To the best of my knowledge an amp wont fix it. It may make it worst, but dont qoute me on that.
I would check the settings on the box of your head unit to see if there are any sound cut outs at a certain level to protect hearing loss. I know it seems kinda dumb, but you can never tell with todays technology. Also, i would recheck all your wiring in the back of the head unit also.
1996 Chevy Impala SS BBB -
1996 Chevy Impala SS DGGM -
Replaced BBB on 4/30/2012