Rather than attempt to explain the concept behind this gadget, I made a short demonstration video. I shot underneath the table to prove there's nothing other than the legs holding it up. Even with me messing with the legs, the record continues to play with no distortion of any kind.
In the video, I move the feet slowly. If they were to be "flicked", like they would in an accidental bump, the torque on the balls would be greater, causing them to break free from a standing position much quicker. In other words, the faster the motion, the better the feet work.
The next video shows me violently moving all the legs at the same time. I wack the substrate they're setting on with a mallet creating movement like there'd be in an accidental bump... At the same time, risking my AT440MLa cartridge, so I must be confident in my engineering... Enjoy.
As you can see, there's no energy passed from the feet to the turntable deck. Stronger magnets and glass plates on top and bottom of the BBs may allow more movement than what my feet allow, but what are the chances of that happening? :) UPDATE:
This video was missing for a bit... Evidently, ASCAP didn't like me playing 30 seconds of Skeeter Davis' "End of the World" so they shut the sound off on my video... Kinda sophomoric, when the idea behind the video was to hear the sound. This is the replacement, using classier music than what ASCAP had anyway. Enjoy.