Subwoofer feedback

[Deshantai]

I installed a new amp with a 12” sub, every time I turn off my car just before the radio turns off I hear feedback from the sub. It’s a bit louder than whatever my radio volume was set at so if it’s low it’s just above that if it’s loud the feedback so loud it’ll startle you. Any ideas what causes feedback from my sub

 

[adrianp89]

Active Noise Cancelling. Where did you tap your wires? Which system do you have?

 

[Deshantai]

I had it done at a shop but I believe they tapped in the right rear speaker. After they finished I left and immediately went back because the anc was causing feedback from the sound of the exhaust. They said we need to disconnect the mics they did.

 

[Deshantai]

They disconnected them from the headliner not the amp which I’ve read a lot of people do.

 

[adrianp89]

It the cheap way to do it. They make modules to do it correctly and retain ANC.