Sounds great, Keith. I will look them up. Thank you. Did you post the links further up this thread in an earlier post?
What do you use for vibration isolation?
- Thread starter Reid.Whitney
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Sounds great, Keith. I will look them up. Thank you. Did you post the links further up this thread in an earlier post?
I totally understand and it reinforces one of my reasons to no longer actively participate in this forum.
That along with the name calling, personal insults, and adults acting like children.
There are people who feel equally strongly on both sides of the fence on many topics. They are not necessarily "wrong" when others disagree with them.
If anyone gets frustrated, just know that both sides have their hard-heads and want to forward their point of view.
On the side, while making a large donation is admirable, it doesn't mean you get to have your way in what gets enthusiastically discussed by some people.
Play on. . . . .
Gary, the comment on contributing is beside the point, I shouldn't have mentioned it. Actually this thread got deleted before it developed any steam. I'd rather just let it lapse, agree w/you I have no right to pick and choose.
I'll do my best to revert to withering sarcasm when jolted into action, not throw my toys out of the pram.
I'll do my best to revert to withering sarcasm when jolted into action, not throw my toys out of the pram.
YashN, I don't agree with everything you've stated but you are to be commended for your thoroughness. Very well thought out.
A reason is never an excuse for behavior that should be beneath you.
BTW, The question was rhetorical just so I could flaunt my psychic abilities again.
Thanks, I've found that being thorough about things is a good way to repeatedly get great results.
I must apologize as I have just returned to this thread to find it reopened 6-7 months ago after being left alone for three years. For those who have provided technical questions regarding ground-borne/air-borne vibrations, I am happy to provide insight based on my experiences providing vibration and acoustic isolation systems over the years. Granted, the systems we provide are geared towards scientific research-focused applications, but the same principles should apply.
If anyone has technical questions they want to share, I am happy to review them and speak to our technical team if they are above my understanding.
One consistent thread throughout the 19 pages of comments I read was the question of how much air-borne vibrations influence the utility of a turntable. My experience suggests this is relative to how well shielded the cantilever tip is of the turntable and if there is some barrier between the tip and the external noise of the room. Granted, not all turntables have an enclosure shielding them from errant acoustic noise/air-borne vibrations, which makes the impact of this noise source source relative to the level of noise in the room and the structural characteristics of the tip. Active vibration isolation systems (ones that utilize electrical components/sensors for isolation purposes), tend to not only isolate ground-borne vibrations, but also provide some level of isolation from instrument borne vibration noise as well. The amount reduced is not to the same degree as ground-borne vibrations, but it does exist and is also relative to the characteristics of the component requiring isolation.
When we work with atomic force microscopes, which are very similar in how they operate to a turn table (cantilevered tip travelling across a surface), air-borne vibrations and acoustic noise must be mitigated, as the tip is inherently sensitive to all forms of environmental noise. An example of this can be found in the provided image link:
Granted, the analog between the two may not be 100% sound, but it gives you some insight into how similar applications resolve this problem.
I hope this has been somewhat helpful and as I mentioned above, please feel free to reach out now that I know this thread is active again.Also, I am not a coffee connoisseur, so I will not be able to speak with authority on that matter.
If anyone has technical questions they want to share, I am happy to review them and speak to our technical team if they are above my understanding.
One consistent thread throughout the 19 pages of comments I read was the question of how much air-borne vibrations influence the utility of a turntable. My experience suggests this is relative to how well shielded the cantilever tip is of the turntable and if there is some barrier between the tip and the external noise of the room. Granted, not all turntables have an enclosure shielding them from errant acoustic noise/air-borne vibrations, which makes the impact of this noise source source relative to the level of noise in the room and the structural characteristics of the tip. Active vibration isolation systems (ones that utilize electrical components/sensors for isolation purposes), tend to not only isolate ground-borne vibrations, but also provide some level of isolation from instrument borne vibration noise as well. The amount reduced is not to the same degree as ground-borne vibrations, but it does exist and is also relative to the characteristics of the component requiring isolation.
When we work with atomic force microscopes, which are very similar in how they operate to a turn table (cantilevered tip travelling across a surface), air-borne vibrations and acoustic noise must be mitigated, as the tip is inherently sensitive to all forms of environmental noise. An example of this can be found in the provided image link:
Granted, the analog between the two may not be 100% sound, but it gives you some insight into how similar applications resolve this problem.
I hope this has been somewhat helpful and as I mentioned above, please feel free to reach out now that I know this thread is active again.Also, I am not a coffee connoisseur, so I will not be able to speak with authority on that matter
.Thank you for your post Whitney which I found very interesting.
My turntable is Townshend Rock V uses a trough filled with silicon damping fluid to which the tonearm is connected. I imagine you are familiar with this turntable which is pretty well documented on the web.
I find it to be an effective approach, not that there aren't others, and wonder what you think of this approach if that is not too much to ask.
