I asked this a while back and didn't receive and answer:
"Quick question... I'd like to make a larger box for my next pair but don't wanna go a big as the tower... would their be a benefit to say going with a 2 to 3 ft3 box? I assume for port length I would just calculate for a 40hz port?"
I'm building a pair of these for a friends and the towers are too big for his space... but he'd like the benefit of floor standers and maybe slightly stronger bass... is there a size/volume in between the regular 2PI and the 2PI tower that will work?