Video: How To Wire A Boat Amplifier For Power
By Matt Champneys
Amplifiers can draw a lot of power so it's important to wire them correctly to get the best performance. This video will explain how to do it.
Before we get started, a disclaimer is in order. We are not certified electricians. Electrical systems on a boat can be complex and we don't presume to know everything about the subject. If you are concerned about the state of your boat's electrical system we definitely recommend consulting a certified boat mechanic. What we present here are just the basic principles involved with wiring a stereo amplifier for power. Working with electricity can be dangerous, so take precautions to protect yourself.
Before you get started with your install, it is important to completely disconnect the battery to avoid any shocking situations. Re-connecting the battery should be the last thing you do when your install work is done.
An amp install kit, like this, will include all the power wires, connections and fuses you might need. You will need to select the proper gauge kit for your amplifier. Gauge is a reference to the thickness of the power wire. Think of a wire like a water hose. The thicker your hose, the more water can flow through it. Likewise, the thicker your power wire, the more electricity can flow through it. If your wire isn't thick enough your amp might not get enough electricity which could result in the amplifier shutting down at higher volumes.
The smaller the gauge number the thicker the wire. An 8 gauge kit will work well for amps up to 1000 watts. Above that, you will want a 4 gauge kit and in extreme cases you may want a 0 gauge kit. Thicker wire can be more difficult to work with in terms of flexibility, so we recommend using the gauge that best fits your amp.
Some people recommend using a capacitor on your main power wire. A capacitor really just helps even out the flow of electricity. But if you don't have enough electricity flow to begin with, evening it out isn't going to help. Using thicker power wire is the best way to solve electricity flow problems.
An amplifier will usually have 3 power connections. One is the main positive power connection, another is ground and the third will be the remote turn off connection.
You will want to run the main power wire directly from the amplifier to the positive terminal on your boat's battery. Avoid wiring to a fuse box because those fuses are typically not rated high enough for the power an amp will need. You will want to use a separate inline fuse on your wire to the battery. An appropriately rated inline fuse and holder is usually included in an amp install kit.
The ground connection can be wired to most any nearby ground. There is no fuse involved with a ground connection, so it usually isn't necessary to wire it directly to the negative terminal on the battery. But you can do that if there is no suitable ground available nearby.
Most amplifiers do not have an on/off switch. The remote turn off power connection is what performs that function.
A stereo head unit will usually have a blue "remote" wire on the wiring harness. Connect that wire to the remote turn off connection on the amplifier. That ensures that when you turn off the stereo, the amp will turn off too. Many amps will not power up without a good remote connection so it is a required installation step.
If you don't have a head unit you can use some kind of switch with the remote connection so you can turn it on and off. If you wire the remote turn off connection to constant power, the amplifier will always stay on and continually drain the battery so that is a situation you want to avoid.
That is all there is to it. Check out our other videos on various aspects of installing your marine amplifier