I find that switching CDs, switching to an mp3 recorded CD or my Ipod, I'm always tweaking slightly....sometimes too much bass, sometimes the mids are too high...one cd does not play the same as the next, that's the beauty of having flexiblity at your fingertips.

As far as speakers, I have 5.25 JL ZRs. I was wondering if a 6.5 could fit in the front door, I haven't taken it apart yet so no idea. They are not much deeper than the 5.25s really at all so I guess it could be possible. If they do, I'd just put the 5.25s in the rear..I know you don't like rear fill though!