It would be a good idea to isolate both the subwoofer and the turntable and all components really. The attenuation of passive iso systems is around 6 dB per octave. But you’re right, the subwoofer’s lowest frequency will be almost entirely attenuated by the turntable’s iso system, assuming a 3 or 4 Hz iso system that’s 99% effective by the time you get up to 20 Hz. The most aggregious frequencies for the turntable are circa 10-12 Hz since they would excite the natural frequencies of the tonearm and cartridge.
Suspensions on turntable...really effective?
Been wondering about this, so did some research, but was surprised I couldn't find any that categorically says that turntable suspensions really isolate/substantially reduce outside vibrations, resonances, etc.
Any reference out there you can point out?
Cheers
Any reference out there you can point out?
Cheers
57 responses Add your response
Dear Ct0517, To answer your question, I have two systems. In both cases, the drivers are based on electro-static principle. In one case, yes, the ESLs are driven by OTL amplifiers that do generate a lot of heat, but never enough to raise the room temperature by 10 degrees Fahrenheit (about 5.5 degrees C). And no, I have never perceived that the heating of the room, such as does occur, has any effect whatever on the sound. (The other system is based on Beveridge speakers which are driven by Beveridge direct-drive amplifiers built into the base of each speaker. Thus no audio step-up transformer in the signal path. Those amps use a solid-state input stage and tube outputs [4 per chassis] that have no measurable or perceptible effect on room temp at all.) |
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"Is there any TURNTABLE out there where I wouldn’t be able to hear the unintended taps, touches and bumps on the rack and sound/vibrations from my subwoofer? Cheapest you can recommend please?" For suspended turntables the reason vibrations like footfalls and other vibrations are audible is because the turntable’s suspension’s resonant frequency is not low enough to block or attenuate them. If the turntable is unsuspended it should be placed on an isolation stand of good design. For suspended turntables with issues remove the suspension and place the turntable on an isolation system of appropriate design. For turntables like Verdier and VPI and Raven and other big heavy turntables one need look no further than my new Super Stiff Springs, which are designed to isolate and support just about any heavy object under the sun. Just the ticket for subwoofers, heavy turntables and heavy amps; minimum weight 75-100 lb. For things like CD players, headphone amps, preamps and other moderate weight components I have a different softer spring, the Cryo Baby Promethean Mini Isolator, cryogenically treated high carbon steel compression springs. Geoff Kait Machina Dynamica |
"Every low level signal phono cartridge consists of key components: the stylus, cantilever, MAGNETS, coils and body. What are we going to now GK......you better go tell every cartridge maker about this." Uh, it’s the size/strength of the magnetic field the mag lev systems produce that’s the issue. And the cartridge is in close proximity to the Verdier magnets, that’s the problem. Hel-loo! I’m not concerned about the Earth’s magnetic field any more than the cartridge magnetic field for that reason. Why do we have demagnetizers for LPs but not for the mag lev magnets? ;-) |
On my wooden floored chalet in Tennessee, my suspended Ariston TT sounds best. Here on my South Florida wood covered concrete floor, my chunk of bathroom sink matching fake marble Kenwood sounds fine. Both have extra motor/platter/tonearm isolation from stock, mostly homemade sponge and foamy stuff O-Rings. |
Geoffkait You said, "Gases are compressible, too." I Never said they weren’t. Sheesh! Never said air is not a gas, either. Furthermore, I said air is a fluid, not a liquid. Hel-looo! Obviously liquids are not compressible, at least not generally speaking. google is my friend. A fluid is any substance in which the molecules are free to flow. This includes both gases and liquids. A liquid is any substance in which molecules are free to flow, and volume is fixed or nearly fixed. Liquids are a subset of fluids. Thanks for validating what I said. So getting back to the the air spring device for a second it acts like a spring because air is compressible and the air inside the airspring is under considerable pressure, that pressure a function of the airspring and the load. I used one of my Nimbus platforms under my Very heavy Maplenoll turntable, so with the ballast (100 lb) plus the mass of the Maplenoll the air spring had to be pumped up to 80 lbs of pressure. |
Geoffkait google is my friend. A fluid is any substance in which the molecules are free to flow. This includes both gases and liquids. Hmm Could this be the reason that Lewm’s "small cans of Mandarin Orange slices in water (sealed, of course) footers" work so well for him and his turntables ? - quote taken from TT for life thread. Now I think that Lewm uses OTL amplifiers ? When I was using a couple big OTL monoblocks the temperature in the room would rise - quickly. So Lewm a question for you out of curiosity. Are your TT’s (and the footers containing water) in the same room as the amplifiers; and if so have you listened to your rig at say 65 degrees F and at 75 degrees F ? Be interested in any differences you found. They say sound travels faster in warmer air, but that sound travels farther in colder air. And I know I have read that cartridge designers test out their cartridges at a specific temp and humidity level. If I am dropping big dollars on a cartridge I would be seeking out this info from the designer. As posted earlier this really is all about the sum of all the parts - including the room and music listener too. Thx diamondears for letting me ramble. Took my mind off of markets, our dollar..for a bit anyway. btw- an Audiogon search on those two tables in your last post produced many forum entries of info. Happy Listening |
