I suspect they were done that way to make them easier to pop off the fiberglass mold.

Working from a 4 ft horn, and 1/4 wavelength, you get 16 feet. At 1100 fps that sound travels in air, a 16 foot wave is 67 Hz. Actually slightly higher since 1100 is rounded down a little.:coffeedrinker:

Stacking 3 might get you down another 10 Hz. 40 is probably the 10 dB down point.
That's why I don't consider them subs at all.

But on eBay crap $30 speakers are sold as "eight inch sub and piezo.":nosepicker:

I suspect a 210 with 80 hz horn and reflex LF extension is gonna be a nicer box, but I haven't heard the Community speaks, just an impression.