Equipment isolation and vibration damping.

[YashN]

Perhaps this is true of whatever you've tried so far. It would seem so if you see oscillations on the order of 10 Hz.

It's what *I'm* doing with my Hip Joints design though. Some of the commercial rollers are doing this too.

 

I'm not seeing oscillations at 10 Hz, this was just an example to think things through and to see if and how we are using the material to reach our objectives. That is, once one understands what we are trying to do, the question is whether we are implementing it in the best way possible.

 

You say you want the oscillations to last longer for better isolation. If we agree on this, then the cups should be large, allowing for greater shallowness. I don't see this in either the commercial versions or your version.

 

There's certainly a practical aspect to what was built on what is available, but my point here is for the horizontal isolation, small cups and high curvature isn't what we should be doing if we want the oscillation to be as free as possible.

 

So, the current implementations are a compromise and sub-optimal.

 

Instead of doing small cups with high curvature, and placing the encasing blocks relatively far away from each other when under a large platform or component, I would advise measuring the largest equilateral triangle, together with the largest block dimension possible around the three former centre-point.

 

This will allow reducing curvature. I am not sure how to determine the curvature to prevent falls, but in theory, we would like the gentlest curve but which does not allow our gear or upper platform to fall off.

 

I therefore envision three large blocks, as large as possible underneath the upper platform or component, and as close to each other as possible, with each having the largest possible diameter of concave space within.

 

This is an example of how understanding the physical phenomenon and thinking things through can help the design and, am hoping, the efficiency and the results.

 

I suppose one could also build an equivalent arrangement with two flat, hard, smooth platforms with the balls sandwiched in between, but with the additional of either beams or springs to move back to equilibrium so that the upper platform doesn't fall off.

[YashN]

Triangle ??

 

Yes, the three points where the centre of the cups are.

 

How did you arrive at that dimension ?

 

By a quick visual and hand estimate of my Panasonic amp: looking at it from above, and considering solely the component's size. I want the 3 largest blocks I can place so that I can host the largest and gentlest curvature inside them. Actually, I think the dimensions should be even bigger.

 

 

 

I don't think any of the parts we are talking about will undergo any deformation at all, in the modest service of our audio applications. With the possible exception of a severely overloaded acrylic block. Not to worry

 

You assumed 'normal operation', I didn't.

[YashN]

Since the Linn LP-12, and a few other audio encounters, I have disliked any kind of springs in things audio. They all have resonances, but some think thay can tame them. I have my doubts...

 

Everything has a resonance...

[YashN]

It isn't the dimension of the Sorbothane, it is its inherent resonance, which in my opinion, is way too high to be effective for my purposes.

 

My question was what dimension did you use.

 

If you watch the Minus K animation, their implementation uses a tiny pad, as relative to the upper platform dimension.

 

If you used a larger pad of the dimension of the platform or component and had bloated bass, maybe the other way doesn't have this effect, and additionally deals with tilt.

[YashN]

It isn't the dimension of the Sorbothane, it is its inherent resonance, which in my opinion, is way too high to be effective for my purposes.

Basically, anything that has a resonance in the audible bass range is going to cause bloat -- the nature of the bloat being tied to exactly where the resonance peaks and to its Q (i.e., bandwidth).

 

What is the resonance of the inner tube air-cushion?

[YashN]

Very cool - have you priced these isolation platforms? Roughly $2K and up.

 

Yes, they are very expensive. They are meant for Laboratory stabilisation initially, together with stabilising telescope optics and other larger structures.

 

If you watch the turntable video above, you will know the price of an audio component which incorporates that technology as well...

[Daudio]

I want the 3 largest blocks I can place so that I can host the largest and gentlest curvature inside them. Actually, I think the dimensions should be even bigger.

 

 

I think you misunderstand the bowl dimensions. You can have a 1" diameter 'bowl' in some material, but the curvature can be just about anything you want. From Hip Joints at a 2" curvature, to my acrylic blocks at 1.3", or make it 4", or 48" if you really want to go shallow. And they all can fit into that 1" circle in that little bowl block. It is just the depth at the center of the bowl that changes - and the curvature, of course.

 

I don't think making a huge 'runway' for the ball is of any value, and just wastes metal and money. The vibration isolation magic is going on in the visibly stationary bearing ball (and it's interfaces). Once these devices are setup, you don't want them wandering about

[bdiament]

What is the resonance of the inner tube air-cushion?

 

Hi YashN,

 

Unlike a solid material like Sorbothane, the resonance of an inner tube used as air bearing will depend on the amount of inflation.

