Vibration Theory - Isolate or Drain?

So many factors, unknowns, and interactions -- it seems like only trial and error can produce satisfactory answers. The goal is to prevent vibrations at the resonant frequencies that most harm a piece of equipment's performance from affecting that piece, regardless of whether those vibrations are generated internally or externally, right? So, to start with, how many of us know what those harmful frequencies are with regard to most of our equipment? And then, choosing an overall isolation philosophy versus a distribution philosophy probably means choosing some tradeoff between goods and evils, which of course is normal with this hobby.

I use the word distribution instead of coupling because it strikes me as a more worthy opposite to the word isolation in terms of indicating what we're trying to accomplish. It indicates that we're trying, through coupling techniques, to make our piece of equipment become part of a larger system whose overall vibrational characteristics are more favorable in terms of the piece of equipment's performance. We might be trying to bind our piece of equipment to a shelf, a rack, the floor, or even to bedrock. (I'm in the camp of those who think "draining" is a misleading term.)

Mass-loading, which has been brought up almost as a third approach, falls into the distribution approach, both by changing the immediate characteristics of the piece of equipment's case and by increasing the effectiveness of the coupling between the piece of equipment and the shelf underneath and who knows what beyond.

Notice that coupling has to play a role no matter which of the approaches, isolation or distribution, we (think we) are taking. If we're using isolating footers, we have to make sure the footers make really good contact with the equipment. Luckily, this seems to be a built-in characteristic of most squishy footers. Let's say that for isolation we're putting a heavy sandbox or lightweight Neuance-type shelf under the equipment. Then we might want to choose footers for the piece of equipment that (we imagine to) have good coupling characteristics. Otherwise, we might not realize the benefit of all the trouble we've gone to to provide a special shelf for the equipment.

Of course, it's all a bunch of compromises anyway, and it may be that in the case of any particular piece of equipment, the designer has chosen a compromise solution that's as good as any we'll come up with. Sometimes it strikes me like trying in the stock market to beat an index fund, but actually, the odds are much better here, since we have some degree of control over our equipment and rooms.

Clearly, there is some good we may be able to do through our obsessions. That is, some solutions do reduce distortion that we are able to hear. After that, there is a whole bunch of sound tuning that we can do to indulge our infernal restlessness.

Anyway, various people have put forth some useful concepts about what vibration control approaches work best for particular parts of the system. In practice, since vibration is attacking from both land and air, as well as, I guess, from within, probably neither isolation or distribution is theoretically a perfect answer. But we can't execute either strategy perfectly, either, so it's all good! Random trial and error may be as effective a strategy as one of the more coherent conceptual approaches, but it probably doesn't make us feel as good about ourselves, which is probably another inherent goal of the hobby, eh?

Pubul- I never damped a tube amp chassis, only CDPs and pre-amps. I also packed rope caulk around the transport mechanism.

With amps, I usually try to drain out vibration via cones onto a constrained layer platform (Symposium),especially when the Ps and transformers are mounted on the bottom plate of the component chassis.

This is really something you have to experiment with.

CD/ISOLATE
That will be $50 please

I have often asked this question myself. Currently I'm working both sides of the fence so to speak. I have a Mapleshade Samson 4 shelf rack with Heavyfeet thick carpet spikes penetrating through the carpet to the concrete floor below. My amp and preamp both use the Mapleshade model for draining vibration; a maple platform supported by their Isoblocks with cones mounted rigidly to the chassis. My CD player sits on Herbies IsoCups and my DAC is on Herbies Tenderfeet. I also use mass loading in several different applications: HRS damping plates on top of my amp, preamp, and CDP, Mapleshade Heavy Hats sitting on Herbies Grungebuster Dots are on my speakers and power conditioner. This is definitely not my first go round at vibration control, and I'm pretty happy with the present configuration.
I have noticed that the Samson rack is picking up a significant amount of vibration from the floor below. It appears to be 60 cycle hum possibly from an improperly isolated distribution transformer in a nearby electric room. It seemed to me that much more vibration was being transmitted TO the rack than what was being drained FROM it. I contacted Mapleshade with this question and got the following answer: "1. Back in 1986, I did a very careful experiment that proved conclusively that internally-generated vibrations in components have a major degrading effect on sound while external vibrations (in the floor and in the air) have a negligible effect. This is the whole basis of our approach to vibration control.

2. The Samson rack's function is to drain vibration out of every component into the maple shelves and from there down into the floor via the most direct path. Isolating the rack would simply block the vibration path into the floor.

3. Steady-state vibrations or random noise vibrations that are not correlated with the music
have essentially no effect on sound quality (the same is true for electronic noise). It is vibrations that are correlated with the music that seriously degrade sound.

By the way, testing for vibration problems by feeling vibrations (or measuring them with accelerometers) in the component--or by rapping on it (as audiophiles do instinctively with turntables and speaker enclosures) is a total waste of time and never correlates with what you hear. The only useful way to "measure" vibration problems is to change something in the vibration path and then, by listening to your standard music test tracks, determine whether the change improved or worsened the sound of the music. Nothing else works"
I heard a very good point brought up in another forum regarding the draining of vibrations: does the draining occur before or after the detremental effects are felt? Think about that one for a while...

Using rigid devices to "drain" vibration is mostly audiophile voodoo, IMHO, and mainly espoused by those that sell products designed to "drain". Honestly, as someone who has tweaked ad nauseum with all kinds of isolation devices over the years, I am convinced that this is one of the most over-hyped areas of this hobby and one of the least beneficial expenditures of an audiophiles dollars (exceeded only by jitter reduction devices and followed closely by AC conditioning devices). I suppose a brass footer, for example, that reduces to a small point may help (or seem to), simply because it reduces the contact area between a component and its point of contact with the rack. On the other hand, absorbing material used as footers will definitely help prevent the vibrations generated by component from transferring to the rack, but obviously does not stop the source of vibration within the component. To stop the source of the internal vibration, you will have to open the component and damp the offending source, such as a CD transport or power supply. With well built and designed gear (which often equates to "heavy"), I haven't found much need for either internal or external damping. I put my gear on inexpensive absorbent rubber footers (Herbies) and after having thrown lots of money down the rabbit hole, I've discovered there isn't a true need for anything more.