Ok, i need help here. I've been installing gear on and off over 14 years and i've never encountered this. I hope it's simple and i just missed something....I have a Panasonic CQ-dvr909u deck, and i have feedback coming through the speakers. It sounds like humming, or a buzz of sorts and changes very slightly with idle., not alt. whine, at least not high pitched.I've tried 4 diff. amps, and 2 different decks, and diff. rca's. The noise stopped with a low-voltage entry level sony, but a high end old school kenwood with 4v preouts, same thing. I have the amps grounded to the bolt on the rear strut tower...by the way, veh. is a 93 accord EX. Help!..............