process involves many parts, so make sure you follow our guide carefully to avoid mishaps. 

Your system ought to be working at this stage. It would be best to use high-quality materials. And if you are not confident about your electrician skills, consider asking a professional to carry out the project for you.  

Hopefully, you will find this article helpful. Thank you for reading!


Can you hook up two amps to one sub?

Yes. We call this process “bridging” or “strapping,” which can deliver the power level you need. However, you can only join two identical amps. Next, identify whether you have a single or dual voice coil sub. The outputs of a single voice coil sub can’t function with the two amps and will get burnt as soon as you switch it on. But if the woofer has dual voice coils, then you can.

How do you hook up two amps?

As long as you connect them correctly, you can deploy any combination or number of power amplifiers in your car audio setup.

How do you hook up two amps?

A power distribution block gives the best solution to connect several amps to a power cable. It enables you to link to each amplifier using shorter separate wires after using a power cable for most of the line, including the essential section that travels through the firewall.

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