When I began my journey in high-end audio 36 years ago….no-one ever wrote about arm and cartridge matching nor tonearm resonant frequency…? Over the last 10 years or so…this topic has become not only ubiquitous, but has mutated beyond its definition, to THE guiding principle of matching cartridge to tonearm….❓❗️😵 The Resonant Frequency can be calculated using a complex formula relating Tonearm Effective Mass to the cartridge’s Compliance….or it can be simply measured using a Test record of various frequency sweeps. The RECOMMENDED Resonant Frequency of any tonearm/cartridge combination is between 8-12Hz. But WHY is this the recommended frequency and WHAT does it really mean…?
The raison d’etre of this Resonant Frequency…is to avoid WARPED records inducing ‘resonance’ into the tonearm….. Say what…❓😵 WARPED records….❓❗️ Yes…..ONLY warped records❗️😎 But doesn’t it have any meaning for NORMAL records…❓ None whatsoever…..😊👍 Let me explain….🎼
A badly warped record induces the tonearm to rise and fall rapidly on the ‘sprung’ cantilever of the cartridge. Depending on the severity and frequency of this warping…..a subsonic frequency between 2-5Hz is induced so if your tonearm/cartridge Resonant Frequency dips into this frequency range….it will begin resonating and thus miss-track and/or induce hum through your system.🎤 Keeping the lower limits of your tonearm/cartridge Resonant Frequency to 8Hz simply insures against this possibility.🎶
So what about the 12Hz upper limit…❓ This simply insures against the possibility of any ultra low-level frequency information which MAY be on the record, also inducing this same miss-tracking or hum. For instance if your tonearm/cartridge Resonant Frequency was 18Hz and you had an organ record or one containing synthesised bass going down to 16Hz…..your tonearm may miss-track or you MAY develop a hum❓😢
So how many badly WARPED record do you possess…❓ I have three out of a thousand or so……and have NEVER experienced miss-tracking or hum even on these three…❗️😍
Yet these days….everyone (without exception it seems)…even tonearm and cartridge designers….happily follow the dictum of this Arm/Cartridge MATCH as if it affected sound quality…..❓ This Resonant Frequency has ZERO affect on the sound quality of a particular tonearm/cartridge combination and I have proved it hundreds of times with a dozen different arms and over 40 cartridges.
The best match for ANY cartridge ever made….is simply the very best tonearm you can afford…whatever its Effective Mass…😘
Picture Ella Fitzgerald focusing her voice on a crystal goblet. She finds the resonance frequency of the goblet and then sings holding that frequency steady. The glass responds to that input. The goblet starts to ring and the amplitude builds until the glass shatters. All with the relatively small energy input of her voice.
I don't believe Ella ever managed to do this...❓😎 In fact....there is only one scientifically recorded instance of the human voice ever being able to do this under controlled conditions....and the SPL needed to succeed was greater than 110 dB...😱🎵 Incidentally...it is not the glass itself that reaches its Resonant Frequency.....it is the VOLUME of the glass with water that allows the Resonant Frequency to be raised to a level where it is audible....remember playing tunes on the rims of differently filled glasses....❓😎
Hi Halcro, I gave one example from a personal experience. The tonearm/stylus was cycling at 16 Hz while playing a record. It was interesting to see. Long term it would have worn out the stylus for sure. The other thing that I have seen happen before is the stylus jump the groove with only the slightest provocation. That makes me think of something: Is it only me or do others try not to cue the needle in the middle of the record? I have this feeling that dropping the needle, even ever so slowly in the middle of the record will leave some minor damage in the groove. So I tend to cue at the beginning and let it play through to the track that I want to hear. Is that a pointless exercise?
Halcro, I think I see where you are having difficulty. The FR-66 is not a "very high-mass" tone arm- although its on the high side for sure, but not 'very' high. Additionally, its tracking weight method uses a spring, which can reduce the effective mass somewhat. Since the counterbalance is part of the effective mass, the result here is that the actual effective mass is probably lower than you imagined.
What is the highest compliance cartridge that you have used with this arm?
Calculate the moment of inertia then divide by the square of the effective length. The MOI is = mass times distance squared. Or use the calculator.
