A Guide ToHome Theater Tactile Sound

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Home Theater Tactile Sound

Chapter 1: Introduction To Tactile Sound• About Sound ------------------------------------------------------------------------ Page 4• What musicians have to say about tactile sound -------------------------- Page 5• A letter from Patrick Moraz------------------------------------------------------- Page 6

Chapter 2: The Physiology of Sound• Hearing via air movement -------------------------------------------------------- Page 7• Feeling via deep tissue movement -------------------------------------------- Page 7• Feeling via skeletal Joint movement ------------------------------------------ Page 7• Feeling via tactile stimulation --------------------------------------------------- Page 8• Feeling via bone conduction --------------------------------------------------- Page 8

Chapter 3: Tactile Equipment Profiles• RBH Sound -------------------------------------------------------------------------- Page 10• Clark Synthesis --------------------------------------------------------------------- Page 11• ButtKicker ---------------------------------------------------------------------------- Page 14

Chapter 4: Installing Tactile Transducers• Using chairs and couches ------------------------------------------------------- Page 15• Moving floors ------------------------------------------------------------------------ Page 17

Chapter 5: Wiring Tactile Sound Systems• Cables --------------------------------------------------------------------------------- Page 18• Connecting to the tactile amplifier --------------------------------------------- Page 19• Connecting to Transducers ------------------------------------------------------ Page 20

Chapter 6: Calibrating Tactile Systems• How to calibrate a tactile system ----------------------------------------------- Page 21• What about imaging ---------------------------------------------------------------- Page 21

Appendix• Specifications for Clark Tactile Outputs --------------------------------------- Page 22

4Chapter One: Introduction To Tactile Sound

Remember the scene in the original Jurassic Parkwhen all the landrovers sputtered and stalled duringthe park tour? The rain was drumming hard on the

roofs of the vehicles and the tension begins to rise. Slowlythe camera zooms onto the surface of a still glass of waterand then the surface begins to ripple. Here Spielberg wastrying to visually give you a sense of something big aboutto happen. Because he was unable to shake the actualtheater floor, he used the next best thing; a visual effect ofwater rippling. However, justsuppose he was able to shake theentire theater floor and shake it inthe way that a nearby 20 tonstomping T. Rex could. That wouldraise a few goosebumps would itnot? Well, maybe the local theatercan’t do it, but you can at homewith Tactile Transducers.

Tactile Transducers areelectromechanical devices that aredesigned to drive large surfaces,such as seats and floors, withauditory information ranging from1hz to 800hz. They are verypowerful devices, but areintentionally installed andcalibrated so as to subtly add thetactile sense that is missing frommusic and movie sound tracks.The result is nothing short ofengrossing. Anyone who hasexperienced it will tell you thattactile sound adds anotherdimension to home entertainment.

About Sound

Many people conceptualize ”sound” as the perception ourbrain produces as a result of auditory energy travelingthrough air and stimulating our ears. This is furtherreinforced by the audio/video industry because

loudspeakers, the industry’s standard sound reproductiondevice, do just that. They are designed to push the airmolecules closest to the drivers thereby creatinglongitudinal waves that eventually reach our ears. Theresult is what we call sound.

However, this is a one dimensional way to look at ourperception of sound because the phenomena of soundinvolves many more facets. In fact there are several otherpathways that acoustic energy travels to us that reinforceour perception of sound, even though they do not enterour ears the standard way, that is, through our ear canals.

In the following section you will see that there are fiveways that pulsations in the auditory frequency range,when applied to the human body, can be perceived. Eachof these sensory pathways has a different mechanism butall of them can reinforce the sounds that come in throughour ears. The general term that seems to have beenadopted for all these additional four pathways is “TactileSound”.

The range of tactile sound, as identified by ClarkSynthesis, is from about 1 hz to 800hz. As you can see,

this is quite a bit higher thanwhat subwoofers deliver andextends into the lower registersof the human vocal frequencyranges.

