Vibration Air & Roller Bearings - Thanks to Barry & Warren

[jabbr]

15 hours ago, fas42 said:

 

This is as good a description as any of how the replay improves when using the 'right' type of tweaking, whether it's vibration conrol or anything else. Sometimes external methods of attenuating vibration make sense, but I tend to dive inside and stabilise, in various ways, the actual parts of the component that may be causing issues - different strokes for different folk ...

 

Many people use little pieces of polymer etc around or to hold various components, boards etc, but none of this works nearly as well as the type of vibration isolation being discussed here with rollerballs and inner tubes. The inner tubes could be improved upon but not by "winging it" rather youd need to use nonlinear springs e.g. Euler etc and youd need to properly measure vibration in order to do this -- in effect, unless you have scientific equipment the best way to isolate vibrations in audio equipment are the techniques presented in the referenced thread and attributed to @Barry Diament

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25 minutes ago, Ralf11 said:

to me, the interesting question is what exactly is being affected by the vibration - except the obvious of course (tubes)

The question is what degree of vibration is audible -- can't answe that.

 

A surprising number of electrical components are vibration sensitive, not only crystals -- let me google the somewhat famous EEVBlog voice doe where he wraps the probes on the table and the squiggles on the screen are quite visible... 

 

here  it is: 

 

[jabbr]

9 minutes ago, fas42 said:

 

My mindset is to fix the problem at the source - would you prefer strong bones; or soft ones, which meant external crutches and mechanical aids to support the body? Internal stabilising using the right techniques and materials is not trivial, but to my mind is a far more satisfactory approach - it also means one learns a great deal about what matters, and what doesn't ...

 

Ok you are just being totally random here. What you are talking about has nothing to do with this thread about vibration isolation. Whatever. 

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10 hours ago, Ralf11 said:

who is going to 3D print some of the cups?

A few years ago there was discussion about a group buy using the specifications that Barry posted to the thread. Ultimately didn't get done on the thread because if the usual arguments about what is "perfect" but I can tell you that with sufficient numbers of the item (the setup cost is substantial and machine shops don't want to be bothered if the job is too small) we were able to get exactly what we wanted. Silicon Nitride ball bearings are also commonly available or use anything. I just do it pretty much exactly as Barry Diament posted.

 

If you are looking at one set then the commercial vendors are the most cost effective. 

 

The roller led blocks and balls really work great for horizontal including rotators vibrations -- the inner tubes are fiddly need to be refilled and are as good as any spring. A Euler spring would be better and I have some carbon fiber tubes lying around for constructing some but that involves work-- there's prob a limit of incremental benefit until good measurements are taken.

[jabbr]

The spherical shape of the bowl ensures that they work on a slight unlevel surface (and the inner tubes ensure the surface will be slightly unleveled). The hardness and polish and uniformity of the surfaces ensures a very low resistance to horizontal  translation -- which is what isolates vibrations in the horizontal plane.

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55 minutes ago, rando said:

Barry has been somewhat coy about offering anything but generalizations as to implementation, insofar as I've seen.  I have no doubt whatever fas42 is dropping clues towards is drastically more refined and livable than the rudimentary practice of settling equipment atop cup and ball which is in turn perched on a bicycle tube.  It should be obvious this is a potentially wondrous and simple solution if and only if it meets the specific needs of the item

 

Actually careful reading through the public ally available prior thread will give tremendous and very specific information. The solution I ended up getting was organized by another individual who was not happy with the commercially available products (at least at that time) -- he had contacts at a local and excellent machine shop -- Barry gave us our blessing but specifically asked that we not support commercializations of his technology (not that I had interest but as a consequence will not repeat the exact specifications) in any case anyone interested can do the research in the old thread and a satisfactory solution is available.

 

Sorbothane, yes sorbothane let's just say that there are many scientific, military etc needs for vibration reduction and sorbothane is a well known material and it's limits are well known. No harm done because if you don't get perfect vibration isolation, the world will not end nor will puppies starve ?

[jabbr]

A couple things to consider: as far as I can tell the "Symposium" line of roller ball products have been developed with their own IP i.e. Independent of Barry Diament's design.