My turntable is Townshend Rock V uses a trough filled with silicon damping fluid to which the tonearm is connected. I imagine you are familiar with this turntable which is pretty well documented on the web.
I find it to be an effective approach, not that there aren't others, and wonder what you think of this approach if that is not too much to ask.
Hi Barry,
If your turntable is similar to the Rock 7 found on Townshend Audio's website (http://www.townshendaudio.com/the-rock-7/), it appears the support points are made of a proprietary spring + sorbathane foot, which typically has a resonance in the lower frequencies (depending on how the spring is tuned). Townshend likely tuned the spring in a manner that is ideal for the resonances of their system (which they mentioned in the link previously provided; a resonance of 10 Hz).
It would be interesting to see what data they have on the level of dampening at 10 Hz as it may be sufficient to dampen the natural resonances of the system, but if there is a substantial 10 Hz signature in the environment, the springs may or may not be sufficient causing an excitation in the sensitive components. We see that a lot in research labs, where instruments will be moved to new environments with greater levels of vibration noise at their natural resonance, causing distortion in their images that was not present in the previous environment.
Regarding the viscous silicone fluid: their approach is very interesting, one not often seen in the research industry. I will need to share this link with our technical group to gain their insight on the matter.
Thanks Whitney.
The Townshend Rock design is different from the current Rock 7. It proved a very costly design and only about 45 were ever made. Happily I have a very good example.
If you Google Townshend Rock V Reference you'll find aTechradar review which gives a good description of it along with other sources of information on this turntable. The tonearm on mine is an Origin Live Encounter and not the Excalibur and I have the original Merlin Mark 3 power supply.
It is a very interesting design which I suspect you will enjoy reading more about.
I'll look forward to hearing from you after you have had chance to consult your technical group and thank you for your interest.
The Townshend Rock design is different from the current Rock 7. It proved a very costly design and only about 45 were ever made. Happily I have a very good example.
If you Google Townshend Rock V Reference you'll find aTechradar review which gives a good description of it along with other sources of information on this turntable. The tonearm on mine is an Origin Live Encounter and not the Excalibur and I have the original Merlin Mark 3 power supply.
It is a very interesting design which I suspect you will enjoy reading more about.
I'll look forward to hearing from you after you have had chance to consult your technical group and thank you for your interest.
Hi Barry,
I received the following from our group here:
"This is called tuned damping. A mass is tuned to a specific frequency based on how it is supported, then the mass is submersed in a fluid like oil that is very viscous. When tuned to the resonance of the structure, the resonant energy goes into the damper, instead of the structure. This is what all of the honeycomb breadboard manufacturers use in their damped tables." An example of a honeycomb breadboard can be found here for your reference.
I received the following from our group here:
"This is called tuned damping. A mass is tuned to a specific frequency based on how it is supported, then the mass is submersed in a fluid like oil that is very viscous. When tuned to the resonance of the structure, the resonant energy goes into the damper, instead of the structure. This is what all of the honeycomb breadboard manufacturers use in their damped tables." An example of a honeycomb breadboard can be found here for your reference.
Thank you very much Whitney.
That is really useful and supportive of the Rock V design
I was not aware of the Newport products which look very interesting.
It's a pity they don't quote any prices on their site but I can always email them for more info
Not sure why the link does not appear on your post as I'm sure it would be of interest to other members and not just to me.
Really appreciated!
I must apologize as I have just returned to this thread to find it reopened 6-7 months ago after being left alone for three years. For those who have provided technical questions regarding ground-borne/air-borne vibrations, I am happy to provide insight based on my experiences providing vibration and acoustic isolation systems over the years. Granted, the systems we provide are geared towards scientific research-focused applications, but the same principles should apply.
If anyone has technical questions they want to share, I am happy to review them and speak to our technical team if they are above my understanding.
One consistent thread throughout the 19 pages of comments I read was the question of how much air-borne vibrations influence the utility of a turntable. My experience suggests this is relative to how well shielded the cantilever tip is of the turntable and if there is some barrier between the tip and the external noise of the room. Granted, not all turntables have an enclosure shielding them from errant acoustic noise/air-borne vibrations, which makes the impact of this noise source source relative to the level of noise in the room and the structural characteristics of the tip. Active vibration isolation systems (ones that utilize electrical components/sensors for isolation purposes), tend to not only isolate ground-borne vibrations, but also provide some level of isolation from instrument borne vibration noise as well. The amount reduced is not to the same degree as ground-borne vibrations, but it does exist and is also relative to the characteristics of the component requiring isolation.
When we work with atomic force microscopes, which are very similar in how they operate to a turn table (cantilevered tip travelling across a surface), air-borne vibrations and acoustic noise must be mitigated, as the tip is inherently sensitive to all forms of environmental noise. An example of this can be found in the provided image link:
Granted, the analog between the two may not be 100% sound, but it gives you some insight into how similar applications resolve this problem.