That is why I say to use *only* enough inflation to lift the load off the inflation valve. Properly done, we can get the resonance in the target zone.

 

Townshend has done this too with some of his products.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[bdiament]

...If we agree on this, then the cups should be large, allowing for greater shallowness. I don't see this in either the commercial versions or your version...

 

So, the current implementations are a compromise and sub-optimal...

 

If you read my earliest posts, you'll see that I was saying this all along. (Remember when you wanted damping and a steeper-walled bowl?)

 

Practical considerations come into play in order to fit a trio under gear. Yes, a larger diameter bowl would lower the resonance. The idea however is to get the resonance down into the low single digits. Taking it from 2 Hz or 1.5 Hz to 0.75 Hz would offer a *theoretical* benefit and *perhaps* a practical one but the former will already be effective. (We're talking about isolation taking effect at 2.8 Hz or 2.1 Hz vs. 1.05 Hz.) Still, if you want to, consider the largest bowl you find practical.

 

This is an example of how understanding the physical phenomenon and thinking things through can help the design and, am hoping, the efficiency and the results.

 

I've long been an advocate of understanding the phenomenon and thinking things through. Add some direct experience to the theoretical analysis and you'll have it nailed.

Remember to have fun!

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[YashN]

Unlike a solid material like Sorbothane, the resonance of an inner tube used as air bearing will depend on the amount of inflation.

That is why I say to use *only* enough inflation to lift the load off the inflation valve. Properly done, we can get the resonance in the target zone.

 

Townshend has done this too with some of his products.

 

I'll see if i can find some additional info on the air-cushion arrangement. Townshend for the speakers you mentioned before? Still haven't checked these out.

[YashN]

I think you misunderstand the bowl dimensions. You can have a 1" diameter 'bowl' in some material, but the curvature can be just about anything you want. From Hip Joints at a 2" curvature, to my acrylic blocks at 1.3", or make it 4", or 48" if you really want to go shallow. And they all can fit into that 1" circle in that little bowl block. It is just the depth at the center of the bowl that changes - and the curvature, of course.

 

Well, the question should really be how do we optimise the free oscillation, and how that relates to curvature.

 

Yesterday, I thought about something a little different: what if we use a recipient which is flat for the most part, and then curves at the end. Technically, this should make for a free run for the most part, and then only use up energy as work at the edges. Shouldn't that be better?

 

I don't think making a huge 'runway' for the ball is of any value, and just wastes metal and money. The vibration isolation magic is going on in the visibly stationary bearing ball (and it's interfaces). Once these devices are setup, you don't want them wandering about

 

Maybe.

[bdiament]

I'll see if i can find some additional info on the air-cushion arrangement. Townshend for the speakers you mentioned before? Still haven't checked these out.

 

Hi YashN,

 

Townshend's speaker stands use big springs. He *used to* make air bearing platforms. Not sure if he still does or has moved over entirely to springs. Max Townshend is one of the pioneers in isolation and the demos I've heard of his products exhibited results that were quite convincing and far from subtle.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[1markr]

The top section is spherically cupped, and the bottom section is a straight edged cup, about a 1/4" deep.

 

I will experiment with just the spherical cupped end on the bottom, with the chrome steel ball on top, and the speaker siting on top of the ball. Only problem there is that the speaker has a slightly textured finish, which is not ideal for isolation based on everything mentioned in this thread. Won't hurt to try.

 

 

Checked them out at this Soundstage review. They look cool and not too expensive. Are the tops curved as well?

 

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[TD=width: 20%]Sound[/TD]

[TD=width: 80%]"The clarity of the music improved, the soundstage became more specific, and the bass seemed to tighten and become more authoritative."[/TD]

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[TD=width: 20%]Features[/TD]

[TD=width: 80%]Three pieces -- top, bottom and ball bearing -- that "float" components under which they are used, isolating them laterally.[/TD]

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[TD=width: 20%]Use[/TD]

[TD=width: 80%]Doug found them to work best under CD players; under solid-state electronics, "the changes range from, 'uh, maybe,' to 'yeah, perhaps.'"[/TD]

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[TD=width: 20%]Value[/TD]

[TD=width: 80%]"Is there any competition for Daruma 3-IIs in their price bracket?" "Their $99-per-set price is quite reasonable."[/TD]

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[YashN]

If you read my earliest posts, you'll see that I was saying this all along. (Remember when you wanted damping and a steeper-walled bowl?)

 

Yes, so why are you using a small device with a curvature that is not shallower?

