Why cant you use a 15" for SQ? I know Alma Gates uses 15's in the Beast this year for SQ and its winning every comp it goes to. This myth that a 15 cant be accurate is just that. . . a myth. With the correct enclosure, correct setting on the amp and head unit and proper listening material (no MP3 or other compressed media) a 15 can be just as accurate as a 10.