No, I wasn't confusing resonance of the arm tube with low frequency resonance, but they're inextricably linked. The idea is to prevent resonance from increasing into an atomic explosion, while dissipating vibrations. I'm not advocating resonance outside of the neutral zone, just pointing out a couple of conceptual errors. Regards,
Tony & Lewm, Don´t worry, The Calculation exists. The question is who has the ability to find out the Equation and solve the mystery ;) We must call Stephen Hawking immediately ! My hat off to Mark Kelly as well. Btw, one of my test records is 2 mm off-center, hardly can measure anything that truly makes sense ? :/
Some calculate the effective mass of the tonearm/cartridge system backwards, starting with the compliance of the cartridge and the observed resonant frequency, using a test LP. But that depends upon the accuracy of the manufacturer of the cartridge in stating compliance. Also, Mark Kelly has developed a rather simple method to estimate effective mass; the problem is that I have forgotten it. However, search the archives on the Vinyl Asylum or try Vinyl Engine.
Harold, there is no single equation that I am aware of for determining the effective mass of the tonearm in grams. It is an involved calculation based on the mass of the tonearm and the moment of inertia of the tonearm assembly which, as you said must be broken down for both sides of the fulcrum. Also, the effective mass is not likely to be the same value in the lateral direction (unless the tonearm and counterweight are straight cylinders), just like the cartridge compliance will not be the same value in the lateral direction. That just means the dynamic response laterally will be different from the vertical dynamic response. And there again, the static forces should be the same in both the horizontal and vertical planes. I can't think of a reason why they wouldn't be.
The point that I was trying to make is that when an input frequency dwells on the resonance point of a mechanical system, the output amplitude tries to go to infinity. Of course, there are limitations but usually the limitation is failure of the system- something breaks. Picture Ella Fitzgerald focusing her voice on a crystal goblet. She finds the resonance frequency of the goblet and then sings holding that frequency steady. The glass responds to that input. The goblet starts to ring and the amplitude builds until the glass shatters. All with the relatively small energy input of her voice.
Tony, I re-read you statement more closely but don´t agree about "near infinite energy out", I assume this is a typing error ? It´s annoying that one can´t edit own posts shortly afterwards, we all make typing errors occasionally. Anyway, the Equation is well known for ages and refers only for the effective mass of wand + cart because the fulcrum kinda splits the whole moving part (inertia mass) in two parts. There is another equation for the whole system ? I´m very curious to study it. Agree otherwise as I wrote.
^^ the above seems to read as if there is confusion between the resonance of the arm tube with the mechanical resonance of the arm mass combined with the cartridge and its compliance. The two are different.
The adage that rules are made to be broken is in itself a generalization.
The reason the 10Hz target is desirable is not a rule- its a recommendation for best results. If you spend a lot of money on an arm and a cartridge only to have it mistrack by ignoring this recommendation, it is money poorly spent.
Generalizations, half truths, and oversimplification lead to erroneous conclusions even if they work. Rules are made to be broken and it's results that matter. You want to know the resonant frequency of your arm/cart? Buy a test record.
How is it that Halcro can track almost anything with a resonant frequency below the recommended range, magic? It's because his set-up isn't easily excited by acoustic/mechanical impulses and he probably doesn't play severely warped records. They sound like crap anyway, so why?
Resonance doesn't result in near infinite energy out. Even an atomic bomb is finite and we're not converting matter to energy, but the propagation of resonance can be a problem, mimicking oscillation. Ever see the original Origin Live mod of the Rega arm? They cut two slots along the bottom of the armtube to prevent increased vibration/resonance propagation. The armtube can be sort of like an echo chamber for vibrations.
