I am looking at downsizing and doing a sub forward/port forward box for behind the rear seat in my truck for a single 10" sub. This pic is minus the front baffle but you get the point. I need to know weather I figured the port length right and what the tuning will be the dimensions are all there but the box is 15" tall outside dim. with a port of 5.5X5" inside dim. Anybody want to figure it for me? I was shooting for about 38Hz how close did I get?