this is all using the torres box calculator.
my outside dimensions are LxWxH 40.5 x 24.5 x 19.5 it comes out to 9.7 gross cubes. bracing displacement is .11 cubes, driver displacement is .28 cubes. that leaves me with 9.31 net cubes before port displacement.
my problem is i cant seem to tune the box to 30 Hz without volume dropping drastically AND maintaining 12-16 square inches of port area AND a 1:6 port ratio.
i tried the port at 18" high X 6" wide X 30" length and that drops me down to 6.82 NET cubes, 108 square inches of port area, and 1:3 port ratio.
i tried 18" high X 3" wide X 11" length and that drops me 8.68 NET cubes, 54 square inches of port area, and a 1:6 port ratio.
this is for 2 15s and im trying to maintain at least 4 cubes per sub. what am i doing wrong?