The back speakers have been dead in my car for years and I see no reason to get them fixed - that's how not-picky I am about sound quality. But this adapter is awful even to my undiscriminating ears. Any hint of bass in the music, even at a low volume, and you get a buzzing, popping sound from the speakers. If the singer has a high voice, it comes out very muffled. It's not the tape player -- regular audio tapes sound fine, as did my old no-brand adapter until it had soda spilled on it. This is just a piece of junk.