 

Anyone could start with 1/2" stainless ball bearings atop very smooth porcelain plates (doll house sized e.g. 1 1/2 to 2 ")

[jabbr]

11 minutes ago, rando said:

Among the troubles the simple air bearings he mentioned highlights is using a round tube under a rectangular platform.  Taking a rectangular piece of equipment with uneven weight distribution and replicating it's dimensions into an outsized shelf which it is placed onto off center to create equilibrium strikes me as poor implementation and design.  

 

Ultimately there are many ways to get a "spring" including magnetic. These are all springs. The inner tubes are cheap & work.

 

There are also wire rope based vibration isolators -- this is a whole category and these are better -- but more expensive and you need to tailor the product to the weight of the device being isolated:

 

[jabbr]

20 minutes ago, Audiophile Neuroscience said:

 

Well some compromises need to be made. I also gave up on wearing those full body contamination suits as it went against the audiophile's creed that one must sit naked while listening to music.. The bass waves resonate certain jiggly bits of anatomy and improve SQ !

 

Heigthening the importance of vibration isolation so that when you, err, dance, the standing waves don't damage your DAC ?

[jabbr]

30 minutes ago, JohnSwenson said:

So, anybody want to try this?

 

Hi John, interesting approach. Do you think the steel wire based isolator might have a non-linear/Euler like effect if the steel wires were sufficiently narrow & loaded?

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11 minutes ago, JohnSwenson said:

I looked at the wire devices a couple years ago, as far as I remember they are in the damper category, as the top plate moves is causes the wires to twist, causing strand to strand movement dissipating movement as heat.

 

John S.

 

Yeah the military/aircraft ones are very stiff.  The video I referenced above looks less stiff. I was considering drilling some holes into a block and inserting narrow carbon fiber tubes into a similar arrangement. If the tubes are bent to a "C" shape they should be in the nonlinear region?

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3 minutes ago, Ralf11 said:

There are dat a sheets for Sorbothane posted somewhere on the internet

 

 

What I am looking for is some cheap, easy to obtain smooth cups...

 

Try something like: http://www.ebay.com/itm/Set-of-4-Dollhouse-Miniature-Fancy-White-Glazed-Porcelain-Dinner-Plates-SPL05-/371818369682?hash=item56921a1292:g:4J4AAOSwImRYV40A

 

as a start, if you hear a difference you may wish to investigate the more "official" solutions...

[jabbr]

2 minutes ago, Ralf11 said:

I've found some of those but thought they were too flat.  Also, do you think they have adequate surface  smoothness?

 

Flat is fine -- the edges prevent the balls from rolling off -- you may find that the balls go to the edge which will lose effectiveness. Smoothness is ok -- better than nothing. 

[jabbr]

I tried concave lenses -- didn't like the SQ -- damped them with some putty/goop but this soon started to slide around ... then I got the alu bowls (per BD)

[jabbr]

35 minutes ago, Ralf11 said:

 

re: machining - if they were 3D printed then plated, a run could perhaps be made for fewer $$

 

3D printing metal can be done but is expensive. Strongly suspect prices would be $$$

[jabbr]

2 hours ago, rando said:

I won't search to quote this but @jabbr also mentioned he feels a substantial improvement in how the air bearing is implemented as highly probable.

Based on mechanical design, springs couple resonances, and this can be improved -- the question is how much of an audible difference. 

 

Ive been very happy with the BD system and although got some carbon fiber tubes that I was going to play around with, haven't gotten around to that...

[jabbr]

5 minutes ago, Audiophile Neuroscience said:

 

Hi Jabbr,

We seem to be both on the same page and happy with the BD system.

 

Did you have specific ideas on how the air bearing could be improved? It will also be interesting to hear about JohnS' ideas when they come to fruition.

 

Also, where did you eventually get your roller bearings from, local machinist or a commercial seller? If you feel comfortable in answering, how much was the cost?

 

Cheers

David

 

Yes, Barry spent a considerable amount of time designing, listening etc. and although it could be improved, not easily, in my opinion, and not without real engineering/measurements etc.

 

The air bearing is mechanically a spring. I considered magnetic discs but these are also mechanically springs. I considered air levitation but same ... and lots more work... I considered surplus vibration isolation tables but very heavy and not very practical.

