Could be both. Do your lights dim? That'll tell you how much current the amp is drawing. A JBL 1200.1 at full outputcan pull more than most stock alternators can put out, not accounting for the accessories the car has to run. The shivas can be used in a lot of boxes, but I'd go at least 1.5 per driver. You could also check the speaker polarity. Camry's have a good bit of sound deadening, let down your seat and see if that helps. If it does, you may need to couple the trunk w/ the cabin.