Why would there be a high pitched noise coming from my car speakers when i accelerate and my rpms rise?

Question

So coming from my speakers in my 1997 Chrysler Sebring LXI is a high pitched whistling noise that happens when i accelerate and when my rpms rise. Also the faster i go and the higher my rpms the louder the high pitched noise is. I have been told that it may be because my alternator is worn down and cannot block sound as well, also i have been told it may be because my ground wire is not grounded correctly, or it may be because i have too many grounds going to my cd deck which is a Sony CDX-GT300. The two speakers in the back are stock and they are being amplified by my cars stock amplifier that was put in when it was made because it had the infinity sound system in it, i have replaced the cd deck and the front speakers, the front speakers are 6 by 8 infinitiy references, i had to rewire the front speakers because when i switched out the front speakers they became crossed over due to the stock amplifier. so why do you think my car make the high pitched noise? what can i do about it?

Answer 1

Sounds like you have a ground loop between the sony and the factory amp; I've had relative success by grounding everything in the audio system at a common point.  The buzz is caused by voltage potential being created across the chassis of the vehicle, or across a loose connection.  Make sure all of your components are firmly grounded to bare metal; preferably the chassis of the car.

Answer 2

Snow Patrol.

Answer 3

Alternator feedback, you can buy a relay to fix that.

Answer 4

its very possible its not grounded right.. also it could be if somehow you have 2 wires touching. make sure all your wires are taped up so they dont gound out also