In home theater and audio enthusiast circles, the development of a separate tactile (motion) channel has been the stuff of legends. Such a technology would allow sound engineers to record motion signals to accompany audible soundtracks for playback through an audio receiver/processor to a discrete tactile channel. The current industry “standard” for surround sound, known as “5.1,” is defined by Dolby Laboratories as follows:

“The 5.1 configuration features five discrete full-range channels—left, center, right, left surround, and right surround—plus a sixth channel for those powerful low-frequency effects (LFE) that are felt more than heard in cinemas.”

The development of a discrete tactile channel will require motion, or “tactile,” devices to reproduce accurate movement through home theater seating, much like loudspeakers now reproduce audible sound signals through the air. Although rumored for many years to be in development at major sound engineering laboratories, the consumer world has yet to see such a motion recording and processing technology make the leap from myth to market.

An inquiry to Dolby Laboratories about the possible development of a discrete “tactile channel” in 2003 returned this simple response:

“Dolby Engineers are aware of tactile products and are investigating their applications. More detailed information is not currently available.”


Decades ago, companies like Rolen Star, RBH and Aura Sound introduced products now commonly known as “bass shakers.” These devices all operated on the principle that low frequency “sounds” are felt as well as heard, with the motion component of sound becoming more dramatic as the frequency drops. The term “bass shaker” has since become a ubiquitous moniker used to describe a wide and varied array of tactile devices. Much like the word “Coke,” technically a brand name but now rather indiscriminately applied to various soft drinks, the term “shaker” has since been applied to all kinds of tactile devices, which often are listed in the subwoofer section of home theater buyers’ guides for lack of a more appropriate category.

By and large, “shaker” devices provided a cost-effective accessory to augment audible low-frequencies with vibrations, adding “oomph” to movie and music sounds through a vigorous shaking effect. Other companies, established in the 1990s, improved upon “shaker” technology with devices that were more powerful and which boasted higher degrees of sonic accuracy than their previous-generation counterparts.


We have recently seen the development of “motion simulators,” perhaps most prominently in amusement park virtual-reality rides and in the past several years in high-end home theaters through the use of hydraulic long-throw actuators and specially designed seating. This motion simulation most often utilizes post-production motion programming which, when played via an outboard motion processor in sync with a movie soundtrack, delivers thrilling pitching, tilting and rumbling effects.

In 2003, Crowson Technology, LLC introduced a dramatically different technology, “Linear-Direct-Drive™.” LDD technology is integral to the design of Crowson’s TES-100 (Tactile Effects System). Crowson’s motion device is neither a “shaker” nor a hydraulic “motion simulator,” but something quite different altogether…

The TES-100 is a compact, electromagnetic, short-throw linear actuator which, akin to a “shaker,” responds to audio signals to generate motion, rather than requiring outboard motion codes. But unlike “shakers,” the TES-100 linear actuator creates motion by physically lifting home theater seating up and down in the vertical plane. As a result of its direct application of motion, rather than by “shaking,” the TES-100 Linear Actuator delivers an uncommonly flat frequency response, and its operating range includes frequencies never before achieved in sound reproduction — all the way down to 1Hz. This capability to respond to ultra-low frequencies with a high degree of accuracy opens exciting new doors for sound engineers who have thus far been unable to realistically convey the inaudible ground motion which exists all around us in the real world.

Crowson is proud to be joined in our esteem for tactile technology by industry leaders like Parasound and Marantz America. Marantz graciously hosted Crowson in their 2005 CES eight-seat active theater demonstration. Parasound’s Halo series C1 Controller, with 7.5 Channel “Enhanced Surround” is widely known as the first pre/pro to include four (4) fully programmable output channels intended specifically to accommodate multiple subwoofers and tactile devices. In November, 2005 at Electronic House Expo (EHX) in Anaheim, CA, Paul Brownlee, Director of Operations for Parasound Products Inc., remarked enthusiastically, “It is always nice to see tactile products pushing the boundaries in our industry!”

