What do you think about this sub?

[jsr]

That's right, I'm using this to herd the cattle! Haha.
Its not really that large and smaller than many of the commercial subs that can't dig this deep. I was thinking about dimensions 19.5 x 21.5 x 20...about 3.7cf gross.

If you like smaller subs, I have a couple of designs that are much more compact. One is 1cf gross digging down to below 23Hz F3. The other is 1.3cf gross reaching 15.2Hz F3. And this is without room loading and no EQing. I design my subs to run flat without the need to EQ up the low end. But these designs are limited to 200W. But the footprint is only about 9 x 14.