Ok, not trying to be a douche.. and sorry about bringing this thread back to the top lol I was just browsing the forums, but SX's DO have better SQ than L7's... ya, ya, install and such does take a lot into affect, but with the same install (ok, not same install, but if both were setup in the same vehicle at different times and tested in THEIR optimal enclosures/installs) the SX has better SQ than the L7.
Just like AQ's aren't known for having the greatest SQ, but some people have made good, LOUD nonetheless, but good SQL systems with AQ HD's, the L7's have obviously had some owners who installed them right and got some decent SQ out of them.. but as far as general "SQ" goes, I have to say, every L7 (though I have only heard a few systems with them) system I have ever heard sounded like balls..
But I do agree with MikeyB that the more power the L7's have the better.. because the best "SQ" (I put it in quotes because at 1500+ watts true SQ kinda goes out the window somewhat) I ever heard from L7's was my buddy's two L7 15's in a massive ported box (probably 10+ cubes) in his 90's Yukon XL with 3200 watts total, and even it was still pretty much just noise and air lol..
But anyways, my opinion and personal preference ANY day, if I HAD to choose between L7 or SX:
SX. No doubt. All day everyday. And I'm not a fanboy, I have AA Arsenals lol..
Trevor