Active versus Passive Isolation Platforms for turntables

[Stacore]

Thank you guys for the kind words. Marketing is one thing but the intellectual stimulation is another. I need it
and you are great in providing it!

Marc: Yes, you got the sense of my words. This does not apply only to Stacore or stabilizing platforms but all and every audio component and audio decision.
Specs are great as they provide something objective to hang on to but what we are missing badly in audio are CORRELATIONS between the specs and the audio perception.
How we perceive sounds is a very complicated psychological process and few numbers or curves cannot grasp it.
The well used and abused example is the THD. Now we know that it is the harmonic spectrum, its 1/n falloff and time/signal stability that matters not a single number THD.
But in general, AFAIK correlational research has been abandoned in audio science long time ago save for how to compress more "without a loss of quality". Thus, we have no other choice as at the end go by trial and error.

Peter: 1) Not really, they are in the biggest equilateral triangle while the air springs are in another arrangement. Stress is not an issue with our construction of the top plate
2) We could do autolevelling but we see very little sense in it. The pneumatic installation is very tight - my business partner Bogdan Stasiak is, among others, a specialist in high pressure installations (in naval engines) so he knows how to make it all airtight The platform needs a little pressure adjustment every 2-3 months. It all takes a bout a minute and with a bit of practice the initial leveling is preserved. Autolevelling is important in a lab when the isolated equipment is moved frequently to save time on re-leveling. It needs an active compressor, which by itself will generate noise and vibrations. So we decided not to take this path.
3) The max load on both Basic and Advanced is about 65kg but we the Basic can be custom beefed up to accept much higher loads, >160kg no prob.
BTW, for future reference you can find all those data at our pages here: http://stacore.pl/en/

Peter, can I now ask you something? I took a look at your system and realized your Pass vibraplanes are very close to your speakers.
Would it be possible that you temporarily put the platforms under the speakers and describe what you hear? I'm challenging the
common beliefs that speakers must be "grounded" and look for evidence. If interested/doable what I'd suggest is:
a) take the amps off the Vibraplanes and critically listen; this will be the reference
b) put the Vibraplanes under the speakers; do not change the speakers position; critically listen
c) repeat a -b if needed/possible
d) tell us the a - b difference (taking into account some 3" higher tweeter position on Vibras)

 

[Reid.Whitney]

Jarek, this is an interesting line
That the Stacore Advanced can't match the absolute specs of the best active isoln, but this in effect isn't as critical as the holistic effect of unique combination of pneumatic springs, lateral isoln, mass loaded slate/constrained layer construction
You're in effect saying even if a Herzan beats yr Stacore Adv on paper, there's no guarantee it'll do a better job in practice, and unlike Herzan, yr product should purely be judged on how it enables the tt to sound, and that COULD be better than the Herzan because the latter doesn't combine as many isolating techs and materials as yr Stacore?

The point of experiencing the benefits in person versus comparing specs at face value is sound. As mentioned in my previous post, the individual vibration signature of an environment plays a significant role in determining which solution to consider. More often than not, we advise users of sensitive equipment to consider relocating their equipment so that the ambient vibrations are not being exasperated by factors that can be easily mitigated (i.e. taking equipment from the top floor of a building to the basement). Other recommendations are shared for damping noisy equipment in the room to prevent the disruption of sensitive equipment. This is common in research labs, but may also be found in high-end audio setups as well. When all else fails, we tend to see equipment users look towards solutions like passive or active systems, often guided by the equipment manufacturer for what is recommended.

We deal with and encourage comparisons and in-home demos, because there are a lot of options available to try and a lot of data that can be difficult to discern relative differences. There are even differences in active isolation technology (Feed-Forward versus Feedback and Serial versus Parallel) and how companies mischaracterize active systems. I don't know if this is common in the high end audio community, but some manufacturers supporting the research community label "active leveling" systems as active systems, which is incorrect. Active leveling systems typically pertain to air-based systems that auto-level to weight distribution, while still providing only passive vibration isolation. There is a lot I can (and have) write about on this topic, but my point is having these demos will also help dispel confusion created by suppliers.