You said, "Gases are compressible, too." I Never said they weren’t. Sheesh! Never said air is not a gas, either. Furthermore, I said air is a fluid, not a liquid. Hel-looo! Obviously liquids are not compressible, at least not generally speaking. Education is what’s left after you forgot what you learned in school. |
Frequencies above the resonant frequency get attenuated at a rate determined by the low pass filter so that if the resonant frequency is 3 Hz the effectiveness of isolation at 5 Hz is very poor say 5-10% but at 20 Hz the effectiveness is up around 95%. The iso system acts like a classic mass-on-spring mechanical low pass filter. |
Sorry for the newbie question, but just wanna make sure I get it right...resonant frequency is the frequency that passes thru the whole suspension and gets transferred to or received/absorbed by the plinth, platter or whatever is above the suspension? So, frequencies other than that resonant frequency gets isolated/inhibited/blocked? Or only frequencies above the resonant frequency gets blocked? |
The claim that Basis makes is that the suspension works both to isolate the plinth from structure-born vibration (i.e., from the outside and from the turntable motor) and to dissipate vibration created by the interaction of the stylus tracing the groove (primarily energy transmitted from the arm into the plinth). The supposed downside is that decoupling the plinth from the motor introduces one additional element that may cause instability in the speed of the platter (Michael Fremer, the reviewer from Stereophile speculated, but never demonstrated, that the plinth could rock back and forth and this would change the platter speed). What I do know about my Basis Debut table (with the vacuum clamp) is that it does an amazing job of isolating the arm/cartridge from external vibration and at dissipating energy generated at the interface of the record and stylus. If you place the stylus on a static record and hit the support surface that the turntable is on, very little gets played through the system (as heard at the speaker). Also, if you tap the surface of the record itself close to the cartridge, the Basis tables also transmit far less energy to the cartridge than most table/arm combinations. This translates into much less obtrusively loud ticks and pops; the energy of such sharp impulses is damped very quickly and effectively. However, it is a matter of taste and system tuning as to whether such high damping of vibrational energy is desirable or not. The Verdier tables are also in the highly damped camp. The sound is "dark," and like the Basis tables, some might call it "dead" sounding. I like the Verdier tables a lot. Whether it is magnetic suspension, the extreme mass, the isolation of the motor by placing it on a completely different platform, or any number on other design factors, these tables sound good to me. |
Of course the spring can be an air spring, air being a compressible fluid, no? And designed just like steel compression springs to have a certain spring rate, which one selects for the load under consideration. Did I forget to mention my sub Hertz iso stand of yore was an air spring design? Of course, like everything else air spring designs are complicated by internal friction and damping. Some air springs have too much friction and or internal damping. And my single spring "Unipivot" Nimbus platform achieved 0.5 Hz resonance frequency in several directions. The Nimbus was also the only iso stand with six - count ’em! - directions of isolation. |
By the way, Diamondears, a spring need not be a metal coil---air can also function as a spring. A DIY isolation platform can be made by placing a barely-inflated inner tube (the lower the pressure, the lower the spring rate/resonant frequency) between two Baltic Birch plywood shelves. The discontinued Townshend Audio Seismic Sink was just such an isolation product, though fabricated of metal. Townshend now offers the Seismic Pod, a metal coil inside a rubber bellows, available in different rate versions (for different mass loads). The Townshend site has technical information, including a video demonstrating the Pod in use, explaining the theory behind the Pod. |
Dear Ct, What GK was referring to regarding the tendency of magnets oriented such that like poles are facing each other to want to slide sideways, around rather than toward each other, is indeed happening in your Verdier turntable. Only the mating of the male and female elements of the bearing holds the platter in proper position over the base; otherwise the platter would slide off onto the floor or shelf. This means that for better or worse there is always some additional friction generated, in the horizontal plane within the bearing assembly. No criticism is intended; it's a fine turntable for sure. No design is perfect. Likewise, every magnetically levitated shelf I've seen has some "stops" built in to it to prevent side to side motion of the levitated element of the shelf. |
