bose
Actually, I have been told that there is partial amp power at the control unit and partial amp power at the speaker. You may just need to change out the speaker. I hate this bose system. It is the most difficult to upgrade because of this. You can not use a regular speaker in its place. You either live with the ok sound or totally change out everything to get good to great sound. I have heard that others like their system, but I don't care for it. Bose squeezes its sound into narrow wave bands so it can get loud with little cheap speakers and a piece of crap wave base system, but after a while you notice how bad it really sounds.
I gutted my BOSE system and put in a custom system. I will never buy a BOSE product. Your problem, yes I think it's the amp in the door that the speaker sits in. FInd one used b/c BOSE will charge you a ton of money for a peice of crap peice. I have the speakers for sale but only as a set. Good luck


