Bass Shakers

Want to take your home theater experience to a new level? You may think that the way forward is a more powerful subwoofer. But be careful; doing so may result in an unbalance home theater sound – one where the sound from your subwoofer would outdo that from the rest of your home theater speakers.

The truth is that a correctly balanced bass setting is one where you feel rather than hear the bass. A more powerful subwoofer is not necessarily the answer to a shaking home theater experience. A better way to feel the bass and complement a correctly-set subwoofer is to add a few bass shakers or Buttkickers; these tactile transducers can transform your home theater experience from ordinary to ultimate… without annoying your neighbors!

Discover more in this guide to tactile sound in the home theater.

ButtKicker BK-LFE
Full-size ButtKicker transducer requiring a minimum of 400W input power for a truly
bass shaking experience!

(Available from amazon)

Feeling the Action:
Home Theater and Tactile Sound

Home theater is all about being immersed into the movie action. A proper setting of the movie image and sound is essential for an enjoyable home theater experience.

But there is more to home theater than just the use of your sight and hearing, if you want to enjoy the best in movie watching for a truly immersive experience.

You need to feel the action. In other words, you need to add the accurate sensation of tactile sound using a few bass shakers, Buttkickers, or any other appropriate tactile transducer, to take your home entertainment to a totally new dimension!

Tactile sound makes for a more complete experience when watching a movie. You get easier immersed into every movie action by combining the sense of touch with your sight and hearing. It lets you feel the jolt as the Titanic hits the iceberg, or the ground shaking as the creatures in Jurassic Park walk by. But…

What is Tactile Sound – Perceiving Sound Energy

Airborne vibration is not the only way sound reaches our ears. Sound energy is also perceived through various pathways within our body:

– Muscle and deep tissue

– Sense of touch (skin sensation)

– Bone conduction – in particular the skull.

All these fall within the category of ‘Tactile Sound’. Expressed differently, tactile sound is ‘felt sound’. It is the low frequency feeling one gets when a large magnitude event takes place nearby. Most humans can feel sounds in the range 10Hz to a maximum of 800Hz.

Tactile Transducers in Detail

A trend that has been catching up with home theater enthusiasts is the mounting of tactile sound transducers – to add that extra dimension in your viewing experience – hence the term 4th dimension when used with 3D TV viewing.

Often referred to as bass shakers or butt kickers – tactile transducers are mounted under home theater seats and couches. This is typical with low power transducers such as the range of Aura Bass Shakers. Low power tactical transducers are generally designed for single seating applications but you can always mount multiple transducers under a couch for a more shaking effect.

Some home theater seats come in a tactile-ready version; this means that they come pre-equipped with the necessary bass shaker or butt kicker hardware; all you have to do is to connect to your tactile amplifier and it’s all done!

Tactile amplifiers are basically the same as subwoofer amplifiers, designed to handle the low frequencies within the sound track. You can always drive your tactical transducer using the LFE output on your AV receiver but a dedicated amplifier is generally a better option.

It is also possible to mount tactile transducers on wooden floor support structures such as home theater risers or floorboards, as well as 2- or 3-seater couches. The Aura bass shakers referred to earlier on are not really suitable for this purpose; you need more powerful transducers such as the comprehensive line of ‘ButtKickers‘ from Guitammer Company Inc., to move these heavier structures.

ButtKicker BK-LFEKit Low Frequency Effect Kit with 2,100W  LFE amplifier, mounting kit, and rubber mounts for your furniture.

A case in point is the ButtKicker BK-LFEKit; this comes complete with a suitable low frequency 100W amplifier, furniture mounting bracket, and rubber mounts for use under your home theater seat or couch. The latter are essential for the best bass shaker performance.

Wiring a tactical transducer to your couch can be an issue, especially with existing home theater installations. A possible option is to use one of the many wireless audio deliver systems present on the market as further detailed in our wireless speakers guide.

But in the case of the ButtKicker kit referred to here, a cheaper alternative is the ButtKicker BK-LINK wireless system. Apart from being less expensive than many of the wireless audio systems present on the market, this ButtKicker wireless link is specifically designed for use with the ButtKicker line of products.

Tactile Transducers Basics

The majority of tactile transducers are simple low frequency electromechanical devices – with a rather very limited frequency response. Particularly, this is the case with line of Aura bass shakers – which come with a usable frequency response of 20-80Hz.

Tactile transducers are designed to attach directly to large surfaces such as home theater seats, couches, and flooring. Once activated, these will drive the supporting surface structure into vibrations over the tactile range. The surface now acts as the diaphragm, somewhat similar to the cone in an ordinary speaker.

Unlike Aura bass shakers, some tactile transducers will even cover the lower end of the audio spectrum. For example, ButtKicker bass shakers have an effective operating frequency range of up to 200Hz. On the other hand, Clark Synthesis transducers can reach 2000Hz in the tactile range even though the human tactile response falls off at around 800Hz.

Tactile transducers help the viewer feel rather than hear the low-end frequencies found in movies and music. This also explains why tactile sound is often referred to as ‘silent’ sound.

Tactile transducers are calibrated specifically to produce an accurate tactile sense, otherwise missing from music and movie sound tracks. When attached to a resonant surface, they will effectively increase the portion of tactile sound as ‘felt’ by the viewer in comparison to that produced by sub woofers and ordinary speakers. Consequently, the viewer will be able to feel the natural percussive impact of sounds when watching a movie or listening to music.

Unlike subwoofers and normal home theater speakers, tactile transducers do not make the room overly loaded. The greater perceived loudness of a tactile sound transducer equipped system allows listening at lower sound volumes.

