whining from speakers and popping noise when using trim control

I had a problem with speakers popping when using trim tab control, fixed that by installing 63v 100uf caps on 3 leads from rocker switch, popping was really bad ,was awful thru my Rev8 towers,so I am glad this is fixed. But I still have a issue with alternator noise thru boat amp and tower amp, if I disc RCA at amp noise goes away and I have tried RCA isolators but they did not help. Maybe I have one bad amp and issue feeds back onto good amp?? or is this just a ground loop issue somewhere in my wiring. Head Unit is now grounded at same place as amps so maybe issue will be better but I still had noise when using ipod direct to amp, to take HU and WS-420 of the mix to try and identify the problem. Should I try a noise filter on alternator output?? I have 2 new batteries and all power cables are #4 copper and I have a battery switch in case of fire or electrical problems. Any suggestions??? Thanks Dave

Dave,

Since the noise goes away when the RCA cables are disconnected from the amps, this indicates that the noise is coming in on the signal line and is upstream of the amps. They are simply amplifying whats coming in.

With a dual-battery setup, all the audio components need to share the same power source. It sounds like the amps and head-unit, and possibly the WS-420, are not on the same battery B+. My guess is that that amps are connected directly to a battery and the head-unit is still powered via the factory harness, thus connected to the original battery or C post of the switch. 90% of the cases I see, relocating the head-units yellow B+/MEM is the fix. This may be whats needed for you, but depending on your battery setup and switch, you may need to do some additional rewiring.

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Originally Posted by Wylietunes

Dave,

Since the noise goes away when the RCA cables are disconnected from the amps, this indicates that the noise is coming in on the signal line and is upstream of the amps. They are simply amplifying whats coming in.

With a dual-battery setup, all the audio components need to share the same power source. It sounds like the amps and head-unit, and possibly the WS-420, are not on the same battery B+. My guess is that that amps are connected directly to a battery and the head-unit is still powered via the factory harness, thus connected to the original battery or C post of the switch. 90% of the cases I see, relocating the head-units yellow B+/MEM is the fix. This may be whats needed for you, but depending on your battery setup and switch, you may need to do some additional rewiring.

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Micheal thanks for your advice, I have rewired head unit to same power source so I just need to pull boat out of garage and run engine and see if noise is gone now. But I did try ipod direct to amps and noise was still present, I will also try resetting the gain controls on both amps to see if they are turned up to high and not in balance with input signal, I will use a test tone cd for this and set ac output voltage on speaker outputs to match Jl Audio's recomended voltage

I had this issue a few weeks ago I had to find the rca isolators that had the ground and attach it back to the engine block and it halfway was gone I dubbled them up and it was completely gone. I do know some isolators will not work in a marine stereo I bought the jl modles that had a ground

Michael you were dead on about grounding head unit with amp power wiring, noise is gone and stereo sounds great, I spent a fair amount of money this year buying rev8 towers, 4 XS 650 speakers and 2 JL amps. I never had this issue with my Clarion amps but new JL amps draw more power and have more output power.

Anyone having popping noise when using trim pump, easy fix is install 3 50v 100uf capacitors on blue,yellow and green leads at trim switch and then ground all three caps to main circuit board where breakers are under the dash. I stripped the insulation off the leads and sodered caps to wires then used glue gun to insulate leads at capacitors also sodered all 3 caps ground leads to ground wire. This
repair worked really well, I was worried about damage to cross over board in tower speakers as popping noise was very loud***