Equipment isolation and vibration damping.

[sig8]

Give bamboo a try as well if you can.

I meant to ask, where you find bamboo boards.

[Gilles]

I meant to ask, where you find bamboo boards.

 

The bamboo board that I think drew attention is that one from Ikea, see

APTITLIG Chopping board - IKEA

 

Best,

 

Gilles

[YashN]

I meant to ask, where you find bamboo boards.

 

I'm not sure what I'm using for the speakers is available in your area, but it's just a very simple small-size chopping board with green rubber lining on two sides, and an area hollowed out as a handle (also lined in rubber). The rubber can come in different colours. They cost $2 each or so.

 

It's probably easy to find larger chopping blocks.

 

Gilles' suggestion is a good one, I have seen a few reviews and feedback posts online mentioning it.

[InfernoSTi]

+1 on the IKEA bamboo cutting boards...

 

John

[AnotherSpin]

I meant to ask, where you find bamboo boards.

 

I was playing with different types of bamboo boards, from cheapest to expensive Japanese imports. Most expensive from them are quite thick, and they add to sound characteristics rather than isolate. The idea is everything what we use to support components needs to be neutral, is bamboo neutral?

 

One good thing, if you decide to put that pricey Japanese board out of audio your wife will be most than happy to see it in the kitchen.

[4est]

How are you using them? Barry suggested an equilateral triangle, which makes sense to me. How does one do that with an 11x17 board?

I was playing with different types of bamboo boards, from cheapest to expensive Japanese imports. Most expensive from them are quite thick, and they add to sound characteristics rather than isolate. The idea is everything what we use to support components needs to be neutral, is bamboo neutral?

 

One good thing, if you decide to put that pricey Japanese board out of audio your wife will be most than happy to see it in the kitchen.

[AnotherSpin]

How are you using them? Barry suggested an equilateral triangle, which makes sense to me. How does one do that with an 11x17 board?

 

First, I use another type of boards, which are pretty big size square. Second, I use them as a shelfs on a top of tires, and under cups/balls. On a top of cup/balls, which are placed in triangles, a have hard alu plates and components on them. I think in this set bamboo influences pretty much nothing, I use it because i have bamboo boards from times before I started experiments with cups/balls. Today I will not go for bamboo again, I think I would have plywood cut to measure instead.

[bdiament]

I know Barry has ssuccessfully implemented marble tile under equipment, and in my case almost everything is going to need something like a marble tile, and non- ringing marble tiles are hard to find honestly, so I was thinking alternatives.

 

I was thinking to use plywood instead of marble tile and put something hard between plywood and ball. I came across these Quartz discs. I think Quartz is very hard and flat. See specs at the bottom of page.

 

Technical Glass Products: Plates and Discs

 

Thoughts please. Thanks.

 

Hi sig8,

 

I would recommend against small plates of any material. (Glass, in my view, is a bad choice anyway because it flexes. The contact surfaces must be very smooth *and* very hard. Glass might be smooth but it isn't hard enough.) Small plates tend to "chatter" resulting in a brightening of the sound. Proper isolation will not alter the tonality at all.

 

If you are willing to use plywood, the combination with a tile will help deaden any tile. I seek out dead tiles but in almost all instances, combine these with plywood (where the edges have been neatly rounded and the appearance "warmed" with Watco's Danish oil). In my experience, tile --if it is smooth enough-- works better than a sheet of metal and is almost always less prone to ringing. With a plywood completely covering it, the main thing for the tile is a very smooth surface to face downward atop the roller bearing balls. I suggest a thicker tile too, e.g., 1/2".

 

Hope this helps.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[sig8]

Is it advisable to use a smaller tube, say 12" or 16" for smaller and lighter equipment? I am asking because of space constraints for few things.

[bdiament]

Is it advisable to use a smaller tube, say 12" or 16" for smaller and lighter equipment? I am asking because of space constraints for few things.

