simply put, they are transducers you attach to your couch. fed by a signal from the LFE channel, and powered by an amplifier they produce LFE that shakes the couch
AHH - like the old sensesurround they had in theaters for Midway.
HECK - who needs that with a SVS LOL.
HOWEVER - curious - how much are they ??
I like the message The psychological effects of tactile transducers is unknown. But some subjects have felt continued shaking and vibration hours after the transducers have been turned off. The long term effects of tactile transducers could lead to nervous disorders or paranoia. Just like video games have the epileptic seizure warnings, caution should be practiced with tactile transducers.
Brian, other links on the referenced FAQ site give a rough pricing for some of the mentioned brands. The non-pro Auras seem to have been abandoned (not supported) by Aurasound and go to about 30 bucks a pair on Ebay