^^^ exactly. The box will be determined by the theile-small parameters of the subwoofer. Go to the manu's website or check the manual and find out what the recommended air space is. The shape of the box doesn't matter (as long as it's not perfectly square) as long as the internal airspace is correct. To calculate air space of an enclosure you want to build, multiply the w x d x h and divide by 1728. This will give you the air space in cubic feet. Hope this helps.