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How to Install a Capacitor to Two Amps? (w/ Diagrams)

Written by Edwin Jones / Fact checked by Andrew Wright

how to install a capacitor to two amps

Capacitors are arguably one of the most debatable pieces of electronic equipment in a car audio system. A lot of people like them, but a lot of people hate them. You can get some benefits when you wire a capacitor to an amp, though, and it may be connected to your car’s two-amp system.

How to install a capacitor to two amps? It’s best to install it to the subwoofer’s amp of your audio system, but you can also put it between the battery and the two-amp’s distribution box.

Should I Connect 2 Amps to 1 Capacitor, or Connect Only the Subwoofer to the Capacitor?

The main reason we wire a capacitor for car audio is to provide enough current for the amps during the short instances when our audio system draws a huge amount of energy, such as when playing loud bass.

During these instances, the current draw might be so great that it affects other electrical components of your car like your headlights.

It is practical to hook up capacitor to the subwoofer’s power line after the distribution block (or power block, as some might call it) to help the subwoofer amp during intense bass notes because the current released by the capacitor will easily get to the subwoofer amp with less wire resistance.

Here is an amp capacitor wiring diagram if you decide to connect the capacitor to the mono sub amp and subwoofer in a two-amp system:


Image A – 2 amps 1 capacitor wiring diagram with capacitor connected to subwoofer

But you can also hook up 2 amps with 1 power wire and a capacitor by placing the capacitor before or into the distribution box that connects both the 4-channel amp and the subwoofer amp. Here is Image B – an example of what it would look like:


Image B – Capacitor that wire two amps together diagram

Step-by-Step to Install a Capacitor to Two Amps

Step 1. Decide if you want to connect the capacitor before or after distribution block if you have 2 amps in the car.

You can use one capacitor for two amps like in image B or connect the capacitor to the subwoofer and the mono amp like in image A.

Step 2. Prepare the mounting hooks for the capacitor.


The mounting hooks should be secure enough to hold the capacitor in place to prevent any injuries that may happen when the capacitor suddenly gets dislodged and flies somewhere. The capacitor should be as close as possible to the amps.

Step 3. Disconnect the battery, prepare a power wire for the capacitor, then connect it to the power wire of your


If you want to connect only the subwoofer to the capacitor, then connect the capacitor’s power wire to the subwoofer amp’s power wire, as shown in Image A. But if you want to wire 2 amps in car capacitor, connect the capacitor’s power wire before or into the distribution box, as shown on Image B.

Step 4. Prepare a ground wire for the capacitor then connect it to your grounding pin or to your car chassis.


You can start putting a ring in at this stage to easily connect the wires to the capacitor’s terminals. You also use some zip ties to keep your wiring nice and clean.

Step 5. Charge the capacitor to recommended level using a resistor or light bulb.


Make sure to follow the manufacturer’s instructions. If you have a Boss Audio System capacitor, make sure you follow Boss capacitor install instructions, especially the wiring diagram on how the resistive elements connect to the positive and negative terminals of the capacitor.

Connect the batteries, start charging and wait for the capacitor’s voltage to reach the recommended level. Some would recommend up to 6 volts, but always check the manufacturer’s manual. You could damage the capacitor if you charge it wrongly.

Step 6. Connect the capacitor to the power wire and ground wire.


Once you’re done charging, remove the resistive element and connect the power wire to the positive terminal of the capacitor, and connect the ground wire to the negative terminal of the capacitor. Follow Images A or B depending on what you decided to set up.


Is it good to install a capacitor to two amps?

It can be a great way to make sure you have enough current to pump out during intense bass sounds.

However, before you even consider a capacitor, make sure that the total current needed by your system can be fully supplied by your car’s battery and alternator. Also, if you decided to install capacitor car audio really won’t be improved but just allow the amplifier to operate properly.

Can you strap 2 different amps together?

Yes, you can. Just make sure that you connect the positive terminals of the capacitors together and connect the ground terminals together as well.

How do you hook up a capacitor to an amp?

Make sure that the right terminals of the capacitor connect to the power cable and the ground. Do not connect both terminals to the power wire at the same time.


Capacitors have their own space in the car audio world. You may find them useful to optimize your car amps’ output, but some will not favor these devices. However, once you know how to install a capacitor to two amps, you could think and decide if having a capacitor is right for you.

Just like how you followed the diagram when you install 2 amps in a car diagram, setting up capacitors should also be done in steps to avoid any problems, from installation up to charging. With this in mind, you can guarantee continuous audio output from your system.

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