Hi diamondears imo - You will always get only one view, opinion when reviewing white papers. A recommendation, I did this myself and it worked for me. Talk directly with the TT manufacturers whether you own their table or not. They will send you the information you are looking for. You will discover the levels of study and analysis that they went to. A TT itself is a Sum of its parts - imo I like this definition from the internet. A concept in holism. Related to the idea that the total effectiveness of a group of things each interacting with one another is different or greater than their effectiveness when acting in isolation from one another. It conveys the meaning to me that you can not just look at one aspect of something - especially in this case where we are dealing with vibrations, resonances. Too many audiophiles, including myself can get buried too deep. Go too far down the rabbit hole. fwiw I had many conversations with JC Verdier prior to and after my purchase of La Platine Granito Vintage thread model. It has pneumatic shoes and a granito plinth. JC Verdiersome pics of it here. http://www.jcverdier.com/ADSL/platineVintage.html diamondears - Re magnets, when the magnet moves, so does what’s on top of it? Not sure I follow what you mean here. Are you referring to my previous post on La Platine ? On La Platine, the bottom magnet is part of the plinth. The top magnet is part of the platter. There are many pictures showing both ends at this link. Just scroll down the page. http://www.jcverdier.com/ADSL/platineV.html |
It can be plucked while the record is playing, and so far no listening can tell I am doing it. lol Sorry for the error and the others in my previous post. That’s it... out with these new Arabica beans my wife bought me - in again with the Costco Zavida. The Arabica brand aren’t kicking in fast enough. correction to the previous post. It can be plucked while the record is playing, and so far no "one" listening can tell I am doing it. ******************************************************
@Geoffkait and all manufacturers, designers, dealers, distributors, and all those in the audio business...... posting on Audiogon. Why don’t you guys take the opportunity to show your company name in your monikers box so all like myself, non professionals, can see your professional affiliation? Just sayin... Kudos to those like PBN Audio who have already taken this opportunity. |
Basis uses a combination spring and fluid damped suspension in my table and I believe most of their line. AJ Conti (the man behind the company) has many technical papers about his products on his website, including the suspension system he uses--since you asked for it, see this link: http://basisaudio.com/docs/SuspensionTP.pdf There are plenty of other ways to design a turntable, as evidenced by the many fine products out there; this is AJ's take on the subject. As I posted before, this suspension is very effective, IMHO.. |
As a designer of isolation devices since Jesus was a Boy Scout I would just say the spring rate in pounds per inch is related to the resonant frequency of the iso system by the equation, system resonant frequency Fr equals the square root of (total) spring rate over total mass. So the more springs employed the higher the total spring rate (the stiffer the suspension) and the higher the system resonant frequency. The way I obtained extremely low resonant frequency for my sub Hertz platform was use only one spring. Whaaaaat? Most spring systems are too stiff to be effective dealing with extremely low frequency vibrations that are the issue, the ones produced by footfall, traffic, the speaker feedback, Earth crust motion. Even iso systems that provide Fr of say 3Hz are not really that effective when it comes to dealing with extremely low frequencies since the iso system acts like a mechanical low pass filter and won’t attenuate very effectively much until the frequency of vibration reaches say 15 or 20 Hz. How to easily measure the Fr of the turntable suspension. Push up and down on the (suspended) turntable and time the motion with a stopwatch to obtain cycles per second. 3 Hz is a relatively slow undulating motion. A more rapid motion will be up around 8 Hz or whatever, which is too high to be effective against very low frequencies. |
I could be wrong, but I doubt you could find any white paper specifically on turntable suspension. The audio industry just doesn't seem to publish that detail. You would have better luck looking into industrial products like TMC: http://www.techmfg.com/products/at_a_glance.html |
Diamonddears, I'm no mechanical engineer, but a spring has a resonant frequency (it's "rate"), above which it isolates whatever is sitting on it from whatever the spring itself is sitting on, and below which it does not---the mechanical energy passing right through the spring, un-attenuated. The isolation resembles an electronic filter, with a roll-off slope beginning at the center frequency. A turntable suspension, therefore, should have as low a resonant frequency as possible, 3Hz being an attainable number. The lower the desired frequency, the "looser" the suspension, and the slower the table will bounce when pushed down upon. A table tuned to a low resonant frequency will have soft springs, like an old Cadillac. |
Thanks for the responses, all. What I'm looking for is some white paper or really comprehensive post or thread discussing the merits (and demerits) of suspensions on turntables. Primarily, I'm wondering how spring suspensions could isolate from vibrations when the spring itself is still connected from one end to the other end? Re magnets, when the magnet moves, so does what's on top of it? |
diamondears - Suspensions on turntable.......really effective ? I think that the OP - diamondears is thinking about what type of shoes the turntable is wearing ? Women have this thing for shoes you know. But truth be told I think I do too. My SP10 MKII has worn maybe 15 sets of shoes during past bouts with audiophilia. Each set of 3 shoes transformed its’ personality each time. Yes, turntables have three legs. Well, they only need three legs. We have all heard the term "clothes make a man". How about shoes make a TT ? Geoffkait Oh no.... Every low level signal phono cartridge consists of key components: the stylus, cantilever, MAGNETS, coils and body. What are we going to now GK......you better go tell every cartridge maker about this. Now the platter itself on my La Platine is this big aluminum thing, and I think it isolates pretty good as it allows me to use a direct shot of unshielded phono wire.
