So today I hooked my door and rear speakers up to a 4 channel amp in my 99 Camaro. They are making this horrible whining noise & it gets worst while accelerating and with the ac on.
I know the amp & wires aux cables are good. The funny thing is that I don't have the amp connected to a stereo , the only thing connected is the 12v and the speakers to the amp, its not grounded or anything.... Any suggestions? I had it grounded and it did the same thing , I un-grounded it and its still making the noise.

 

sounds like you are getting alternator noise on the speakers, do you have the whine when the car is off? I'm assuming you won't simple few things to check out before you freak out, do any of your power lines to the amp or head unit come close to any of your audio wires?