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Make Your Music Sound Fantastic with an Amp

Some essential tips for installing an amp

Installing an amp can be fun

An amplifier is your key to enjoying the best musical experience you'll ever have in your car. Installing one is a cool project — getting to know your car inside and out is often fun and satisfying. And the results will be well worth it: giving your music the power to overcome road noise has the potential to bring you joy every time you travel.

Here are the basic elements of any installation, including some tips from our tech support specialists aimed at preventing the problems customers most often call about. These tips will help you install your amplifier successfully the first time around, and enjoy it for a long time to come.

When you install an amp, you'll need to focus on these four areas:

  • Providing the proper size of power wire, ground wire, and fuse
  • Passing the power wire from your vehicle's battery to the interior through your vehicle's firewall
  • Connecting speaker and signal wiring to the amp
  • Mounting the amp with plenty of space
Car overhead

Large enough power wire and fuse

Power wire and fuse

Amps don't come with wiring — you must get that separately. And your amplifier needs large power and ground wires in order to operate correctly and deliver its maximum amount of wattage. The manufacturer of each amp specifies the size (called "gauge") of wire and fuse that will work. Adequate gauge wire is crucial for an amp's performance — too small and the amp starves and can't produce full output. Amplifier wiring kits come with in-line fuse holders and fuses that match the wire's current-carrying capacity. For the safety of you and your car, you must install the main fuse as close to the battery as you can — within 6" is best. This is so that in the event of an electrical malfunction, instead of the wire melting and possibly setting your car on fire, the inexpensive fuse blows.


Passing the power cable through your vehicle's firewall

Vehicle's firewall

The power cable must pass from your battery to your amp through the firewall, the metal wall that keeps engine heat away from your knees. Finding a suitable pass-through is a common challenge in amp installation. But with a little patience, and a flashlight, you should be able to find a grommet in the firewall that has wires passing through it, and which has enough room for the power wire to fit through, too.


Getting signal to the amp, and then to the speakers

RCA patch cables

In most cases, the amp's input signal (the music itself) comes from your receiver by way of RCA-type patch cables. These should run down the opposite side of the car from the power cable to avoid picking up any electrical interference. If your receiver doesn't have RCA outputs, you can use an amplifier with high-level inputs and get the signal from your vehicle's speaker wiring, either from behind the dash or from a convenient speaker location like the rear deck.

In many cases, to get the powered signal from the amp to your speakers, you can run speaker wires to the harness that's behind your receiver, where all your car's speaker connections are accessible in one place. Otherwise, you'll need to run new speaker wire from each amplifier output to each speaker.


The ground is the most important connection

Solid ground connection

The metal frame of a car serves as its "ground," the part of its electrical system that provides the reference point for the system's voltage, and represents the return path for current flowing from the positive power lead, through the system, back to the battery. To receive power, an amp must have a solid ground connection — a wire that makes contact with bare metal in your car. A loose or non-conducting ground is by far the most common problem our techs uncover when troubleshooting amp issues. Bad ground connections are responsible for many different problems, including noise, music fading in and out, and the amp cutting off entirely.

Use a crimped-on ring terminal on the wire, or a dedicated grounding block to connect the cable to the metal chassis of your car. To ensure solid contact, thoroughly scrape all paint from the chassis where the ground terminal will make contact with it. And make sure the terminal and the bolt or screw you use to attach it are also clean and free of paint and grease. This will ensure solid electrical contact after you tighten it all together.


Give your amp room to breathe

An amp puts out heat as it operates. This heat must be allowed to escape away from the amp, or else the amp will overheat and shut down — a common problem our techs hear about. Even smaller Class-D amps still need sufficient room to stay cool and play dependably. Mount your amp with plenty of air space around it and in a position to dissipate the heat properly. In other words: not upside down.

You'll also need to securely mount the amp so in the event of a sudden move it doesn't become a hunk of dangerous flying debris. A problem Support Techs hear about occasionally is noise created when someone mounted an amp's case with the screws making contact with the metal body of the car, creating a "ground loop." If you have to use screws to secure your amp, mount it onto a small piece of plywood first, and then mount that to the car.

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