Where to ground Amplifiers?
 

Like the title says. Amps are under the seats in the middle of the boat. NO metal to be seen other than where the guages are grounded and even at that its only a small piece of flat stock.

it must go to batteries, and use same gauge wire as your + side.

I've been told a few time doing that is incorrect and will fry the amps. Have you done it that way?

No it won't fry amps. Thats the best way to do it. Most performance boats are not built with metal frames like a car, so you have to go back to the battery. The best ground you can get in a car is to go back to the battery, same for a boat.

I did exactly as I was told, I connected a wire to the ground.

I can't go to far from shore but the stereo sounds great...

ground it to the engine that is the best way. also use a larger ground than the power.

Where do you think the batteries are grounded too?

So engine or battery?

You beat me to it!


Thanks guys

i know where the batts are grounded.it is better to ground to the engine than directly to the battery.

can you explain why?

The battery is the largext filter capicator you can get. Why try to introduce noise into the system by grounding to the engine?

There is absolutely no reason to ground the amp to the engine. Either run each negative supply wire to the battery or create a common negative bus near the amps with a single run to the battery or main accessory negative bus.

Ground it to the battery.

Been in the electronics business for 30+ years. The battery is your best place. Use decent cable for both pos & neg.

Thanks guys.

I'm using 2/0 guage wire so it should be plenty. I'm used to car audio where the ground has to be as short as possible.

Mine is grounded to the jumper posts by the Perko switch under the rear bench.

Seems to work well and is more accessible when working on the stereo. Always disconnect the ground when working on your stereo!

Ok i stand corrected:D I was just taught years ago when I took my MECP certification that it is better to ground to the engine in a boat due to the fact that it does not flucuate as much as the ground on the battery and it offers less resitance. Don't ask me why i do not remember.

With that said i have never run into a problem grounding to the engine, and that is how i have done all the systems in boats.

I ran 0/1 gauge for power wire,used a distribution block with 4 gauge ground to battery.is this right? 1 jl 250/1 and 1 300/4

whoever told you that is an idiot don't take any more advice from them!

Agree.

The idea is to provide the lowest impedance return path possible back to the power source (the battery). Assuming your connection from the battery to the engine block is solid, either place is fine. Whichever is most convenient.

Same amps I just installed. JL recommends 8/0 wire at min for those amps. With a distrib box, then 4/0 to the blocks, then 8/0 to amps. So you are fine, as long as we ain't talking about a 50' run. :)
I ran 4/0 to both amps with no dist. blocks.

Take a good digital meter. Connect one end to the negative battery post and the other to the engine block. Set the meter for low volts AC. Start the boat. If it reads ANY voltage, that will show up as noise on your amps. Thats why directly connecting to the battery is the best bet. A battery by its very nature is a capacitor.

The idea that the ground "varies" at the battery more than at the engine block is totally illogical. The engine block ground source IS the battery. If it varies at the battery, it varies even more at the block due to AC leakage from the charging circuit.