Looking for 2 15" subs that can go in a smaller ported box. Say maybe 4ft3 to 4.5ft3 total. so 2ft3 to 2.25ft3 per sub. I am going for spl or the best spl I can get with this amp and box size. I have a sundown saz-1200d amp to power these. Looking to spend $250 or less per sub.