Fast one

I'm installing a new Kenwood DNX995S in a '98 C5 to replace an old Alpine head unit that turned on a 5 channel Helix power amp. When the audio system is on and the car is shut off there is a slight thunk sound out of the speakers, the old Alpine head unit that was connected to the Helix never did this. Is there a fix for this, is it inherent in the head unit design or does the head unit need to be returned? Kenwood said that it shouldn't do this and to send it back for testing but they also have no installation advice other than to go to an installer.

TorchRedFred

I'm not an expert but check and make sure the gains are adjusted properly for your new head unit. If your gains are turned up too high it could cause the issue you are describing.

Fast one

It turned out to be an external audio source run through the optional AV connector, when this source is turned off there is no thunk.