whinning sound, lookin for a quick fix

ok so i hooked up a cd player in a acura legend a few days ago and it has a whinning sound when the cd player is on. when i unhook the rear right speaker is goes away completly. everything else in the car is stock has a stock amp. now my dad has a system in his truck 2 8's and a alpine deck. 2 amps in it also. he hooked a new 4 channel amp up yesterday and hes getting the same whinning sound also. what can i do to get rid of this annoying sound?

I've heard of alternator noise but never heard it myself. Did you place your RCA's and your power wires by each other?

its probably the stock amp doing it, try bypassing it.