wat box would be good for a 15" mojo dual 2 ohm powered by a pma800 from alphasonik.. last time i metered with 2 comp vrs in 6 cu. i was peaked out at 43 so i might tune this one @ 42 . but what would be good cu ft for a single mojo.. i'm buying 2 of them but i think a single one on 2900 would be better then 2 on 1400....thanks for any help