Alright guys im deciding to ditch my kickers and go with some fi. Im running a kicker zx1500.1 amp and cant build a box up to 4 cu ft.(gross). I want to compete in a competative class next season called basic 2. and can run three tens, two twelves, or one 15. I also have a trunk car, with seats that fold down. I have been thinking about getting two 12" ssd's or a single BL 15" (loaded). Which would be louder or what would you recommend? Note: i really like the single 15 setup vs two 12s.