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YashN

Equipment isolation and vibration damping.

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If the inner tube pokes out a little under the sides of your plywood plate, I wouldn't be too worried about it. I have one that buldges out a little under a BDR Shelf. As long as the top, load bearing, portion of the tube is in contact with the plate, I'd be happy.

 

Did you fully inflate your 18" tube to see those dimensions ? Remember it should only be partially inflated. Just enough to lift the load above the level of the tubes's stem. Maybe that will bring the diameter down some ?

 

I have blown it without load right now, so when it loads it will go down, but I do not think dia will reduce much.

 

16" will be better I think. Anything wrong with that?

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I have blown it without load right now, so when it loads it will go down, but I do not think dia will reduce much... 16" will be better I think. Anything wrong with that?

 

You'll never know for sure until you try !

 

I don't know about a 16", for your situation. They are cheap enough to just get one and see for yourself :)

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The ceramic bowls and plates have arrived from Thailand.[ATTACH=CONFIG]19806[/ATTACH]

[ATTACH=CONFIG]19807[/ATTACH]

 

I spotted a few of these at the Chinese shop the other night, saw some of them have a bump in the middle, but some items are smooth.


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An 18" tube blows to a 23" ring, I just pumped air in one, is that the idea? It is too big for a 22"x22" plywood. I don't think we intend to have plywood smaller than the tube.

 

May be I should use 16" tube, which might blow to 21", and then 22"x22" ply might be ok.

 

Hi sig8,

 

I'm at a loss to figure out why an 18" inner tube is describing a circle much more than 18".

I'm using 18" x 1.75" inner tubes and they would appear to describe nothing larger than an outer diameter of 19" or a bit less. I have them under 20" x 20" platforms and the inner tubes stop a least 1/2" before the edge.

 

I prefer to have the full surface of the inner tube covered, with nothing bulging beyond the edge of the platform.

First thing I'd suggest is to ascertain whether those are in fact 18" inner tubes, or were perhaps mislabeled.

If they are, and they describe a circle much larger than 18", I'm still at a loss, but would then suggest trying a 16" tube (or another 18" to be positive you have the right size).

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

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Click on the various photo highlight circles to see what's on offer from HRS and how they work.

 

isolation_base.png


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Hi Dave, Why assume the floor vibrations you felt were vertical?

 

Barry, I replied to you in post #546, but that may have become covered up by the normal accumulation of forum detritus over the weekend :)

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Slightly off topic but on the subject of isolation, vibration etc, how much harm are humming transformers going to do to ones sound? Presumably there's a lot of vibration caused, is this going to be significantly impacting SQ (apart from about as long as a piece of string)? This is leading to- how much effort to I put into resolving this (balanced transformer, move home..)? Ta.

 

Sorry if this is detritus, just trying to get perspective...

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Sorry if this is detritus, just trying to get perspective...

 

One man's detritus, is another man's interesting conversation. Just a matter of perspective :)

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Barry, I replied to you in post #546, but that may have become covered up by the normal accumulation of forum detritus over the weekend :)

 

Hi Dave,

 

I saw the post, then got distracted by some non-audio necessities (aka Life and the health of a loved one who was in the hospital for a heart operation).

Also, I didn't really have much to say.

 

I don't know that I would draw the same conclusions, i.e., that the vibrations were vertical in nature.

Even if the subs are in direct contact with the floor (I'd consider "floating" them too. ;-}) and even if the floor is suspended on joists, I could be mistaken (of course) but I don't see why these would suggest the vibrations in the floor itself travel across the floor vertically rather than horizontally. Vibrations may *enter* the floor vertically but I'm not so sure this means they stay that way once the floor is energized.

 

As I said, I don't know. I would just tend to think the *primary* vibrations are horizontal if they are felt in a part of the room well away from where the subs contact the floor. Not to say the floor isn't *also* moving vertically. I'm thinking of seismic vibrations in the earth: the P (primary) waves move horizontally, the S (secondary) waves move vertically. Those P waves are what appear to do most of the damage.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

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Despite most of that HRS stuff being well out of my price range i wonder how these would go.

 

Nimbus System

 

they are well priced and they say it works on any shelf system so it might be a replacement for the cup and ball?

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Those of you who have tried bicycle tube method, including Barry, I have a question:

 

I think the idea is to keep the tube valve stem towards the outside for access. As we all know it is designed to be towards the inside of the ring, but I think once we force it and put some load on it, it will probably stay outside for access.

 

Is that how it is or am I missing something and we would need flexible valve extension, etc. for sure.

 

Please let me know. Thanks.

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Nimbus System

 

they are well priced and they say it works on any shelf system so it might be a replacement for the cup and ball?

 

Looks like squishy stuff in a metal cup to me :)

 

I wouldn't replace roller devices with them, But, I think it's great for people to experiment, listen, and judge for themselves. And then let us all know their results.

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I think the idea is to keep the tube valve stem towards the outside for access. As we all know it is designed to be towards the inside of the ring, but I think once we force it and put some load on it, it will probably stay outside for access.

 

Is that how it is or am I missing something and we would need flexible valve extension, etc. for sure.

