Has anyone ever heard of this?

http://www.eminent-tech.com/RWbrochure.htm

it's an ultralow frequency subwoofer -- for the 1 (yes, 1) to 30 Hz range, +/- 4 dB.

more info here:

http://www.eminent-tech.com/howitworks.htm

I have to wonder how this might work with an LFM-1 Plus and a crossover.

I saw some mention of a "sub" like this a couple months ago. There's some part of me that feels a bit odd connecting any amplifier to an electric motor, though.

They have a downloadable DVD to show off their sub. Would you be willing to try it on your system?
http://www.rotarywoofer.com/demodvdwebpage/eminentdemodvd.html

Yike. I guess that if you wanted to try to do some destructive testing on a sub driver, that'd be a good candidate for source material.

Are there not many among us that chafe at the thought of noise that has nothing to do with the intended signal coming from one or more components of our system? Without some very creative cabinetry, this thing would be generating way too much extraneous noise for my taste.

I thought it was interesting that they recommend (require, actually) this thing go in an infinite baffle rather than a conventional cabinet enclosure. Presumably in a case like that you could share the same IB with some traditional drivers for the >20Hz bass information.

What would really intrigue me (although this is probably the fan guy coming out in me) would be some data on the fan: RPM (it would presumably be variable to adjust SPL level with the blade pitch changes providing frequency modulation), airflow in CFM (cubic feet per minute, although this will also vary pretty widely), or maybe just a fan curve (or curves, since each RPM and blade pitch would produce a different curve). With a couple of those tidbits, I could probably spec a really obnoxious single-frequency tone generator (fixed blade pitch) with an off-the-shelf fan...

I believe I read about this a while ago...
if I remember, they were charging something in the area of $11000 for this set up.

maybe they came to there senses and its cheaper now.

But why stop at 1Hz? Go down to 0.0000000001Hz!

Another unique design for your considerations. An ingenious fellow by the name of Thomas Danley has employed a Direct coupled DC motor to drive a subwoofer many years ago. Differently than Eminent-tech for certain, but never-the-less very effective. His patent was bought out by Servo-Drive I believe. Check out www.servodrive.com to see the current pro and home versions. Also interesting was the project, from which the design for the Servo-Drive subs evolved from. The original Tom Danley designed sub, the Pachyderm, was created to reproduce subsonic bass below human audibility. The Pachyderm http://www.ultimateavmag.com/features/704way/index3.html. I have "experienced" the Contrabass, and folks it just don’t get much better - :-) in my humble opinion. The real ingenious part of this design to me, is how efficient it is, and the fact that the woofer becomes more linear the harder(louder) you play it – the opposite of conventional cone subwoofers.