You could build something in between 2pi & 2pi Towers. A box with measures 40" X 13½" X 12" (H x W x D - outer dimensions) build with 18-19 mm (3/4") sheed will give you a volume of aprox. 2½ cb.ft. (70 liters). Tuned at 40 Hz the F3 will end up just below 50 Hz. So you'll end up with a floorstander of more manegable size than the Towers, albeit with not quite as deep bass. Just a suggestion.