hunterw
+1y
15s can give you tight responsive bass and also better (IMO) lowend bass performance then 10s or 12s. but 6.5 cubes isnt alot of space for 15s. i would do 4 10s in a ported enclosure. but i think whatever size sub you go with id go with either all sealed or all ported. when you mix boxes it can create cancellation. you can get more effeicient performance out of a tuned enclosure that can be responsive and tighter then a sealed enclosure. as far as woofers go. i would do 4 fi car audio q 10s. or even dr sound labs level 3 10s