Equipment isolation and vibration damping.

[semente]

I have been experimenting with a somewhat unusual method for isolating small light weight devices (such as a microRendu): suspend it from low constant springs, my favorite is Slinky Juniors. If you make it a couple feet long you get low frequency resonance in the horizontal planes (normal pendulum) and low frequency vertical resonance from the low spring constant.

 

There are some issues:

the cables have to be very flexible and light weight, I had to make my own short pieces of cable to make this work.

There is very little damping so it keeps on swinging for some time if disturbed. Its hard to do much damping without changing the isolation effectiveness.

 

A rather unusual approach but it does work very well.

 

I don't have this setup right now to take a picture, with what is going on right now I am constantly moving devices around,this scheme does not work well under those conditions.

 

John S.

 

What about using rubber bands/strings as suspenders?

 

R

[JohnSwenson]

What about using rubber bands/strings as suspenders?

 

R

 

Rubber bands tend to have too high a spring constant, thus too high a resonant frequency. But there probably exist some elastic materials that would work well, it would take some experiments to find a good solution.

 

The Slinkys tend to have a good spring constant for lightweight items as is.

 

John S.

[jabbr]

Rubber bands tend to have too high a spring constant, thus too high a resonant frequency. But there probably exist some elastic materials that would work well, it would take some experiments to find a good solution.

 

The Slinkys tend to have a good spring constant for lightweight items as is.

 

John S.

 

Interesting approach -- I'm looking at a base with Euler springs or similar on a table and placing both light and heavy components on the base --- it would be a huge amount of work to tune each component otherwise -- and the interconnects are rather stiff -- except optical fiber [emoji6]

[JohnSwenson]

Interesting approach -- I'm looking at a base with Euler springs or similar on a table and placing both light and heavy components on the base --- it would be a huge amount of work to tune each component otherwise -- and the interconnects are rather stiff -- except optical fiber [emoji6]

 

Yes Euler springs are one of the few good techniques for dealing with the DC bias of the weight of objects, and a real pain to match to the load!

 

I've been thinking about building a spring/pendulum isolated DAC with the DAC board isolated inside the case, using carefully design power and signal wires so as not to mess up the isolation. That way the user gets to use whatever they want connected to the case.

 

John S.

[jabbr]

Yes Euler springs are one of the few good techniques for dealing with the DC bias of the weight of objects, and a real pain to match to the load!

 

I've been thinking about building a spring/pendulum isolated DAC with the DAC board isolated inside the case, using carefully design power and signal wires so as not to mess up the isolation. That way the user gets to use whatever they want connected to the case.

 

John S.

 

I'd like to see that case!

 

I've been playing around with similar to : Circular Wire Rope Isolators and Military Shock Mounts, Industral Applications to see if they are "eurlerish", actually with carbon fiber rods and perhaps you can add rods to the discs to tune the weight within certain ranges... still need balls and cups for the x-y axes though ...

[semente]

How about a sponge?

 

R

[sdolezalek]

It would be great if this thread could actually clarify what exactly we are trying to accomplish with isolation and damping:

a) keeping environmental resonances from reaching our equipment (if so what frequencies are we trying to keep out?)

b) draining vibrations and resonances existing in our equipment out of the equipment (same question re relevant frequencies)

c) isolation in all directions or coupling in vertical and isolation in horizontal?

d) what are the actual resonant frequencies of the materials/equipment we are trying to use for this (for example what frequencies are drained by sorbothane, versus an airtube, versus stillpoints footers, for example?)

 

There are lots of interesting approaches and even more manufactuer/user comments about how great this or that solution is, but very little in the way of science that links the problem (what resonances are we trying to kill) to the solution (what resonances does your device actually absorb, drain, isolate from).

 

I have read Barry Diament's good posts on this, as well as those from a dozen or more manufacturers, but even the best are short on identifying specific resonances and none I have seen dared to show a before and after measurement that actually reflected real isolation.

[KnockKnock]

I would like to suggest Mad Scientist Audios Footers, they are fantastic !

They are way better then Nordost Sort Kone or Ansuz Feet!

[Cornan]

I have read Barry Diament's good posts on this, as well as those from a dozen or more manufacturers, but even the best are short on identifying specific resonances and none I have seen dared to show a before and after measurement that actually reflected real isolation.

 

Well, not really. There is one manufacturer that shows actual measurements. Solid Tech http://www.solid-tech.net/about-us/tech-talk-4537427

See the PDF dokument in the bottom of the page.

 

 

 

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[sdolezalek]

Well, not really. There is one manufacturer that shows actual measurements. Solid Tech Tech Talk | Solid Tech

See the PDF dokument in the bottom of the page. [/url]

 

Thank you. I had not seen these before. The measurements shown do suggest these are having an isolation effect at 50Hz and 70Hz but I have to admit that I'm at a loss to understand how fairly heavy looking metal springs can provide isolation at frequencies that would seem to be far below the resonance frequency of those springs. None of the reviews I found on-line provided any further enlightenment.

