High End Isolation - HRS, SRA, Active platforms

I would appreciate any opinions on cost-no-object isolation strategies. I have highlighted several in the title, but would appreciate any others which may be lesser known and underappreciated.

Please state whether you have first-hand experience with the product. Very important if you went from one product to another due to an improvement.

Also, please disclose if you are a dealer, distributor, or representative for a product. I think dealers have valuable information since they are enthusiasts that typically choose products that are most enjoyable.

I personally use Symposium Ultra shelves and solid couplers under my amplifiers and linestage, and Svelte Shelves under my speakers. I am particularly happy with what the shelves do under my speakers (tighten up the bass and improve clarity).

But, these and any other isolation devices are "tuning" devices and can alter the sound in both positive and negative ways. In particular, I've heard such shelves used under CD players that made the sound dramatically drier and analytical sounding. It would be simpler if "more" or "better" isolation was always better, but that is just not the case. One has to experiment.

A friend has a massive, three section HRS stand and separate amplifier stands from HRS. I cannot really say how each affected the sound, but, his system sounds very good with these items. The big component stand is incredibly well built and beautiful to look at; what else matters?
..i would put the star sound technology 'sistrum platforms' depending on how heavy the gear ..the sp-1 or sp-101 ...up against all comers...they are superb ..and they are based on science....
Cheap yet highly effective Machina Dynamica Promethean Springs sandwiched between your choice of wood or acrylic boards those you buy locally to save shipping
I first heard of this one man company via a PS Audio newsletter last year. Paul McGowan liked his stands.


Unfortunately, the website is in German but there are lots of pictures featuring his hand made modular stands. I purchased a couple of his bases and few sets of his feet. Not cheap but the bases added both warmth and clarity when used under my PS Audio Premiere and TT. This is usually rare for me. I'm planning to buy some modules for a stand but am still thinking about the configuration and finish I want.

I had mixed results with the feet. They added a lot of clarity when used under my Rhea but it came with some glare. Most of the glare went away when I added a thick bubinga shelf on top of the thin mdf one in my very old target stand. I have been switching back and forth with BDR #4 cones. The BDR cones sound a little smoother but don't deliver nearly the same level of musical details as the feet; the music was slightly smeared. With the feet under the Rhea, I found it much easier to set my VTA. I suspect the feet work best on stands made from the same material.

Beauty is subjective but if you like a minimalist modern style of stand that could also be furniture these are very attractive.

Don't be fooled by the pictures as they are extremely heavy, almost like concrete. I imagine it's some sort of resin composite. I was told by the owner, Roland, that a set of stands can only be shipped by sea freight.

I like the difference his bases have made to my system but I don't have experience with any other stands. Roland claims the other brands in Germany "Finite element or Copulare – they have almost the same price, but they are toys against my products – promise".


Many of the products mentioned are indeed quite good from a first hand usage perspective (SRA, GPA & Symposium being three audiophile oriented brands for which I do have some affinity/bias). Machina Dynamica's Nimbus is certainly a cut above the Promethean mentioned -- however does have mass constraints imposed due the nature of the air spring-based design.

In terms of cost-no-object I must qualify that a typical audio style rack in general is a logistical compromise between performance, aesthetics & general space constraints. This is in a way no different to having to share outlets from an electrical perspective.

If given an opportunity for an optimal configuration it would consist of a composite of dedicated high mass / active isolation stands for the most sensitive source components & an advanced multi-tier solution for the remaining portion of the system. Do keep in mind for larger reference systems tertiary sources aren't used in parallel so it's far harder to justify a dedicated means of isolation. Plus it saves some space in the long run.

Following with this theme is relying upon the existing room structure to augment the isolation method (alcove or partially enclosed area). The simplified 'room-within-a-room' principle can be used to decouple the equipment from the surrounding area yet still maintain a somewhat amicable appearance. Some things quite frankly are easier to avoid entirely. An example being some time back I loaned a Vibraplane to an associate only to discover his listening area was directly adjacent to the primary HVAC.

