i have a little 2003 pontiac grand am and i just blew out both of my rear speakers which i believe to be 6 x 9s so i went down to my closest speaker shop and talked to a guy who told me some aftermarket speakers i could get but the wiring is a little different so those speakers would not produce bass just treble. he said i could get sub woofers for my bass which i had wanted anyway no the question is he has 10s for $250.00 plus installation and 12s for $350.00 plus installation is there really that much of a difference between 10s and 12s?