PiAlign recommends a cabinet of 4.0ft3, tuned to 30Hz with a rectangular port 2.25" x 4" and 3.6" long. Response is nice and flat, having f3 of 40Hz and f10 of 25Hz.

If you go larger than this, you'll probably want an EBS alignment. EBS alignments offer extended bass, but at a reduced level. An excellent EBS alignment for this driver is 10.0ft3, and tuned to 23Hz. This provides flat response down to 25Hz, and the reduction in output is only 3dB. In other words, output between 25Hz and 100Hz is flat, but reduced 3dB from the level above 100Hz.

I wouldn't make the cabinet much larger than this, because the alignments get too touchy. Some guys put these things in very large sealed boxes, but I wouldn't do that either. You can see what I mean using BoxPlot or another response modeling program.