Energy damping or energy transfer?

If you want to maintain dynamic coherence within your system then pursue direct coupling of resonant energy and its discharge to the the higher mass or ground.

That's probably true in most cases. In my case, there's likely more energy coming from the structure of my building than from my turntable. At least that's my guess as to why I like my turntable better with the airbox. But, again, I live near a busy intersection, and I live on the third floor of an apartment building. Between the traffic and other residents' activities & appliances, I may have a higher than average amount of building-borne vibration to deal with.

Brent

1. How about putting that inner tube in a solid box with the inner tube inflated just enought to stick above the top of the box so that the shelf that the TT sits on still floats slightly above the box, but the box itself restricts any lateral type movements that result from vibrations.

That's almost exactly what I'm using. Only difference is that the top of the platform is slightly lower (~1/8") than the top of the box, but there's a big enough gap that the platform doesn't touch the box. It began life as a sandbox. I recently dumped the sand and stuck a 16" BMX tire tube in there. As I said, not elegant, but if it works...

2. Acknowledging Krell man and Stehno's assertion that "nothing can stop airborn vibrations", what if you had a large dust cover that could cover the entire TT and rest on the shelf itself and then weight that down with something quick? Would that work in helping stop airborn vibrations?

I've had similar thoughts, maybe putting a turntable inside a cabinet, & then isolating the 'table from the cabinet/shell. Rega recommends listening to their turntables with the lid on. I would guess that this is to isolate the cartridge & arm from airborne vibration. Consensus on the web is that the lid resonates and transmits airborne vibrations to the plinth & the rest of the 'table, which is sonically detrimental. I prefer listening with the lid off myself.

Brent

Cbrentc,

LOL ....your thoughts make me think that someone should extend their noise cancelling headphones into a device to cancel vibrations....all you need is a 3 axis accelerometer tied to the device you want to stabilize and then a negative feedback loop to a 3 axis vibration servo that actively vibrates the device in the opposite way and cancels out all vibration ...airborne or otherwise.....this is the kind of stuff which is used in inertial guidance systems...it would not be cheap! (Of course the device would need its own internal damping...but this is common already)

Worth a patent perhaps?

Shadorne, in fact the vibration servo device could be another small speaker installed in the stand or support device! Brillant idea!
Bob P.

What would be the resolution and the bandwidth of the servo?