hello. Im having some noise issues with my 2011 mustang audio system. I have installed an aftermarket amp/speakers and subs. Im using an audiocontrol LC2i LOC and getting the signal from the front speaker wires coming out of the radio harness. Using a kicker IX 1000.5 amp. Here is the issue. I have a high pitched noise coming from the speakers. It only happens when the car is on and does not fluctuate depending on engine rpm. I've check and rechecked all my grounds and all is good. even grounded straight to battery just to be sure. I even installed a ground loop isolator with no luck. I had a spare oem radio which I switched out and problem is still there so it cant be the headunit. Gain on the amp is a little less than half way and I did notice that if I turn the gain to about 1/4 the noise goes away but at that point I have to max out my volume to get a somewhat decent loudness. What could the problem be?? any help is appreciated.