Theres a light fuzzy sound with the car off and the head unit on, once i turn the car on i get very profound screeching/whining sound. i understand this is called and alternator whine, that changes with how much throttle im giving the car. i am mildly experienced with sound systems and have tried all i know as well as google to fix the problem with no luck. My audio wires are run on different sides on the car as the power and remote wire. I have put on a ground loop isolator, a noise suppressor on the power wire and i tried running a wire from the body of the head unit to the amp. i am using a 4 channel amp 2 of the channels bridged to a jl 8" sub, other 2 channels to pioneer door speakers, on a pioneer headunit. i have tried hooking up a different 4 channel amp with no difference. i hook up a pos 2 channel amp to only the door speakers it goes away. Thanks for any help

 

Any suggestions?

 

I'm not familiar with the location of the fuel pump in the s2k but I do know it can introduce the "whine" into the system as well. Have you tried running the speaker wire down the other side of the chassis? What concerns me is that the ground loop isolator didn't remedy the situation.