The coaxials behind the seats have started to buzz after the OEM head-unit was replaced (JVC unit), but only with the air conditioner on. Power is coming from the OEM harness. Any suggestions? Run a clean power line? Noise filters etc.?

 

I have a slight "Buzz" too. All my speakers are amped so it could be distortion from the RCA or maybe even noise from the power cable who knows. I dont hear it with the volume up though only when the speakers arent putting out any sound