[esldude]

Thank you. I had not seen these before. The measurements shown do suggest these are having an isolation effect at 50Hz and 70Hz but I have to admit that I'm at a loss to understand how fairly heavy looking metal springs can provide isolation at frequencies that would seem to be far below the resonance frequency of those springs. None of the reviews I found on-line provided any further enlightenment.

 

[video=youtube;7Q-5EZHrtiQ]

 

This video demonstrates how cup and cone isolators work though this isn't directed at audio gear. Works only for horizontal vibration.

 

I share your wish for measurements. Especially of the output signal. Other than speakers, and tube gear, I believe other gear is pretty much immune to most vibration it sees in a home.

 

Can't come up with the video right now, but one of the speaker stand makers has a good demo of isolating speakers. Rigidly coupling speakers with spikes doesn't drain vibration from the speaker (or other gear) so much as couple the lower frequencies into your floor.

 

As long as most audiophiles are happy with informal listening impression reviews and fanciful imagined explanations I doubt the situation will improve.

[semente]

I don't think that measurements of the output would be of any use but I'd like to see manufacturers produce measurements of the effectiveness of their products.

 

R

[esldude]

I don't think that measurements of the output would be of any use but I'd like to see manufacturers produce measurements of the effectiveness of their products.

 

R

 

Yes, that would be a first step. However, ultimately, if the output signal is unchanged then what does it matter?

 

Some small simple experiments are possible showing one can considerably reduce vibration in the cover of a piece of electronics gear. Does that improve things? Usually it has no discernible effect on the signal in that gear.

[semente]

Here's an example with measurements:

 

 

http://www.fastlaneaudio.com/anti-res.html

 

Note: the video contains scenes that nay shock the nature lover...

[Cornan]

Thank you. I had not seen these before. The measurements shown do suggest these are having an isolation effect at 50Hz and 70Hz but I have to admit that I'm at a loss to understand how fairly heavy looking metal springs can provide isolation at frequencies that would seem to be far below the resonance frequency of those springs. None of the reviews I found on-line provided any further enlightenment.

Solid Tech's line with Feets of Silence and Discs of Silence are weight dependent. You buy the Feets for your perticular gear weight (3-10kg, 4-14kg, 10-20kg, 14-26kg etc) and the springs are of course not that heavy on the lower specs. IsoClear works a little different since you can add your own springs in different strenght to fine-tune it. I hope that helps!

 

Discs of Silence is very good for vinyl and stands (equipment and loudspeaker) and Feets of Silence is exellent for DAC, amps, preamps integrated amps etc IMO. IsoClear is not as good (although pricewise a good option)...mostly because it is too slippery which is kind of annoying. YMMV of course!

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[semente]

Solid Tech's line with Feets of Silence and Discs of Silence are weight dependent. You buy the Feets for your perticular gear weight (3-10kg, 4-14kg, 10-20kg, 14-26kg etc) and the springs are of course not that heavy on the lower specs. IsoClear works a little different since you can add your own springs in different strenght to fine-tune it. I hope that helps!

 

Sent from my Nexus 7 using Computer Audiophile mobile app

 

 

 

Do they provide measurement equipment or are we supposed to fine-tune by ear?

 

This reminds me of add on supertweeters and subwoofers...

The effectiveness of tuning by ear is nothing more than wishful thinking, a false sense of control. In my opinion.

 

R

[Cornan]

Do they provide measurement equipment or are we supposed to fine-tune by ear?

 

This reminds me of add on supertweeters and subwoofers...

The effectiveness of tuning by ear is nothing more than wishful thinking, a false sense of control. In my opinion.

 

R

Well, that is why I edited my previous post with some personal opinions as well! IsoClear is not as good!

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[jabbr]

 

I share your wish for measurements. Especially of the output signal. Other than speakers, and tube gear, I believe other gear is pretty much immune to most vibration it sees in a home.

 

 

Crystals are certainly sensitive to vibrations -- it would be great to see the effects on phase noise plots.

[Cornan]

One thing that I have noticed is that damping the speaker cables at the speaker connection are very beneficial for SQ. I personally used a black jewellery bags filled with clear quartz to dampen the vibrations on each speaker. Same thing on the amp side. Just a tip!

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[esldude]

Here's an example with measurements:

 

 

Anti-res

 

Note: the video contains scenes that nay shock the nature lover...

 

Hey a nice simple DIY shelf and some evidence it really works. Thanks for the links to that.

