Sub Giving Feedback, Not sure what to check next. . . Options

[My94RedCelica]

Quick question for you all. I tried a search but didn't find what I need. I have a Kenwood in dash DVD player connected to a Kicker CVR 12" The set up and wiring was working completely fine, but after a week I started getting horrible feedback from the sub. My friend had installed the headunit, so I went back and traced the wires. He had the RCA, remote, and power wires running together. So I seaperated the RCA's from the remote wire and I still have feedback. I checked the amp ground. moved it around a little. Now I have a humming feedback, and it gets higer pitched when I hit the gas. i'm not quite sure what to check from here, so any advice would be appreciated!

[Digndoug]

I more or less simple ment, I have been told that they should be, but that was just hear say. I have done it, and sometimes i havnt. I didnt on my car/celi, just cause the first time i ran the wires i cam short. but I have never had a problem, thereforth it dosnt matter. But im also using all high end rockford wiring.

Also if its so low that i cant hear it, I dont think that counts.

When it comes down to it, just use good wiring.

Also have you heard of any thing such as a ground fault intruptor? Its somthing like that. I used it on my old car setup and it helped a lot with feedback. It only costy like 10 bucks too. its just inline with the rca's.