Well, I can tell you that La Platine is anything but slippery. In fact the opposing magnets provide braking action to deal with the records behavior, at the record location. Do any others do this ? Kinda cool. The distant motor happily provides pulses of power through loosely applied thread. It can be plucked while the record is playing, and so far no listening can tell I am doing it. This is really fun to do with Audiophiles that are used to "loading" up the record, "loading" down with heavy clamped center weight and heavy peripheral weight; ready now, activate speed controller, ready, ok. push start ........at speed in milliseconds ...... La Platine - very much like a little girl pushing 6 - 200 lb guys on a playground merry go round. hey its a unique experience - not for everybody. sidenote Audiophiles are immediately attracted to La Platine because all the family jewels are exposed, accessible, and they think..oh my .. so much to access and modify here. The problem is ...from what I have heard .....true audiophiles all end up doing the same thing with her... they mess too much with the design...they go to far, and they then get bored because they have destroyed its genius dna, and created "audiophile bedlam". You heard it here first. |
The bass produced my Linn Basik/Akito rig is astonishingly good…why? Is it the Mogami din plug cable I put on it to replace the original that had actual rat bites (!) through to the wire? Is it the Sumiko Pearl cartridge that was embarrassingly inexpensive by any elitist geekdom standard? The relatively el cheapo (a pattern…I see a pattern here) Cambridge 640P/Pangea P100 (power supply) preamp? Why? Why? |
With all due respect to the OP, the question posed is a bad one from a scientific point of view; it cannot be answered simply or with a simple experiment. The responses that go in all possible directions so far are consistent with that fact. The huge variety of turntable suspensions (also counting no-suspension as a form of suspension) offered in the marketplace is further evidence that there is no "correct" answer to the question. In my opinion, those who try to develop suspensions for turntables must be very brave; it's a pit of snakes. No matter what one does, there is a new problem that comes with it. Personally, because of this, I favor unsuspended turntables, massive plinths, heavy duty shelving, concrete floors, etc. If you can afford a Vibraplane or Minus K, they're probably superior to most built-in suspensions but not perfect. For one "concrete" example, I've set up a second system in my basement, on the poured concrete flooring. This did great things for image solidity and reducing spurious noises that can be produced when the needle is disturbed in the groove, with a Lenco that I had earlier auditioned in my "upstairs" system. A few guys mentioned great bass from a Linn. While I can like the sound from a well set-up Linn, I always find the bass to sound "light", not to say lacking. I've owned a SOTA Star Sapphire Series III; the bass was downright muddy, could as well have been due to belt stretching as to suspension flexing. However, I do agree that later generation Sota's are better in this respect. |
Actually, magnetic suspensions on the tables I have seen are effective only in the vertical direction. The platter is held in place by a spindle in a vertical bearing. There is virtually NO movement permitted horizontally by that bearing. The magnets support the platter only allowing for up and down motion. If you press down on the platter it moves downward, but, the magnets act like a spring. The farther the platter is displaced downward, the closer the magnets move and the greater the opposing force, and hence the force trying to restore the platter to the equilibrium position (like a spring). |
One problem I have with mag lev suspension is that the heavier the object isolated the more powerful the magnets required. But we know that magnetic fields are bad for the sound especially in proximity to low level signals. For that reason I'm out. Of course the other objection is the very slippery nature of the opposing magnets doing the levitating. It is impossible to stop the top plate from moving laterally without putting uh stops in. |
A question on magnetic suspension - I can see how it might be effective for lateral vibrations, but how about vertical vibrations? Once the magnets are strong enough to support the weight of the table assembly would they then not then be stiff in the vertical plane, thus transmit any vertical vibrations? As you may guess, I’m not an engineer. |