There are two basic ways to deal with any resonance and vibrations, and the cart will put vibrations into the headshell regardless of resonance. They are damping and dissipation. Over-damping compromises transient response and makes it sound dead, but judiciously applied will mitigate amplitude of resonance and aid tracking. What's the difference between damping and bearing friction? Not much methinks. Dissipation is channeling energy down the armtube and out, hopefully. The trick is not to have mechanical vibrations go the other way. That's where high quality equipment and set-up comes into play. A well designed table will do this for you if it's set-up right. Regards,
For a few years, I have bought and sold a variety of vintage MM and LOMC cartridges together with vintage Japanese tonearms of different masses and designs....and I have been astonished at the sound quality that is possible compared to the modern genus of LOMC cartridges and their currently lauded tonearms....👀❓ The most startling aspect of these experiences...has been the elevation in sound quality when using cartridges in arms that are decidedly a 'bad match' according to the theoretical Arm/Cartridge Resonant Frequency equation....😎❓ With the very high-mass FR-66s tonearms.....virtually ALL the high-compliance MM cartridges I mount on them, transcend their often humble status to become magical devices emitting radiance, tranquility and bliss unheard from them in lesser arms....😘 I'm not talking degrees of betterment here.....I'm talking paradigm shifts of exaltation...👋🎼🎵🎶
For five years...I have been trying to reconcile this fact against the apparent collision with scientific thought...😱 And I now think I have...😃
It really matters naught to me and my musical enjoyment that the majority of audiophiles accept the dictum that "heavy arms are better for low-compliance cartridges and light arms are better for high-compliance ones"...except that:- 1. They are depriving themselves of potentially mind-blowing experiences 2. Their constant recommendations to Newbies on the multiple audio Forums based on this dictum, are depriving others of possible wonderful experiences
Now I have sold many MM cartridges which I bought but which failed to excite me on any one of a dozen or so arms...😭 What's the big deal...❓😎 So what's the big deal if you try a cartridge and arm combination (which is NOT recommended)...and it doesn't work for you...❓ So sell one or the other... It's not the end of the world...😃 And you may be in for a big and exultant surprise...😘❓🎶
The danger is that being outside the quiet zone (10Hz +/-) can result in excessive wear or even damage to your cartridge and records- even if it sounds fine.
In the interests of science.....further elaboration and evidence would be appreciated...❓👀
Can´t agree more on everything you say. It is exactly the same what I have experienced over the decades. The magic of 10 Hz +/-2. We must aim exactly there. Everything else is superstition.
The SME III and all series have 2 options to increase mass on headshell: 2.2 g and 4.4 g metal ballast weights, very simple method to move the peak area. My SME provides 6.6 g of total extra mass. http://www.ebay.co.uk/itm/SME-SERIES-309-SERIES-IV-SERIES-V- 4-4-GRAM-METAL-BALLAST-WEIGHT-BRAND-NEW-/141436953524? hash=item20ee4ca3b4
Additionally, the super rigid titanium-nitride wand has 4 teak ribbons inside wand & is fluid damped outside. SME arms have very informative sheet for effective mass & frequency resonance values. SME III is Classic Beauty with fine lines & gorgeous curves... like Sophia Loren ~ :^) Never underestimate damping, it´s the essence.
Many arm manufacturers provide a dubious figure for their arm's Effective Mass whilst a large number provide no figures whatsoever....😷 The cartridge manufacturers simply provide a 'design target' for their compliance figures which can vary significantly from unit to unit....and also possibly changes over time...
'Effective mass' is the combination of the cartridge and arm, as seen in the post from Tonywinsc. As a result an arm manufacturer can't really publish an actual figure, unless they know the mass, compliance and tracking force of the cartridge (since the position of the counterweight will have an effect).
Harry, I don't think you need any more numbers. Take the grills off of your loudspeakers and see how much woofer excursion you are getting. If its a problem- for example if that is how the amplifier power is being gobbled up, you have a problem. If not- maybe you're in the right window.
If the cartridge can track through anything without breakup then you're fine. If not this is something to look at. Some torture tracks:
'Paranoid' by Black Sabbath - Vertigo white label LP (bass energy brings many systems to their knees in a heartbeat)
Village Music of Bulgaria - Nonesuch LP (massed females voices should sound clear)
Verdi Requiem side 1 track 2 - RCA Soria series LP (wide daynamic range with big bass drum whacks)
'Garden of Worm', side two of 'In the Wake of Poseidon' by King Crimson, pink Island LP (heavy Mellotron tracks tend to break up)
All of these recordings should sound really clean and undistorted in any way.
If you can track these without breakup you are in the window.
