Upgrades, adding an amplifier to your boat stereo.

One of the most popular options on a new boat is the music system. Lots of speakers, multiple amplifiers and remote controls all over the boat. Whilst great, what happens if you are upgrading an older boat and just want to up your music game? one of the most popular upgrades is adding an amplifier. In this post I do not want to get too technical, there are people who can far better explain all about amplifiers, the various ratings and so on, more, lets concentrate on installation on a boat.

Why upgrade?

A lot of upgrades are more replacements, the original amplifier that can with the boat is either faulty or failed or just does not sound that good any more. The other reason is to up you #boatmusic game. Boats are often open and even good stereos can have a hard time keeping up, if you want a subwoofer, you really need an amp. The difference in the sound quality and clarity between having and not having an amplifier is night and day, even the standard two or four speaker set up will sound so much better with an amplifier.

Buying tips

There are two types of amplifier, ones made especially for boats and ones that can be used in cars and trucks too. Marine amplifiers are made to be more resistant, being on a boat, water and exposure being the important factors. If you can protect your amplifier, then an automotive style one will be fine.

Amplifier output is measured in watts, the more watts the louder it will be, your speakers have a rating of how many watts they can handle before being damaged. In a perfect world, the amps rating would exceed the speakers rating, that way the amplifier does not have to work as hard to drive the music through the speakers.

Before starting

• Cables, amplifiers draw quite a lot of amperage, they require large sections cables to power them, typically 10mm2 and upwards is normal, but some can be much larger than this. They also require fusing appropriately.

• Power consumption, do you have a very basic and low capacity battery system? Might have to upgrade that first before thinking about installing an amplifier.

• Heat dissipation, amplifiers do (or can) produce a fair amount of heat, you want them mounted in an area that has enough air flow.

• Setup, you could have the best system on the water but if the amplifier is not set up or "tuned" correctly it will not sound good. Take the time to read the instructions and know where the adjustments are, If I can, I like to do this before fitting the amplifier in it´s final position, sometimes the adjustments can be very hard to reach otherwise.

Installation

Sony 1000W 4 channel amp installed behind a helm panel, bottom are the red and black power cables, the gold RCA cables are in the middle and the cables with the blue terminals are for speakers.

Location, location, location, this will vary very much from boat to boat, you want it fitted in the location that offers the best protection but also not too far from the stereo, in a perfect world the main power cables would not be overly long either.

The blue & white cable, this is the wake up cable, typically blue with a white stripe or tracer that will go from the stereo head unit to the amplifier, usually to a terminal marked "remote" or "rem".

The power cables, amplifiers need varying degrees of electric current to drive them, to pass this current to them they will need cables thick enough for the job. The actual way this is done will vary from boat to boat, often the positive cable is run straight from the amplifier to the battery switch or a buss bar straight after the switch. the negative cable will have to be grounded, also usually to the main negative buss bar located near the batteries. 

Some boats already have been upgraded with much larger section battery cables and so its possible you can wire to buss bars or distribution blocks much nearer the amplifier, this is not always a given however and is not that common. Remember to run your cables in protective sheathing, especially where they pass behind panels or through bulkheads.

Terminating the power cables at the amplifier will depend on the model of amplifier, most have screw down terminals, so the end of the cable will need a bootlace ferrule terminal to finish it and stop the individual strands of wire from splaying out. Pay attention to any torque specs in the manual for the amplifier.

Product review, uninsulated terminal and copper lug crimper

Product review, heavy duty crimpers

A typical fuse for an amplifier, this is a Maxi style fuse, the bottom photo shows its size comparison next to a standard automotive blade fuse.

Fusing, As near as possible to the battery after battery switch (you don´t want the amplifier permanently connected to the battery), read the manual to know the correct fuse rating (in amps) required. There are more than one kind of fuse, one is slow blow and the other fast blow or fast acting, the fast blow is what you usually use, slow blow is for things with motors or similar that have a possible high initial rush of current and the fuse allows this to pass for a certain amount of time without breaking. I like Maxi type fuses, their holders are large enough to accommodate the larger section cables required.

When selecting your fuses and holders, please make sure you use ignition protected items, sometimes the fuses are protected, others have to be inside of a specific holder to comply, Blue Seas makes some nice ones. The ignition protection is especially important if the fuse is fitted in a petrol (gas) powered boat.

RCA cables ready to be assembled, this type has a spring that protects the cables.

RCA cables, depending on the stereo head unit, it may already have RCA outputs to go to an external amplifier, if it does not then you will have to make some up, don´t worry its not difficult. You could always just buy some ready made, I find making my own easier as it can be difficult yo know the right length and, pushing RCA cables through bulkheads or between gaps in panels can be a pain.

There are many tutorials on YouTube showing you how to solder up these connectors, this is one of those times that its okay to make a solder connection on board. The important thing is the centre pin is the positive connection and the exterior ring is the negative.

Speaker cables, If your speaker cables are in good condition you could just leave them, if however, you have that very thin ultra cheap stuff that looks like its from the 70s then I would replace it.

My hearing is not brilliant, but I know a few people who are very good with stereos and HiFi, they told me it wasn't actually worth spending a fortune on high end speaker wire, twin1.5mm2 should be absolutely fine.

Final steps, as mentioned before, the final set up is important, play some of your favourite music (follow #boatmusic for some great tracks) and adjust the amplifier levels, usually marked as gain, please refer to the instructions, as various adjustments do vary by manufacturer, if you omit this step your music system will not sound its best, I don´t mean will not be loud enough, it just won´t sound right to you.

I am quite a fan of the Fusion brand of products, they make stereos, speakers & amplifiers that are only made for use on boats. They have a particularly useful app (Fusion Link) for setting up stereos and other accessories, its easy to use and really helps with the final set up if you have one of the compatible stereos.

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