Ive had many people i shouldn't bother replacing my 6x9s in my car cause the rear deck is weak for quality. They are being forced up by my woofer and pop so i just may take them out and leave the holes for vents into the cabin.
Anyway, does the 6x9 rear deck in a car contribute much? I planned on having loud as fvck 6x9s and tweets in the front. (2 sets of tweets, run one off the rear channel)