Tactile sound reproduction canbe utilized for many purposes. Ofprimary interest is the addition oftactile frequencies to thereproduction of recorded musicand movie sound tracks. Theeffects in both of these arenascan be quite dramatic.Participants often refer to theexperience as being thoroughlyengaging, and describe a feeling“that encompasses a sixthsense”. That six sense is theincreased realism obtained whentactile cues are added toconventional air-transmittedsounds.

In addition to standardentertainment venues, tactilesounds and transducers find

their way into other venues. These devices are one of theonly ways that the profoundly deaf can experienceexternal sounds. Tactile transducers have been usedunder Wenger floors at concerts for the hearing impaired.The results have been described as a miracle by manyparticipants.

IntroductionTo Tactile

Sound

Chapter One: Introduction To Tactile Sound 5

The original environment for tactile transducers iscommercial. In military simulators, for example, they areused to generate motion cues, These very low frequencycues are necessary to impart realism into flight and tanksimulators. At the various Disney theme parks, hundredsof tactile transducers are employed in conventional ridesand simulation rides.

What Musicians Have To Say About Tactile Sound

One of the earliest groups to embrace the use of tactiletransducers is musicians. In order to understand why thisis so requires a look at the physical mechanisms at workin a live music performance. Let’s take a violinist, forexample.

When you listen to the recording of that violinist youattempt to recreate the exact perceptions that one feelsduring a live performance. It may surprise you to realizethat what you feel and what the violinist feel are twodifferent things. Here’s why:

When a violinist performs, he/she is drawing a slightlyabrasive set of strings (the bow) across a set of finelytuned steel wires. This excites the wires to resonate andwe hear these vibrations through our ears. However,consider our performer. He/she also feels these sounds.This feeling is direct in the fullest sense of the word, rightup from the chin piece into the violinist’s body. The threemain sensation mechanisms for a musician then are: 1)Through the ears via air-transmission, 2) through their skinvia tactile sound reception 3) through their Cochlea viabone conduction. In short, musicians during a liveperformance experience music quite differently than we doas passive listeners.

You can thus guess at what it is like when a musicianhears tactile sound for the first time. They are usuallyecstatic

A Famous Conductor Experiences Tactile SoundReproduction...

This anecdote was related to us by Tom Fenner atClark Synthesis: During a reception, the conductor forthe Denver Symphony Orchestra stepped out onto acedar deck that was playing a Bach orchestral piecevia Clark Synthesis transducers. After several minuteshe exclaimed that he had never heard reproducedorchestral music so clearly and with such feeling. Heexclaimed that he could hear and feel each instrumentindividually. Soon, he was sprawled out on the deckwith his eyes closed and a grin on his face.

Musicians do indeed here music with a different frameof reference than the rest of us. If you want to be privyto their inner sanctum of musical euphoria all that isrequired is a properly designed tactile reproductionsystem. On the next page we show a letter formPatrick Moraz, the keyboardist for the Moody Blues.Patrick is now a big supporter of this technology.

6Chapter One: Introduction To Tactile Sound

Chapter Two: The Physiology of Sound 7

In order to better understand the physiology of sound,let’s take a look at the launching of a space shuttlemission. In the illustration below have a man and his son

watching a lift off. The sonic impact of this event on ourtwo observers involves two distinct pathways and a varietyof psychophysiological mechanisms.

First, let’s examine the event itself. When the spaceshuttle’s engines are initially ignited, a tremendous blastoccurs at the launch site. The enormous energy releasedtravels through the earth and is transferred to our twoobservers via the ground they stand on. This energy is feltalmost immediately because sound waves travel very fastthrough solid media. Next, after several seconds, theactual sound of the shuttle reaches our observers in athundering roar. By this time both father and son havegoosebumps covering their entire backsides. The reason

for this is the overlapping of five different perceptualphenomena:

1) Hearing Via Air Transmission (Energy Pathway A)

The standard way we perceive acoustic energy is throughour ears. The mechanism is pretty simple. Vibrating airmolecules enter the ear canal and push against the airdrum. This energy is transmitted to the cochlea throughthe inner ear bones. The cochlea is a fluid-filled senseorgan in which small hairs (Cilia) convert mechanicalvibrations into the perception of sound.

