The
Exodus Audio Shiva X2 would also be a suitable driver for a premade enclosure in the 2.0ft^3 range.
It will yield an anechoic f3 of 32hz sealed at 107db with only 500 watts. -6 db would be at 25hz and an f10 at 19hz. This is very nice sealed performance with no EQ. With some Eq added in room I would expect that +/-3db response could be had from as low as 25hz or or better up to the xover point.
Moving to 1000 watts would yield an additional 3db across the usable range but would begin to limit the use of optional eq.
