I have had this nightmare before on 2 Pioneer screen radios. After trying all, only thing that solved it was using a single set of rcas. In retrospect I deduced it started when I accidentally touched one of the rca's tip to the amp chassis.Awesome, thanks for the help. This amp has speaker level inputs, so if that fixes the issue then good enough. The sub has to run RCAs, but it doesn't seem to be able to hit frequencies high enough to make the noise, so no issues there.