- Reid, Herzan

 

[spiritofmusic]

Hi Whitney, yr feedback much appreciated esp yr open, non hard sell, collegiate approach to helping us all thru what is exciting, but complex tech
There is a UK based lab grade isoln company, w many clients of the type you also serve, and the chief designer has been adamant in his advice to me that the particular demands of tts suit a passive rather than active approach
His contention was that the nature of tts in that they are constantly moving re platters spinning, arms tracking, lps undulating, lend themselves to benefitting more from passive
In fact he advises passive often w lab gear where there is a lot of inherent component-borne mvt and vibns
He also commented on tts having other unique demands that he genuinely felt weren't best served by active isoln
I don't expect you to comment too specifically, just whether you at all understand where he's coming from

To back up his opinion, I said what if I insisted on going active? His reply was that his company would be stealing £4K from me, ie the price differential btwn passive and active platforms

 

[Percent]

Hi Whitney, yr feedback much appreciated esp yr open, non hard sell, collegiate approach to helping us all thru what is exciting, but complex tech
There is a UK based lab grade isoln company, w many clients of the type you also serve, and the chief designer has been adamant in his advice to me that the particular demands of tts suit a passive rather than active approach
His contention was that the nature of tts in that they are constantly moving re platters spinning, arms tracking, lps undulating, lend themselves to benefitting more from passive
In fact he advises passive often w lab gear where there is a lot of inherent component-borne mvt and vibns
He also commented on tts having other unique demands that he genuinely felt weren't best served by active isoln
I don't expect you to comment too specifically, just whether you at all understand where he's coming from

As you've already ruled out active on the basis of cost, and pretty much set for passive, then why not consider Herzan's Onyx? It's more than twice cheaper than Stacore Adv. and Speirs. For the price, you could get two platforms. It can be upgraded with auto-leveling also.

 

[Reid.Whitney]

Hi Whitney, yr feedback much appreciated esp yr open, non hard sell, collegiate approach to helping us all thru what is exciting, but complex tech
There is a UK based lab grade isoln company, w many clients of the type you also serve, and the chief designer has been adamant in his advice to me that the particular demands of tts suit a passive rather than active approach
His contention was that the nature of tts in that they are constantly moving re platters spinning, arms tracking, lps undulating, lend themselves to benefitting more from passive
In fact he advises passive often w lab gear where there is a lot of inherent component-borne mvt and vibns
He also commented on tts having other unique demands that he genuinely felt weren't best served by active isoln
I don't expect you to comment too specifically, just whether you at all understand where he's coming from

Hi Spirit,

Typically when we evaluate issues relating to moving stages and the supporting platform, we look at the weight of the moving stage, the rate at which it is moving, the distance across which it is moving, and the relative weight of the stage to the overall system itself. We deal with this frequently in the semiconductor industry working on wafer fabs, so there is an equation we take into account involving these variables.

To date, we have not seen the movement brought on by a turn table to cause an issue with our systems due to the response time (or settling time). The response time of the system referenced in Ron Resnick's comment is 10 - 20 ms, which has an ability to dynamically respond to most movements or changes in a stage. Note: not all response times are equal between active systems and should be reviewed when comparing or evaluating them at home.

The most common issue we have found when pairing high end audio equipment and active systems is the horizontal and vertical rigidity of support stands not being adequate. The primary way to minimize the effectiveness of an active system is to place it on an unstable support structure, so we advise either placing the system on the floor (which is not always practical), or looking into a support stand that has strong horizontal support points and is made of a rigid material (steel works well in most cases).

I am not trying to take away from what your colleague is saying as I believe he is correct in his understanding based on his experience. It also seems he has a lot of industry knowledge that we can learn from. Our frame of reference is primarily rooted in the research industry, but it is fascinating to see the parallels within the high end audio community.


- Reid, Herzan

 

[Stacore]

To date, we have not seen the movement brought on by a turn table to cause an issue with our systems due to the response time (or settling time). The response time of the system referenced in Ron Resnick's comment is 10 - 20 ms, which has an ability to dynamically respond to most movements or changes in a stage.

Reid, 10-20ms = 100-50Hz and you state 1000Hz bandwith or I'm missing something?

 

[Percent]

Hi Spirit,

Typically when we evaluate issues relating to moving stages and the supporting platform, we look at the weight of the moving stage, the rate at which it is moving, the distance across which it is moving, and the relative weight of the stage to the overall system itself. We deal with this frequently in the semiconductor industry working on wafer fabs, so there is an equation we take into account involving these variables.