2) Feeling Via Deep Tissue Movement (EnergyPathway B)

The ground that is vibrating almost imperceptually beneathour observers is stimulating nerve endings that reside indeep tissues and muscle mass. This sense is called“Kinesthetic”. It comes from the Greek word, Kinos, whichmeans “to move”. These kinesthetic sensations are gutfeelings that occur when powerful objects excite theground near us.

3) Feeling Via Skeletal Joint Movement (EnergyPathway B)

The ground that is vibrating beneath our observers is alsostimulating nerve endings that reside in skeletal joints and

ThePhysiology of

Sound

8Chapter Two: The Physiology of Sound

deep tissues. This sense is called “Haptic”. It comes fromthe Greek word, haptein, which means “to touch”.

4) Feeling Via Tactile Stimulation (Energy Pathway B)

The ground that is moving beneath our friends is alsostimulating the nerve endings that reside just under theouter layer of skin. This sense should be familiar to you, itis your sense of touch. Ordinarily, the sense of touch doesnot come into play with acoustic events but in the situationwhere loud noises are being produced it does. It alsocomes into play for musicians who hold their instrumentswhen playing.

5) Feeling Via Bone Conduction (Energy Pathway B)

If you look at the diagram of the inner ear (on the previouspage) you will see that the Cochlea, the sense organ thattakes the mechanical movements of acoustic energy andtranslates them into nerve impulses, is firmly encased inthe skull bone. This bony protection allows for asecondary pathway for sound waves to reach theCochlea; directly through the bone mass itself.

The phenomena of bone conduction is well known andhas been exploited by many people. For example; incases of structural hearing loss, where the ear drum or theinner ears bones are damaged beyond repair, variouscompanies manufacture bone conducting “hear aids”.These devices clamp onto the back of the ears, or areactually implanted into the skull, to directly stimulate theCochlea via local bone conduction.

Nerve Receptors in Skin Surface

Nerve Receptors in Muscle Tissue

Chapter Two: The Physiology of Sound 9

Diagram of The Inner EarSound waves push on the eardrum which mechanically stimulates the three ear bones .

These push on the oval window of the cochea and create the sensation of sound.

10Chapter Three: Tactile Equipment P rofiles

TactileEquipment

Profiles

SAM-200 Amplifier Technical Specifications:Amplifier Type: Discrete Class A/B

Power Output: 200 Watts into 4 ohms @ 1% THDDistortion (THD): <.15% @ 1 WattS/N Ratio: >75 dB (without filter)

Input Impedance: 45 Kohms (line level in)200 ohms (speaker level input)

Input Sensitivity: 18 mV (line level input)100 mV (speaker level input)

Crossover Slope: 12 dB/octaveCrossover Freq. Range: 40Hz-180Hz (-3dB)

Auto Turn-on Sensitivity: 6mV @ 50HzFrequency Response: 10Hz-40kHz (-3dB) (crossover off)

10Hz-Variable from 40Hz-180Hz (-3dB) (crossover on)Damping Factor: >100

Dimensions: 17" W x 4" H x 13" DWeight: 17 Lbs.

FX-80 Motion Actuator Technical Specifications:

Frequency Response: 15Hz-90Hz (+3dB)Resonant Frequency: 43 Hz

Recommended Power: 20-150 WattsImpedance: 4 Ohm

Force: 60 Lbf @ 100 WattsDimensions: 4 3⁄4 Dia. x 2 3⁄4" H

Weight: 3 Lbs.

