alright if train A is heading east at 65 mph and train B is heading west at 45 mph..yah anyways 
ok here we go. recently I installed an avh p5700dvd into one of my vehicles. now i am getting some kind of feedback through my subwoofer like when i put a cd in or change song i get random bass. plus the subwoofer is constantly moving. when the car is off but the key is turned on it still does it but it is barely noticeable. I tried all the grounds and they are good. I tried grounding the casing and that didn't make a diffrence. I tried running new rca's across the car and that didn't help. I tried one of those rca filters and that just blocked all signal from getting to my subwoofer. when I unlpug the harness that has the video and subwoofer ouputs on it the feedback stops. I am leaning towards something internal with the headunit. this same setup was ran with a panasonic deck and had no problems at all. basically, what I am wondering is does anyone know of any other things I can try before i send the headunit off for service?? thanks for the help