I have heard really nice systems with magnetically suspended tables (Gabriel and Verdier), but, I have no idea how to attribute the sound to the particular suspension; these tables also have in common the fact that they are extremely massive. With both tables, I have only heard systems that were in rooms where footfall was not a problem so I don't have any idea whether they do a better or worse job in that area. I also heard the MASSIVE ClearAudio Statement table (the most expensive table I have seen/heard), and it too has a suspension (both magnetic and a mechanical suspension); it was in a dealer system that was not my kind of system so I don't really know what the table is capable of doing. I haven't seen a clear correlation between suspended vs. non-suspended in terms of what sounds good. Of the suspended tables I am quite familiar with, I like the Basis Debut (the table I own), the Gabriel, the Verdier, the three motor Audio Note table, and, I even liked a Linn LP-12 with a Naim ARO arm on it (completely different sound, but, appropriate in the particular system it was in (heard a direct comparison with a Basis 2500). I liked many non-suspended tables, like the TW Acoustic and refurbished Thorens 164. I would not rule any particular design out just on theory. |
I don't know if suspensions are necessarily designed to reduce the impact of footfall. The Linn simply sound better--lively and better bass--when the suspension is correctly tuned and the table is placed on an appropriate support surface. I have experienced all sorts of tables having problems with footfall so I don't know if certain types of suspensions are particularly vulnerable. As a rough guess, I would say that light tables with suspensions, like the Linn and some JA Michell tables seem a bit more vulnerable to footfall. I suspect that a much heavier suspended table, like my Basis Debut, is less prone to problems with foot traffic. |
I think the issue is, really effective against what? For example, a Linn, although spring-mounted, is terrible with footfalls, while a Basis, also spring mounted, is much better. There are many theories as to how to design a tt. Some say that spring-mounted tables are always in a state of oscillation and that a heavy plinth is the way to go. So the short answer is - I don't think you can generalize about these things. Each table has to be judged for its own merits and you shouldn't be shopping for a tt based on whether it is suspended or not. There are just too many factors that contribute to the sound. |
I use a "vintage" Linn Basik (Akito) with no suspension to speak of except the large rubber hollow feet it sits on (the turntable is on a light but stable little table of its own, as per the Linn instructions!). I recently obtained a second REL sub and it's about 4 feet from the turntable, all on a classic potentially bouncy wood floor. The result is zero footfall disturbance, when I touch the side of the turntable when blasting something no vibration is getting through (at least that I can feel by touch)…and the damn table sounds great and plays beautifully. I keep threatening to replace this table but it works so well I can't get rid of it. |
I've used SOTA turntables (Sapphire Deluxe, then Cosmos IV) and have seen how they really isolated the playing from footfalls, etc. in a "medium" bouncy wooden floor setting. I now have my Cosmos sitting on a Herzan active vibration cancelling base (yes, the type used to isolate scanning electron microscopes), and it just transforms the table into a much more neutral device and improves the detail retrieval. The Minus K product mentioned above is also excellent for this. |
Compare a Sota Jewel to a Sapphire. They can sound almost identical. However, the suspension in the Sapphire can definitely help if there is any movement at all. However, a bad suspension is worse than no suspension at all. I had a Thorens 125 with and SME arm and it was so bouncy that the hanging weight on the arm kept getting tangled... |
I'm not quite sure that I fully understand your question, but I will say that a good suspension will definitely isolate a turntable from footfalls and other vibrations. A stunt I use to prove it to non-believers is to hit the suspension of my Basis Ovation turntable with a hammer (covered with cloth to keep from marring the suspension, of course) while a record is playing. None of the energy from the hammer is transmitted through the speakers. While my prior (non-suspended) turntable, a Well-Tempered, was pretty good at isolation due to its mass, it still could be affected by vibrations from heavy footfalls--it clearly could have benefited from a device like a Vibraplane or Seismic Sink, but they cost more than the table and arm itself. |
