Energy damping or energy transfer?

Krell man's chemist friend is correct when he said, "nothing can stop airborne vibrations".

That's why you need to expedite the transfer of resonant energy away from the component.

Of course if you'd like to trap those vibrations (captured in a moment-in-time but can only dissapate over a period of time)inside your component you can always put some kitty litter or sorbithane material underneath the component.

-IMO

I've been thinking about this topic some lately. It seems to me that the ideal system would be a combination of isolation and coupling. Depending on where you live, floor- & structure-borne vibration can really kill your hi-fi's low-level resolution, especially for vinyl playback. That's where isolation comes in--air suspensions, sandboxes, squishy feet, etc.--to keep the floor & structure-borne vibes from getting to your component. On the other hand, component-generated and airborne vibration are also destructive to low-level info. In theory, coupling seems to be the solution here, whether it's to a support that dissipates vibrations quickly (constrained layer platforms, some solid wood platforms) or to a support that resists movement in the first place (heavy stone slabs and the like). So my theoretical ideal would be to couple the component to a vibration 'sink', and then to isolate that system via some kind of suspension. This ignores energy storage in suspensions or coupled platforms, and probably other issues I'm unaware of.

This idea is based in part on personal experience. I live near a busy intersection. By far the best thing I've put under my turntable--an unsuspended Rega P3--is a DIY, inner-tube-based air platform. The improvement is not subtle. My theoretical explanation is that the air suspension is isolating my TT from traffic-generated vibrations. Second part of my idea is based on my experience that my 'table sounds better if it has hard feet between it and the suspended platform (made of mdf). The setup is pretty crude, but it will remain in my system until I buy or make something prettier that does the same thing.

I've also put my tube amp on a similar air-suspended platform, but I don't hear any obvious differences with it. With speakers, common sense tells me that the speaker cone's mass is too small a fraction of the cabinet's mass for it to make a difference, but damned if I don't like my stand-mounted speakers better on spikes than on blu-tak. This could have to do with cabinet resonances rather than movement of the cabinet relative to the speaker cone though.

Brent

Krell man, you're right. My "statistical summary" was kind of tongue in cheek; sometimes kind of hard to get that across in print. Given the frequency with which this topic is apparently covered around here, I guess I didn't really expect a lot of posts, hence my summary.

I would like to try both approaches in developing my rack. Without going to the expense of buying lots of brass cones, any suggestions for testing out the coupling idea? Thanks.

Cbrentc, I've thought about similar turntable damping tweaks. 2 thoughts come to mind, there.

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.

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?

It wouldn't be a good solution for heat-producing components, but for a turntable? Maybe....

Anyone ever try shipping peanuts (those styrofoam things) as damping material?

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. You must focus and direct energy, shorten.. and not impede or slow its path. I agree with Stehno make it go away as quick as you can. In my opinion mechanical damping of most electro-mechanical devices is analogous to the variable and mostly deleterious effects of capacitor coupling within speakers and electronic audio components. Tom