I'd replace your front speakers first then. Find a set you like and install them properly. That includes deadening the door, preferably sealing it as much as possible so you can get the most out of your new speakers. If you're still not happy, then look into a processor like a Cleansweep.
MODS: PW TMIC, Cobb catted DP, HKS cat-back, AVO filter, Bren e-tune; Konis/Epics, Advan RCII