RBH Sound, Inc976 N. Marshall -Bldg # 2 Unit 4

Layton, UT 84041800-543-2205, Fax: 801-543-3300

info@rbhsound.com

On the next three pages w eprofile three manufacturers of

tactile sound equipment

Chapter Three: Tactile Equipment P rofiles 11

Clark Synthesis, Inc8122 Southpark Lane, Building 300A

Littleton, CO 80120303-797-7500

Fax: 303-797-7501info@clarksynthesis.com

Clark Synthesis was one of the first companies totarget the home theater market with their tactilproducts. Today they remain one of the best tactileproducts available. On the next page the wide varietyof tactile products that they offer are profiled.

12Chapter Three: Tactile Equipment P rofiles

1229 PACKAGESpecial Two (2) TST229 One (1) Amp One, Two (2) XCF50 Crossovers, Two Year Warranty $699.99

TST 229 Tactile SoundTransducer Magnet: 20 oz. Ceramic, Tactile Force: >1.6lbs/wattApplication: Single seating In home theater and carInstallation $199.95

TST 329 Tactile SoundTM Transducer Magnet: 20 oz. Neodymium, Tactile Force:>2.8 lbs/watt Polyswitch ProtectedApplication: Risers and seating In home theaterInstallations $499.95

TST 3710 Tactile SoundTransducer Magnet: 25 oz. Neodymium, Tactile Force:>3.5 lbs/watt Polyswitch ProtectedApplication: Risers and seating In home theaterInstallation $599.95

PLATINUM I Tactile SoundTransducer Magnet: 25 oz. Neodymium, Tactile Force:>6.9 lbs/wattApplication: Risers and seating In home theaterInstallation producing maximum low end response$699.95

TST 229WP Weather Proof Tactile SoundTransducer Magnet: 20 oz. Ceramic, Tactile Force: >1.6lbs/watt Polyswitch ProtectedApplication: Decks Benches and outdoor use, highhumidity environments $239.95

TST 329WP Weather Proof Tactile SoundTransducer Magnet: 20 oz. Neodymium, Tactile Force:>2.8 lbs/watt Polyswitch ProtectedApplication: Decks Benches and outdoor use, highhumidity environments $529.95

TST 3710WP Weather Proof Tactile SoundTransducer Magnet: 25 oz. Neodymium, Tactile Force:>3.5 lbs/watt Polyswitch Protected, Weather ProofApplication: Decks and outdoor use high humidityenvironments $629.95

TST 229 WT Water Tight Tactile SoundTransducer Magnet: 20 oz. Ceramic, Tactile Force: >1.6lbs/watt Water Tight submersible 60 p.s.i.g.Application: Retro-- fit spas Marine applications boat hulls,bilge's $259.95

TST 329 WT Water Tight Tactile SoundTransducer Magnet: 20 oz. Neodymium, Tactile Force:>2.8 lbs/watt, Water Tight submersible 60 p.s.i.g.Application: Retro-- fit spas Marine applications boat hulls,bilge's $549.95

TST 3710 WT Water Tight Tactile Sound TransducerMagnet: 25 oz. Neodymium, Tactile Force: >3.5 lbs/watt,Water Tight submersible 60 p.s.i.g.Application: retro-- fit spas Marine applications boat hulls,bilge's $649.95

Aqua 229 Aquasonic©Tactile SoundUnderwater Speaker Magnet: 20 oz. Ceramic, TactileForce: >1.6 lbs/watt Sound Lens for high fidelity sound,Application: Small Pools, Spas $359.95

Aqua 329 Aquasonic©Tactile SoundUnderwater Speaker Magnet: 20 oz. Neodymium, TactileForce: >2.8 lbs/watt Sound Lens for High fidelity sound,Application: Pools, Spas, Underwater communication$599.95

Aqua 3710 Aquasonic© Tactile SoundUnderwater Speaker Magnet: 25 oz. Neodymium, TactileForce: >3.5 lbs/watt Sound Lens for high fidelity sound,Application: Pools, Spas, Underwater communication$699.95

