I apologize for not being able to track down where I saw the
picture of this. What it looked like was a scaled down version
of what we think of as a plate amp sub.
The company noted as manufacturer has product listed
for home theatre as well -- 5:1 setups.
There have been several small designs at _audioXpress_
over the last few months which look like a match for such
a unit. The Fitzmaurice Tuba (forthcoming) would be one and the
G.R. Koonce project for small 8" vented subs is the other.
My interest in this is a bit tepid though. You see, right
now I am hearing what passes for subwoofer output is a dull
thud through the wall from my neighbors in the apartment complex.