Also... there has been a slight change in plans sadly... my window line is 18", and the bellmouth on the 12" port is 16", and if the sub is above the window line that puts me in the "wall" class, so I am going to have to run 6" or 8" ports instead and I think I will end up with about 7-7.5 ft^3 instead of the 8.5ft^3 I had originally planned. I have been working with some pretty serious SPL competitors and, well, to be honest, I am listening to everything they say as one of them is hitting like 153+ in his trunk with a single 15" and like 3Kw so I think he knows his **** pretty well...