Yesterday I installed an in-dash 10-band equalizer. After installation (which only required connecting power and ground wires, plus unplugging and plugging a few RCAs) I can hear feedback through my interior speakers. I only hear the feedback when the car is running, and only when my equalizer is turned on. I don't hear any feedback through my subwoofer, but it's not run through the equalizer, just directly from the head unit. I'm positive installation was good; I just rechecked today. Also, the feedback pitch gets higher as engine RPM gets higher. With the music at decent volume, the noise is drowned out, but I still would prefer it not be there. Any ideas?