Hey ok this is my second thread on my amp problems, when I put it on no filter I get that winny noise that sounds like a bad ground. And when its on low-pass filter, I get no noise. So I belive its a ground problem so how do I fix it and where is the problem.

 

I read your other post.
1) Try to reground head unit. Do not use stock ground wire(if there's any), but screw it to the car chassis.
2) If you have outboard xover or EQ, try to reground them
3) If all above will not help get ground loop isolator at Radio Shack and install it at RCA cables going into amp. It's $20 item and it will get rid of all noise. One drawback-it will cut your high frequency output just a little bit. You probably won't even notice it.
Alex

 

Thanks

 

Paolo, how are you posting if you were banned?