I hope that I can clarify a few things for everyone. Resonance is a phenomena where a small amount of energy in results in near infinite energy out. It can occur in either mechanical or electrical systems. Static forces and dynamic frequency response are independent of each other. ie. Tracking force does not affect the natural frequency of the cartridge/tonearm system- unless you have so much tracking force that the cartridge suspension is bottomed out. You'll know that is the case if you see a thin ribbon of vinyl curling up behind the needle while playing a record. Effective Mass is a shortcut for calculating the tonearm/cartridge system natural frequency. Effective mass is really the inertia of the tonearm expressed in grams. That's because the tonearm is resting on a fulcrum (pivot). The tonearm and counterweight weigh much more than just a few grams. Additionally, the effective mass can vary depending on the position of the counterweight. So a lower mass cartridge will lower the effective mass of the tonearm since the counter weight will be closer to the pivot. I guess the tonearm manufactures provide us with a nominal value. Don't forget to add the mass of the cartridge, not just the spring rate to the natural frequency calculation. The only magic about 10Hz +/-2 Hz is that this is the "quiet" area. Below 8 Hz is the range of record warps and footfalls. Above 16 Hz is getting into the range of the music. The tonearm/cartridge system is still responding at 10Hz. Any energy input will make it respond at that frequency. The key is not to have input at 10Hz. This is so the inherent damping of the stylus suspension and any tonearm pivot bearing friction can be effective at keeping the tonearm/cartridge calm. That small amount of damping keeps things under control. If the tonearm system has a response at say 3-5Hz then the resonance- infinite energy out will overwhelm the damping properties and the tonearm will be greatly excited when rising over a record warp. You could certainly not have a problem with a tonearm system response of 5Hz as long as the records are perfectly flat, hole dead center and the turntable well isolated from footfalls. I had a cartridge/tonearm system at 16 Hz once. It sounded ok but when I looked closely, the stylus was constanltly moving up and down. I rectified the problem by adding a 4 gram mass to the headshell. That dropped the natural frequency to about 10Hz. Everything was steady then. The danger is that being outside the quiet zone (10Hz +/-) can result in excessive wear or even damage to your cartridge and records- even if it sounds fine.
Just taking a shot in the (very) dark here, but isn't it likely that in practice it is the amplitude of the resulting resonances in the tone arm/cartridge/room/speaker system that are at least as critical as the resonant frequency itself? Such that the frequency range for various cartridge/arm combinations does not vary by that much, but the intensity of the response at the primary and harmonic frequencies can vary by a lot between various arm/cartridge combinations? The result being that theoretical and measured resonant frequencies look roughly the same for many combinations and nearly all within the "accepted" range. But in practice these resonant frequencies are actually excited by and interact with record grooves, room construction and sound fields from speakers such that the AMPLITUDE of the resonances of different cartridge and arm combinations in different listening environments can vary over a wide range, sometimes becoming problematic.
I don't even know enough about physics to get into real trouble, but the above is my very dumb way to try to summarize some elements of the discussion so far so that I can understand it. And it demonstrates to me why a better designed tone arm is highly desirable and can command a higher price, and perhaps why Halcro sees the whole problem as a myth. This coming from a bottom feeder who has only owned 7 turntables in five decades of listening, all cheap, used and/or free, and probably fewer cartidges over my listening life than Halcro has in his current collection, but I have run into this problem in a serious way at least twice.
I would just like to emphasise Kirkus' point about 'calculated' Resonant Frequency...and 'measured' Resonant Frequency because they are rarely (if ever) the same...⁉️😫 Many arm manufacturers provide a dubious figure for their arm's Effective Mass whilst a large number provide no figures whatsoever....😷 The cartridge manufacturers simply provide a 'design target' for their compliance figures which can vary significantly from unit to unit....and also possibly changes over time...❓😱 The Fidelity Research FR-66s tonearm is renowned as one of the highest mass arms at 38 Gm Effective Mass...😲 I have measured the Resonant Frequency with a dozen high-compliance MM cartridges using the Shure V15 Type 5 Audio Obstacle Course test disc and have not recorded a figure lower than 8Hz or higher than 13Hz...👍 So either the Test Record is wrong❓.....or the recommended range is easily achieved in 'practice' as opposed to in 'theory'....❓👀
Henry, Its more than being about warped records, if you read inbetween the lines of Kirkus's post above- if the effective mass is incorrect, you can actually have the stylus jump out of the groove of a perfectly flat, concentric LP.
An excellent example is a Grado on a Graham 2.2- does the well-known 'Grado dance' shortly before exiting stage left (IOW, jumps out of the groove).
The other issue is you won't be able to get the cartridge to track complex material correctly. So its a big deal and not just about warp.
