Let me start off by saying I am not trying to gain any benefit over using a slot port. This is more of a just for looks box, but I still want it to be tuned right. I'm not sure about what subs yet, but I think it will be 2 Memphis PR 10's in a Ford truck with no extended cab. How do you do the math for 2 round pvc ports sticking about 1 foot outside the box and what's the best box program to use for this?