Upper Level Vintage DD Strenghts and Weaknesses

Townsend is talking about vibration coming from the earth up into the speakers. He expects the speaker enclosure to be 'solid enough' that it doesn't move, but let's not shake it (the enclosure).

That's what I need to prevent happening up to my TT from my springy floors, vibration any fool can feel.

So I use Isoblocks below the plinth that let the shake calm down by the time I walk away and the 1st track's content begins. Once the plinth is stable, it doesn't hurt to put it on something soft, thus I recommend it.

If you look at my system, photo of speaker face down with back removed, my speakers are on 3 hard caster wheels, and are angled up (see the block of wood above the 2 front wheels), thus the tops are slanted. This projects the tweeters directly at seated ear level, and prevents reflections parallel to the floor or ceiling. Toe-in prevents parallel side wall reflections. And slanted front effects time alignment if you think it matters.

Now look at the 1st photo, all the pretty things sitting on the slanted speaker tops. Vibrate/slide? Nope.

The 15" woofer weighs 37lbs, a monster magnet, the two horns are heavy.

Zero vibration, nothing moves just the cones, the air, far better than you would expect without computer designed internal bracing of any kind.

I ordered softer wheels based on Townsend's 'theory' (probably measurable, thus no longer theory). The wheel's axels were 'loose', no good, put my original ones back on.

I think you can make a mess of things trying to fix some infinitesimal .... 

I'm seeing references being made on conjecture as to the effect a Suspension Support/ Footer can offer to a Device, which is suggesting the use of one is to be detrimental to a performance.
It would be a much more Valid statement if the claimes were supported by I have used the types of Support/Footer being discussed and during my usage I did not detect any of the merits they are receiving from other users.

Experiences of individuals who have used the Support/Footers are being reported on within this Thread.
Where the evidence of having used the Support is perceived as a
'actual' occurrence has been noticed, and one for the betterment of the device being supported.

Hands on experience is a Great Tool to be used in conjunction with the weapons in a Armoury. 

"Townsend is talking about vibration coming from the earth up into the speakers."

"That's what I need to prevent happening up to my TT from my springy floors, vibration any fool can feel."

I hope max isn't suggesting it is the planet vibrating (mass of 5.972 × 10^24 kg); I know he has had some strange ideas.  Assuming not, the remedy is not to use rooms with 'springy floors' for listening.  You can never make a silk purse out of a sow's ear.  All you will do is build up the boing.  Boing floors; boing footers, your speakers will be rolling around.
The simple and best solution is to connect speakers directly to concrete floor laid on the ground, as @lewm so rightly says.  Best for turntables and amps too.  If you are a flat dweller it can be tough.

Vibration from the Earth ? Go to any professional studio and see how the main monitors mounted. Look at Rey Audio for example. The monitors are installed in the wall or placed on a wooden stands (on the floor). There are NO esoteric anti-vibration platforms anywhere. 

UM you guys do realize this was a discussion about upper end DD drive units?