 

Hi sig8,

 

My experience has been that the larger the circle described by the inner tube, the easier it is to level the component it supports. (Of course, this requires a larger shelf too, in order to accommodate the entire inner tube.)

 

This may be less of an issue with small, or light components, so experimentation is always a good idea. That said, I've also found that tubes that describe smaller circles tend to be a little stiffer than those that describe larger circles. A soft, floppy tube will be easier to keep at minimal inflation. Remember to inflate *only* enough so the load is not resting on the inflation valve. One pump too much and the benefits drop rapidly while the bass will tend to bloat. (Again, proper isolation will not alter tonality.) And remember air bearings will need periodic inflation readjustment - just like any other use of an inner tube.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[sig8]

Thanks Barry. Forgot to ask one more thing;

 

Is it advisable to put more than one component on one 18" tube and 20x20 ply arrangement; say a small computer (9x9) and a liner power supply of similar size.

 

Thanks.

[bdiament]

Thanks Barry. Forgot to ask one more thing;

 

Is it advisable to put more than one component on one 18" tube and 20x20 ply arrangement; say a small computer (9x9) and a liner power supply of similar size.

 

Thanks.

 

Hi sig8,

 

I've not noticed any ill effects from sharing a platform with a second, smaller item. One shelf on my rack has the QBase ac distribution block and the power supply for my ULN-8 converters. Each has its own Hip Joint roller bearing set but they both share the same 20" x 20" x 1" maple ply platform atop a single 18" x 1.75" inner tube. (They are also at opposite ends of the platform, to keep them separated as much as possible.)

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[Daudio]

... I've also found that tubes that describe smaller circles tend to be a little stiffer than those that describe larger circles. A soft, floppy tube will be easier to keep at minimal inflation.

 

My experience is that the softer tubes are bicycle inner tubes that are only available at a minimum of 12" diameter (also 16", 18", 20", 27"). I use an 16" under my turntable, and a 12" under my Mac Mini/DAC combo.

 

The smaller diameter tubes (6", 8", etc.) are made for lawnmowers, yard carts, go-carts and such. They use a heavier, stiffer rubber to support heavy loads with a small wheel. I got a few and didn't like them at all. One had an awful chemical smell that would not go away no matter what I cleaned it with. Unacceptable for indoor use.

 

So my advice is to only use bicycle inner tubes. The nice thing about them is they are very inexpensive and widely available (got mine at Walmart).

 

Whether there are some 'Hi-end', softer, inner tubes for the cycling enthusiasts (as crazy as audiophiles !), I haven't explored. I'd ask wgscott, but he seems to have gone around the bend

 

 

And remember air bearings will need periodic inflation readjustment - just like any other use of an inner tube.

 

I made sure to buy the tire tool and tighten the little valves in the valve stems before adjusting the inflation level and putting them in use.

 

That was late last year, and I haven't seen any evidence of deflation yet. Not that 6 months is that much of a test, but sometimes the little things can help more then you think. A couple of years is a better test. I'll let you know then

 

 

One other hint about inner tube air bearings. The plate or shelf that sits on top of the inner tube needs to have a hole in the center to equalize the air pressure in the middle of the ring of the tube. Otherwise there will be a pneumatic resistance to vertical movement reducing the isolation effect. If you can't put a hole in the plate (like if its glass), a small straw laid along the top of the ring somewhere along its circumference, will do the equalization job.

[bdiament]

I would suggest using a "platform" sized to completely cover any inner tube used under it.

The IKEA item linked to in an earlier post is 11" x 17" which I would take to limit inner tube size to about 10" -- in my experience, quite a bit too small to work well - unless you don't mind lop-sided gear.

 

Neither I wouldn't want parts of the inner tube bulging outside of the platform. Hence, the symmetrical, square shape I chose for the platforms on the Enjoyyourshelf rack. (The rack size was determined *after* the required platform size.)

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[sig8]

 

I made sure to buy the tire tool and tighten the little valves in the valve stems before adjusting the inflation level and putting them in use.