To date, we have not seen the movement brought on by a turn table to cause an issue with our systems due to the response time (or settling time). The response time of the system referenced in Ron Resnick's comment is 10 - 20 ms, which has an ability to dynamically respond to most movements or changes in a stage. Note: not all response times are equal between active systems and should be reviewed when comparing or evaluating them at home.

The most common issue we have found when pairing high end audio equipment and active systems is the horizontal and vertical rigidity of support stands not being adequate. The primary way to minimize the effectiveness of an active system is to place it on an unstable support structure, so we advise either placing the system on the floor (which is not always practical), or looking into a support stand that has strong horizontal support points and is made of a rigid material (steel works well in most cases).

I am not trying to take away from what your colleague is saying as I believe he is correct in his understanding based on his experience. It also seems he has a lot of industry knowledge that we can learn from. Our frame of reference is primarily rooted in the research industry, but it is fascinating to see the parallels within the high end audio community.


- Reid, Herzan

I agree. Passive have long settling time and low stiffness which results to resonance at low frequencies, which could be amplified ten-fold depending on the load that affects performance. Add also that there is a decrease in efficiency as the center of gravity goes up. A well implemented active platform is immune to these aspects because the response time is faster.

 

[Percent]

Reid, 10-20ms = 100-50Hz and you state 1000Hz bandwith or I'm missing something?

Hello. Can I ask what's the avg settling time of your platforms within min-max load? Thanks.

 

[Reid.Whitney]

One of the reasons piezo sensors and actuators are utilized is to remove the internal resonances of the table created by its construction and internal damped springs. The primary frequency of concern is more narrow than the complete 1,000 Hz bandwidth, to provide greater effectiveness within that region and allow for the sensor to be more compact. Beyond about 200 Hz, the internal damped springs are providing a significant degree of isolation on their own. If you would like a deep dive on the technology and design philosophy behind it, the creator of these tables wrote a white paper 30 years ago discussing the early phase of this technology. Feel free to PM me or I can direct you to a link if desired.

 

[Stacore]

Reid, thank you. I understand now: 200Hz fully active, then damped springs. I PM-ed you

 

[Reid.Whitney]

Hello. Can I ask what's the avg settling time of your platforms within min-max load? Thanks.

Hi Percent,

With respect to the TS tables, there is no theoretical minimum load as the top plate automatically adjusts itself to account for the weight and weight distribution. There is a maximum load, which when exceeded, impedes the performance of the table greatly as the actuators are unable to benefit the top plate.

I will need to share your particular question with my technical team as I am not aware of the impact weight has on the settling time of the table (if any). It is my understanding as long as the maximum load is not exceeded, the settling time falls within the range shared previously. I also do not know if the table has been tested under those conditions to measure the change in settling time, but will report back with my findings.

- Reid, Herzan

 

[Stacore]

Percent, we did not measure it.
May I ask you how do you know our prices?
They are not a secret for anyone interested of course, but out of pure curiosity?

 

[Percent]

@Reid.Whitney

Ah... yes, I'm aware that TS platforms are not sensitive to load as long as the max is not exceeded.

My question earlier was for Stacore.

The reason why I meantioned min-max load because passives are load sensitive.

 

[Percent]

Percent, we did not measure it.
May I ask you how do you know our prices?
They are not a secret for anyone interested of course, but out of pure curiosity?

I see... anyways, thanks
---
spiritofmusic mentioned it somewhere in this thread.

 

[Stacore]

Percent, thank you, just checking our visibility

We did not think the setting time could have a direct impact on a sonic
performance. Would be interesting to hear your thoughts on that.

 

[spiritofmusic]

Percent, since we're on the subject of prices, what is the rrp of the Herzan Onyx passive?
The Speirs Robertson AMB air rolling diaphragm passive is circa £1900, and I believe the Stacore Regular is €2000 and Advanced €3750
The advantage I have w the Speirs is it's sourced in N London, only 75 miles from me, hence trial and costings v manageable

 

[Stacore]

Marc, one correction: our Basic is 2500Eu.

