Townshend Seismic Podiums

@flaxxer - Not all things measurable are audible, and not all things audible are measurable. It's a good start, but not the be all and end all.

When I say "draining" vibrations, of course they don't disappear, they dissipate through multiple levels within a platform, one being foam, which absorbs some of it and vibrations then go from the platform to the floor (which is why wood is better than concrete or other hard surfaces).

The speaker needs to have maximal contact with the platform to be effective - no spikes, discs or whatever in between. Like I said, you can put pods or spikes under the platform for more isolation, but the key with speakers is eliminating internal vibrations, just like with amps and phono stages, CD players, etc.

The improvement in sound from the speaker with the platforms was immediately apparent. Better clarity and separation by eliminating the noise created by vibrations. Better separation of voices for example, more precise bass response, and more like live music.

An alternative to pods are roller blocks which have ball bearings inside housings that move in the xy plane giving things on top of them the floating effect like springs do, but with no resonance and no adjusting, so long as it is in the weight range for them to be effective. Because the top of therm are flat, they also do vibration transfer, and having them be on top of wood is optimal.

This sure is getting interesting and thanks for everyone’s input.

Sam

With the Podiums (or Pods) in place, the loudspeaker enclosure does not move in response to the moving mass of a woofer reproducing a very low frequency,

“For every action, there is an equal and opposite reaction”
Newton’s third law of motion.

The optimum outcome is for the spring material to deform to accommodate the cabinet vibrations which would normally be transferred into the substrate and anything connected to it. Leaving the speaker’s center of gravity to remain as close as possible to a status quo.

The materials and geometry of coiled compression springs lends itself to broad frequency isolation with a broad amplitude capacity in almost all directions. It’s been used in all manner of vehicles for quite some time.

Possibly one improvement that could be made is to allow them to spin on a bearing as they compress and decompress. Using multiple springs will result in friction as they each try to twist on different axis at the core of each spring. It would be interesting to discover if springs using the same rates wound in opposing directions make any difference in the manner in which they attenuate vibrations?

There is a way to drain cabinet resonances, using a TMD (tuned mass damper) as used in skyscrapers that help mitigate movement during high wind. Using a mass and a material that will deform under loads, so that the mass remains stationary as the cabinet vibrates.

 Samgar2@

Sorry for the late reply. The Liszt speakers had their spikes removed but the outriggers were left in place. Worked well.