 

The roadblocks in setting up a group buy are documented. Not everyone could agree on what they wanted, nor willing to firmly commit for a certain volume, and prototypes did not pass muster with some people who were willing to purchase a sizeable number of bowls. Folks need to remember that wanting something that's gone through extensive testing goes against getting a cheap price, and that it takes a considerable amount of upfront investment to get a product to market. In any case we ultimately settled on a mirror polish and one of the CA members was able to get a small run made in a local machine shop, which turned out great. This was a couple of years ago and I believe the price was between $10 / bowl for a run of 100 at a mirror polish. A standard polish of 16 RMS would have been $7.50/bowl. The discs were 2" diameter with a bowl depth of 1/8".

 

The shop DID NOT want multiple customers asking for 3 at a time etc and asked us not to publicize their name. I have zero interest in being a retailer.

 

Regarding ball bearings ... I use 12mm (1/2 inch). There's a site "Craig Ball Sales" which has great prices. VXB bearings is also good. I've tried stainless, Silicon Nitride and Silicon Carbide. Balls also come in different grade "round". Silicon Nitride is not unreasonably priced -- generally much cheaper than Silicon Carbide, though has nearly the same hardness.
 

So, next steps in case that ever happens... I now have a spectrum analyzer that measures down to 60 usec frequencies and so could see what the loaded frequency of the vertical iso platform would actually be. Folks have looked at tetrahedra: http://vibrationacoustics.asmedigitalcollection.asme.org/article.aspx?articleid=2608874 and other structures. I have some other ideas using CF tubes (1mm thick) ... but don't want to get into details until I'm ready to also publish measurements.

 

Really in the meantime, Barry's ideas are the way to go.

 

[jabbr]

18 hours ago, rando said:

Doing some reading on 7085 tonight to see how feasible this idea is.  Forgo lengthy expensive mirror polishing.  Instead have reasonable time and cost effective finish applied at machine shop.  Then have approximately 50% greater than bearing contact patch in bottom of cup coated with very hard and low friction treatment that will bond to rougher surface.  I'd like to see a high level of molecular bonding occur that will assure longevity.

 

As I said it was extra $2.50 per piece to get mirror polish ... can remember but anodization/polish was way more...

[jabbr]

2 hours ago, Ralf11 said:

Rando - the same problem I mentioned my own impending test applies to forgoing mirror polishing - you may not detect a difference that would exist if it had been used.

 

 

 

We await your systematic testing and results. There are so many different variables I look at that frankly my brain gets scrambled trying to do too many comparisons -- I chose to let BDs ears and work tell me what to do and then implement that. Rigorous SQ comparisons would be very helpful e.g. can you hear the difference between SS, SiN and SiC bearings?

[jabbr]

15 hours ago, Ralf11 said:

This should keep you busy until @jabbr resurfaces

 

Good reading... my own viewpoint is that vibration isolation should take care of the 1/f vibrations (amplitude goes up as frequency goes down). This has to do with physics. May actually have to do with gravitons, but 1/f noise is both amplitude and phase and there is a nonlinearity that relates 1/f noise to 1/f phase offset noise. That's electronics/physics.

 

Because the roller balls have low friction, the are excellent at isolating even low frequency oscillations. The goal of improving the vertical isolation beyond what the springs/inner tubes are able to do would be to reduce the low frequency coupling which is where nonlinear springs such as Euler, come into play, and this has been studied in the graviton detection literature.

 

 

How much this matters from an audibility point of view has not been rigorously tested/determined to my knowledge.

[jabbr]

32 minutes ago, Johnseye said:

Here are some other ways to isolate.

 

minus k

 

Vibraplane

Minus K looks good but expensive. Question would be how much better than Barry Ds inner tube? Vertical does have a conventional spring but all in the implementation. 

 

Clearly though the idea of so-called “negative stiffness” is similar to the nonlinear springs described  as Euler Springs. If you have an unlimited budget prob a good product. 

 

The other link link didn’t have enough info to comment on — would suspect more traditional vib iso .

[jabbr]

2 hours ago, sdolezalek said:

Does anyone have a good explanation of why someone hasn't come out with a set of true isolation products, at an affordable price that are also backed by some real measurements?

Nice description — probably because the different issues haven’t been bro ken down as you describe. 

[jabbr]

Ever been to a packed outdoor rock concert where you can feel the bass through your legs (when standing in a packed crowd, your legs are  exposed very little directly to sonic waves through the air).

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8 hours ago, marce said:

Playing with these on a job...

http://topline.tv/Vibration_Damper.pdf

Not snake oil more rocket science, NASA developed them initially.

Very interesting technology

[jabbr]

WTF does that mean “constrained layer”? Really technobabble..