would it be worth getting say a 4 channel brideable amp, running the door speakers of 2 channels and briding the other two for my sub? the only bad thing about 6x9 is being placed in the parcel shelf is as the the sub vibrates it also vibrates the whole shelf including the speakers, cant be doing the speakers wonders. aw well, i wouldnt know where else to mount speakers in the rear. oh whats a sound stage :$ and double oh, just realised that those alpine speakers are 4" mine are 5.5 but look the same