Symposium (with Billy Bags+filled stands), GPA & SRA do fine job of providing a high performance tiered rack solution. In terms of active platforms as always the Vibraplane seems to come up in audio related discussions. If you do any research you'll quickly see that a single high quality active isolation platform can commonly exceed the costs of some of the most esoteric racks available (albeit keeping to the theme of costs no object).

As a final commentary if you're considering a significant investment I'd encourage you to work with a party who can provide a sufficient 'try before you buy' policy. Each of our environments are unique as are our components (and personalities for that matter). The final outcome may certainly require a hybrid approach to get things dialed in where you want them to be. Again depending on your budget it's not always necessary to simply buy off the rack if you have a more specific requirement.

Some of the individuals best known for their room tuning solutions also have exposure to some very good mechanical isolation products. Ultimately tuning in this well rounded fashion seems to turn out the best.

Hi, I went from a Arcici Suspense stand with Symposium Ultra shelves on top of the stock acylic shelfs, to a Finite Elemente Pagode master reference. Also added Finite's cerabase feet for the rack and 5 sets of cerapucs for the equipment.

The diff? Noise floor dramatically dropped. Allows details, spatial clues, coherence etc emerge. This was not subtle.

Hope this helps you some...
For active isolation (ie. Halcyonics), is there a benefit to isolating each individual component to it's own platform, or could one place several stacked pieces. I'm thinking of a DAC/transport stacked onto one platform. Appreciate anyone with first-hand experience.
Be careful, there isn't a "one size fits all" isolation solution. It is sort of like asking - "what's the best food?". Depends upon what your system needs and what you have a taste for.
My preferred "cost no object" strategy is to get the room / environment right and not even try to deal with transmitted vibration after the fact. A neat benifit is that stand choices can then be about looks and convenience and economy.
I have to deal with vibration sourced quality & reliability issues as a job thing now and then, it is pretty tough to get the best vibration readings if you are measuring something mounted on a vibrating floor structure. Also, the fix for one problem (adding mass for example) is the curse for another.
In my experience air isolation is not the Valhalla of isolation. Sometimes the sound becomes a bit disembodied, loosing some of it's palpability. Imho some sort of constraint layer damping is superior in case of audio. Of course in high tech laboratories they use tables with air isolation. But laboratories have nothing common with high quality sound reproduction!

I can only add a few comments and perspective from what I have recently experienced. My previous rack was one that I put together based on a design similar to the Mapleshade Samson rack. (I only mention Mapleshade's rack to give a visual of the type of rack I was using. I have no experience with their specific racks). My previous rack served my needs of holding all my components. I imagine it also did something (as slight as it may have been) to address the problems of vibration and resonance. I recent changed to a rack that made a HUGE difference. I purchased a rack from John Stehno of Dynamic Contrasts. The rack I purchased is a prototype of a racking system John has been developing the last number of years. He will be releasing his new rack design in the next couple months. John's new rack has significant improvements over the prototype design I purchased. When I installed my new rack, I could not believe the improvements. I was shocked at the level of improvements in all areas of performance. The soundstage more that doubled; significant improvements in every area . . . clarity, detail, air, dynamics, noise floor, etc. absolutely jaw-dropping results. The day after my new rack was setup, a number of friends were over. I played something that they were all familiar with and had heard on my previous setup. After the first four notes of the first song, one individual looked at me in amazement and simply said, “WOW”. The improvements were not subtle and everyone else easily noticed them. The incredible thing is that with my new rack, I have realized improved performance from every component installed on the rack. Imagine making a major upgrade in every component at the same time. That is the result I have experienced. I am not affiliated with Dynamic Contrasts, I’m just one very satisfied customer. We all desire to get the maximum potential performance from every component in our system. I think I am much closer to that goal with John's racking system. I haven't tried everything else out there. However, based on the improvements I have experienced, I have to say that John has a true solution to vibration and resonance control, or management, no matter how you look at it. I now realize that the rack is a vital component (maybe the most significant component) in my system. It put a new perspective in me regarding the importance of getting the rack right. BTW, the rest of my system is comprised of the following: Theta CD and DAC, Nuforce amps and preamp, Aerial 7B speakers. By no means the best out there, but no slouch either. The sound I am now getting is way beyond what I thought possible.

