Thanks for all ur feedback. I'm fully convinced that ported will be my style of box. I'm still waiting for Fi to finish my sub. I currently have a 5 cu box tuned to 40 hz laying around. I plan to use that as a temporary box for my sub's break-in period. I realize Fi has their parameters available, but feel isn't as accurate due to a tighter suspension. I'll play the sub a lot longer before I bench test it using my Dats Wt3. The modeling program I use is winspeaker, and willing to try something else if recommended. I think 6.5cu seems like a good number! My current box is a sub up port up...good for spl, bad for sound quality. I wonder if aeroports have something to do with that....