Verified answer

Alphasonik is a bit of a flea market brand... their power ratings are inflated a bit.... not the best quality. I did have a lower end alphasonik years ago though, and it did do the trick.

The problem is, will you have enough amp power to supply them all that wattage? And if so, can you afford the high output alternator you will need since stock units cant really handle over 1500 or so watts?

That box is WAY too small for those subs... 1.5 cubic feet is more for 10's, your 15's will need AT LEAST 3 cubes ported, for EACH sub.