In regards to your question of stacking components, my new rack has three shelves. This leaves me to stacking two components. My DAC is on it's own shelf, my transport and pre are stacked. I have not yet experimented with a different arrangement. My future plans are to either go to a single box CDP with digital inputs or go to a computer fed DAC. I'm sure I would see/hear improvements by not stacking components, but, that remains to be seen/heard. I just think that stacking is a bit of a compromise of the fullest benefit of the racking system design.

Rob, you have a great system. I am convinced that John's racking system would take your system to levels you didn't think were possible, as it did mine. I noticed you are using Sistrum stands under your amps and speakers. John approaches vibration and resonance from the same direction as Star Sound Technologies. I believe he has far surpassed them in his implementation. John is also a member of Audiogon, do a member lookup search for: Stehno or email him at: [email protected]

I hope this helps.
Add Critical Mass platforms to your inquiry.
The Copulare equipment racks are considered exotic and have a nice system to isolate vibrations using lead/sand wooden filled platforms and the base of the racks filled with the same thing. You can customize the fills with quartz sand, lead sand or some other stuff. Their new Coral series have received a lot of attention lately.

I have one Halcyonics platform and two Critical Mass Grand Masters. RTNL -- In answer to your question about stacking components on the Halcyonics platform, it depends. The Halcyonics Micro 40 will hold 100 kilograms (about 220 lb), however, you don't want whatever stack you create to be too tall. I am stacking two components with a total height of about 12 to 14 inches and haven't had any problems, but a taller stack (which I have tried) creates sort of a vertical cantilever effect which (particularly if the components are heavy) if bumped, can cause everything to oscillate while the platform tries to regain control of the mass.

In the case I tried, I was attempting to put a lightweight rack on top of the Halcyonics platform and then add components to the rack. It was just too tall.

Having said all that, IMO there is no better isolation platform extant than the Halcyonics.
I have never used an active platform device. Having read some descriptions of such, I have a few questions. What is the bandwidth and reactance speed of the Halcyonics?
How does a platform mechanism such as this deal with self induced vibration internal to the device its trying to protect? Would not stacking more than one electromechanical device on a platform change the inneraction and transfer function of the platform. The reactance time of the platform is going to vary based on the mass and the horizontal movement as well as the center of gravity to all supported components. Tom
I hope an engineer can chime in here, but I'll take a shot at this. A rack really will only deal with vibrations that come through the floor. These are traveling through concrete or wood, and are low frequency. I personally do not see how any rack could effectively reduce air-borne vibrations which are much more brief and of higher frequency.

The active platform will automatically level the platform, and adjust for the center of gravity at the beginning. Sensors will continually monitor the motion to mathematically model the vibrations. It will then create a counter-reaction to bring the platform to rest. Based upon some graphs on the website, it appears that the system will react as soon as the first wave hits, and can settle the platform within a few tenths of a second. This is in contrast to a passive system where the vibration would continue for over a second before coming to rest. All of this depends upon very responsive sensors which are continuously modeling the behavior of the platform in all directions. The concept of halting a resonance in a single direction seems easy to grasp, but it's quite amazing that this can be integrated in 6 different directions with relative speed.

Self-induced vibrations should be effectively controlled as well. This should include spinning platters and humming transformers. Anything that alters the center of gravity or the absolute weight, such as moving the component or opening the drawer, would require the equipment to take a second to automatically relevel and compensate.

The website has some technical papers and graphs that will give an idea of the speed and frequencies involved.
Prospective buyers of vibration control products should know the basic definitions of, and the distinctions between ISOLATION and DAMPING to enable them to make informed purchases.