 

Taking it from 2 Hz or 1.5 Hz to 0.75 Hz would offer a *theoretical* benefit and *perhaps* a practical one but the former will already be effective. (We're talking about isolation taking effect at 2.8 Hz or 2.1 Hz vs. 1.05 Hz.) Still, if you want to, consider the largest bowl you find practical.

 

I think John mentioned 1 Hz. I am also thinking about something a little different, which is to have larger recipients, but with a mostly flat surface, until the edges where it is curved.

 

Technically, these should allow for freer oscillation.

 

I've long been an advocate of understanding the phenomenon and thinking things through. Add some direct experience to the theoretical analysis and you'll have it nailed.

 

Yup, that's the plan: I only have some small marbles for now, and my 6th cup is ready today for machining with the others.

 

If the weather allows, I have some work to do with the Dremel in the garden today for the blocks + cup arrangement. Not too sure how this will pan out as I don't have a way to drill large circular holes. The idea is to secure the cup within a block of wood and deaden the arrangement.

[YashN]

Townshend's speaker stands use big springs. He *used to* make air bearing platforms. Not sure if he still does or has moved over entirely to springs. Max Townshend is one of the pioneers in isolation and the demos I've heard of his products exhibited results that were quite convincing and far from subtle.

 

If he's the same Townshend who made the Rockport headshell-side fluid damping, I'm already a big fan of his work.

 

My DIY fluid-damping is counter-weight-side, not ideal, but works (audible, positive effect, especially the bass I believe and on warped passages): it's just a bent, flat pin, blu-taked, and wallowing around in oil. But if could make a headshell-side damper that would be fabulous.

[YashN]

The top section is spherically cupped, and the bottom section is a straight edged cup, about a 1/4" deep.

 

I will experiment with just the spherical cupped end on the bottom, with the chrome steel ball on top, and the speaker siting on top of the ball. Only problem there is that the speaker has a slightly textured finish, which is not ideal for isolation based on everything mentioned in this thread. Won't hurt to try.

 

Interesting: they prefer the curve to be component-side and the flat surface to be below. I wonder if there is an audible difference and/or advantages.

 

Use another platform to hold your speakers: this way you can have a smooth surface against the ball, and secondly, preserve your speakers' textured finish simultaneously.

[bdiament]

The top section is spherically cupped, and the bottom section is a straight edged cup, about a 1/4" deep.

 

I will experiment with just the spherical cupped end on the bottom, with the chrome steel ball on top, and the speaker siting on top of the ball. Only problem there is that the speaker has a slightly textured finish, which is not ideal for isolation based on everything mentioned in this thread. Won't hurt to try.

 

Hi Mark,

 

Try using a dead marble tile, smooth side down, under the speaker and atop the rollers.

The key is to find a very smooth tile that doesn't "ring."

 

Hold the tile at the corner using your thumb and forefinger. Hold it up near your ear and rap on its center with a knuckle on the other hand. A dull "thunk" is preferred over a distinct ringing pitch. (Warning: Folks at the tile store might look at you strangely. ;-})

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[bdiament]

Yes, so why are you using a small device with a curvature that is not shallower?...

 

Hi YashN,

 

This is iteration #1. It works.

That is precisely the reason why I'm using this design. It works. It works superbly.

 

 

I am also thinking about something a little different, which is to have larger recipients, but with a mostly flat surface, until the edges where it is curved.

 

Technically, these should allow for freer oscillation.

 

Actually, I believe it will technically make for an absence of isolation. The ball (or more properly the supporting shelf) is not going to move *that* much. If the design is flat in the middle, it will only serve to allow the supported device to roam a bit. There will be no resonant peak and hence no roll off to provide the isolation.

 

But do try your idea and see. I'd be the last to say "don't try it." There is always something for all of us to learn. I look forward to hearing of your experiences.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[bdiament]

deleted

[1markr]

That sounds reasonable Barry, and worth a try. I would think a smaller but thicker piece of marble would not ring like one with a larger area. Something like a 2"x 2" piece over each steel ball?

 

 

Hi Mark,

 

Try using a dead marble tile, smooth side down, under the speaker and atop the rollers.

The key is to find a very smooth tile that doesn't "ring."

 

Hold the tile at the corner using your thumb and forefinger. Hold it up near your ear and rap on its center with a knuckle on the other hand. A dull "thunk" is preferred over a distinct ringing pitch. (Warning: Folks at the tile store might look at you strangely. ;-})

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[Daudio]

The top section is spherically cupped, and the bottom section is a straight edged cup, about a 1/4" deep.