I'm sorry I didn't get that from Kirkus' Post....❓👀 Apart from the possibility of Structure-Borne Feedback exciting the exact arm/cartridge Resonant Frequency.....the only other ways I know of, are by warped or off-centre records..❓👀 If you have other science-based evidence...or if Kirkus could support your claims...I'd be interested...😲❓ In any case...over hundreds of combinations of arm/cartridge interactions....I've never experienced what you claim....😃 Fairly good odds in my book...😍
Thank you all for the kind words, and thank you Al for correcting my sloppy math . . .
On the issue of acoustic feedback, I'd just like to add that it rarely occurs at the tonearm/cartridge main resonance point, simply because it takes a speaker with extremely powerful subsonic response to produce enough energy to "close the loop" at these frequencies. But with a big subwoofer, it can definitely happen. Usually it seems to occur at a frequency that's modally related to room dimensions, or in the mid-bass region where the loudspeakers are efficient, but the turntable's suspension isn't.
I have (and had) combinations which have been between 9.7 -10.0- 10.4 Nearly super (from that Theory) but I was amazed that some carts performed MUCH better in Arms where the "calculation" showed different datas.
If you're not actually measuring the resonance point, there's no way to know whether or not you're getting the best results within a given range. Keep in mind that manufacturer compliance and effective-mass data varies wildly in its accuracy - and poor data isn't an indicator that the theory of operation is incorrect. Similarly, many speaker drivers have inaccurate specifications for their Thiele-Small parameters . . . but this doesn't mean that the matching of the driver and the cabinet is any less important.
Of course, the tonearm/cartridge resonance envelope is just one of myriad factors that determine sound quality in LP playback, but it is one of the fundamentals. It's also something that is particular to playback . . . that is, it's one of the ways in which a turntable is fundamentally different from a cutting lathe.
I wanted the DiskTracker so badly- never got one. Now, don't need one but somehow, I still want one.
It's as though everything I wanted to get in 1977 or 1978 but could because I just didn't have the dough, I want to own now, even if for a little while. What's been on that list that I've actually bought so many years later? Thorens turntable, Philips GA312 turntable, AR turntable, a Marantz receiver, ohm F speakers (still in my garage). Never yearned for Mac gear.
Syntax sez's, even more audible internal turntable vibrations ( bearings , belts , motor (s) platter, suspension , They degrade the possible maximum performance more then anything else.
10-14-14: Halcro As anyone with ‘feedback’ problems knows…..with the stylus stationary on the record, as you turn up the volume you will suddenly hear a deep and progressively louder continuous ‘drone’ emanating from your speakers…🔊 This (I suspect) is the Resonant Frequency of your tonearm/cartridge combination being excited by the harmonics of the structure-borne floor....
One thing puzzles me and perhaps Kirkus or Al can help here……😃 The ‘feedback’ on the stationary stylus increases when the volume is turned up….but I thought this is amplified AFTER the cartridge in the preamp stage….❓
The continuous drone you are referring to results from a feedback loop breaking into oscillation, at a low frequency. A feedback loop by definition involves a closed loop, which is to say a continuous path from input to output and back to input.
In the situation to which you are referring, some fraction of the acoustic output of the speaker is ultimately finding its way back to the cartridge. That acoustical/mechanical path from speaker to cartridge forms part of the loop, which is completed by the electrical pathway through the audio system. The volume control setting affects the gain of that electrical pathway, of course.
The gain that is necessary to set the loop into oscillation at a susceptible frequency can exist anywhere in that loop. Susceptibility depends, in addition to the gains that exist within the loop, on the phase shift and frequency response characteristics of what is in the loop, including any resonances which may exist.
So Zavato, with clarification from Rodman and Timeltel it was the Disctracker, sold by Discwasher Inc.
Now in addition to the info in links offered by Timeltel we have cartridges with "damping" brushes such as Shure, Stanton, Pickering, etc. (although they may have had other intents as well). And the Townshend Rock attempted something similar with a silicone filled trough and a paddle extending from the headshell.
A number of arm manufacturers address damping with some fluid around the bearing, or immersed in it such as Well Tempered. Then SME and KAB offered external damping troughs at the bearing end of the arm rather than the cartridge end.
So over the years many attempts to attack the resonance issue. But if anyone of these had proved successful wouldn't nearly all arms offer that today?