ISOLATION refers to the process of preventing (minimizing) externally generated vibratory energy from reaching a structure or component. Although this includes acoustic or air-borne vibration that is difficult to manage in exposed audio/video equipment, we are primarily concerned with the transfer of mechanical vibration. And, it is essential to understand that there is no significant mechanical isolation possible unless there is relative movement between the component and its supporting structure to prevent sympathetic movement with the supporting structure. Therefore, only a device or material that can compress like a spring or deform like an air-bag or a viscoelastic part, or “roll” like a bearing, can be an isolator. Exceptions to these “passive” examples include “active” systems that have electromechanical “self-leveling” capabilities. Obviously, hard “spikes” and (bare) "platforms" or "shelves" are not isolators.

DAMPING is the dissipation of energy in a vibrating structure or component. It refers to the process of removing (minimizing) internally generated vibration that is inherent in a component AND any external vibration that, for lack of adequate isolation, may enter the component, by converting the mechanical vibratory energy of solids into heat energy - a process called hysteresis. Damping is generally accomplished by the bonding of viscoelastic materials to the (vibrating) internal surfaces, mechanisms and parts of a component and by external coupling to viscoelastic materials or damping devices.

In consideration of the foregoing, it is obvious that no isolation platform or device, regardless of its sophistication, can provide effective damping. In other words, while the isolator may essentially "hold the supported component still", the component will nevertheless
be awash in self-generated and acoustically transferred vibratory energy that remains undamped.

In short, to achieve isolation AND damping there must be BOTH isolation and damping mechanisms and/or materials applied to the component!

In my opinion, both isolation and damping are essential to achieve the very best component performance. Therefore, the best solution is not a "cost no object" isolator but rather, a well engineered product that provides both isolation and damping.

Disclaimer: I manufacture vibration control devices.
Our Nimbus and Promethean isolation stands incorporate "selective frequency damping" and viscoelastic damping to "quiet" the top plate and other critical parts.

Our damping techniques address airborne and component generated vibration as well as residual structureborne vibration.

Nimbus is a 6 degree of freedom design with resonant freq. as low as 0.5 Hz.

NB - We design isolation and resonance control products.
I have no doubt on the ability of cones/spikes, elastic interfaces, and shelves of varying density to affect oscillations and change the sound for the better. I have tried some varieties of all of these things.

However, it seems the passive approach is limited by (1) the efficiency of bringing the object to rest, and (2) the selection of frequencies which are a function of the material being used.

I would think that an active system would isolate a component by damping the oscillations. Just as a swinging pendulum is brought to a stop by using your finger as a counter-force, so will an active system bring an oscillating platform to a rest by applying appropriate counter-forces. An active system would also have an advantage of operating over a wide frequency range.

It seems that the other problem with a passive approach, is that they could potentially induce their own oscillations. Placing a component on a displacable material will enhance it's ability to move at certain frequencies. Also, footers are a 2-way street, are not truly fixed, and probably resonate at their own frequencies.

Of course, nothing is perfect. I am also thinking that the only way to truly shield a component from air-borne vibrations is to literally place it in an insulated box.

It is too bad that manufacturers of racks do not routinely provide real data to aid in their design and help consumers make informed choices. Also, our rooms have very individualized frequencies being transmitted through the building structure. Hence, I agree with Jeff above that there is no one-size-fits-all. What may work well in one person's room may not work in someone else's room.

Finally, the huge advantage of passive isolation is obviously cost. Therefore, it remains a useful approach as we are all seeking to obtain the best value for our sound.
I disagree that a rack is designed only to isolate components from vibration coming from the floor. Most rack/shelves are also designed to dissipate vibration coming from the component itself (e.g., the vibration of power transformers). Couplers are used to transfer the vibration to the shelf and the shelves are designed to convert the vibrational energy into heat. Tap the case of a component coupled properly to a well designed shelf and one just sitting on rubber feet on an ordinary rack and you can hear a big difference in how quickly the vibrations are deadened with a good shelf/rack.
Any passive design will have a resonant frequency, below which it will not isolate. In fact, around resonance it will amplify the vibration. Although some passive systems are designed to be tuned to the specific weight they will support, many designs are not and hence, their properties will vary with the supported mass.

