Yes, I have two amps, one for speakers and one for sub. 4 crossovers, 4 speakers, 4 tweeters.
Yes I figure I have a ground loop, but unable to find it. That's the tricky part, nobody seems to be able to figure out how to locate the ground loop.
Your suggestion lifting the ground portion of rca cables is interesting. I never heard if before. I need to bend them away? I guess this would destroy the rca cables for future use?
I've just ordered an alternator filter just in case.
Just to rule out any ripple effect from the alternator.
Kinda expensive but I don't have too many ideas. I just want to fix this problem
https://www.wmjmarine.com/150a.html