ok , so i should have said that my box isnt square, its actually a pentagon. it took me a min to get the area anyways, i got 733in^sq= 5.09ft^3 my port area can be H4.5x W12.5 X 22LONG ??? tuned to 33hz Yes ?... no? i just email fi an requested to change my sub from dual 1 to dual 2... hopefully its not to late