Hi guys. I'll be building a ported box for 2 audiobahn 10" this weekend, and I have a question. The Vas for this particular sub is .85 cuft, displacement is .10, which gives .95cuft per chamber. Since I'm porting this box, should I increase the cuft per chamber? Would appreciate some numbers . Also, this box will be for SPL, tuned at 40-45hz. Round or Square ports, which would be better?