Henry, Its more than being about warped records, if you read inbetween the lines of Kirkus's post above- if the effective mass is incorrect, you can actually have the stylus jump out of the groove of a perfectly flat, concentric LP.
An excellent example is a Grado on a Graham 2.2- does the well-known 'Grado dance' shortly before exiting stage left (IOW, jumps out of the groove).
The other issue is you won't be able to get the cartridge to track complex material correctly. So its a big deal and not just about warp.
Thanks Professor (Timeltel)...😘 You more than anyone knows how long I have struggled with this apparent dichotomy....❓👀 It's good to see you back here after so long...✋👀
And thank you for those Links...👏 I haven't yet finished them... There was a lot of intelligent thinking about vinyl way back then in the States....although most of the writers seem to have oodles of warped and off-centre records that they play with...😰❓The days before record clamps...😊❓
The general opinion is, that it is fine when the result is between 8-12. It is overrated and I don't give much for it. Today you have different materials in the Arms (Steel, Aluminum, Wood, Titan etc. etc.). There are also different Tonearm geometries out there, some have less distortions at the beginning, some more in the inner grooves, most audiophiles think, when they buy an "Arm" then it is done perfect in every way but I think, that's the mistake of their audiophile life. Did no one ask why some arms are straight and some not? And why? (the straight ones are cheeper to make and need no knowledge...) and what the arch angle is good for? ..... These materials all have different resonances. Next, you have different kind of bearings (from construction and from design). these differences can be huge.Or, is the Arm a rigid design or not, what's with the energy transfer? How fast is this one? Does it even exist, or does the Arm save it to a momentum and starts to vibrate on its own and reflects this back into the tracking process...long story short: does it allow fast transient transmission? Back to life I have (and had) combinations which have been between 9.7 -10.0- 10.4 Nearly super (from that Theory) but I was amazed that some carts performed MUCH better in Arms where the "calculation" showed different datas. This calculation is more or less a help but after all I don't give a dime for it. A good designed tonearm is much more important. I wrote several times about that when I made my comparisons with my Arms and Datas and the result was always the same, the best quality Arms worked best with a lot of cartridges at superior level. And other Arms only with a few ones. Btw. Cartridge Design does not stop with compliance. Their reaction with a tonearm can be totally different, but you will never read something about that. The best cartridge is a sold cartridge and based on that you will also find the general "recommendation" about loading: 100 Ω 47kΩ :-) Example: Lyra Titan / Olympos are superior from sonics in top Arms only (energy transfer via Headshell into the Arm), when used in Arms with cheap bearings or bad geometry you get an analytical sound which is not a pleasure to listen to. But let's not forget: All has to go through a Phonostage and that one can change the results also. Or, even more audible, internal turntable vibrations (Bearing, Belt, Motor(s), Platter, Suspension ...), in my personal opinion, I think, they degrade the possible maximum from sonics more than anything else.
Many thanks for your thoughtful Post (as usual).....and it has made me realise how wrong I am about the importance (or lack thereof) of the Arm/Cartridge Resonance…..😲❗️ I’m really kicking myself now because I’ve done a great deal of thought and study on the subject of Structure-Borne Feedback as it relates to Audio and yet…..because I fortunately don’t suffer from it myself…..I completely ignored its possible relationship to the Arm/Cartridge Resonance…😅❓
As I have written many times previously….EVERY suspended floor structure….be it timber, steel or concrete…..is under stress. At points of maximum bending and deflection…this stress induces low subsonic frequencies which can be so severe in certain cases…that vibrations may even be felt....🔊 Contrary to popular belief…..a suspended reinforced concrete slab can often be worse than a suspended timber floor, especially in modern high-rise apartment buildings which commonly use thin prestressed, post-tensioned slabs with little standard steel reinforcing…😱 The subsonic frequencies in most suspended floor systems are commonly in the order of 2-5Hz and vary in location and intensity on an individual basis. In other words….no two audiophiles are experiencing exactly the same conditions….but ALL audiophiles with a turntable located on a suspended floor are living with a vibrating ‘singing’ demon under their feet….