TACTILE PRODUCTSPRICE LIST

Chapter Three: Tactile Equipment P rofiles 13

TST 229 WTL Aquasonic© Tactile SoundUnderwater Speaker Magnet: 20 oz. Ceramic, TactileForce: >1.6 lbs/wattApplication: Flush mount in American Products Amerlitelight niche’underwater swimming pool light fixture $339.95

TST 329 WTL Aquasonic©Tactile SoundUnderwater Speaker Magnet: 20oz. Neodymium, Tactile Force:>2.8 lbs/watt Polyswitch ProtectedApplication: Flush mount inAmerican Products Amerlite lightniche underwater swimming poollight fixture $575.95

TST 3710 WTL Aquasonic©Tactile SoundUnderwater Speaker Magnet: 25oz. Neodymium, Tactile Force:>3.5 lbs/watt Highest Fidelity &OutputApplication: Flush mount inAmerican Products Amerlite lightniche’underwater swimming poollight fixture $675.95

Amp 1 Amplifier Amplifier2 Channel, 135 Watts per channelat 4W, Front panel gain control,Mono Bridgeable, Stable into 2W,Line out jacks, unswitched 120voutlet .04THD. 110 db S/NDimensions 16 1/2W X 2 3/8H X 11 5/8D $299.95

Amp 3 Amplifier Amplifier2 Channel, 240 Watts per channel at 4W, Front panel gaincontrol, Mono Bridgeable, Stable into 2W, Line out jacks, A&B Speaker Switching, .04THD. Dimensions 16 1/2W X 23/8H X 11 5/8D $549.95

Amp 5.2 Amplifier Amplifier1 Channel, 240 Watts at 4W, Front panel gain control,Stable into 2W, RCA and XLR inputs, small profile.Dimensions 5 1/2W X 4 1/2H X 11 1/2D $249.95

EQ 2 Graphic Equalizer TenBand StereoSpectrum analyzer display,

Channel Level controls, Twostereo line inputs, Dual Tapemonitor loops,unswitched 120voutlet .01THD. Dimensions 161/2W X 3 1/2H X 11 1/2D $159.95

LLC Line Level ConverterConverts Line level (speaker level)to RCA (low level) Made in USA$34.95 Y3 Y Cable Gold Plated“Y” Splitter, 2 female X 1 MaleRCA connector $7.95

XCF500 Crossover500Hz Low Pass Gold Plated

inline crossover 12db per octave.Application: reduce localizationand high frequencies in hometheater applications. $34.95

XCF200 Crossover200Hz Low Pass Gold Platedinline crossover 12db per octave.Application: Reduces localizationand high frequencies in home

theater applications. $34.95

XSF20 Subsonic FilterSub sonic Gold Plated inline crossover 12db per octave.Application: Reduces ultra low frequencies in signal that isnot needed in some applications. $34.95

XCF500/XCF200 Crossovers

14Chapter Three: Tactile Equipment P rofiles

The Guitammer Company, Inc .PO Box 82

Westerville, OH 43086support@guitammer.com

Voice: 888-676-2828Fax: 815-346-9532

SPECIFICATIONS:

Impedance: 4 ohms, inductivePower Requirements: 350 watts minimum,

1000 watts recommended1200 watts peak

Resonance: 9 Hz.Response: 5-200 Hz.

Size: 7.5" W x 7.13" H x 6.0" DWeight: 18 lbs. (22 lbs shipping)

Thermal Limit (internal): 150 F. (70 C.)

The Guitammer Company offers their Buttkickerseries of tactile transducers to the home theaterenthusiast. These transducers are large but verypowerful. Note that they need powerful amplifiersto drive them also (1000 watts recommended)

Chapter Four: Installing Tactile T ransducers 15

All structures suspended between two or more hardpoints will bend and shake between those hardpoints, depending on the construction and rigidity of

the suspended sections. For example consider a roomwith suspended joist floors. The floor is supported aroundthe edges (at the walls) and is capable of bending andvibrating in the area between its supported hard points.This is similar to a guitar string that can vibrate betweenits supporting hard points at each end of the string. Thisfloor would be best shaken by a tactile transducermounted to the floor in the center area of the room.

