When I turn my headunit on/off my subs make a thud noise. It is the factory headunit and it is hooked upto the acc wire. I was told that a toggle switch would solve this problem since the amp should be coming on after the headunit and not before like it was doing. Well it fixed it partially now the thud is only then i flip the toggle switch off.

Any ideas? Is this thud noise hurting the subs?

Thanks!

a question...what is the "it" that is hooked up to the acc wire and controlled by the switch...the HU or the remote turn on lead to the amp?

the answer is a bad ground, either at the HU (first choice) or at the amp. unplug the RCA cables that input signal to the amp and turn the system on again. if the thump is gone its the HU ground, if the thump is still there its the amp ground.

Originally posted by SPL_Eclipse
a question...what is the "it" that is hooked up to the acc wire and controlled by the switch...the HU or the remote turn on lead to the amp? the answer is a bad ground, either at the HU (first choice) or at the amp. unplug the RCA cables that input signal to the amp and turn the system on again. if the thump is gone its the HU ground, if the thump is still there its the amp ground.

Either that or it's an old amp that doesn't have the turn on power control or whatever they call that these days. Old amps used to thump like that.

The "it" is the remote turn on wire. The turn on wire it connected to the acc wire at the headunit and it is hooked upto a switch. I still have to factory headunit so that is the only wire that I though i could hook it upto

It's an old amp without shutdown protection.

It won't blow your speakers, but it won't make them last any longer either.

why do you have a switch? The headunit automatically switches it on when powered up. no need for another switch.

You def. have a BAD ground somewhere.