just installed new amps(2) with subs(2) and speakers(4). problem, i am getting a popping sound when activating any 120 ac or 12 dc power from the control panel. also comes from trim tabs, and drive trim, but not from other switches on the dash. sound is not continuous, just a pop when the switches are thrown. speakers hooked up to the radio itself do not pop. radio is wired as an accesory in the control panel. tried isolating rca cables, as well as hard wiring stereo/amps to a neutral battery(not hooked to boat). same problem. any thoughts??