aight i bought a pack at wal-mart with a cd player two front speakers and two back speakers(sony xplod) for my car.i havent installed the two front ones and the cd player itself werks fine but the two back speakers to replace the stock ones dnt seem to get loud or even bass that good at all.im not expecting subwoofer power jus good.i mean the stock speakers in the front sound better.the pack itslef was 99$ from wal mart.any idea why my speakers arent working good?