Experience with Townshend Seismic Podiums on Concrete Floor (they're great)

@hilde45 and @mapman .  To the points you have made above.

  I did not include vibrations transmitted to the speakers that have its origins outside the confines of the listening room as a 4th type of kinetic motion because the medium through which those vibrations are transmitted is the room flooring.  So my type 3 above is inclusive of anything that is transmitted to the speaker via the flooring.

In addition, I don't think anyone has said that such vibrations are not audible.  But I did say that they are probably orders of magnitude less significant on concrete than they are on typical wood subflooring over a crawl space or in a second floor application.  In my estimation and in my experience, the worst offender is usually type 2 if one is on wood flooring.  If not, then it would appear that type 3 vibration is the more significant.

The problem here is that we can't determine with any degree of certainty which of the 3 types is most significant in our particular setting.  Another problem is that addressing one type of kinetic energy may exacerbate the other two.  This is why I don't hear many people claiming spikes are the answer.  

The answer here is finding a way to rapidly (instantaneously would be ideal) convert these three (or 4 if you insist) types of kinetic energy to heat.  The idea of isolation only works if you are isolating from an external source (seismic, as example).  If you are talking about type 1 energy, you might address the movement of the speaker using spikes.  But the law of conservation of mass and energy tells us that the energy that wanted to move the speaker and now can't, must express that energy in some other form.  So spikes are converting the type 1 energy to a combination of type 2 energy plus heat.  Thus, if type 2 energy is worse in terms of audible effects than type 1 energy, spikes could make your speakers sound worse. And spikes can't do anything at all to address type 2 and type 3 vibration. 

This same argument can be applied to products designed to address type 3 or type 2 energy.  Unless a particular device is capable of converting all three types of energy to heat, and doing so rapidly and efficiency, the device is robbing Peter to pay Paul.  

I really think the manufactures that are super engineering their speaker cabinets have recognize what I am saying above.  That is what these super rigid cabinets are doing.  They are efficiently and rapidly converting type 2 kinetic energy to heat.

For those us that don't want to pay more for our speakers than we did for our house, we are forced to look for products like the Townsend for a poor man's solution, and the reality is that we are going to have to try some different types to see (hear) what works best in our particular setting. 

@brownsfan  Good point. Type 4 (seismic) is part of type 3, and would be small in comparison. It would be nice to see an interview with a speaker maker that addressed these vibrational issues in these terms. 

@benzman  -- I love your description and it is certainly what I heard, especially: "My biggest takeaway from them are the space around the instruments and not only the depth of the stage but the actual placement of the players. Live recordings are especially impressive as you will hear the audience in front and the singer a few feet back and guitar player a couple more feet back and to the left  and the drummer 12 ft behind the singer but 8 ft behind the guitar player etc. I guess you would call it layering . 
All the other goodies apply, texture in vocals, improved bass control, etc."

@hilde45 I agree regarding the desirability of having the manufacturers actually get down into the grass with consumers on the physics and their engineering answers to the physics.  Unfortunately, their first task is to retain a competitive edge in a competitive market.  So everything runs through the filter of how does this advance sales.  Nothing wrong with that.  That is how the free market operates.  Also, not all audiophiles are interested in understanding the science, indeed, some people are put off by excessively technical explanations. 

It is easier from me to get from St. Louis to the west coast than it was for Lewis and Clark.  The difference is entirely one of knowledge and understanding.  It is hard under the best of circumstances to get an audio system to really sing in our homes.      Starting from an understanding of those things that always must be true in every instance is very helpful.  That can take us a long way, but in the end, there are important things that can't be known by a home audio guy in sufficient detail to obviate the value of empiricism.  Sharing of knowledge and experience in this forum is really a somewhat efficient and cost effective way to mitigate the inefficiency inherent in pure empiricism.  OK, I've used up my daily quota of big words and need to shut up. 

It is one of the few audio products that is universally praised by people who actually own them.

I agree the overwhelming proportion of reports on the Townshend isolation base/bars are positive.  That's one of the reasons I tried them (Isolation Bars).

Unfortunately I found they weren't to my taste.  I lost a bit too much "room feel" in the bass and they changed the tonality a bit more than I wanted, and also reduced a bit of the "body" of the sound.   My speakers sounded a bit more tonally full, dense and energetic without the Townshend bars so I returned them.

Most people keep them, though.

@prof 

Unfortunately I found they weren't to my taste.  I lost a bit too much "room feel" in the bass and they changed the tonality a bit more than I wanted

Good evidence that (a) the room-speaker dyad is a huge factor which cannot be predicted with certainty and (b) that taste is the final arbiter.