Thanks to all that reply. Like many, I'm satisfied with the bass and midrange in my Sony 12 speaker system (2012 Limited). However, I would like more treble. Does anyone know the size and impedance of the front pillar speakers? I'm assuming they're tweeters? Also, how much of a PITA would it be to change out the center dash speaker if anyone knows? Also it's size and impedance? Once again, thanks!