Hey guys, this is a problem that is driving me insane, I have tried almost everything with this car and cannot figure out how to get rid of this noise. I am recieving a high pitched noise coming through the tweeters of the car as a rev the engine. I work in the car stereo industry and have had two seperate installers, each with well over 7 years experience look at it and none of them can pin point the problem. The car i drive is a 2001 ford mustang, it had the mach system in it, but i had it torn out, deck, amps, speakers and all. I replaced it with an Avic-n1, and infinity 5x7 components, kappa perfect 5 1/4 components in the kickpanels, and kappa 5x7 2 ways in the back. The amps being used to power it is one 1200 watt infinity amp, a 400 wat 4 channel infinity amp, and a 200 watt 2 channel infinity amp. the 1200 watt amp is powering 2 kappa perfect 12dvq subs, the 4 channel is for the door and rears, and the 2 channel for the kick panels. the amps are in the back and a custom box was made so that there are three drawers that slide out when you pull down the back seats. on the bottom drawer sits the 2 and 4 channel amp, the middle one has the 1200 watt amp, with the 2 farad cap, and on the top sits the crossovers for the kickpanels (just for show) and the tuner box for XM. The power cables im running are 2 4 guage cables, running down the side of the car, eventually one of them is split into 8 guage for the 2 bottom amps. the other 4 guage goes directly to the cap, then to the 1200 watt amp. the rcas im using are monster cable noise filtered cables, running down the opposite side of the vehicle. the stereo was wired in to the car using a wireharness, i added extra grounds to the battery and alternator, but that has had no effect. I tried disconnected the antenna, but when i did the noise became very loud from the speakers, but when i reconnected it, it turned back to being quiet with the exception of the original noise. i will try to post some pics up in a day or so, but does anyone have any ideas that i may not have thought of? ive tried swapping out the deck and the amps, but they are all fine and not defective. I dont know if it helps or not, but im also using tsunami power and ground terminals at the battery (for show as well, they are nickel plated). at the moment, the only thing i can think of would be that the amps are so close together, forcing the rcas to cross power lines (the 8 guage ones), but this is only where the rcas and power cables connect since the amps are side by side, there is no way to avoid this. could it be that since there are so many power cables and amps in one spot (and above each other) that it is just creating a massive electromagnetic field that is effing up my rcas? Any suggestions would be very welcomed, ive torn this car apart about 15 times, so im at the ends of my witts.