Another example: consider a room with a concrete slabfloor, laying directly on the earth. This floor will bepractically impossible to shake. In your main listeningarea, your favorite couch is the next viable option. Thefeet at the ends of the couch are pressed and held firmagainst the concrete slab by its weight and are thereforeunmoving hard points of the couch. The length of thecouch between the feet is suspended and will bend andshake only to the degree allowed by its materials and

construction. As it sets, the furniture may not respondproperly at low frequencies.

Using Chairs and Couches

Two primary reasons for shaking furniture rather than thefloor are:

1) It is not possible to move the floor. If your floor is aconcrete slab, and therefore resting totally on the earth, itwill not move. Shaking your entertainment room furnitureis the next viable alternative.

2) You choose not to move the floor. If you live in anapartment building with neighbors below you, you maywant to enjoy the low frequency shaking of a tactiletransducer without disturbing their privacy. Shaking yourfloor may mean that their ceiling will also shake. Thereforethe furniture to be shaken must be isolated from the floorand driven more directly.

For full low frequency response in any configuration, thefurniture on which you sit must be allowed to move with orwithout the floor. The best experience is obtained byshaking the floor and everything on it, because the floor isyour physical connection to your environment. Moving thefurniture alone, and therefore only part of the body,presents the distinct disadvantage of allowing the feet torest on solid, unmoving ground, allowing your mind todeny all other senses input. This disadvantage can bedrastically reduced by adding a properly built platformunder the furniture with a forward extension for restingyour feet. Since both configurations will be applied, we willcover each separately.

Most furniture will not provide adequate low frequency

InstallingTactile

Transducers

Mounting Underneath AHome Theater Room Floor

16Chapter Four: Installing Tactile T ransducers

2x6 Bridge Details

Construction Of A4’ by 4’ Home

Theater Room Riser Platform

Chapter Four: Installing Tactile T ransducers 17

A Tactile Transducer MountedUnder A Sea t

response while resting directly on an unmoving floor.Therefore, some kind of "cushion" needs to be placedbetween the furniture feet and the floor to isolate thefurniture from the floor allowing the furniture to vibrate.With some kind of rubber cushion between the furniturefeet and the floor, the furniture is allowed to move withoutthe floor moving. The material and shape of material aredependent on the mass of the furniture and occupantssupported by the material. One simple solution is to use arubber isolator of some sort (see image below). This offersa small surface suspended above the floor on which thefurniture can set. If the weight supported by the isolator istoo much then use multiple isolators.

An extremely effective alternative is a simple platform,large enough for the furniture it will be under, and the

users feet. The tactile transducer(s) may be mounted ontop of the platform, either under the couch or chair(remove dust covers) or behind the couch or chair.

Moving Floors

The floor of your entertainment area is your physicalconnection to your environment. A suspended, joist floor isthe preferred mounting surface for the tactile transducers.Best results are obtained by installing two 2" x 6" boardsbetween two floor joists (see the diagram on the previuospage). Place them near the center of the room, or near theseating area of the audience, avoiding any supports andbracing that would not allow the floor to move. Thenmount the tactile transducer to the two 2" x 6" boards.

Buttkicker Attached directly to ChairWooden F rame

Rubber Isolation Feet

18Chapter Five: Wiring Tactile Systems

Connecting Tactile Transducers to existing audiosystems and home theaters is pretty straightforward. Conceptually it is similar to connecting an

external amplifier and additional speakers to an existingsound system.

Not all sound sources are alike

Tactile transducers respond to a broad range of bassfrequencies, including those far below what we hear, orway down into the feeling range of sound. Today's digitalsound sources are capable of carrying signals down to 5

Hz, but it is the producers who determine the content of asound track. Therefore, the level and range of basscontained within any given sound track will vary. Eventhough a video may show the launch of a rocket, the audiowill contain only what the producers chose to include inthe audio track. Tactile transducers simply respond withgreat fidelity to the existing low frequency content, muchas a speaker responds to the signal given it.

