Transcript:
Connecting your marine stereo to an amplifier is simple, but there are a few different ways to go about it. In this video we will discuss those options and the pros and cons of each.
The most common method is to use the RCA pre-amp output jacks on the back of the stereo. Some are embedded right in the chassis of the stereo like this. Others are on wires extending out from the stereo like this. You can identify them by the red and white color coding used to separate right and left stereo channels. Some stereos will also have RCA inputs so be careful that you don’t get them mixed up.
You will use an RCA cable like this one to connect the outputs of the stereo to the inputs on the amplifier.
The pre-amp outputs provide a low voltage, but very clean audio signal to the amplifier. That is the main advantage to using them.
The number of pre-amp outputs will vary from stereo to stereo. Most will have at least one set, but they can have up to 3 or even more pairs. A stereo with 3 pairs of outputs will usually have a pair for the front speakers, a pair for the rear speakers and a pair for subwoofers.
Likewise, amplifiers will have varying numbers of inputs depending on how many channels the amp has. If the number of outputs match the number of inputs, your job is easy. Just use as many RCA cables as you need to connect them up.
If the number of outputs don’t match the number of inputs then you’ve got some decisions to make. There is no requirement to use all of the pre-amp outputs. If you are using a 2 channel amp, then just use the front outputs. If you are using a 4 channel amp, then just use the front and rear outputs. Only use a subwoofer output if you are using a subwoofer.
But what if your stereo has fewer outputs than the amp has inputs? Many amplifiers will have an input mode switch. Say your stereo only has one pair of outputs, but you want to connect to a 4 channel amp with 4 inputs. Connect your one rca cable to channels 1 and 2 on the amp. Switch the input mode on the amp to 2 channel. The audio signal input from channels 1 and 2 will then be equally distributed to channels 3 and 4 as well.
No input mode switch? Then you’ll have to resort to using RCA splitters like this to match the number of outputs to the number of inputs.
Consider that how you arrange the outputs and inputs may affect how much control you have over the sound from the stereo face. For example, fade control adjusts the volume between front speakers and rear speakers, but if you only use the front pre-amp outputs and not the rear, then fade control won’t work.
What if your stereo has no pre-amp outputs at all? You’ll have to use a different method. Use the powered speaker outputs as your audio signal source. Using a higher powered audio signal can introduce a small amount of distortion and static into the final audio output, which is the main drawback of this method. Most people will find it acceptable, but it might bother you if you are picky about your sound quality.
You’ll need to pick up some RCA connectors like these to put on the ends of the speaker wires attached to the head unit. Then you can plug then into the inputs on the amplifier.
A higher power signal can overdrive your amp and cause damage so you’ll need to adjust some settings to compensate. Some amps will have an audio input switch that will allow you to switch between high and low power. You’ll want to select the high power mode. Most amps will also have one or more gain controls. You can dial that down compensate for the higher power signal.
Is there ever an advantage to using the powered speaker outputs instead of pre-amp outputs? Well, if your stereo only has 1 pair of pre-amp outputs and you’d really like to preserve the fade control, then using the front and rear powered speaker outputs will let you do that.
But all things being equal, you will usually want to use the pre-amp outputs instead for the best sound quality.
Thanks for watching!
In another video we will talk about how to optimize the gain control on your amp for the best sound quality.
Transcript
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