Active isolation; what can it do for music reproduction?

i would not begin to talk tech with Geoff. :-)

horses for courses.

solutions are scaled to the target situation. not sure electron microscope targeted tools (the intended scientific use for these active devices) is appropriate for the uses Geoff refers to. but.......science and industry has chosen these active units over other choices. and their tools ’work’ for our High Fidelity purposes with a few modifications.

i’ve not heard anything do what the Tana active devices do in my system.

far be it from me to suggest that maybe better choices don’t/can’t exist. i will watch for Geoff to introduce his new LIGO spec isolation hifi product line. i think that maybe when we build our rooms we do some of what Geoff refers to here. for instance; depending on the distance from major sources of ground noise we might use sand or some other material under our concrete floors. as i’m in the mountains, away from highways, surf, or train tracks, on glacial till, away from any urban center, in the middle of 5 acres, in a separate building from my house.......6 inches of concrete did the trick. does this go as far as the LIGO approach? maybe not. but those factors are passive things we do to set the stage for our other efforts.

i agree with the associated equipment comments; the link i posted above to the Herzan tutorial goes to great lengths to address that issue. ultimate resonance isolation needs a comprehensive approach.

i am planning on suspending my speaker cables from ’half rounds’ with a series of bungee cords. i have the bungee’s and am looking for the proper ’half rounds’ that will work. i want something in metal or hardwood that fits into my system vibe. even though i can quickly A/B on and off and hear the active contribution i know it will improve, as my speaker cables are heavy and i know it’s damping the reaction performance of those Tana’s beneath my amps.

and there are passive components to the Tana shelves. which i did describe above.

so i’d say i have no issue with any of what Geoff describes.

For informational porpoises 🐬 only,

The description of the various isolation techniques used in LIGO, the Mother of all Isolation Techniques, 

https://www.ligo.caltech.edu/page/vibration-isolation

Geoff Kait
Machina Dynamica
Give me the right spring and I’ll Isolate the world 

Thinking about it from a scientific standpoint, the reasons for isolating a turntable are obvious and I have been using passively isolated turntables exclusively since the late 70's with one silly exception ( a Transcriptors).
There are two types of vibrational influences on turntables, structural vibration and air born vibration (sound). Both the SOTA and SME shield themselves from structural vibration down to 3 Hz with dampened spring loaded systems. The isolation platforms do essentially the same thing. Do they do it better? Mike thinks so but I am not so sure. The isolation platforms are limited to 200 Hz, the SOTA and SME are not. I can jump up and down right in front of both turntables without any effect on them. That is pretty decent isolation. I assume you can put something like a Clearaudio table on an isolation platform and get the same result...up to 200 Hz. Then there is air born vibration. On tables with massive sub chassis and platters air born vibration will have virtually no effect. The problem will be exposure of the record, tonearm and cartridge. As far as the record is concerned both the SME and SOTA have excellent record hold down mechanisms that fix the record to the platter. Then there is the tonearm and cartridge. The dust covers I use give almost 6 dB of attenuation at 1000 Hz (measured with a meter) which is better than nothing. The best way would be putting the turntable in a sound proof room. The isolation platform does nothing for air born vibration only structural. Funny thing is that with new phono amps that have balanced outputs you can now put the turntable and phono amp at some distance from the preamp without ill effect making this a more practical idea and indeed if I ever build another house I might just design it with a turntable closet! So, IMHO the best way to isolate a turntable would be to get a well designed suspended turntable with a good record hold down mechanism and put it in an isolation closet. 
Next comes other electronics. The reasons for isolating a scanning electron microscope are pretty obvious. It takes several seconds for the microscope to complete a scan with resolution down to angstroms. The object being scan has to be absolutely still relative to the scanner or you get a blurred picture. It is a purely mechanical problem not an electronic one. Does motion or vibration affect electronics in any way? You could argue that mechanical devices like switches, relays and mechanical contacts might be affected. You could argue that capacitors might be affected. Is there any evidence for this. Not that I can find. If anybody can find something on this please post a link. Can vibration affect the travel of electrons through anything else? Only in your worst nightmares. Imagine what the traction control in your car would do. Or the auto pilot in an airplane. IMHO anybody that argues that it does is not lighting up on all eight cylinders. 
What about people like mikelavigne who say they can hear a difference when they turn the isolation platforms off? I do not expect anybody to take for granted what I say I hear. That is entirely a matter of my perspective and psychological state at the time. If 100 people hear exactly the same thing at the same time now perhaps I can make a believer out of you. Whose brain (ego) wants to admit they just wasted 17 K on a lark? Maybe some day I will get to hear Mike's system and even hear what he hears. One good thing I can certainly say for Mike is that he does not sell these things which makes his assessment more valid even if he has the silliest looking amplifiers on the market:)  Never believe a human who is trying to sell you something. 

What about people like mikelavigne who say they can hear a difference when they turn the isolation platforms off?

i welcome skepticism.

just to let you know, last Thursday i had visitors to my room who asked me if they could turn those Tana active platforms off and see the effect, so i said go ahead. that was their viewpoint. there were 4 of us in the room at the time.

here is a link to those comments;

http://www.whatsbestforum.com/threads/taiko-audio-sgm-extreme-the-cr%C3%A8me-de-la-cr%C3%A8me.27433/page-64#post-603082

come on over anytime and hear it for yourself.

twice in the last year i had some local audio friends come over and check my own perceptions on the active Tana shelves prior to buying the last couple. i wanted to make sure i was not being delusional.

this is not any subtle feeling over days of listening. this is poke you in the nose obvious.

would the effect be as obvious in every system? of course not. my system is all about hearing everything. as i said above, this is the kind of thing you do when you have done everything else, and you have the optimal environment to get the most out of the investment.

and having 5 of these in the system increases the effect since any resonance feedback restriction is broken by removing one. so that’s a bit of a multiplier effect on turning one off. not saying you are accepting that, but that is what i observe.

Three things. Isolation platforms are not (rpt not) limited to 200 Hz. The way they work is that as vibration frequency goes up so does isolation effectiveness. Thus, for a 3 Hz passive platform the effectiveness at 10 Hz is about 50%, at 20 Hz about 90% and over 30 Hz at least 99.9%. Passive devices have a 6 dB per octave slope for the mechanical low pass filter. It follows that the lower the Fr of the device the more effective the isolation will be throughout the frequency range (of the vibration). The low pass filter has a hyperbolic function.

Two, as we now know from the Townshend speaker passive isolation video on YouTube, mass-on-spring iso platforms reduce vibrations on the platform itself, including those produced by acoustic waves. So, the iso platform is a two-way device. 🔛 As I’ve oft pointed out the top plate of the iso device can be damped using one-way devices to improve the evacuation of energy from the top plate.

Three, the audio signal is affected by vibration wherever you find it, wiring, capacitors, printed circuit boards, electron tubes, transistors, power supplies, power cords, fuses, etc. Therefore isolating as much as you can - everything - has it’s advantages