Help Tuning Sub Box?

[Gil Loyola]

Hi everyone im new to this forum......ive been looking around for this answer now and im just confused. Here are the outside dimmensions for my box for 1 18" re sx...36W x 14H x 44D thats 10.6....cubic foot or so. My question is when tunning this box do i use the 10.6cuft too put into the calculator or do i first subtract the woffer displacemnet and bracing. I want my port to be 10w x 12.5h.