 

 

What is that tire tool you are referring to? Could you provide a picture or link please. Thanks.

[bdiament]

...One other hint about inner tube air bearings. The plate or shelf that sits on top of the inner tube needs to have a hole in the center to equalize the air pressure in the middle of the ring of the tube. Otherwise there will be a pneumatic resistance to vertical movement reducing the isolation effect. If you can't put a hole in the plate (like if its glass), a small straw laid along the top of the ring somewhere along its circumference, will do the equalization job.

 

Hi Dave,

 

Aside from the pneumatic resistance created by a seal of the inside of the circle described by the inner tube when there is a shelf below and a platform above, that "chamber" will have a resonance of its own.

 

If one can't put a hole in either the shelf or platform, as you mentioned, a small straw crossing from the inside of the circle to the outside will accomplish breaking the potential seal of the inside of the circle. For folks who are having trouble visualizing this, picture a letter Q (or an upside down Q if you place the straw toward the back of the inner tube).

 

I've always suggested the straw to folks trying inner tubes for isolation but forgot about it in this thread until I went to respond to your post. Then I saw that you covered it.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[AnotherSpin]

 

One other hint about inner tube air bearings. The plate or shelf that sits on top of the inner tube needs to have a hole in the center to equalize the air pressure in the middle of the ring of the tube. Otherwise there will be a pneumatic resistance to vertical movement reducing the isolation effect. If you can't put a hole in the plate (like if its glass), a small straw laid along the top of the ring somewhere along its circumference, will do the equalization job.

 

Straws (I put two under each tire on opposite sides) works fine for me.

[YashN]

One other hint about inner tube air bearings. The plate or shelf that sits on top of the inner tube needs to have a hole in the center to equalize the air pressure in the middle of the ring of the tube. Otherwise there will be a pneumatic resistance to vertical movement reducing the isolation effect. If you can't put a hole in the plate (like if its glass), a small straw laid along the top of the ring somewhere along its circumference, will do the equalization job.

 

That's an interesting point: it's similar to what Townshend does in his latest devices, and there are isolation tables used in Scientific Research that use the principle of an air diaphragm with a valve inside for isolation.

[Daudio]

What is that tire tool you are referring to? Could you provide a picture or link please. Thanks.

 

 

sig,

 

It is more properly called a '4-way Tire Valve Stem Core Tool' (just rolls right off your tongue, right

 

Here is a link to one

 

The small diameter extension without threads is the valve driver, to tighten and loosen valves inside the stem.

 

 

I forgot to mention another necessary tool. An air pump ! I picked up a cheap Schwinn frame pump at Walmart when I got the inner tubes and valve tool. There are lots of different kinds available, and I'd suggest a small, manual pump that is Schrader and Presta Valve compatible. Unless you already have something, because it just isn't that important for the occasional air addition.

 

This one from Amazon looks nice with a built-in pressure gauge (wish I'd seen that before !)

[sdolezalek]

To the extent that any of these must bear a certain amount of weight over a given surface area size, isn't the "resonant frequency" ultimately determined by the weight of the device plus the platform? In other words, a lighter weight can use a less inflated tube, therefore a springier, lower resonance. A heavier weight object will put more pressure on the tube, thereby raising the effective air pressure and the resonant frequency. Obviously you can increase the size of the tube only so much...

 

Am I missing something?

[sig8]

I have read the whole thread, and lot of people have given lot of very important feedback, thank you all for that.

 

I have a question before I implement this to my system. I know it is very cost effective arrangement, but is it better in performance compared to few other systems like Stillpoints; which I don't understand how it works, but that is what they claim. Why I am asking is also because I am little afraid that things might tend to slide off or not really be stable (I have lot of money invested in the gear). So question really is; how is the experience with stability (say a heavy amp), and how this arrangement compares to other commercial offerings.

 

Do things tend to slide off, say due to change in air pressure in the tube because a valve leaked or something.

 

Thanks again.

