Tag: installation

How to Install a Car Amplifier

How to install a car amplifier

Learning how to install a amplifier in your car is easy. All you need is the the proper supplies, a couple of hours, and the willingness to pull off some panels from your car. Once you have all of that, follow the steps below to begin installing your new amplifier!


Confirm all your gear is compatible

Before you even think about installing your new amplifier, it is important to make sure that your gear is compatible.
Car Amplifier – Will it phonically fit in your car? How are you going to run signal to the amp from the car stereo?
Power / Ground cable – Is it the recommended gauge for the amplifier?

Do you have the right wire?

You will want to make sure that your amplifier installation kit includes the right sized power and ground cable. A general rule of thumb is the following:

Wattage of all amps Recommended Wire Gauge
up to 400 watts 8 AWG
400 to 1000 watts 4 AWG
1000+ watts 0/1 AWG


Mount the Amplifier

This is important because the location of your amplifier will determine how long your runs of wire are. Typical locations for an amplifier are under seats, in the trunk, or even mounted to the subwoofer box. However you mount the amplifier, make sure that it is secured to the car. Most amplifiers will come with mounting directions. For most installations where you are putting the amp on carpet, you can slide a piece of MDF under the carpet to screw the amp into.


Run Power and Ground wire

The first set of wires you will run is the power and ground. This will provide the power to turn on your amplifier and ensure proper grounding. The power cable (positive) is run from the positive terminal of your car battery to the positive input terminal on the car amplifier. Your ground cable (negative) is run from the negative terminal on the amplifier to a grounding point on the vehicle. A proper grounding point will ideally be joined to the chassis of the vehicle.


Give the Amplifier signal

Once the amplifier has power, you will need to give it signal and tell the amp when to turn on. From the back of aftermarket car stereo, connect the RCA interconnect cables and then run them to amp. It is highly recommended that you run the RCA cables along the opposite side from which you ran the power cable. This will prevent any noise or interference that can transit from the power cable into the RCA signal. Once the RCAs have been run to the amplifier, plug them into the appropriate RCA input.

Next, run the remote turn-on wire from the car stereo to the amplifier. This is the small 16 gauge wire that cam in your amp kit. It will need to be connected to the remote turn-on wire from the wire harness on the back of the stereo. Run this wire with the RCA cables and insert it in the remote turn on input terminal on the amplifier. This will tell the amplifier to turn on when the car stereo turns on.


Connect amplifier to speaker or subwoofer

Now that the amplifier is powered and is receiving signal from the car stereo, it is time to send that signal to the loudspeakers. Run the speaker wire from the amp terminals to the terminals on the speakers or subwoofer. As a general rule of thumb, I recommend using 12 AWG wire for subwoofers and 16 AWG wire for speakers.

If you are connecting subwoofers, double check the wiring configuration to make sure that the impedance between the sub and amp match.


Test Everything

At this point you should everything connected and wired properly. Turn the car on and play a track on the stereo. You should be able to hear sound coming from the loudspeaker connected to the amplifier. If you don’t hear anything, you will have to trouble shoot the installation and find out whats wrong. If it is playing music, then you can turn the car off and put everything back together.

That’s it! If you can install an amplifier in your car, then you can install pretty much any other type of aftermarket car audio gear.

Pro tips!

    For first time installers, disconnect the negative batter terminal to prevent any electrical issues before or after the installation.

  • Dry fit everything before mounting the amplifier. This is ensure that the amplifier will fit and the wires are long enough.
  • Tune your amplifier! Once you confirm that the amplifier is functioning properly, spend some time tuning the amp to make it sound better.


Subwoofer Wiring Diagrams

The most important thing about installing a subwoofer is making sure that it is wired properly to the correct impedance. For the first time installer, it might seem like a tricky and confusing task, but in reality it is a really simple thing to do. If you know what wiring configuration you want to use, click on the link below for a diagram and explanation.

Wiring Diagrams & Explanations:

Subwoofer Wiring Recommendations

Not sure which to use? If you haven’t purchased your sub and amp yet, the following popular wiring configurations can help you in your buying process.

One subwoofer to Dual 2 ohm

This is my preferred method for a single subwoofer (and probably the most popular). Dual 4 ohm subwoofers are common and the simple wiring config down to 2 ohms provide a good balance for more power while still staying stable.

Two Subwoofers to Dual 2 ohm

When installing 2 subwoofers, I recommend maintaining a final impedance of 2 ohms. This is for the same reason as the one subwoofer to 2 ohm (more power and stable). This is done by getting two dual 2 ohm subwoofers and wiring them to 2 ohm.


How to Install a Car Subwoofer

Installing a subwoofer in your car can be one of the most musically rewarding upgrades that could be made to a car. That is because most factory car audio systems do not include a subwoofer and are unable to accurately play the lower frequencies of music. When a sub is installed in the car, the overall frequency response of the car widens and the user will be able to hear the bass notes along a wider range of viable frequencies. This page is dedicated to helping you understand how to install a car subwoofer.

What you will need:

  • Subwoofer
  • Subwoofer Enclosure
  • Speaker Wire
  • Quick Disconnect Connectors
  • Wire Strippers
  • Polyfil (optional)
  • Industrial Strength Velcro (optional)

1. Wire the subwoofer to the correct impedance

The most important part of installing a car subwoofer is making sure the sub is wired to the correct impedance. This is very simple if you follow the wiring instruction that came with the subwoofer or view my wiring diagram pages. Make sure that the RMS wattage and final impedance of the subwoofer(s) match the RMS output of the amplifier at that same impedance.

For example, if you have a 500 watt dual 4-ohm subwoofer that is wired to 2-ohm, make sure that the amplifier puts out roughly 500 watts RMS at a 2 ohm impedance.

I recommend using 12 AWG speaker wire for making these connections. Only use thicker gauges in rare cases when the RMS of the subs are 1500+ watts. Failure to properly wire the subwoofer will result in improper wattage seen at the subwoofer and can cause permanent damage to the subwoofer and/or amplifier.

2. Mount the subwoofer in the box

Once you have wired the subwoofer to the proper impedance, you will be ready to mount the woofer to the box. Start by connecting the positive/negative speaker leads from the subwoofer and connect them to the inside of the subwoofers terminals. Usually this is done easily with quick disconnect connectors. With everything wired up, line the box with a healthy dose of polyfill (optional).

Assuming your box has a cut out the same size as the subwoofer, you should be able to simply set the woofer in the box cut out and prepare to screw it in place. Make sure that the subwoofer is lined up properly and not upside down. Then use some standard wood screws to mount the subwoofer to the MDF box. Be careful to not over tighen, but create a secure fit.

3. Connect the subwoofer to the amplifier

On the outside of the subwoofer box terminal (that has been connected to the speaker wire used to wire the subwoofer), you will be able to run positive and negative speaker wire to the amplifier. At this point, I recommend double checking all the connections and sending signal to the subwoofer to test it out.

4. Tune the Subwoofer

With everything connected, you can now tune the subwoofer to your liking by adjusting the subwoofer settings on your amplifier. This includes frequency response, bass boost, gain, subsonic filter, and other settings depending on the amplifier.

That’s all there is to it. Enjoy the Bass!