Well me and my buddy Kieth just got donw installing in my new system. We modified the bose kick panels to except 5.25" infinities. The installation went very well jsut took some time.However, their is a very distinguished whine which comes through the speakers when the rpms rise. Its very annoying!Im pretty sure we need to get a new ground spot for the amp because we put it on the metal rod which holds the spare tire in. I have gold plated and shielded rcas from walmart and gold plated y connectors for the back of the head unit. The head unit is a Kenwood but doesn't have a noise filter. The only other thing i can think of because this problem wasnt their before the amp is that we ran the rcas, speaker wire and the power wire under the brackets in the car. Would this make that bad of a whine? Besides the noise though the job turned out kick @$$. Should i get a noise filter for the alt and not the head unit? ANy help is appreciated.

 

Did you run the power wires near the RCAs? If so that could be your problem. Re-run the cables apart from each other. Also, get a better ground on that amp NOW. A bad ground at the amp could KILL your HU and could be the problem to start with.

Is it there with the radio and CD or just the radio? If just the radio it could be an antenna problem. Unplug the antenna and see if it’s still there.
If both try, unplugging the RCAs from the back of the radio. If it is gone it’s probably coming from the HU. If it’s still there unplug the RCAs from the amp, if it’s gone it’s probably coming from the RCAs.

Didn’t the Kenwood come with a noise filter on the power leads?

 

It's a ground, just like you suspect. Find a better ground for the amp, and most likely that will solve your problem. The problem is what's called a "ground loop" and it results by the presence of a voltage potential between two ground planes. In easy-to-understand terms, it means that there's actually a small voltage between your radio ground and amp ground, which is carrying the noise into the amp. Getting a better ground will eliminate the voltage potential and in turn, will eliminate the noise.

 

Yea you should be able to fix it with a good ground.

A ground should be as big as the feed 12v+ wire and as short as possiable.

 

And equally as important, it needs to be terminated somewhere clean and of low resistance, such as the subframe or at least part of the unibody construction.

 

Yep,