A 15" cube really wont give you the enclosure volume needed for a low tuned sub even with PR's, the drivers will eat up too much volume. You really need to go with a 16" cube. A 10" driver would also be more optimal for digging deep in low volume. Yes you are going to give up output and sensitivity, but that is the trade off for low and small. A HiVi SP10 paired with dual CSS APR12's (loaded at 900g) will basically get you flat to 20hz and handle about 650 watts.
2/21/14 at 8:45pm