Cables

The use of a large cable between the amplifier and thetransducer is important, particularly if long cable runs arerequired. For shorter runs, 16-gauge wire would beminimum and 12-gauge is recommended. For lengths over25 feet, 10-gauge wire is recommended.

Choosing Power Amps

Check with the manufacturer of the tactile transducer forminimum power requirements. Clark Synthesisrecommends a minimum of 100 watts and suggests more.Buttkicker recommends a minimum of 350 watts andrecommends up to 1000 watts.

Wiring TactileSound

Systems

Chapter Five: Wiring Tactile Systems 19

When choosing a power amplifier for tactile use, please beaware of the low frequency response of the amp. Manymanufacturers rolloff, or cut frequencies below 20 Hz,usually because anything below 20 Hz has beenconsidered unusable and damaging for speaker systems.Therefore, amplifier manufacturers often include additionalcircuitry in their amplifiers to reduce or eliminate thosedamaging "unusable" signals before they are amplifiedand sent to the speaker. This roll off of low frequencies(also called high-pass filtering) is not good for tactiletransducers, although a shallow roll off can be tolerated(i.e. -1.5 dB to -3 dB at 10 Hz). A full cut at 20 Hz andbelow is not acceptable because it will severely limit someof the tactile information reaching the tactile transducer.You should find frequency response listed among theamplifier manufacturer's specifications.

Connecting A/V receivers and Pre-amplifiers to theTactile Amplifier:

The tactile amplifiers need a source of full range (notsubwoofer, rolled off) signal. As shown on the previouspage, we illustrate the Clark/Carver TFM-6 amplifier whichhas two sets of inputs for flexibility. The first set of inputsis for line level, left and right, audio signals. These can beaccessed from A/V receivers and pre-amplifiers viaseveral audio outputs. In our diagram, we show these

signals being accessed via the Tape Monitor outputs. Thisis probably the most popular way because few A/V andmusic audio systems have two tape players these days.Another method is to use the subwoofer out and a Y-connector to split the signal. This method is illustratedbelow.

If line level audio is not available, Mobile Authority offersthe HSHL-2 Adjustable Line Level Convertor. This passivedevice takes speaker level audio and drops it down to linelevel with no distortion. This device derives line level audiowhich can be fed directly to the amplifier.

Connecting to the Tactile Amplifier to theTransducers:

Connecting the tactile transducers to the amplifier issimilar to connecting speakers to an amplifier. As ourdiagram on the next page shows, you can useconventional heavy gauge speaker wire. (Note: be sure towire the transducer in-phase. Two speaker cones pushingair out of phase is bad enough. Imagine two tactile driversdriving your floor out of phase. They will basically canceleach other out.)

20Chapter Five: Wiring Tactile Systems

Mobile AuthorityHSHL-2

Adjustable LineLevel Converter

-Drops speaker level audiosignals down to line level

Chapter Six: Calibr ating Tactile Systems 21

Calibrating the Tactile Transducer System isimportant for several reasons:

1) If the relative level of the transducers is set too low thenthere will be insufficient tactile transduction to the floorand/or seating surfaces. This, of course, would beunfortunate because it ruins the potential effect of tactilesound.

2) If the transducers are set too high, two things canoccur:

1) The tactile effect can be simply annoying. The drivensurfaces will be thumping and resonating constantly. Thiswill ruin the desired effect which is to subtly add “detail” tothe lower frequencies in the audio tracks.

2) You can violate the Haas -10db level (See side barbelow). When this occurs, the higher level tactile soundwaves can mix with the speaker sounds and createimaging problems.

How to calibrate a tactile system:

1) Using a test CD or built-in test tone generator (All DolbyPro-Logic Decoder have this) play a 1 Khz test tone.

