Boy, Oh Boy! Towshend!

I wouldn't mind advice for my situation.I have a 300 pound Sound Anchors rack. It is solid steel bars filled with sand. With spikes and discs on each corner.
On top of the rack will be a Basis 2001 with silicone filled suspension pods(allows the table to shimmy if touched) and a Vertere Acoustics MG-1 with its own suspenion system. Both on MDF wood planks that seat within the rack...
I used to have a Townshend Seismic Sink under the Basis but the air bladder blew out. Twice. But I'm not certain how much benefit the table received from it. 1, due to its own suspension and 2, the Sound Anchors immobile rack. The rack is unaffected by footfalls or anything.
I wonder if any of you have an opinion on any significant benefit of putting isolation platters under suspended tables on an immobile rack.
Also, I have 140 pound JM Lab Mezzo Utopia speakers each on 4 fat spikes/metal discs with felt bottoms on tile which is on top of the concrete foundation.
They sound fantastic but I don't know if they could sound better with different Townshend isolation bars/podiums...Any thoughts would be most appreciated. Thanks.

From My Experience and these following comments are from a personnal view point.
Not using a Turntable Support as an example, as there are major benefits to be discovered from using permutations of Isolation/Support under one.

A Isolation Placed Under a Shelf/Sub Plinth on a Rack has not changed anything to the point it is recognised as a noticeable improvement.
From recollection the use of the Isolation might alter the perception of the way the device is presenting, but this could also be imaginary.
Using the same type of Isolation that has been used under a Shelve/Sub Plinth and used as footer separating a Device from the Shelve/Sub Plinth Material has shown more meaningful and noticeable changes to a Devices performance.
A delivery can be perceived as ranging from Bass is Light Footed to Bass is Heavy Footed, depending on the Footer Material and Design.
I try and keep these types of footers not too complicated as design and a affirdable to source material.
When a Footer is discovered that is seemingly adding a value to a device being used, I will then use this footer under the Shelve/ Sub Plinth as a measure of a self satisfaction, whether needed or not.

I have trialed with different Shelves/Sub Plinth Materials and MDF has not been a preferred material.
I also trial with Tiers of materials to produce a Shelve/Sub Plinth and MDF has not found its way as go to material in these permutations either. 
It has been a long time since MDF has been trialed so I can't quite recollect why it was not desired, but any material that I perceive as
Bass Heavy Footed is rejected by myself, as this in my mind is smearing the details and suppressing the Mid's to Highs of the frequency range.

Most of my Shelves/Sub Plinths have a Granite in use as one of the Tiers.
Different Densities of Foam are regularly used as well and a Cork Pad that will usually be found as separater of the the materials from the Supporting Frame and be used under a device as the footer. 

After various Permutations of Materials to used to support my Mono Block Amp's.
I have produced a Sub Plinth, that consists of a Material used under Laboritory Floors to absorb Micro Vibrations, this is Multi Tiered and has produced two Piers to a Height of 500mm.
Sitting on the Pier Material is a Granite Lintel that weighs in at 250Kg (550lb)
Seated on the Granite Lintel that Bridges onto the Two Piers is a Layer of Hard Foam which offers a resistance to being compressed, as well as a Layer of a Highly Compressed Foam Board which has structural. properties.
The diffference of the perception of the Amp's presentation when lifted from the Floor on a Sub Plinth to the seating on the Granite is immeasurable, it was a instant WOW!.
The fine tuning with the Foams as the final tiers in the permutation was more of the obsessive personality than essential, but the Foam Board is my go to material as much as Granite in a Sub Plinth that has additional tiers.

My Hifi Racks Rigid Frames and all the Shelves are with a Granite as a minimum sitting on a Cork Pad.
This Rack was a few years ago seated onto a Purpose Produced Sub Plinth Support.
Again this added treatment was perceived to have produced a small improvement, but most importantly it gave a reassurance and future endevours are starting from the best base. 

Starting the experimentation is the key, finding a material of permutation of materials that are perceived as a time well spent and a noticeable improvement over the previous used will be the reward.  

    

Starting the experimentation is the key, finding a material of permutation of materials that are perceived as a time well spent and a noticeable improvement over the previous used will be the reward.

Great post!

Your experiment correlate with mine to some degree...

I used what i called a "sandwich" under my speakers which are on my desk and the same sandwich with dac and amplifier...

Quartz feet,granite plate,sorbothane in between, another granite plate, cork plate, bamboo plate...

This improve the sound quality...

BUT,

It was not enough....And i was not conscious of what was missing..... 😊

I used then 2 set of 4 boxes springs, one set of 4 under the speaker over the sandwich, another set over the speaker, under a fine tuned damping load of concrete ( 78 pounds)...
The essential point is the application of a dyssimetric compressive force between the 2 sets of springs which are then compressed with a different load....This decrease the negative effect of resonance of the rectangular enclosure....I was inspired by the " building tuned mass damping" principle....


Results : Amazing....On all acoustic count, timbre, bass, high frequencies....

Cost: under 100 bucks....

I had another idea about this to improve it , i must wait for another experiment in the week to come....


I dont think that those who cannot afford costly method must renounce isolation.... Isolation control is mandatory....

@vinylshadow - if you can, post a picture of those items you are specifically talking about on a system page. Something about a picture says a thousand words... I’m not even suggesting your whole system if it’s an issue, just that which you are enquiring about.

Using the same type of Isolation that has been used under a Shelve/Sub Plinth and used as footer separating a Device from the Shelve/Sub Plinth Material has shown more meaningful and noticeable changes to a Devices performance.

Yes!

I also trial with Tiers of materials to produce a Shelve/Sub Plinth and MDF has not found its way as go to material in these permutations either.
It has been a long time since MDF has been trialed so I can’t quite recollect why it was not desired, but any material that I perceive as
Bass Heavy Footed is rejected by myself, as this in my mind is smearing the details and suppressing the Mid’s to Highs of the frequency range.

MDF laminated to steel plate - ever try that? It’s good. HDF laminated to steel plate, is even better.

I have produced a Sub Plinth, that consists of a Material used under Laboritory Floors to absorb Micro Vibrations, this is Multi Tiered and has produced two Piers to a Height of 500mm.

I don’t care if you PM me with it, I just have to learn what it is ... please??

@rixthetrick

Thanks but I wasn’t able to figure that out.
But if you go to imgur dot com slash a slash FEI0zPQ pics are on im gur.
If you are able to, you’ll see the 300 pound Sound Anchors rack and the Basis turntable. But I’m adding a 2nd to the left of the center speaker.
Then you can see 1 of my speakers on the spikes/disc and a Rowland Model 12 behind it. Also on a spiked Sound Anchors amp stand.
Hope that helps!