 

[PeterA]

Thank you guys for the kind words. Marketing is one thing but the intellectual stimulation is another. I need it
and you are great in providing it!
(...)

Peter: 1) Not really, they are in the biggest equilateral triangle while the air springs are in another arrangement. Stress is not an issue with our construction of the top plate
2) We could do autolevelling but we see very little sense in it. The pneumatic installation is very tight - my business partner Bogdan Stasiak is, among others, a specialist in high pressure installations (in naval engines) so he knows how to make it all airtight The platform needs a little pressure adjustment every 2-3 months. It all takes a bout a minute and with a bit of practice the initial leveling is preserved. Autolevelling is important in a lab when the isolated equipment is moved frequently to save time on re-leveling. It needs an active compressor, which by itself will generate noise and vibrations. So we decided not to take this path.
3) The max load on both Basic and Advanced is about 65kg but we the Basic can be custom beefed up to accept much higher loads, >160kg no prob.
BTW, for future reference you can find all those data at our pages here: http://stacore.pl/en/

Peter, can I now ask you something? I took a look at your system and realized your Pass vibraplanes are very close to your speakers.
Would it be possible that you temporarily put the platforms under the speakers and describe what you hear? I'm challenging the
common beliefs that speakers must be "grounded" and look for evidence. If interested/doable what I'd suggest is:
a) take the amps off the Vibraplanes and critically listen; this will be the reference
b) put the Vibraplanes under the speakers; do not change the speakers position; critically listen
c) repeat a -b if needed/possible
d) tell us the a - b difference (taking into account some 3" higher tweeter position on Vibras)

Thanks for the response, Jarek. Regarding your suggestion to place my speakers on the Vibraplanes, I must say that is an interesting idea, but could be very difficult to implement. First, I did try some Stillpoints under my speaker stands and was roundly criticized when I reported negative results. The basis for this was that the Stillpoints were not designed to be placed under speaker stands.

I agree with removing the isolation from under the amps to listen as a base line, but one would then need to put 5" of blocks under the speakers to mimic their height for when the Vibraplanes are under them. I can't put the vibraplanes directly on my floor, because the 220 year old boards do not provide a level or even platform. I could listen like this, but raising the speaker up 5" would dramatically effect the sound of system. I could raise the listening seat up the equivalent 5", but the ceiling reflection and interaction with the floor would change the sound pretty dramatically. I have low ceilings. I am also concerned about the back and forth rocking that the drive movement would impart on the speakers. The air springs of the Vibraplanes are not stiff like the Herzan, and there would be movement.

I just think in theory at least, it is not such a good idea. And practically, it would be a real challenge to do a proper test. The speakers weigh almost 200 lbs each. The Vibraplanes and amps and ballast plates are all about 130-150 lbs each times two. I align the speakers with a laser for precision which takes a lot of time. A/B/A this would be very difficult work. Results would also be based on a sound which would be different from the sound once I lower and return the speakers 5" to their original height. It just sounds like a difficult thing to test accurately and my sense is that there would be too much movement.

Thank you for the suggestion though. I do know that people are experimenting with placing isolation under speakers.

 

[Stacore]

Peter, sure, I understand all the trouble and thank you for at least thinking of it
This proposal is actually directed to anyone bold enough to go against the grain and try suspending
speakers. Lack of platform is not a problem - I can instruct how to make a fast -n - dirty one for
few $

We tried putting simple stand monitors on our Basics https://www.facebook.com/stacoreantivibration/posts/702630639898041
The result was very surprising: same sense of clarity, improved articulation, better dynamical contrasts etc as with e.g. the source
but the change was not so strong as with the source can be. I'd love to see more data on that from various systems/listeners.
I do believe the speaker-floor interface, ruled now by spikes, should be given a fresh
look. I think its much more important to cut the speakers from exciting the floor than chasing the Doppler effect.
Spikes do not do that - whatever you think they do not act as a diode.

 

[spiritofmusic]

Fwiw, I've removed the spikes from my Zus and replaced w Symposium Acoustics Rollerblocks upon a Symposium Svelte Shelf
A combination of lateral isoln and vibration attenuating layer
Initially I thought things were worse w less bass
Then it became apparent there was less boom, and the correct amount of bass
Now, I'd never go back to hard coupling via spikes