i replaced all my speakers with jbl gto's and added two 12 skar subs in the trunk and put a pioneer nex 4200 in the dash. now when i decelerate or push on the brakes i get a high (and i mean high and annoying) pitch noise coming through the speakers. i have tried wrapping the crossovers in foil. i have added sound matting under the amp. any ideas.
You are on the right track but somewhere you have the emf still entering your audio wires. More than likely it's pre-amp.
