2020 update : JC Verdier La Platine

@thekong 

Hi @Dover, I am interested at your comment! Not meant to argue, but these optical tables are exactly the same ones that came with the Rockport TTs, and they were originally designed for electronic microscopes which required maximum stability! So, why would you think they are unstable? 

Its the lack of grounding.

So years ago my ref TT was set up on an airbag, next to a Goldmund Reference.

Much better TT than the Goldmund other than a mid base "fatness". Well, remove the air bag an voila, no mid base fatness, bottom end cleaner, quicker, more agile and more transparent.

To be fair my TT is designed specifically to dump energy to ground and uses a superplastic zinc alloy in the plinth that dissipates any disturbances between 10hz and 100hz via grain sliding at a molecular level. So it only has to worry about anything under 10hz.

Historically I believe TT manufacturers targeted a suspension to cover any disturbance at 3-4hz, which if I recall correctly is the typical resonance of a footfall on a sprung timber floor. 

I had an old villa built in 1924 with tongue and groove flooring over joists. Now I have a mid century house with substantial concrete floors, not thin floating concrete as is the norm now, 2ft thick with substantial amount of gravel base.

What I have  found with the wooden floors over the years is that with my ref heavyweight TT ( I've had it for close to 40 years ), hanging the TT on a structural wall is superior to air suspension. Quicker, cleaner and more precise. The isolation may not be as good in theory, but I still get a massive drop in noise floor compared to any rack on the wooden floor.

My guess is that all these TT manufacturers offering air suspension solutions are simply ensuring their TT's can cover the worst possible environment without bad customer feedback. Imagine selling a $100k plus TT to someone who expects the best, and the needle jumps out every time they breathe.

Reading the last comments made from the few contributors, matches my own reports.

My reports are based on a subjective evaluation, but it is experienced that when the under TT structure is considered and how the structure is anchored to the local structures of the home, really does create a change to the perception of the End Sound capable of being produced.

When a particular configuration is used the perception that the End Sound has tidied up considerably is unavoidable to notice.

In relation to having materials in use that are with properties that efficiently dissipate and Damp. The use of a Board Material produced from a Resin Impregnated Densified Wood Board is the easiest route to create this desirable property at a mechanical interface. 

The Plinth for the Verdier Platine in my assessment will become a much improved mechanical interface if produced from a Resin Impregnated Densified Wood Board as the upper most tier of the support structure. Using the same material as sub tiers will add to the value of the support structure.  

@mr_gray What is your wall made out of? What kind of wall shelf?

@thekong You are right about my vibration comment. I have conflated several isolation technologies by simply lumping them into a vibration vs vibration interaction. The optical table has air bearing devices at the top of each pillars. Vibration is counteracted by a floating film of air….my mistake. BTW I found a link to a locally made optical table worth an inquiry: https://www.unice-eo.com/product/%E5%85%89%E6%A9%9F%E6%A2%B0%E5%85%83%E4%BB%B6/%E9%9C%87%E5%8B%95%E6%8E%A7%E5%88%B6/%E5%AE%A2%E8%A3%BD%E5%8C%96%E5%85%89%E5%AD%B8%E5%B7%A5%E4%BD%9C%E6%A1%8C/uctr-series---granite-vibration-free-workstation, worth looking into. 

@dover Your house has 24” ( 60 cm ) concrete floor slab. That’s not a typo? Wow! And I assume your TT is located on the ground floor. 

@dover Your house has 24” ( 60 cm ) concrete floor slab. That’s not a typo? Wow! And I assume your TT is located on the ground floor. 

Yes, at the moment. House was built in 1962 - they must have had shares in a concrete company. However if I move the main system upstairs it's back to tongue and groove and joists. There is a large unused fireplace upstairs that has a massive concrete foundation direct to ground that I could redeploy if I move the main system upstairs. 

Hi @Dover , thank you for the detailed description! May I ask what air-suspension table you were using at the time?

My audio room is on the 5th floor of a high rise building (20+ stories) with concrete floor. The TMC optical table that I am using can actually be used in 2 modes. Without air, it act as a sturdy steel table with no compliance; when the air pump is switched on, pistons in the 4 legs raise up by 3/8” and offer air-suspension! 

In my system, and to my preference, with air-suspension the sound is more airy, blacker background, soundstage noticeably wider, and separation between instruments also better! Together with the widened soundstage, imaging size of the vocal and instrument also expand slight, which I consider more life like. One time I forgot to switch on the pump, and immediately felt something was off! 

I tend to agree with you that the mid bass seems to become a little bit fatter with air-suspension. I consider that simply as more mid bass, but without any loss of definition, so a positive to me. I do understand some audiophiles don’t like air-suspension, thinking it has a “sound” of its own, and I am sure personal preference and the room/system play critical roles in choosing anti-vibration platforms!