I hope this has been somewhat helpful and as I mentioned above, please feel free to reach out now that I know this thread is active again.Also, I am not a coffee connoisseur, so I will not be able to speak with authority on that matter
Interesting take. First, regarding your analogy, the applications and operating environments are certainly different. One type of sensitive instrument (an audio component) is intended to function (hopefully well) in a vibration-rich environment. On the other hand, you should never find a researcher using his atomic force microscope at crowded disco on a Saturday night. Right?
The stylus of a TT makes contact with the grooves embedded in the vinyl, thus generating its own vibrations therein. As I recall an atomic force microscope never actually makes contact with the scanned surface.
Also, you make mention of some shielded barrier between the "tip" and the "external noise" of the room as if that somehow prevents air-borne vibrations from inducing their harm into the area you're attempting to shield from vibrations. Have you ever been sitting in your car at a stop light with a subwoofer from the car behind you wreaking havoc on your entire vehicle? Especially, something easily excitable like your rearview mirror? Yet, you seem to imply all's one should have to do in this scenario is roll up their windows and vibrations cease or at least harm is minimized. To the contrary, I've not noticed any real difference with windows up or down.
Moreover, if there were some type of shielded barrier, isn't it likely that somewhat flimsy barrier would vibrate in sympathy with vibrations captured and perhaps make matters even worse?
IOW, couldn't the significance of air-borne vibrations (the harm they induce) be tainted or swayed by your company's presuppositions?
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Hi Stehno,
You are correct in that the analogy isn't perfect, which is why I prefaced my comment as such. The optimal barrier between the tip of a cantilever and the environment is not merely a piece of metal used as a wind-breaker, but something more complex to mitigate acoustic noise over a broad frequency spectrum. More dense materials help address lower frequency acoustic noise, whereas less dense materials are better suited for higher frequency acoustic noise. My apologies if my suggestion of a barrier was overly ambiguous, I just tried to keep the representation of the solution simple.
Yes, I read your preface and that's why I was polite even though as I implied your analogy was a bit of a reach.
Referring to my analogy, wouldn't you think that modern day vehicles with windows, seals, sheet metal, insulation, air-filled tires, etc, would actually make for a pretty robust barrier against air-borne vibrations? Especially in the great outdoors / not confined to a room?
How does my inside rearview mirror (including my body sitting in a nice cushioned seat) get so darn excited, whether windows are down or up when faced with the subwoofer in the car behind me?
Seriously, short of a vacuum chamber, what do you propose?
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Hi Stehno,
I think instead of making specific recommendations without knowing the individual systems needing to be shielded or the surrounding environment, my preferred route is to provide the general theory behind acoustic absorption and reduction as that is an area where we have more experience and knowledge.
Noise reduction is the blocking or deflection of sound energy. The best way to achieve noise reduction is to use material that is rigid, massive, and high density. Materials that are soft or low density transmit noise easily and are not well-suited for deflecting noise. Noise absorption requires materials with different properties. Softer materials can actually be quite effective at absorbing sound. Pliable materials with high surface area, such as foam sheets, are great for absorbing, and thus neutralizing high frequency noise.
Depending on the frequency and energy level, some noise is more susceptible to deflection and some is more susceptible to absorption. Since an ideal isolator will provide noise reduction over a broad frequency spectrum, one should employ materials of variable densities to achieve maximum noise reduction.
The optimal acoustic barrier for systems is to have it be air tight, which is not feasible for certain applications like turn tables. When an air-tight operating environment is not an option, there are alternative ways to reduce the impact of air-borne vibrations from exciting sensitive components.
One of those ways is to improve the impedance of systems. Improving the impedance of a system increases the amount of energy required to excite the system. The most common route to increase the impedance of systems is to increase its mass, which is often addressed by the system manufacturer itself.
Structural stability also plays a role as a system that is not well-supported or adequately rigid will have poor stability. Lack of stability translates into structural resonances, which amplifies incoming kinetic energy. This is an important consideration for acoustic isolation because acoustic energy, when it encounters a solid structure, imparts energy in the form of mechanical vibrations. Even if an enclosure/barrier has good acoustic properties, if it is not structurally stable it will transmit acoustic energy into the system in the form of mechanical vibration.
Much of the information above is transcribed from our website, but effectively covers much of our experience on the matter. I'll be happy to answer any additional questions you may have.
Hi, Reid. Thank you for your thoughtful words.
From a fundamental mechanical energy perspective I'd venture that we are in agreement with maybe 50% of what you say here. That may not seem like much but IMO that puts your company light years ahead of most companies manufacturing vibration controlling products. And certainly enough to potentially realize very distinct audible gains much of the time.
Thanks, again.
-John
p.s. You mentioned without knowing more about a system's specific needs. Would you not agree that the behavioral characteristics of mechanical energy is universal, regardless of specific needs? In other words, if mechanical energy behaves the same at all times, then shouldn't the proposed solution be equally universal regardless of specific needs?
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