Crowson’s devotion to accuracy delivers an audiophile-grade motion which requires no equalization or diversion from the movie-makers’ original intent. On the contrary, the experience more realistically mirrors nature’s blend of motion and sound, previously unavailable except through inordinately high sound pressure levels in addition to an often non-linear response. Coupled with Crowson’s BMP-3S (Bass Management/Pre-Amplifier) multiple TES-100 Actuators also deliver steered, or “stereo” motion effects: A first for low-frequency reproduction.

Although motion simulation via programmed motion codes is indeed a stimulating achievement for home theater, Crowson believes that the next step in immersive home theater will be achieved with accurate motion recording and a discrete tactile channel. Motion should be measured from accurate sources and compiled into a motion component of a soundtrack, just like audible sound is accurately measured for a soundtrack. How do we get from there from here? One thing’s for sure – Crowson’s team of innovators isn’t satisfied to stand by and wait…


At CEDIA Expo 2005, Crowson unveiled a proprietary sound and motion recording technique which is so new that it is yet to be named.

Back at the Santa Barbara, CA lab, Crowson engineers had used seismic measuring equipment to record the motion of the frame of an actual, running motorcycle. The motion recording was taken of a 2000 Harley-Davidson Softail (FXST), equipped with a Stage 1 Screaming Eagle Kit on an Evolution 88 V-Twin engine and Samson Shorty Shotgun pipes (Gross weight: approx. 630 lbs). The audible sound from the exhaust pipes was simultaneously recorded using cutting-edge, professional sound engineering hardware and software developed by Echo Digital Audio Corporation, also a Santa Barbara County, CA company. The resulting two-channel recording was mixed down to be played back through conventional audio equipment (sound: channel 1) and TES-100 Linear Actuators (motion: channel 2).

In Indianapolis, the Crowson team contacted custom bike builder John Retzlaff of CycleMax to secure a show bike for the CEDIA Expo booth. Cyclemax generously provided Crowson with a beautiful motorcycle: the perfect showpiece for a moving demonstration. The bike was customized with a significant amount of Küryakyn Chrome accessories and a Big Bore Kit-equipped V-Twin engine (gross weight = approx 620 lbs). The demonstration was then set up with channel 1 processed through a high-end Marantz multi-channel integrated receiver to a Von Schweikert Audio, eight (8) driver loudspeaker near the rear of the bike (simulating the exhaust location) while channel 2 was applied directly to the bike (whose frame was directly supported by an array of TES-100 Linear Actuators).

The result was an unbelievably accurate and authentic simulation of a running motorcycle. The perfect blend of motion and sound was in fact, so accurate that several “riders” were completely dumbfounded. One confused AV dealer from Maryland remarked, “How can you get away with this in here? Where does the exhaust go?”

The motion and sound recording started slowly and went through an entire cycle of revving, stalling and finally, the characteristic smooth low rumble. The bike became a popular place for pictures and a very convincing demonstration of the TES 100’s incredibly accurate frequency response, even in the ultra-low frequency range (below 20Hz). Check out Maureen Jenson, Editor of Home Theater Magazine, going for a cruise – what a great sport!

Crowson’s first demonstration of a motion recording and playback through a dedicated tactile channel was a resounding success, but there is much work to be done before these techniques are adopted by major audio engineering companies and implemented by component manufacturers and sound engineers. With the continued persistence of forward thinking home theater enthusiasts and manufacturers, dedicated tactile (motion) playback as a new standard in home theater cannot help but become a reality. And when it does, you can bet that Crowson will be there.

The Crowson logo is a trademark of Crowson Technology, LLC. All other trademarks, to include Harley Davidson’s Softail and FXST classification, Samson, Küryakyn, Marantz, Home Theater Magazine, Parasound’s Halo Series and those of Echo Digital Audio Corporation, RBH, Aura Sound, Rolen Star and Dolby Laboratories, Inc. remain the property of their respective owners. No portion of this article constitutes an endorsement, sponsorship of or between any companies herein or licensing of their respective products.