2) With a Sound Pressure Level (SPL) meter such as theRadio Shack 33-2050, adjust the tactile transducers 10dbless than the main speakers using the “C” weighted scale.

It’s that simple!

What about Imaging?

A common question and possible objection to tactile technology is the effect of other transducers in thelistening environment. Many A/V enthusiasts spend a considerable amount of time choosing the type andbrand of audio equipment they use. Often they expend a similar amount of energy finding the best location forthis equipment for optimum imaging and sound quality. Mention to an audiophile that you want to drive thewhole floor with sound energy and you are bound to get a strong response. Maybe even a panic stricken one.

Fortunately the situation is clear cut. Tactile transducers DO NOT interfere with other transducers when theyare calibrated properly. And we have a German Scientist by the name of Helmut Haas to thank.

The Haas Precedence Effect identifys the phenomena by which the human auditory system combines soundsreaching our ears within brief intervals. For example, in an auditorium situation, our ears and brain gathertogether all reflections arriving within 30 to 50 msec after the direct sound and integrate them into the thesame sound perception. The exception occurs when the sounds during this time interval are greatly different inamplitude. Haas measured this amplitude difference and discovered that the number necessary to decorrelatethe fusing of sounds is approximately 10 db. Sounds that are more than that in amplitude are perceived asseparate sounds, sounds less than that are not.

Conclusion: By calibrating the tactile transducer volume to 10 db (or more) lower than the primary speakerswill eliminate interference. Imaging will remain intact yet the valuable tactile energy will reach the audience.

Radio Shack33-2050

SPL Meter

CalibratingTactile

Systems

22Appendix

Specifications for Clark Synthesis™TACTILE OUTPUT™ for Electronics

Products

The Clark Synthesis Tactile Output™ may be incorporatedinto stand-alone 5.1 signal processors or componentssuch as home theater receivers that contain a 5.1 signalprocessor.

The Tactile Output shall be made available through adedicated pair of RCA-type jacks as either a letf/rightstereo signal or as two (2) identical left+right monoauralsignals. The default output configuration shall be left/rightstereo.

The Tactile Output signal shall be derived from the frontleft and front right channels, the LFE (.1 or Sub) channel,and the rear left and rear right effects channels. Inaddition, users will have the option of mixing in as muchas 50% of the center (dialog) channel. This option, whichincreases dialog intelligibility, is intended principally forhearing-impaired users.

The Tactile Output signal shall be subject to a user-adjustable delay ranging from 0ms to 50ms. This delayallows users to compensate for the time differentialbetween feeling the sound vibrations (immediate) andhearing the sounds (delayed by distance fromloudspeakers).

The Tactile Output signal level shall be user-adjustablefrom 50% of the 0dB reference level to 100% over the 0dBreference level, via either a hardware or a softwarecontrol.

Composition of RIGHT Clark Tactile Output Signal50% of FRONT RIGHT channel50% of LFE channel50% of REAR RIGHT channel0% to 50% of CENTER channel

Composition of LEFT Clark Tactile Output Signal50% of FRONT LEFT channel50% of LFE channel50% of REAR LEFT channel0% to 50% of CENTER channel

Composition of MONOAURAL Clark Tactile Output Signal25% of FRONT RIGHT channel25% of FRONT LEFT channel50% of LFE channel25% of REAR RIGHT channel25% of REAR LEFT channel0% to 50% of CENTER channel

Hardware or Software Controls to be IncludedMODE – Stereo or MonoDELAY - from 0ms to 50ms in 1ms intervalsCENTER BLEND - from 0% to 50% in 1% intervalsLEVEL - from -50% to +100% of 0dB reference levelMUTE - mutes the Tactile Output signal

CLARK SYNTHESIS8122 Southpark Lane, Suite 110, Littleton, CO 80120 P:(303) 797-7500 F:(303) 797-7501www.clarksynthesis.com

Appendix

Appendix 23