Vibration Air & Roller Bearings - Thanks to Barry & Warren

[Audiophile Neuroscience]

1 hour ago, Ralf11 said:

rando - completely dead 1/2" marble tile - is it curved?  how did you know it would be completely dead ??

 

The tile should be flat.

You rap the tile with your knuckles while holding it up to your ear. The "dead tile" produces the least ringing, a dull thud. Barry also tells funny stories of how mothers with their children gave him a wide berth when they came across him so testing tiles!

[Audiophile Neuroscience]

24 minutes ago, Ralf11 said:

Thx - what keeps the ball on the tile if it is flat?

 

The fact that the ball beneath the tile is sitting in a cup/socket shaped convex down (concave up). It is the ground below that moves with respect to the tile and this displaces the ball up one of the sides of the cup. Provided the force of translation is not sufficient to roll the ball out of the cup, it is stable. From my basic physics days this was called an "unstable equilibrium" meaning the displaced object would always tend to return to the origin (like a pendulum). Think of a roller coaster with the carriage sitting at the bottom of the big U shaped track. Any force moving the carriage in any direction will be opposed by gravity returning it to the bottom. Now if you invert the U and stick the carriage at the top, any movement will send the carriage hurtling away from the origin and not to return. The latter an example of an "unstable equilibrium".

 

Edit: I should add that no such restriction to roller movement would appear desirable by the top surface and in the case of the tile would not occur. This would not appear to be the case with 3 piece "roller blocks" (cup below, then ball bearing, then cup above)

24 minutes ago, Ralf11 said:

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

Excellent but It does introduce more variables given that you appear to be bonding two materials rather than relying on a whole piece of aircraft grade aluminum.

[Audiophile Neuroscience]

17 minutes ago, rando said:

I appreciate that you are repeatedly willing to stand up for BD.  At some point you seized the narrative and took it beyond the request for a simple answer respecting the dignity it was phrased to protect.  Let's move on, to more fruitful constructs.  

 

Rando I merely replied to your comment.You are entitled to your opinion that I took it beyond a request for a simple answer. I don't consider the subject material necessarily simple.Yes, I am happy to stand up for BD. However if you do not bring it up, I will not reply.

Cheers

David

[Audiophile Neuroscience]

1 hour ago, Ralf11 said:

 

I understand neutral stability and the associated differential eqns.  but what is the 'cup' you refer to??

Hi Ralph

There was a typo in my description of equilibrium with the first scenario should have read stable not unstable equilibrium.

 

The cup or socket as Barry refers to it in reference to his "hip joint" is the scooped out depression in the aluminium block in which the ball rolls.

[Audiophile Neuroscience]

6 minutes ago, Ralf11 said:

so I'm guessing the tile goes above the ball...

 

Yes smooth side down onto the ball.

It is much more stable in feel than I anticipated.just a nice little wobble when poked.of course you wouldn't want kids or pets crashing into the gear. I have a child proof gate at the end of the corridor leading to the music room.my dog sits and listens glum faced on the other side.as I mentioned in another thread he pays attention to sound that he thinks is real.he likes the addition of the isolators!

[Audiophile Neuroscience]

3 hours ago, AnotherSpin said:

Cups, cups, cups. Roller balls shouldn't just move around, they should oscillate back and forth and this is provided by curvature. Barry was very detailed on this. Cups curvature proportioned well against the diameter of roller balls is critical. You may hear difference in sound just because the cup have more or less deep concave. And again, only best alu will not have dents which will interfere in free movement of the roller balls. Material of roller balls is important as well.

 

1+

 

3 hours ago, AnotherSpin said:

I tried several materials - marble, ceramic, aluminum, glass. As I remember, alu plates worked better, but even they provided some coloration. Finally I set for combination of two cups with roller ball inside for heavy components, and cup+ball+alu plate for light ones.

 

I have a 108Kg amp on a ceramic tile. I placed a light weight timber backing (on the non-smooth side) just because I was frightened the amp would crack the tile. I believe Barry stresses that the support platform needs to be as stiff as possible, the lowest mass as possible, the smooth surface presented to the rollers, as smooth as possible, and as acoustically dead as possible.

 

Well implemented isolation, as per Barry's method should remove coloration, not add. If one accepts this as true, the the corollary is that less ideal methods may make the sound different but less neutral, *less removed of coloration*. You may prefer this result for whatever reason and no-one can disagree.

 

As previously guessed I don't think the 'trio' of roller block idea (cup,ball,cup) is a good idea.In fact I just found Barry's own opinion on this, which at the time I had no idea what he was saying as I was not aware of this 'trio' roller block thing at that time.

 

FYI Barry said "

<QUOTE>With roller bearings, the slower the ball rolls, the lower the roller bearing resonance.  This is important because isolation doesn’t *begin* to take effect until approximately 1.4x the resonance.  So a good isolator will have a resonance in the low single digits.
 
In addition, the longer the ball rollers, the deeper the isolation will be.  Any damping on ball motion will make the roll-off above resonance less steep, i.e. diminish the degree of isolation.
 
So I want the ball to roll as slowly as possible and for as long as possible.  This is achieved two ways.  First, a wider, shallower bowl (to a point before the ball rolls away and the component falls) will slow down ball motion and let the ball roll for a longer time.  Also, by *not* using another bowl atop the ball, we avoid the added damping the second bowl would apply.
 