Therein lies the beauty of active isolation.
I see in your posted system here on these pages that you employ the use of at least four Sistrum SP 101 platforms.
These platforms are designed to be reactive to their environment. Their reaction is induced by the in room air pressure generated by your speakers as well as their cabinet resonances. External modulated vibration as well as self induced vibrations in and around your electronics are then also collected given direction and then mechanically grounded to earth.

I also see in the photos that your system has great horizontal sight lines. If your were to lower each shelf that supports your independent amps to midway of the three support/grounding rods you would reduce the inertia and increase the resonance transmission speed of the platform/amp combo.

Likewise if you were to move your Wadia player to the midway point within your rack you would increase the stability of the transport itself, reducing the amount of timing error correction and shortening the pathway to ground provided by the particular rack in use.

Sistrum does in no way try to isolate. In fact Sistrum does provide a pathway for energy to collect and then transfer to a higher mass/ground. Reducing the amount of time, energy is stored in a component, system or rack is much the same as reducing the time smear self induced by the constructive materials of a capacitor.

I first started as a user of audiopoints many years ago.[1993] I have since 2002, been a dealer of products designed and sold by Starsound. Tom

I've used an HRS platform, Stillpoints cones, Finite Elemente Ceraballs and Cerapucs, and Equarack footers. The only isolation devices sitting under all my equipment are the Equarack footers and the HRS platform (AS turntable only).

IMO, an isolation device should and must be able to control mechanical vibrations from your speakers, airborne energy and vibrations from the audio equipment itself. And it should do all this efficiently, meaning the device itself should be optimized for the weight and mass distribution of the equipment.

HRS platforms are designed for a specific wight range, but do not take into account the mass distribution of the equipment. This should not present a problem since the platform itself is mass loaded.

SRA platforms are designed for the weight and mass distribution of the audio equipment. I don't have experience with these platforms and racks, but I've gone through all their technical information and it all makes sense to me. The only drawback I see is with change of equipment as each platform is sized based on the footprint of the audio gear that it supports.

Equarack footers are customized for the weight and mass distribution of the audio equipment via viscoelastic pellets capable of supporting up to three lbs each. With a simple first-grade-math formula, the user determines how many pellets each footer should have, hence optimizing each footer for supporting a specific wight. This is a similar approach to suspension design for automobiles.

The footer surface that gets in contact with the audio equipment is also a viscoelastic material. This is to dampen vibrations from the equipment itself and airborne vibrations that affect the surface and structure of the equipment. Under the lower face of the footer, there is also another viscoelastic disc that makes contact with the equipment shelf. This should take care of any mechanical vibration that comes from the shelf where the equipment sits on. Two aluminum discs interface with the different viscoelastic layers.

I now have the Equarack footers under every piece of audio equipment I own, except for the Acoustic Signature turntable, which sits on an HRS platform. The sound improvement that these footers have brought in far exceeds their ticket price. The sound improvement is equivalent to going from NTSC broadcast to HD broadcast. With the Equarack footers, everything sounds crystal clear. Acoustic instruments really sound like there is somebody in the room playing, voices have a palpability that I thought can only be achieved coming fro 20K audio gear and the highs are simply pristine.

I think that in order to really appreciate what the audio equipment really sounds like, one should make sure that vibration energy is under control and that clean power feeds all the components in the audio system. Many of us go out and spend the big bucks in trying to get better performance without first having an efficient infrastructure for the audio equipment. Unfortunately, I learned this the hard way. I had known about the Equarack footers for a while, but only decided to give them try at the end of last year. With these footers, I can now hear the character (or lack of character) of each audio piece in my system.

I hope this helps.



Disclaimer: I have no affiliation whatsoever with any of these companies mentioned above, including Equarack. I just happen to be knowledgeable about structural design and work along mechanical, civil and structural engineers.

You might look at a company called MinusK Technology. They build isolation platforms for instruments like electron microscopes.Their products are not inexpensive, but they are less expensive than air suspension systems, and MinusK platforms do not require a compressor. I have used one of their products for a couple of years, and it led to a considerable improvement in sound quality.

I am not a dealer or affiliated with the company.