Shameless plug ...
I thought I was going to build this box, but realized it's too big for where I'd place it. Instead, I'm going for an IB system and have already purchased the new drivers for that install.
I now have a 12" Infinity Kappa Perfect VQ (with *2* 4 Ohm voice coils) available. The mid-Q pole piece has been installed. I don't have the other 2 pole pieces - I'm the 2nd owner.
If you live in the Wash DC Metro, Northern VA area, I want to sell this driver for $80.00. I won't ship it as I've tossed the box.