From the Crowson FAQ:
Quote:Q: Is the Crowson TES-100 different from a "shaker?"
A: Yes, most definitely.
Many people, even some industry "experts" use the terms "shakers" and "tactile transducers" interchangeably, which is not technically correct.
A "shaker" can be a "tactile transducer," but not all "tactile transducers" are "shakers." Crowson TES-100 is a tactile transducer, but does not employ an "inertial-shaking" like any device which bolts onto the internal frame of a chair.
Crowson drivers are true Linear Actuators, not "shakers." They physically lift the seating (in the vertical plane), directly transferring motion at the points that were designed to bear the weight of the furniture.
The result is an incredibly realistic ("fast") motion rather than what can be a distracting, "one-note rumble" (shakers).
Crowson patented technology, Linear-Direct-Drive (LDD TM), delivers an audiophile-grade motion, with a linear, flat frequency response that exceeds even the finest loudspeakers (though it is not designed as a subwoofer replacement).
Imagine attempting to use a siren as a full-range home theater loudspeaker. Sirens are very efficient at a narrow band of frequencies, but terribly inefficient and inaccurate at other frequencies.
Inertial "shakers" can add an interesting, vigorous effect for similarly narrow frequency ranges (different "shakers" are optimized for different narrow frequency ranges), but are severely limited in their overall accuracy due to similar technical constraints.
Crowson TES-100 Linear Actuators are not simple "shakers" and should not be refered to as such.