SQ for me.
Then again, my "SQ" system gets loud enough to compete with some people's SPL setup //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif. I just have to turn up the volume a bit and viola!
I started out with SPL, back when I was 13 or so. Only a year until I got bored of it because I didn't have money to upgrade alternator and battery (was using parent's daily driver).