This does not mean that tactile transducers are there to replace subwoofers or your full range tower speakers. This is not the case; rather their presence should be to complement the subwoofer and speakers performance. Why?

The optimum sound level for a subwoofer is when you can just feel rather than hear the bass. Through the use of tactile transducers, this is even easier to achieve while maintaining the subwoofer sound at a more natural level. In a similar manner, the best setting for the tactile transducer is when you can just feel the seat shaking. Do not overdo it. The illusion that the percussive impact of sound is a natural extension of the movie soundtrack should always remain.

In addition, use of specially designed rubber mounts on home theater seats and flooring equipped with tactile transducers is essential for the best bass shaker performance. The rubber mounts will help keep effects and vibration isolated from other things in the room. In other words, in a proper installation, low frequency vibrations will not be carried throughout the entire house.

Installation of Tactile Transducers

The key to a successful installation of bass shaker and butt kicker tactile transducers in home theater seating is to ensure they are secure enough to shake the entire seat frame structure. Choose a location that is easily accessible. The selected supporting member should be such as to conduct the low frequency vibrations from one piece of the seat sub-frame to another. A flat cross-member connecting the main frame structure is ideal for this purpose.

Kinetic Isolators:

Seats or supporting structures equipped with tactile transducers should be isolated from the rest of the room through the use of kinetic control isolators. These are basically nothing more than rubber mounts designed specifically to isolate the vibrating structure from its surroundings.

This is essential for a full low frequency response of your home theater seats.  Most seats and couches will not provide adequate low frequency response when resting against an unmoving floor surface – especially when driven by low power tactile transducers such as the inexpensive line of Aura bass shakers. The solution is to use some kind of a suitable rubber cushion to serve as a kinetic isolator between your home theater seats and a fixed floor.

Similarly, kinetic isolators are also required if the transducers are mounted on a floating floor structure. Ensure to mount enough isolators to take the full load. In other words, ensure that the aggregated load bearing capacity of the rubber isolators is sufficient to take the full load of your home theater seats, people, and platform/riser if any.

Mounting orientation:

Transducers should always be mounted in the vertical orientation over a horizontal supporting structure. Mounting the tactile transducer otherwise will lead to distortion and increased wear on the transducer moving parts.

Wiring & Audio Connections:

Our recommendation is to drive these transducers using a dedicated LFE amplifier – similar to that used with passive subwoofers. Some home theater receivers incorporate a tactile output; if available, use this signal to drive your tactile amplifier.

Most manufacturers’ instructions suggest running your tactile transducers off your main left and right preamp outputs via a dedicated amplifier. This is not always practical as most receivers have only a fixed level line-output. In addition, the extended frequency response of some transducers may lead to vibrations not normally felt in real life – especially when listening to music.

The best approach is to drive your tactile amplifier using the low frequency end (SUB-WOOFER/LFE) signal. This should give a far better response to the special sound effects and other low frequency signals normally associated with film soundtracks.

Tactile Transducer Options

Which tactile transducers deliver best performance: Aura Bass Shakers, Buttkickers, or Clark Synthesis?

Major tactile transducer manufacturers include:

– Aura Systems Inc. with their bass shaker range

– Guitammer Company Inc. with the ButtKicker line

– Clark Synthesis tactile transducer products

Aura Bass shakers

The Aura transducers are in reality simple low power bass shaker devices with a limited frequency response of 20Hz to 80Hz.

These bass shakers do not have the finesse in their performance as found on Buttkickers or Clark Synthesis tactile transducers. For best performance, these devices should be driven via the SUB/LFE (subwoofer or Low frequency effects) output.

Aura AST-2B-4 Pro
Bass Shaker

Delivering 50W of bass power to your seat.

Power rating is 50W for the Pro version shown here. Due to their relatively low power rating, you may have to use a number of Aura bass shakers to achieve the desired result especially when driving heavier home theater seating.

However, do not underestimate what you can achieve with these inexpensive tactile transducers. Though the Aura bass shakers lack the power of ButtKicker or Clark Synthesis transducers, yet they can still produce several times the sensory bass effect of a subwoofer at a reasonable cost.


If you want something that can kick you hard during action movies, the Buttkickers line of tactile transducers will definitely add a new dimension to your home theater.

These devices respond with great fidelity to the low frequency content (5Hz to 200Hz) in a movie soundtrack.

But ensure that you properly install these transducers. Using rubber mounts as further explained above is essential for a successful tactile transducer installation.

ButtKicker BK-Mini
Low Frequency Effects System

Buttkickers are high power devices – rated at 1500W max. They require a minimum of 400W driving amplifier – 1000W is even better. This explains the impressive shaking force produced by this device once in action.

Clark Synthesis Tactile Transducers

The Clark Synthesis tactile transducer solution is unique. While Buttkickers and Aura bass shakers are more suited for watching movies, and therefore these are best switched off when listening to music, the Clark Synthesis tactile transducer is more of a capable all-rounder.

In comparison to the ButtKicker solution, the Clark Synthesis tactile transducer is rated at around 100W RMS/300W maximum.

Clark Synthesis
TST239 Transducer

Surprisingly enough, the Clark Synthesis still has enough capacity to deliver a good kick during action movies. Furthermore, its response characteristic makes it suitable for music listening as well.

Most bass shakers are designed to cover part of the low frequency tactile range only. In contrast, the Clark’s tactile transducers can produce vibrations over the full range of tactile and audible frequencies (15Hz to 17KHz). In addition, some Clark Synthesis transducers can also handle inaudible frequencies up to 200Khz.

For this reason, its applications go well beyond home entertainment. These include military applications in simulators and submarines, swimming pool installations for synchronized-swimming team training, and also applications in active noise cancellation systems.