That little 2" Fountek cone only has 1 mm of linear excursion. To put things in perspective, so does the Dayton Audio 2" dome midrange. Frankly if I was going to the trouble to build an enclosure, I'd want to use a more capable driver so that it would be worth my build time.
That being said, you can tune a .04 cubic foot box (that's the net internal volume, accounting for the driver's big magnet and the port) to about 65 Hz by using 3/4" diameter tube 6" long. Also get a solid rubber cork to plug the port, in case you get distortion on bass notes because of that tiny x-max. In sealed mode you'd have less low end but be less prone to distortion due to over-excursion. You'd theoretically be -3 dB at 103 Hz vented and 122 Hz sealed, but in vented mode you'd have a 2 dB bump from about 150 to 250 Hz, which would probably be desirable in this application.
If you know in advance what the lowest frequency is that the speaker will be trying to play, and/or how much power it will see, we may be able to tailor the design accordingly.