I have a 2004 durango with the ifinity 6 disc changer in it. I installed an amp about three months ago to add some subsand everything worked fine. The other day i noticed some sounds that were not a part of the song. When I turned down the radio my subs were still makinga pulsing beat.I have tried to see where its coming from. My rear speakers where I got the signal for the amp are not doing it.I hooked the amp in my other car and it is not doing it either.So the only thing left I think is the speaker level converter.Is there any thing else this could be.

 

Does it do it with the engine running or not running....or both?