buzzing/whine from speakers

Just recently I noticed that whenever the car is running that I am getting a buzzing and whining noise that changes according to engine rpm. I have tried almost everything including: 1. upgrading big 3 with 4 AWG wiring 2. swapping out the amp with a brand new one (same model) JBL GTO 100.4 3. tried rerunning the rca cables (had them run through the cabin) 4. used brand new rca cables 5. swapped out the head unit with a brand new one 6. tried grounding head unit directly to chassis and battery 7. 4 awg wiring for both power and ground cables for amps 8. rca cables run on separate side of the car 9. used 2 ground loop isolators (haven't tried using one for all 3 pre outs yet) The buzzing noise seems to change when I take out the head unit from the dash or if I play around with the rca cables. The buzzing noise seems to vary from very little to really loud depending on where the rca cables are placed behind the dash. I have also tried grounding the rca outer shields to the deck chassis but the buzzing is still there. Both amps are grounded to the same chassis point which has been sanded down to bare metal. Here's the equipment i'm running: Amps: JBL GTO 100.4 + Alpine MRP-m500 Sub: alpine type r swr-1242d speakers: 2x jbl gto 938 + 2x jbl p660C head unit: pioneer deh-p4200ub Any help is greatly appreciated as this issue has been bugging me like crazy...

you say JUST RECENTLY... as in you have had the system installed and haven't had any issues? You could re ground and replace rca's if they have become damaged but it COULD be a poor diode in your alternator.Gary Sather

its probably the pioneer. they are extremely notorious for noise issues. if you have already tried grounding the rca shield then one other thing you can do is try using a line output converter to turn your speaker wired into rca jacks. or if your amp has a line level input then you can just run the speaker wires from the back of the radio to the amp. if this doesnt get rid of your noise then something is wrong with your amp or the way its installed.

Try using another ground for your amplifier. I read that you have sanded and all, but it still may not be a proper ground location. I would also use a different ground location for each wire. I recomend these two solutions because they are quick and easy to check, as well as common causes for this problem. I know that sound all too well. Hope you get it figured out man.