 

I will experiment with just the spherical cupped end on the bottom, with the chrome steel ball on top, and the speaker siting on top of the ball. Only problem there is that the speaker has a slightly textured finish, which is not ideal for isolation based on everything mentioned in this thread. Won't hurt to try.

 

I would keep the original 3 parts together, as the flat section is presumably smooth, where the bottom of your speakers are not, and the edges will keep the ball nicely contained.

 

I don't think it matters much whether the curved cup is on the top, or bottom. You can experiment, of course.

 

Could you post a picture or two of this device, when you get a chance ?

[Duke40]

Hi YashN,

 

Townshend's speaker stands use big springs. He *used to* make air bearing platforms. Not sure if he still does or has moved over entirely to springs. Max Townshend is one of the pioneers in isolation and the demos I've heard of his products exhibited results that were quite convincing and far from subtle.

 

Best regards,

Barry

Soundkeeper Recordings

www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

 

+1 on the Townshend speaker stands ... it is far from subtle improvement.

After improving my the power supplies for my rigs, isolation has been the next most significant improvement. I think Max Townshend is one very smart guy.

 

I initially read your postings about DIY platforms and isolation (by the way, Barry ... Thank You!)

on CA and decided to experiment a bit. I have some spare Townshend springs so thought I would make some DIY platforms.

 

"Hold the tile at the corner using your thumb and forefinger. Hold it up near your ear and rap on its center with a knuckle on the other hand. A dull "thunk" is preferred over a distinct ringing pitch. (Warning: Folks at the tile store might look at you strangely. ;-})"

 

I did that in the Hardware store & yes I got some funny looks.

 

After doing the knuckle test and checking for ringing on a wide variety of material ... I actually quite like Aluminium.

 

So then went to my local Metal Work shop and had 10mm slabs of Aluminium cut so I could use them with some spare Townshend springs (I think you can buy them individually these days, they may be called "Pods").

 

Oh, while I was at the hardware store I found some sand filled steel doorstoppers (with rubber base) marked down from $10 to $1 each, so bought a heap of those.

 

After taking care of speakers ... I find my DAC's tend to benefit the most , then source, then amp.

 

Below photo's are an example of DIY isolation platforms from my headphone rig located in the man cave ...

 

 

I am thinking of getting the Aluminium ... anodised.

I believe that will narrow the "resonance band".

 

Oh, I experimented with footers a lot ... decided I actually preferred at least one slab of 10mm Aluminium directly under a component ... so I remove footers from components.

 

Anyway, that is my isolation/resonance "journey" so far. Really just posted here to say thanks to Barry ... when I saw his posts a few years ago, well it led me onto a fun and beneficial (SQ wise) experimentation.

[1markr]

The Final Daruma 3-II s are pictured above, about 9 posts up or so, in YashN's post. Are you looking for something else? If you are, I'd be happy to post more pics...

 

I would keep the original 3 parts together, as the flat section is presumably smooth, where the bottom of your speakers are not, and the edges will keep the ball nicely contained.

 

I don't think it matters much whether the curved cup is on the top, or bottom. You can experiment, of course.

 

Could you post a picture or two of this device, when you get a chance ?

[bdiament]

That sounds reasonable Barry, and worth a try. I would think a smaller but thicker piece of marble would not ring like one with a larger area. Something like a 2"x 2" piece over each steel ball?

 

Hi Mark,

 

Based on my own experience using marble tiles under my speakers, subs, amps, and converters, I suggest a single tile. It should be large enough to accommodate the largest equilateral triangle that will fit under the component, plus maybe an extra inch for a safety margin. What I've found is that individual pieces, aside from being a pain to place, will tend to "chatter" which will alter tonality -- something a good roller bearing will not do.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[bdiament]

Hi Duke40,

 

Those are some cool-looking platforms!

 

...

"Hold the tile at the corner using your thumb and forefinger. Hold it up near your ear and rap on its center with a knuckle on the other hand. A dull "thunk" is preferred over a distinct ringing pitch. (Warning: Folks at the tile store might look at you strangely. ;-})"

 

I did that in the Hardware store & yes I got some funny looks....

 

I've had young mothers place themselves between me and their children as they passed.

Similar things happened when I was testing open cell foam at a local crafts type store. I needed some foam for the baffle I was making to go between my microphones during recording sessions. I already had the closed-cell foam for the core. Now I needed some open cell foam and I wanted it to block as much treble as possible. So I held a sheet of foam up against my ear while rapping on the store's metal shelving with the other hand as I listened through the foam. Couldn't blame folks for thinking they should keep their distance. ;-}

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio