A trolling, a trolling, a trolling we will go. Hi ho the dairy-o, a trolling we will go.
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Cool, but it's not isolation. It's damping. |
Isolation generally refers to mass-on-spring techniques but can also be magnetic levitation, filament suspensions, roller bearing assemblies, negative stiffness, I.e., any technique that attempts to decouple the component from the room structure and the seismic I.e., low frequency vibrations that would otherwise be transferred to the component. Since there are six, count em, directions of motion for seismic vibrations, including three rotational directions, cleverness of design of the isolating system has its rewards. Even a thick granite slab has some benefit for isolation inasmuch as its inherent stiffness resists rotational forces. The Townshend Seismic Sink was one of the very first audiophile isolation devices, the Big Bang as it were was the Vibraplane Stand circa 1996 and Shannon Dickson’s landmark article in Stereophile magazine 1996 on the dodgy subject of vibration isolation, "Bad Vibes."
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It’s really a center of gravity issue. A very heavy subwoofer with a relatively low center of gravity would be more stable on a springy type stand or feet than tall speakers that weigh the same but with higher center of gravity, all things being equal. Employing a wide arrangement of the springs by placing them under a board the dimensions of which are much greater than the footprint of the speaker goes a long way to bolster lateral support and might be the only way to do it sometimes. |
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The good thing about concrete slabs is they are very very stiff so they resist, but not totally eliminate, the rotational forces that result from Earth crust motion, traffic, subways, etc. The concrete slabs do not do so well in attenuating low frequency vertical forces since the entire building is being moved by the motion of the Earth's crust, etc. At the same time I have found very hard cones improve the sound and presumably the isolation effectiveness when employed under both the component on the isolation device and below the isolation device.
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One can't one can't help wondering why LIGO the science project to observe gravity waves didn't use an inexpensive and simple solution for their seismic vibration isolation systems? But instead as a rather complex system of heavy masses and springs as well as inverted pendulums, sapphire thread suspensions and other advanced isolation devices. I sometimes suspect audiophiles don't believe audio electronics are too susceptible to very low frequency vibration or else a certain amount of isolation, but nothing more, is sufficient to get the job done.
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Gee it was only last week I walked a customer through the construction of a double decker mass on spring isolation stand using my compact cryo'd high carbon steel Mini Isolators and a stack of ceramic tiles from Home Despot. Of course, not to be too intellectual about it, you have to arrange things so that the resonant frequencies of the two mass-spring layers don't interfere with each other. Ouch, that hurt just saying that.
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toddverrone
My scepticism arises from the huge difference in wavelengths and the law of something returns.
And that was in reference to? |
"My scepticism arises from the huge difference in wavelengths..."
That's actually the part that threw me. Which wavelengths are you referring to?
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Ak chew ally, Gravity is the weakest force. Nuclear forces are much stronger. In fact the reason why LIGO needed to develop such robust seismic isolation methods was because gravity waves are so weak, having amplitudes around the diameter of a neutron. Thus, the detection of such waves would have otherwise been drowned out by the slightest vibration, even the vibration of atoms in some of the LIGO sapphire filament suspensions were an issue. In audio it’s not difficult to see isolation related issue with the nano scale laser beam and the nano scale data spiral on the CD, even the very small signal in stereo cartridges and tonearm wires and the 10 Hz or so resonant frequencies of the cartridge and tonearm represent challenges since seismic vibrations include that region 8 to 14 Hz. It doesn't take a weatherman to know which way the wind blows.
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Re gravity wave wavelengths:
"The wave-lengths of gravitational waves emitted in such merger events are typically of the same order as the dimension of the system. That is, for black holes with masses between 10 and 100 times the solar mass, wavelengths are typically a hundred to a thousand km – right in the range that LIGO is most sensitive." Feb 10, 2016
confusin', ain't it?
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Then you should probably read Kip Thorne's (LIGO) Black Holes & Time Warps: Einstein's Outrageous Legacy
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The take away from this recent discussion is that not only should speakers be isolated, especially subwoofers, but ALL components as well. The reason is because the seismic forces have frequencies BELOW those produced by speakers, even by subwoofers. Thus, isolating speakers is only a partial solution. Alas! But there has always been a wide variety of solutions available to audiophiles, both DIY and commercial. I’m pretty sure I could count 20 different products and DIY solutions without much difficulty. This all does not preclude the use of damping for certain applications, e.g., damping electron tubes, printed circuit boards, transformers, the top plate of isolation stands, etc. |
I suspect you’ll find that roller bearing assemblies are actually not intended for nor they fix on board issues. They are used strictly for isolation as they provide good isolation in rotational directions and isolation in the horizontal plane, I.e., all lateral directions. That why folks mention combo of springs and roller bearings, you know, to cover all the bases. For on board issues one must select something along the lines of those teeny Marigo VTS constrained layer dots, Mpingo discs, larger constrained layer damping devices, cork, Herbies tube dampers, etc. everything on printed circuit boards vibrate due to transformer 60 Hz hum, along with other sources. Capacities produce vibration themselves and should be dramped. No one promised you a rose garden. Ha ha. I actually think very hard cones generally work very well under speakers, esp. the diamond hardness Super DH Cones from Golden Sound, made of NASA grade ceramics.
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The thing about Mpingo discs is they're *very* directional, top to bottom as well as azimuth. They also are very persnickety as to where they will work. So my advice is keep looking until you find the magic spot(s).
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Hi, mains, I’m pretty sure I answered most of your questions in my last post. Why would you fill the Daruma roller bearing assemblies? The reason I ask is the bearings should not be damped, otherwise they won’t be free to move easily. Isolation can be defined as the freedom to move in the direction of interest without constraint, or without much contraint. That’s why the bearings and the cups are tempered steel or tungsten or some other very hard super-smooth metal - To reduce friction and allow the bearings to move very easily when the bearing assembly/component is acted on by external forces. Internal on board forces may or may not be sufficient to cause the bearings to move. People try to damp springs, too. Big mistake. There are many ways and locations to apply damping, which I mentioned recently. Was it yesterday?
Geoff Kait
Machina Dynamica
Advanced Audio Concepts
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Sorry, don’t like felt or carpet as they interfere with the rapid transmission of energy out of the system and/or interfere with the spring action of Mass on Spring Isolators. Two springy systems things in series is like a car with two sets of shocks in series on each wheel rolling down the road. It would be a *very* bumpy ride. I eschew soft, springy materials in favor of extremely hard and stiff materials. If you have carpets best to use a hole punch to punch through the carpet so the tips of cones will penetrate all the way to the floor. As I said before I always use cones with isolation stands. If I use springs by themselves I do not insert anything between the springs and the component or between the springs and the floor or rack (if someone is determined to have a rack). To summarize, you want to isolate and ground the component.
geoff kait
machina dynamica
home of Cryo Baby Promethean Mini Isolators
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Damping the speaker connectors is a bit of a sticky wicket since even if one were successful damping the connectors all of the internal wiring and crossover components would still be subject to the vibration produced by the cabinet resonance and the back wave of the speaker drivers. On the other hand something can possibly be gained by elevating or suspending all speaker cables and power cords. In the old days Tekna Sonic dampers could be used on speaker cabinets but they ceased to be available some time ago, unfortunately.
You also should ensure that interconnects or speaker cables or power cords do not pull on components on isolation stands as that would hurt the isolation effectiveness since that pull would constrain the top plate of the thing from moving with ease.
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Spikes aren’t cones. With cones - especially the best ones, the NASA grade ceramics that have a rounded tip, you’ll need a hole punch, esp. if there’s a carpet pad. Newport Corp. is the mother of all isolation stands, platforms, table tops, what have you. That’s where Vibraplane and Minus K were born. The Minus K is simply the old Newport Sub Hertz Platform "reconfigured" for audiophile use. The Vibraplane, same type thing.
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The only way to pay other than PayPal is cash, in USD. That would work. I will ship free of charge. Stones should not be bound too tightly, if at all, as they should be free to resonate. I usually just drape them over interconnects. For room corners just sit them on the floor. For glass Windows Scotch tape the Mikro size by the closure end of the zip lock bag so the stones are not constrained from resonating. You can contact me for further details via the email address on my web site. I have Large and X Large for Larger rooms. I also can provide instructions for all four sizes and applications for each size.
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Apparently you can make a payment via PayPal as a guest, using your credit card.
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Lil Abner, Whoa!! What? Take it easy, sweet pea, nothing can remove your own snarky unethical layer of dirt. Relax, it’s an audio forum.
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Certain medical conditions? What in tarnation are you going on about now, gramps? Isn't it time for your nap?
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mains OP
hi
has anyone had experiences with magnetic levitation , i keep seeing these products pooping up but notice a bar running threw the middle of the magnets i believe.
If both top and bottom are still connected how does the product work ?
As long as the effects of the magnets do not interfere with the isolated equipment , seeing a gap between component and solid surface looks very interesting , its just that pole that is going threw the middle makes me think the technique still needs some tweaking.
the issue with magnetic levitation devices of the sort that show up in audiophile systems is that two opposing magnets are used in usually four corners of the mag lev stand. As fate would have it magnets, especially the powerful rare earth type required to lift significant loads, are very slippery in the lateral direction, since there are significant magnetic forces involved that are not all vertical in their vectors as it were. Therefore some mechanism must be employed to prevent the top plate from sliding entirely off the stand and onto the floor.
There are two choices, one is to place "stops" around the stand that prevent the top plate from moving very far (but allowing it to move to some degree, at least until it hits a stop. Since isolation as I said before is defined as the ability to move freely in the direction of interest, in this case the horizontal plane. So, this is one drawback of mag lev. The other way to deal with the issue is to put pins or bars through the middle of the magnets, which accomplishes the same thing but has the same problem. In either case there is a path, albeit a small one, for vibration to be transmitted to the top plate. I built a mag lev stand for my modded Radio Shack CD3400 CD Player which gives you some idea just how long ago that was. Presumably the magnets act like springs, at least to some extent. Springs are better - easier to implement, better isolators, and they sound better IMHO.
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Self serving masterpieces of deception.
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Vibration isolation is a proven science. One need look no further than LIGO (the project to detect gravity waves) to appreciate the insidious, unrelenting nature of seismic vibration and the necessity of real isolation techniques. Advanced audiophiles have been reaping the rewards of vibration isolation for more than 20 years. In fact more than 20,000 isolation platforms have been sold to discerning audiophiles in the last 20 years. It was 20 years ago today I introduced the first 6 degree of freedom Sub Hertz isolation platform at CES with Mapleshade Studio. Still, you find some folks who are either in denial or have some axe to grind hiding in the caves. |
The problem with conical springs is they are not linear since the spring rate obviously cannot be the same from one end to the other. It would be like driving a car with two different shocks in series on each wheel, going down the street would be a very bumpy ride.Ordinary cylinder shaped springs are stable enough as long as their combined spring rate matches the load. It also helps to have high-carbon, heat-treated and cryo’d steel springs. |
A good trick is try to use a single compression spring under the load. That way you can get quite a bit more rotational isolation than with multiple springs. You can potentially get much lower iso system Fr to boot than with multiple springs.
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Let’s review the bidding. There are 6 directions of motion, the vertical, the horizontal plane (which counts as two directions). Then there is twist, the rotational direction around the vertical axis, and rock and roll directions, the other two rotational directions. The reason there are rotational directions is because the seismic forces are frequently in the form of physical waves, like waves on the ocean passing under a boat. This is why granite’s stiffness is good for isolation, it resists rotational forces. It's mass is good for isolation because of its inertia - more force is required to move it.
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Kennythekey wrote,
"I started a post about stabalizing my rack, because I have it sitting out from my front wall on a bouncy floor. My rack is currently spiked to the wood floor, so I’m considering adding footers under the spikes (Mapleshade Heavy Feet). For example, Herbie has a heavy version of their pucks for this. Once, I pick a solution, so that my rack is at its new height, I will secure the rack to the front wall, so that it is rigid."
Yes I know it doesn’t sound right but rigid structures are not really good for sound. Actually the opposite is true: structures that are NOT rigid, but flexible and easy to move are good for the sound. This was the idea behind the Flexy Rack of yore. What happens with rigid structures is they ENSURE that seismic type low frequency vibrations from the wall or floor or ceiling will be transmitted MORE efficiently to the component. Remember, isolation can be defined as the ability of the structure and component to move freely in the direction of interest. So the best isolation would be using a structure or stand whatever that has the ability to move freely in all six directions, including the 3 rotational directions. For the Minus K isolation device placing a penny on the top plate is sufficient force to put the entire top plate in motion, undulating and bobbing up and down. Now, that's isolation!
Cheers,
geoff kait
machina dynamica
isolation & resonance control
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Bicycle inner tubes are not what I would call a great idea. For one thing their geometry is totally wrong and for another noone is sure what pressure to inflate the inner tube. They also lose air pressure because the rubber material is not entirely air tight; thus the inner tube must be pumped up every once in a while. I would certainly try inner tubes under the subs, for lack of something like springs. And inflate the inner tubes with sufficiently high air pressure, maybe 30 psi or thereabouts, so they don’t compress too much under the weight of the subs - and are stable. I now offer Super Stiff Springs for heavy turntables and subwoofers, speakers that are not too top heavy, as well as heavy amps as fate would have it. |
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Just to close the loop as it were lol for inner tube isolation, the reason this DIY technique doesn’t work all that well compared to other techniques IMHO is largely due to the incorrect assumption that isolation is supposed to be "floating on air" whereas real isolation is obtained by the physics of the mass-on-spring behavior of most isolation devices/techniques, where the resonant frequency of the isolation system is equal to the square root of the total spring rate divided by the total mass. The resonant frequency determines the frequency of vibration where the isolation begins. The equation for Fr shows the advantages of high mass and minimizing the number of springs as well as spring rate per spring. That’s how I got the resonant frequency of my Nimbus air spring platform down to about 0.5 Hz (hel-loo!)- my using high mass and a single air spring (!) of the correct geometry and spring rate. A single air spring also allows for much greater horizontal and rotational isolation in addition to vertical isolation.
For air systems, bladders, airsprings, inner tubes, there is what is called a design (based on pressure under the load) for which they behave as true springs. If the air bladders, whatever are not filled enough or filled too much their spring rates will be incorrect. In addition there is the issue of air leakage through the rubber fabric. A much better DIY isolation technique that avoids the pitfalls of inner tubes is bungee cord suspension, a technique that obviously has challenges of its own.
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kennythekey
bdp24 - It makes sense that doubling up on springs would create unstable results. Perhaps, like driving on a washboard surface?
its not like driving on a washboard surface at all. It’s like driving down the road on two sets of shock absorbers that have the same spring rate. The ride would be chaotic and bumpy, but not bumpy like a washboard, bumpy like an aircraft going through heavy turbulence, a series of unpredictable lurches up and down.
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kennythekey
geoffait
The ride would be chaotic and bumpy, but not bumpy like a washboard, bumpy like an aircraft going through heavy turbulence, a series of unpredictable lurches up and down
So, is this why we hear reports of tonearms actually jumping up and down off the record surface?
The reason tonearms jump out of the record groove is because the turntable is not isolated or not isolated sufficiently, or not isolated properly. Then, e.g., when a bus goes by and runs over a manhole cover out front, voila! - the tonearm jumps. It could happen more easily perhaps if someone inadvertently put a spring system under a suspended turntable, that’s true.
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kennythekey
The wall is a bearing wall that sits on the foundation wall, so it’s not wiggly! The rack can only rock forwards and backwards, so much more stable side-to-side. If I stomp/jump in front of it, I can get the stylus to skip. Otherwise, not a problem, so it’s a safety issue.
As fate would have it it’s not only floors that are the problem but also walls and ceilings, they all transmit seismic type vibrations. Unsuspended floors might be more problematic, what with trampoline effect and greater susceptibility to seismic type vibrations, including footfall and mechanical feedback, but even cement slabs and bearing walls on rigid foundations are moving, just not with the same amplitude usually. In areas like Las Vegas where there is rather strong Earth motion you can feel the vibration on the walls with the palm of your hand. Most places you can’t feel it with your hand but it’s there, especially the very low frequency stuff, the stuff below 10 Hertz. That’s because the entire building is being moved and shaken by the Earth’s crust motion and anything else around like wind or traffic or subways. And it’s being shaken and moved in 6 different directions due to the way physical seismic waves travel along the surface of the Earth. Thus, the house is moving up and down, to and fro, back no forth as well as twisted, etc. Most of the energy of the Earth crust motion is down around 0 to 3 Hz, but there is still a lot up to 20 Hz and above. This of course means that in order to escape at least some of the seismic type vibration one needs to decouple from the physical surroundings entirely, including walls. Furthermore the effects of seismic type vibration don’t necessarily manifest themselves overtly, e.g., needle jumping from the groove, it can be more subtle and insidious. You don’t know what you got til it’s gone, like the song says.
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Mains wrote,
"I am now experimenting with Shun Mook Mpingo Discs in various places, which i am enjoying and hearing different effects, thanks for making me aware of these, When i remove the mpingo discs i can say with certainty i prefer the sound with them included in the system, Its quite difficult to explain the improvements they bring, if pushed i would say realism across the board ie bass is better, instruments are clearly defined and vocals gain a human like texture, im not saying the sytem is lacking without the mpingo discs, but definitely improves with them,"
Yup, that pretty much sums up my experience with the Mpingo discs, especially the part about the more human sounding voices. I still remember when the two Shun Mook dudes walked into the room at CES 20 years ago in the Mapleshade room where my knock off of their Mpingo disc was sitting right there on the floor. My heart was in my throat but I'm pretty sure they didn't notice it was a knock off. Lol And knocking them off is no mean feat. If you look closely you can see a small circular area on one side of the Mpingo disc that is a slightly different color from the rest of the wood. That is apparently where a crystal is buried inside, although I've never opened one up to confirm this.
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Mains
@geoffkait - Can you please recommend to me the products that can be placed on top of the cables at roughly the same places as the discs,that you sell, maybe i can then place the mpingo discs on top of the equipment to see if the results are better, or i wonder if i should keep with the mpingos threw out the system, if i win the lottery i would like to use all the Shun Mook products as they are working in my system, have you any experience with the rest of the Shun Mook range please,all your help is very much appreciated.
Geez, you aren’t asking for much. 😛 I have 30 products these days. I recommend ALL of them. I prefer not to get into games like is thing better than that thing as that can serve no real purpose.
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Almost all of the current vibration isolation devices, yes, including mine (the exception is the Minus K platform that gets down to sub Hertz performance). By performance I refer to the device’s resonant frequency under load. But wait! Resonant frequency is not where isolation occurs, it’s where the low pass filter characteristic starts. The real point where isolation occurs, or I should say STARTS TO OCCUR, for a particular direction is actually around 2 times the Fr. Thus for an iso device with Fr of 3Hz the isolation begins at around 6Hz. And even then the percentage of isolation effectiveness is quite low at 6Hz, maybe around 10% and at 10Hz maybe 30%. Robust isolation won’t occur until at least 20Hz, where effectiveness is around 95%. Above 20Hz effectiveness approaches 100% as frequency rises.
So, here’s the problem with almost all of the current batch of iso devices - they don’t go low enough to actually deal with much of the seismic energy produced by the Earth crust motion, traffic, subways, wind and other things which lies in the region 0 to 10Hz. And the main reason why the Fr of these iso devices cannot get down below 3Hz is because so many springs are required for stability. The spring rate for the device is calculated by multiplying the spring rate of one spring by the number of (steel or air spring) springs required, which is usually 3 or 4. The Fr of the device is the square root of the total Spring Rate divided by the total mass on the springs including any ballast (e.g., Vibraplane) and mass of top plate.
The Minus K achieves a sub Hertz Fr because it’s a much more complicated design (negative stiffness) than a relatively simple mass on spring like just about every other platform or stand. My Nimbus Sub Hertz platform of yore, sorry no longer available, achieved 0.5 Hz Fr in some directions because it used a single air spring. This single air spring design is almost impossible to construct because a single air spring is very floppy, so it’s like trying to balance yourself on a rubber pole. And it was limited to how much load it could isolate. But it could easily isolate about 35 lb. With sub Hetz performance now you’re talking some serious isolation effectiveness compared to the 3 Hz crowd. As I recall my spring based Promethean Base and the current mini Isolators can achieve around 2 Hz performance if you play your cards right. And my Nirvana dual layer design can get very close to sub Hertz performance, using two stages of heavy masses and springs.
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Folkfreak wrote,
"Of course they are a little more expensive."
I’d opine beyond the means of most people, in particular most people participating on this thread. Of course you can obtain Halcyonics or TLC or other expensive devices, even the Vibraplane and Minus K are not exactly inexpensive, but if you have many components to isolate one trusts you have really deep pockets for all active devices. Obviously for speakers the problem is a little, well, quite a bit different since the speakers only go down to what, 35Hz - if you’re lucky. |
Folkfreak, how does the Herzan deal with turntables since it’s a six degree of freedom platform? Wouldn’t the twist direction isolation interfere with the spinning turntable platter? As I recall the Minus K disengages the twist rotation isolation to be able to accommodate turntables, not sure if that’s really true but I think it probably is. And everything really should be isolated, the CD player, the amplifiers, the preamps, the DACs, everything! |
Looks like vertical and two horizontal directions in the graphs. Very interesting. Especially with TT on and no isolation. Are there similar graphs for the 3 rotational directions? Thanks in advance. |
Hmmmm...why so many accelerometers? And why only H and V accelerometers? I think it’s so they can use the differences between two or more vertical accelerometers placed in different locations across the platform - for example, to determine velocities due to type 1 bending forces ("Roll"). The center of the top plate would remain relatively stationary for that rotational direction. Ditto for the horizontal accelerometers and the other 2 rotational directions, "Rock" and "Twist." Come on baaby, let’s dooo the twist!🎷
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Weber’s bar was a very large aluminum bar with a large number of piezoelectric detectors attached to the bar allow for six degrees of isolation as well as the ability to determine the direction from whence the gravity waves emanated. Interesting that a gravity wave the amplitude of which is only the diameter of an atomic nucleus was thought by Weber to be able to bend an aluminum bar 6 feet by 3 feet in dimension, no? If there had been more advanced isolation techniques in the 60s his bar would've probably worked.
Wiki
A Weber bar is a device used in the detection of gravitational waves first devised and constructed by physicist Joseph Weber at the University of Maryland. The device consisted of multiple aluminium cylinders, 2 meters in length and 1 meter in diameter, antennae for detecting gravitational waves.[1]
Around 1968, Weber collected what he concluded to be "good evidence"[1] of the theorized phenomenon. However, his experiments were duplicated many times, always with a null result.
Such experiments conducted by Joseph Weber were very controversial, and his positive results with the apparatus, in particular his claim to have detected gravitational waves from SN1987A in 1987, were widely discredited. Criticisms of the study have focused on Weber’s data analysis and his incomplete definitions of what strength vibration would signify a passing gravitational wave.
Weber’s first "Gravitational Wave Antenna" was on display in the Smithsonian Institution as part of "Einstein: a Centenary Exhibit" from March 1979 to March 1980.[2] A second is on display at the LIGO Hanford Observatory.[3]
cheerios
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Funny you should say that. Because if you had isolated your electronics FIRST rather than the speakers, isolating the speakers would not have provided much of an improvement. Why? Because the *lowest frequency* produced by the speaker cabinets that could be transmitted via the floor to the electronics is above where the effectiveness of isolation for the iso stands under the electronics is achieves 99%. AND because you are isolating the electronics from floor borne seismic vibrations, you know, the ones with frequencies way below whatever the speaker is producing.
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schubert
Then why do these British speakers that have thin walls sound so good?
nobody said they don’t sound good. But they would sound even better isolated. And they would sound better still if all the electronics were isolated. Have you not been paying attention?
"Everything is relative." A. Einstein
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shadorne
Isolation works to reduce parasitic sympathetic vibrations from floor and walls. For TT this also helps reduce feedback to the cartridge from floor/wall vibration. Other electronics are not microphonic and do not benefit except equipmemt might last longer in an environment with less vibration...
No brainer.
Oh, brother!
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Shadorne, Huh? I'm just responding to your ridiculous statement. That's all. |
If decoupling, and I mean competent decoupling, didn't work and and didn't keep most seismic type vibrations from getting up into the electronics then LIGO - long distance interferometer gravity wave observation - would not have been successful last year in detecting and observing gravity waves. LIGO would have done so a long time ago if it could but the sensitivity of the experiment required development of exceptionally robust isolation systems.
As has been pointed out already, resonant frequencies of cartridge, tonearm, platter of turntables as well as the resonant frequency of the laser assembly (spring mounted!) of CD players and the Fr of all the various electronic elements in components require relatively robust isolation devices, too. That's precisely why audiophiles discover that more expensive iso systems are superior to the usual DIY inner tubes and tennis balls. It's because their resonant frequencies are much lower and therefore more effective at 10-12Hz or wherever.
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