I bought a 04 cavalier. It has the stock headunit but sounded like blown speakers, speakers couldn't handle much volume or bass. I had some old speakers (also aftermarket but smaller in size/rms) that I put in but it still sounds like crap turned up....is this a problem with the signal from the stock headunit? Would an aftermarket headunit make a difference here? Probably a dumb ass question but I wanted it answered before I decide what I'm going to do.