 

Well, if you can turn an inner tube inside out, my hat's off to you :)

 

But there is the little matter that the inside diameter of the torus is considerably smaller then the outside diameter. So there is less rubber skin on the inside, and more on the outside. The structure will mightly resist efforts to deform it, probably only resulting in damage. But please try it if you think you can. They are certainly cheap enough to experiment with !

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I don't know that I would draw the same conclusions, i.e., that the vibrations were vertical in nature.

Even if the subs are in direct contact with the floor (I'd consider "floating" them too. ;-}) and even if the floor is suspended on joists, I could be mistaken (of course) but I don't see why these would suggest the vibrations in the floor itself travel across the floor vertically rather than horizontally. Vibrations may *enter* the floor vertically but I'm not so sure this means they stay that way once the floor is energized.

 

As I said, I don't know. I would just tend to think the *primary* vibrations are horizontal if they are felt in a part of the room well away from where the subs contact the floor. Not to say the floor isn't *also* moving vertically. I'm thinking of seismic vibrations in the earth: the P (primary) waves move horizontally, the S (secondary) waves move vertically. Those P waves are what appear to do most of the damage.

 

Barry,

 

Think of my floor as a trampoline, anchored at the edges, flexible in the center. That kind of structure supports vertical waves. And the center of my floor was where I first noticed the phenomenon.

 

But, who says it is only one kind of effect ? It is probably a combination of P and S waves. But I still think that S waves are predominant in my situation.

 

How would one measure this kind of thing ? I've been wondering about those accelerometers built in to the various iDevices lately.

Could they be used to accurately and reliability measure these small vibration vectors ?

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Well, if you can turn an inner tube inside out, my hat's off to you :)

 

But there is the little matter that the inside diameter of the torus is considerably smaller then the outside diameter. So there is less rubber skin on the inside, and more on the outside. The structure will mightly resist efforts to deform it, probably only resulting in damage. But please try it if you think you can. They are certainly cheap enough to experiment with !

 

Ok, bad idea, wouldn't work. As you know I am trying to gather whatever I need for a weekend trial, that is why the questions, and I do not have everything to try yet. Thanks for your help, but still questions;

 

I physically tried to turn the tube, but as you said stem tries to go back inside, but I thought it might stay there with load. So the question then is how do you adjust the inflation.

 

I do not want to pick my 75 lbs amp six times to adjust the pressure, and I really wouldn't know how much pressure to put without trying, so what is the answer?

 

Would flexible valve stems work, but would have to pass under the tube like the straw, or we may not need the straw, because flexible hose will create some gap.

 

Also there was a talk about valve extensions, etc. how they apply then?

 

Let me know please. Thank you for your help.

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Slightly off topic but on the subject of isolation, vibration etc, how much harm are humming transformers going to do to ones sound? Presumably there's a lot of vibration caused, is this going to be significantly impacting SQ (apart from about as long as a piece of string)? This is leading to- how much effort to I put into resolving this (balanced transformer, move home..)

 

Good point, I am re-thinking my SET Tube Amp because of that.


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Surround: VLC | M-Audio FastTrack Pro | Mac Opt | Panasonic SA-HE100 | Logitech Z623

DIY: SET Tube Amp | Low-Noise Linear Regulated Power Supply | USB, Power, Speaker Cables | Speaker Stands | Acoustic Panels

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Those of you who have tried bicycle tube method, including Barry, I have a question:

 

I think the idea is to keep the tube valve stem towards the outside for access. As we all know it is designed to be towards the inside of the ring, but I think once we force it and put some load on it, it will probably stay outside for access.

 

Is that how it is or am I missing something and we would need flexible valve extension, etc. for sure.

 

Please let me know. Thanks.

 

Hi sig8,

 

I'd leave the valve on the inside. As Dave rightly points out, there is less rubber on the inside of the circle than there is on the outside.

 

A flexible valve extension helps with access. And yes, it *may* also provide enough of a gap to remove the need for the straw. However, it may also make for a bit of tilt. You would need to experiment to see.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

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sig8,

 

You could use the tank valve G21TVB and the chuck valve pictured on page 7 of http://greenlinehose.com/_pdf/fittings/16.Accessories.pdf and connect them with a flexible hose of your choice, long enough to extend beyond the exterior circumference of the air chamber.

 

I bought a few of these for when I will take the time to try that.

 

Have fun!

 

Gilles


MacBook Pro (OS 10.10.4, 16GB RAM, OCZ Vertex3 SSD, external Oyen HD w FireWire, Audirvana+ 2.5.4, BitPerfect 2.0.2) -> Mapleshade Clearlink USB Plus cable -> UpTone Audio USB Regen w UpTone Audio Ultracap LPS-1 -> Wavelength Brick v3 DAC -> Transparent Wave Link interconnects -> Luxman R-1050 -> Transparent Music Wave Plus speaker cables -> ASW Cantius 504 speakers

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Barry,

 

Think of my floor as a trampoline, anchored at the edges, flexible in the center. That kind of structure supports vertical waves. And the center of my floor was where I first noticed the phenomenon.

 

But, who says it is only one kind of effect ? It is probably a combination of P and S waves. But I still think that S waves are predominant in my situation.