[AnotherSpin]

I have read the whole thread, and lot of people have given lot of very important feedback, thank you all for that.

 

I have a question before I implement this to my system. I know it is very cost effective arrangement, but is it better in performance compared to few other systems like Stillpoints; which I don't understand how it works, but that is what they claim. Why I am asking is also because I am little afraid that things might tend to slide off or not really be stable (I have lot of money invested in the gear). So question really is; how is the experience with stability (say a heavy amp), and how this arrangement compares to other commercial offerings.

 

Do things tend to slide off, say due to change in air pressure in the tube because a valve leaked or something.

 

Thanks again.

 

I do not see any potential dangers in tubes bearings - never had a problem here. Bowls/balls doesn't behave risky for components as well, the only problem - if you push buttons without caution one or other component may change its position slightly on a shelf - several millimeters or so, in time several components will not stand perfectly lined .

 

Speakers are other story. First, bowls/balls still support them much more stable than one could imagine before actual trial. They float freely, but within certain limits. Second, if you have small kids or big dogs, and they are playing near you precious speakers, it may be not safe. Last time my 4 and 8 y.o. grand daughters visited me and decided they want to act Katy Perry's video clips near big Sony screen and heavy speakers I simply removed bowls/balls for a time. Third, it might be tricky to put heavy speakers on bowls/balls/plates - you may want to ask a hand from a friend.

[InfernoSTi]

I have read the whole thread, and lot of people have given lot of very important feedback, thank you all for that.

 

I have a question before I implement this to my system. I know it is very cost effective arrangement, but is it better in performance compared to few other systems like Stillpoints; which I don't understand how it works, but that is what they claim. Why I am asking is also because I am little afraid that things might tend to slide off or not really be stable (I have lot of money invested in the gear). So question really is; how is the experience with stability (say a heavy amp), and how this arrangement compares to other commercial offerings.

 

Do things tend to slide off, say due to change in air pressure in the tube because a valve leaked or something.

 

Thanks again.

 

This is why I use the Symposium Jr HD roller balls under my very large speakers. First, they thread with a 1/4-20 thread. Second, they are two halves rather than open on the top. While that isn't as "perfect" as open on top, it is much, much more stable. I am very happy with the results and find them to be completely stable even though the "wiggle" when bumped. They really can't tip over with the design.

 

I use a set under my DAC, as well, and like it very much. I'm thinking about a second set that I would split into two halves and use under the pre amp and computer since I have extra 1/2" balls. At under $200 for a set of three, splitting them into two halves is less than $100 per set for a nice quality controlled set.

 

John

[InfernoSTi]

Thanks for the post about the straws. I use a heavy duty straw that is cut in half with one half on the left side and one half on the right side of the tube. If you don't, you can't lift the equipment up as the seal is very strong as I'm sure everyone has figured out!

 

John

[bdiament]

To the extent that any of these must bear a certain amount of weight over a given surface area size, isn't the "resonant frequency" ultimately determined by the weight of the device plus the platform? In other words, a lighter weight can use a less inflated tube, therefore a springier, lower resonance. A heavier weight object will put more pressure on the tube, thereby raising the effective air pressure and the resonant frequency. Obviously you can increase the size of the tube only so much...

 

Am I missing something?

 

Hi sdolezalek,

 

The weight of the load *combined* with the amount of inflation is involved in determining the resonance frequency of an air bearing. (The material and construction of the air bearing will also be involved but once selected, this will not change with different loads.)

 

The heavier the load, the more inflation required to reach a given resonance. In other words, for a given resonance frequency--ideally, one in the low single digits--the weight of the load determines the required amount of inflation. With the correct amount of inflation thus determined, the resonance frequency will not be different.

 

This is much like arm/cartridge resonance in a turntable setup: a more compliant cartridge requires a less massive arm in order to achieve the desired resonance frequency (in the case of turntables, this will be around 10 Hz -- below audio frequencies but above warp frequencies).

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio