I hooked up at amp today and have a popping noise when I shut my radio off and it makes a strange thud thud thud noise while the radio is on looks like feedback or something anybody know what this is? I have a very good ground even two of them. Thanks.

 

Anybody???

 

are you running your amp with the factory radio?

 

You should only have one ground to prevent ground loops.

 

do you think i need a ground loop isolater I take one of the grounds off it gets worse.

 

When I hooked up my sub amp last week I had no noise or anything, but when i hooked up the highs amp I got all kind off noise. When I shut the door, turn on the radio, let the window down etc... My friend said my other amp is grounded too close to the sub amp. I'm moving it to the other side today to see if it makes any difference.

 

Your friend doesn't know what he's talking about. Having more than one path to ground is what causes ground loops. Thats why everything should be grounded to the same spot. This is what is referred to as star grounding.

Get yourself a set of RCA plugs. Use a short piece of wire to short the center pin to the barrell of the plug. These are called muting plugs. You can also make a set from an old pair of cheap interconnect cables. Just cut off the plugs and strip back the wires so you can twist them together to make it a muting plug. Remove your RCA cables from your mids/highs amp and plug the muting plugs in. This will give your amp a zero volt input. Now disconnect your subwoofer from it's amp. Start your engine and turn your HU on. Do you hear any noise from your speakers? If not you'll know your amp has a good ground connection and that the noise is entering the system further upstream from the amplifier. If you do hear the noise you'll have to try a different grounding point.

Eliminator,
The thud sound you mentioned almost sounds like an intermittent short in your speaker wiring somewhere. You might want to check to make sure you didn't pinch the wire somewhere causing it to short out.

 

It does it when I change the radio stations or turn it off no wire pinches anywhere.

 

What brand and model amplifier and HU are we talking about here? Some details on the rest of the setup might help too.