G-44 rubber isolator for damping  of home cinema seats & sofas  € 0.50 /piece 

These special rubber dampers are required to greatly enhance the oscillation/vibration capability of seating furniture. The special rubber blocks are compounded of highly pliable and soft (shore 55) material. The correct selection and installation will increase vibrations at least 100% at any given amplifier output.
In comparison with round (spherical) dampers, a three dimensional installation is possible; flat, sideways and upright positioning.
The upright mounting of 44.0 mm produces the greatest spring ratio but more units will be required. Rule of thumb is as follows:
a. height 14.0 mm= 1 each for every 80 Kgb. height 35.0 mm= 1 each for 50 Kgc. height 44.0 mm= 1 each for 20 Kg
44.0 x 35.0 x 14.0 mm height -2 countersunk mounting holes for 5.0 mm screws. Other uses: serve as vibration dampers for washing machines, industrial machinery, isolating pallets, etc.

The effectiveness of all body shakers depends on over 50 percent on the proper installation
1. The spring damping factor
The seating furniture has to be decoupled (isolated) from the floor to establish an effective vibration path. The G-44 rubber dampers are best suited for this purpose as they can be mounted in three different configurations:
a. flat position mount, 14.0 mm, high weight load but lower spring compliance. This positioning is suitable for a single easy chair. Four (4) G-44 should be used.b. side position mount, 35.0 mm, average weight load, good vibration capability. This configuration is recommended for a sofa, couch, chesterfield or a subframe. Eight (8) G-44 are required.c. upright position mount,44.0 mm, low weight bearing capability but excellent vibration extension. This positioning is recommended for highest demands. The oscillation/vibration depends on the weight load and the greater the number of G-44 dampers being compressed, the finer the response will be. 
2. Installation

a. Body shakers have to be mounted and solidly fixed to seating furniture frames or suitable subframes. Any additional large mounting fixtures will only reduce the intensity and quality of the vibrations. Also, adding seating furniture loosely to an existing subframe will not benefit from the shaker effect, therefore it should be fitted with 1 or 2 additional body shakers. The type of seating cushions will also affect the vibration intensity.

b. The vertical vibration intensity (up-down) is generally better than the horizontal (left-right) as it more effectively compliments music and movie sources.

example 1: Podest with size 3x2 m with 2 x BS-200 and 17 x rubber isolators flat
example 2Podest with size 3x2 m with 2 x BS-200 and 28 x rubber isolators upright