Alright, so after an extensive amount of time getting Bass Box Pro to cooperate, then running through about 6 different box shapes and even a few alignment experimentations, I'm 85% sure this is what I'm going to go with and the performance I'm shooting for. This is going to replace the PAP sub on the other side of the couch, so I wanted it to be as end table like as possible, while fitting into an extremely tight footprint. Luckily, and one reason I wanted these drivers, is that they seem to lend themselves to small boxes without losing too much performance.
The current box size looks like it's going to be about 22H X 20W X 21D. For reference, these have an interior diameter of 16.69" and a mounting depth of about 9.5" so there's going to be right around 2" between the magnets. Box volume, minus the approximate volume of the drivers is 3.95 cuft, but that doesn't take into account the bracing. Bracing should yield a negligible impact, especially after the sides are lined with rock wool and it gets stuffed with poly fill. Anywho, for those who have no interest in reading the graphs, F3 is reading 57.63, but that's taking into account maximum output above where my crossover point will be. So if I take the maximum output below my crossover point of 80hz (126db), then my F3 is at approximately 48hz. F10 occurs at 25.5hz (116db). SPL at 10hz should be right around 101db. All of this is with the RMS power of the amp I'll be using with it (1100 WPC). Also, as you can see I'm nowhere near xmax, which is 34mm. At the maximum recommended peak wattage (2000 watts) all numbers get bumped up by about 2.5db's. All in all performance should be pretty much on par with the other dual opposed I have, although it will be interesting to compare distortion between the two.
One last thing. Qtc = .568
