2 dc xl 18" 4th build.. not sure??

[stanbro]

OK, since I'm stuck with these 18's and somewhat limited space do to the distance between my wheel wells.. I've got a shape that seams it will work. I'm not at all sure if the design would be efficient at all but just playing around trying to wrap my head around the design process. Then if the design even has a chance to work, I'm not 100 on my math by any means. I'll try to explain the layout the best I can. Any opinions or knowledge is much appreciated.

Its kind of a doghouse shape. lol the bottom measures at 37.75" with a height of 15.5" before extending on each side a additional 8" per side.. This puts me at a width of 53.75" above my fender wells (to allow room for mounting the subs). Total box depth is 32.25" w/ a port of 4" x 36.25" x 6". the subs would be facing the rear wall w/ port to the front (end of sealed section is 9" from the rear). I'm shooting for 6 sealed / 12 ported w/ a tune around 45hz. Pics are as follows...

*subs= DC XL 18"

*amp= Sundown NS-1

[stanbro]

only thing i can think of is maybe smoothing out the point-e over fender well part to also add a little more room in between subs and rear wall..does it even matter though.. if anything what would be the correct way to figure cube ft in the weird ass shaped box? I just calculated the two shapes separate then added together minus displacement.. then plugged the values into the12volt calculator to figure port... guess i'll snoop around and play with it more later.. ..