 

How would one measure this kind of thing ? I've been wondering about those accelerometers built in to the various iDevices lately.

Could they be used to accurately and reliability measure these small vibration vectors ?

 

Hi Dave,

 

Understood about the floor. However, I still don't see this means vibrations in the floor are necessarily traveling vertically as opposed to horizontally.

 

Not sure how this could best be measured. Probably have to look into how seismologists do it. (There's a job. I can imagine a kid somewhere saying: "When I grow up, I want to be a seismologist." ;-})

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

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I physically tried to turn the tube, but as you said stem tries to go back inside, but I thought it might stay there with load. So the question then is how do you adjust the inflation.

 

 

The tubes I use are pretty stubborn, but I was able to turn them inside out. The simple way is this: I inflate it quite much, turn inside out, look for the valve to be not tilted, put tube under board and component, and after that deflate tube to required level. While being pressed with weight tube keeps circle form and valve stays close to horizontal. I do not see tube is deformed in any significant degree. When valve is operational I can play with inflation level as much as I want.

 

Another thing to be discussed is the type of tubes. I still use the one I first purchased for air bearing experiments. It is Czech made tubes (VELODU), and I would be willing to try something else for comparison. I believe mine are made from rather thick rubber, and even slightly inflated tires are not moving boards with much ease (valve inside or ouside). Any ideas about tires types/manufacturers to share?

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As you know I am trying to gather whatever I need for a weekend trial, that is why the questions, and I do not have everything to try yet. Thanks for your help, but still questions... So the question then is how do you adjust the inflation.

 

I do not want to pick my 75 lbs amp six times to adjust the pressure, and I really wouldn't know how much pressure to put without trying, so what is the answer?

 

No I didn't know about the trial, but I do get the issue with only wanting to lift a 75lb amp once !

 

 

 

Would flexible valve stems work, but would have to pass under the tube like the straw, or we may not need the straw, because flexible hose will create some gap... Also there was a talk about valve extensions, etc. how they apply then?

 

I didn't see much in that catalog Gilles linked to that I liked. Yes, you could get valves, chucks, tubing and such. And then try and get it all assembled, air-tight, and adaptable to some kind of pump. Might work, or not. I would like to find a simple valve extension hose with a similar valve at the opposite end. You could route a 12" - 24" extension hose through a hole in the plate atop the inner tube, under the plate for the roller devices, and fasten it out of the way, but accessible for adjusting the tubes air pressure. With good quality parts and tight setup, it should hold your set pressure for a reasonable time. Add a (low reading) pressure gauge, if you want to get fancy :).

 

So where to get an extension hose ? Well, if you have any high end bicycle stores in your area, I'd try that first. Then there is always Google :)

 

I can't see you finding a hose that would be small and strong enough to pass over, or under, the inner tube ring, without some kind of distortion and interference with its proper functioning. Therefore it has to go out the center, either through the top, or bottom.

 

If you will be using roller devices on top of the air bladder, you have, or can make, space for the inflation hose. Otherwise cut a hole in the base the bladder rests on, and put it on raisers for hose clearance.

 

To help you visualize the idea of threading the air hose through the plates between the air bladder and roller isolation devices, I have a picture of a simple setup using clear acrylic plates. Imagine a 1"-2" hole bored in the middle of the bottom plate, for the hose to pass thru, and maybe some other small holes to tie-wrap the hose flat, and out of the way.

 

Digital VBC setup.JPG

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I think this is incorrect. It is very likely that the crush force of many tubing types would exceed what is exerted. That 75# amp only requires a few psi.

I can't see you finding a hose that would be small and strong enough to pass over, or under, the inner tube ring, without some kind of distortion and interference with its proper functioning. Therefore it has to go out the center, either through the top, or bottom.

 

[ATTACH=CONFIG]19861[/ATTACH]


Forrest:

Win10 i9 9900KS/GTX1060 HQPlayer4>Win10 NAA

DSD>Pavel's DSC2.6>Bent Audio TAP>

Parasound JC1>"Naked" Quad ESL63/Tannoy PS350B subs<100Hz

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I think this is incorrect. It is very likely that the crush force of many tubing types would exceed what is exerted. That 75# amp only requires a few psi.

 

Forrest,

 

What is incorrect ? I'm not following you at all.

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I think that most tubing used to extend the valve would be plenty strong and not compress under the applied force. It would be east to extend. Maybe I misunderstood you Dave?

Forrest,

 

What is incorrect ? I'm not following you at all.


Forrest:

Win10 i9 9900KS/GTX1060 HQPlayer4>Win10 NAA

DSD>Pavel's DSC2.6>Bent Audio TAP>

Parasound JC1>"Naked" Quad ESL63/Tannoy PS350B subs<100Hz

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I think that most tubing used to extend the valve would be plenty strong and not compress under the applied force. It would be east to extend. Maybe I misunderstood you Dave?

 

Yeah, I'm not worring about the extension hose. I'm worried about the inner tube distorting from a largish diameter, stiff tube crossing it and disrupting its ability to flex and provide smooth support. You Ok with that, Forrest ?

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