It has been a while since I built a box and was trying to remember how to figure int. vol. If a box is internally 22.5 x 22.5 x 21.75 you get 11010.937 cu. inches. Next a cu. ft. is 12 x 12 x 12 which equals 1728 cu.in. Then the 11010.937cu. inches and divide by the 1728 cu. in. to get the box volume, correct? Which is 6.37207. So next I need to find out the displacement of driver volume...... Help!! I misplaced my paperwork on the malestrom... What is driver volume please?