Placing a Hip Joint and a Rollerblock side by side with a ball at the top of each roller’s bowl, then releasing the ball, was how I compared them (other than the sonic comparisons).  The ball in the Rollerblock oscillated much more quickly than the one in the Hip Joint.  The ball in the Rollerblock also came to rest long before the one in the Hip Joint, which seemed to just keep on rolling.  Several folks I know compared both in their systems and were unanimously in favor of the Hip Joints. ,</QUOTE>

 

I added the bold emphasis.

 

I note JohnS also doesn't use the roller blocks in this 'trio' arrangement (but I am not saying he therefore says it wrong, just sayin')

 

As Barry *always* says, you may be experiencing a different perception. Again, no-one can disagree.

 

My experience thus far is Barry is spot on. I am currently getting extraordinary SQ using a full complement of room treatments and vibration isolation. The music more freed from the system and room restraints.

 

[Audiophile Neuroscience]

2 minutes ago, AnotherSpin said:

 

I am very much aware of Barry position on 'trios'. In fact, I was using this configuration only under heavy components, because I was not able to find satisfactory alternatives. All tried plates (marble, ceramic, aluminum) added some coloration to the sound. Also, the cups which I ordered were designed after discussions with Barry and were quite wide and shallow. With adding extra cup on the top I didn't notice significant decrease of the SQ in my system.

 

Hi Spin,

Glad this works for you.

 

Just thought it was worth mentioning how Barry approaches heavy gear. Not with roller blocks but with "hip joints" and tile with reinforcement of the tile with plywood. This includes his large "Maggie" speakers. I haven't yet been that game to try under my Vivid G2's. I note that Laurence Dickie who designed them feels that they could be suspended in the air with no need to be 'anchored' to the ground. Haven't tried that either

[Audiophile Neuroscience]

3 hours ago, jabbr said:

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...

 

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

[Audiophile Neuroscience]

8 minutes ago, jabbr said:

 

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.

 

 

Thank you for sharing all of this!

 

So you got the 'bowls/cups/sockets' for a similar price as I did, and for a 100 run. IMO a very reasonable investment and risk to take under the circumstances.

 

If you don't mind and can remember to do so, would you PM me if you ever get around to further experiments?

 

Cheers

David

[Audiophile Neuroscience]

27 minutes ago, Ralf11 said:

anybody own a vibrometer?

 

Sure, but I think the ladies call it ...oh,

[Audiophile Neuroscience]

1 hour ago, AnotherSpin said:

Nothing funny here. I am looking for nicely done drawer pulls web-site from manufacturer who provides satisfaction guarantees and lab tests of materials, etc. Do you know such?

 

 

So long as they are the self closing variety the condition of unstable equilibrium would be satisfied. The pull needs to be long and slow for best resonance characteristics.

[Audiophile Neuroscience]

33 minutes ago, AnotherSpin said:

 

Thank you for polite and thoughtful answer without capital letters. My experiments with cups are over, but if I will decide to resume I will be glad to share and discuss with you.

 

Like Barry before us, polite, thoughtful sharing of ideas is what inspired posting this thread in the first place.Look forward to hearing about any of your future adventures in vibration isolation.

[Audiophile Neuroscience]

4 minutes ago, Audiotruth said:

 

Hello Audiophile Neuroscience,

 

Over the weekend I installed the following isolation devices (Design is courtesy of Barry Diament of Barry Diament Audio Design) in my system. Three air bearings, one under a stack of equipment that includes Pre Amp. (Gryphon Sonata), DAC (Briscati M1) and ISO Regen. The second under an Amplifier (Halcro DM38), the third under a server plus 2  HDPlex LPSU & 3  Uptone UltraCaps LPS-1s. On top of the three air bearings, are three aircraft grade aluminium hip and ball bearing joints.

 

The improvement in SQ is not subtle. If I where trying to avoid hyperbole and instead summaries in three words the difference (Barry Diament designed isolation devices) the devices made in my system and in my room (Your Mileage May Vary) they are, Clarity, Focus and Organic.

 

Thanks to Barry Diament for his generosity and willingness to share his experience and knowledge.

 

Regards

 

Great to hear they had similar as I and others have obtained

Cheers

David

[Audiophile Neuroscience]

20 hours ago, fas42 said:

Just to clarify - has anyone investigated which frequencies or range of frequencies need to be dealt with; and what the level of isolation should be at those frequences - and also possibly whether it varies significantly for different components?

 

 

It stands to reason that isolation should be at least in respect to the lowest audio frequencies and upwards. An Isolator starts to become effective at approximately 1.4x the resonance.  So a good isolator will have a resonance in the low single digits.

 

As Barry says, with roller bearings, the longer the ball rolls, the deeper the isolation will be.  You want the ball to roll as slowly as possible (lowest resonance frequency) and for as long as possible (*least* amount of damping for steepest rolloff above resonance). Any damping on ball motion will make the roll-off above resonance less steep, i.e. diminish the degree of isolation.

[Audiophile Neuroscience]

On 2/28/2018 at 5:16 AM, semente said:

 

Why doesn't the inner tube provide damping in the horizontal and rotational planes?

 

Just my thoughts......The main "spring" action of the inner tube would be in the vertical direction and created by air compression. I imagine there would be some lateral and torsional movement due to deformation of the rubber (and relatively less contribution by air) which is possibly undesirable and hopefully kept to a minimum. I am thinking rubber would introduce its own resonant/isolating/coupling characteristics and also maybe best to have only one "spring action" per plane of motion (in the case of roller bearings the plane remains horizontal whether moving sideways, back to front or 'rotational').