 

You know for some purposes you could measure effects with your smartphone. They have accelerometers built in and software to show the results is common and free or close to it. Just as a quick experiment. I put my phone on a large wooden table adjacent to the listening room. Ran a baseline, then played music a bit louder than usual though not much. No effect in two axis, but the vertical axis clearly tracked some portion of the music. Place onto a smaller glass top table and found much more vibration again in the vertical axis only. Peaks were .03 or .04 G. Would this get picked up by electronics gear and effect its operation? I doubt it. But if someone wishes there is the means to do some testing instead of what we usually see about this stuff.

 

I was using the Physics Tool suite on an android phone. There are many choices for such uses however.

[semente]

An audiophile at wigwam used to work for Garrard if I remember correctly and he said that the measurement equipment they connected to the cartridge (?) on turntable picked up rumbling noise from a truck parked two storeys down in the car park.

 

A Google search might take you to his post but I'm on the phone which makes things a bit too complicated...

 

R

[esldude]

Crystals are certainly sensitive to vibrations -- it would be great to see the effects on phase noise plots.

 

Below is quoted from this article: Minimize Frequency Drift In Crystals | Analog content from Electronic Design

 

Environmental factors vary greatly from one application to another, and each needs to be addressed to minimize its effect on drift. Some factors have only a minimal effect. Vibration caused by acceleration and movement, for example, affects drift on the order of parts per billion (ppb). Given the magnitude of other sources of drift, vibration is not a concern for most applications.

 

Other factors, if not addressed, can have a tremendous impact on drift. Drift from humidity or pressure, for example, can be hundreds of ppm. However, humidity and pressure can be effectively addressed during the manufacturing process by housing crystals in hermetically sealed packaging. Surrounding the crystal with a vacuum or an inert gas like nitrogen eliminates most of the influence of both humidity and pressure. Thus, these factors rarely are a concern for developers either.

 

Typically, the most important significant environmental factor affecting drift for developers to consider is temperature. For example, the same 32-kHz crystal that would have realized a 4.5-minute shift per month over a wide temperature range would only realize a 2-minute per year drift at room temperature. Shifts in temperature can increase drift by tens of ppm over even a standard temperature range. These effects are more pronounced at extreme temperatures.

 

You can google plenty of articles on crystals and how vibration effects the phase noise plots. Usually perusing a few of them accelerations of several G cause quite small deviations in frequency. Some processes use frequency multiplication of crystals such as in radar. The multiplication also multiplies frequency offset effects from vibration. Most audio uses divide higher frequency clocks which should reduce rather than increase vibrational effects. At the very high frequencies vibration of cables is said to cause more issue than with the clocks themselves. So I doubt vibration is a real big deal in audio clocking. It likely results in phase noise variation that is so low as to be unmeasurable and of no real concern.

[esldude]

An audiophile at wigwam used to work for Garrard if I remember correctly and he said that the measurement equipment they connected to the cartridge (?) on turntable picked up rumbling noise from a truck parked two storeys down in the car park.

 

A Google search might take you to his post but I'm on the phone which makes things a bit too complicated...

 

R

 

Oh that sounds perfectly reasonable. Years ago worked in a lab that was part of an industrial building. Sat on the same concrete slab with several 600 hp blowers. Those are loud, and vibrate like mad. Some spots in the lab you could feel vibration in your feet. We used an analytical balance of course and as those measure to the nearest ten thousandth of a gram accurately vibration and the balance don't mix well. These was long enough ago it was an analog balance with precision knife edges.

 

The solution in this relatively hostile environment was simple. You sat it on this.

 

 

A big thick rigid heavy slab of marble with marble legs and a big steel pipe to keep it tensioned together. It worked fine, the balance would settle to a reading quickly and passed annual state calibration testing. This one weighs 700 lbs.

 

They do offer a 13inch x20 inch x 2inch thick 60 pound shelf for much less money. Maybe audiophiles would do well to put these on heavy duty metal shelves.

 

 

Vermont Marble Balance Tables and Slabs - Gawet Marble & Granite

[sandyk]

Some small simple experiments are possible showing one can considerably reduce vibration in the cover of a piece of electronics gear. Does that improve things? Usually it has no discernible effect on the signal in that gear.

 

I use 50mm wide strips of 3M 2552 self adhesive aluminium anti vibration tape in the top cover of my Oppo 103 as well as directly under the Optical Transport area. My equipment cabinet has wooden shelves with Perspex doors , and I also sit it on a thick piece of car sound deadening material that is at least 10mm thick, It is an earlier product that also includes butyl for dampening. Try sitting a CD/DVD player on the carpet to see it if sounds better than on a wooden shelf. Mine is a little less "muddy" sounding , so that is why I do this.

 

Alex

[esldude]

How about a sponge?

 

R

 

How about a sponge in a bath of thick gel?