when im playing a cd or the radio there is a clicking noise in the 2 rear speakers. when i rev the engine the clicking starts going faster and faster. also when the engine is off the clicking doesnt happen. tell me if u guys need to know my system.

 

its ur rca's and ur powerwire. dont know too much about it clicking but from the sound of it thats what it'd be. usally its a whining sound as ur rev ur car.??? try moving ur rca's as far away as possible from ur 12v. let me know what happens..

 

The problem is your groung wire. Take a test light and retest your ground it may be to close to to your battery. If this is a after market system and your not using a wiring kit, use the screw on the right side of your heater control unit and this will git rid of the ground noise. it may sound crazy but it works i've been doing this for years. (and No it won't blow your car up)