👿 Normal equipment racks are of little use against these types of subsonic frequencies and ‘cures’ like rubber, sorbothane and air-bladders may ameliorate some aspects to the detriment of others…😕 Only the expensive ‘active’ acoustic stands developed for electron microscopes (like Minus K) which utilise ‘tuned’ springs along with mass plates designed to handle exactly those frequencies 2-5Hz, will be effective on a suspended floor system…..😃 The best floor of all….❓ A reinforced concrete slab on the ground….which is what I have…👀😍 If you don’t have this luxury…mount your turntable on a shelf fixed to a wall which sits on its own footing. A masonry wall is preferable to a timber-framed wall, as a masonry wall will not support ‘tension’ whilst a framed wall will. Remember…’tension’ equals ‘stress’ equals ‘noise’. If you can’t use a wall-mounted shelf…then try to locate your turntable as close to an external wall as possible. The middle of any floor span has the most stress and deflection….😖
As anyone with ‘feedback’ problems knows…..with the stylus stationary on the record, as you turn up the volume you will suddenly hear a deep and progressively louder continuous ‘drone’ emanating from your speakers…🔊 This (I suspect) is the Resonant Frequency of your tonearm/cartridge combination being excited by the harmonics of the structure-borne floor. If your floor is producing 2Hz…then 4Hz, 8Hz and 16Hz are the harmonics. If your floor is producing 3Hz…then 6Hz, 12Hz and 24Hz are the harmonics. If your floor is producing 4Hz…then 8Hz and 16Hz are the harmonics….and so on.. The common silent woofer-pumping many complain of, seems again indicative of the Resonant Frequency activating the woofers...🔊
This is why I suspect, changing cartridges or headshells or adding mass or damping to the tonearm often ‘solve’ the problem….❓ You are simply shifting your resonant frequency ‘out’ of the feedback harmonics…..👀 You are not ELIMINATING the problem….😞 You are DODGING the problem….😜 If you have this problem.….you could never have 2 turntables, 6 tonearms and 40 headshells and cartridges (as I have) without experiencing a single feedback problem…❓
One thing puzzles me and perhaps Kirkus or Al can help here……😃 The ‘feedback’ on the stationary stylus increases when the volume is turned up….but I thought this is amplified AFTER the cartridge in the preamp stage….❓
Three warped records out of a thousand? You are a very lucky guy. I blew out many woofers(high mass arm high compliance cartridge) until I matched the arm and cartridge. IMHO your findings seem like a lot of hogwash to me!
From 35/40 years back, lots of informative data: http://www.bostonaudiosociety.org/pdf/bass/BASS-03-04-7501b.pdf
If you're interested in credentials, Google Lee Phoenix.
Starting on pg. 9, the practical Peter Prichard; "We really don't know quite what we're doing in this industry": http://www.bostonaudiosociety.org/pdf/bass/BASS-04-08-7605b.pdf
Sources of resonance excitation: "The vibration input to the pickup (both signal and warp) is represented by the constant current generator exciting the circuit. The motion of the stylus assembly is modeled by the current in the CR branch, which shows that the circuit is a high-pass filter, with a resonant peak at the corner frequency." http://shure.custhelp.com/app/answers/detail/a_id/4072#PhonoArmDamping
Thanks, Henry, for another thought provoking thread.
I own a "hot-rodded" VPI Classic. If you read some of my earlier posts from a few years ago, I had a devil of a time matching a cartridge to the VPI JMW uni-pivot arm. Many of the troublesome carties had compliance factors in the 20s.
And no surprise, the effective mass of the JMW arm is high'ish and the best cartridge matches were in the mid to low'ish compliance range. I tried to achieve a theoretical resonance (as computed off the vinyl engine website) in the 8 to 12 Hz sweet spot.
My current cartridge is a Lyra Kleos which I recall has a compliance factor of 12. There is no woofer pumping or bass ringing. IMO, it's a very good match.
Notwithstanding the very minor quibble that I believe the reference to "1/3 octave" should have said "a little less than 2/3 octave," I'll nominate Kirkus' post for best of the month, perhaps even best of the year.
This Resonant Frequency has ZERO affect on the sound quality of a particular tonearm/cartridge combination and I have proved it hundreds of times with a dozen different arms and over 40 cartridges.
Hi Halcro . . . I think the main conceptual problem here is that the resonant frequency is only one parameter that's descriptive of the tonearm/cartridge resonance envelope. Keep in mind that the tonearm/cartridge combination is a mechanical high-pass filter, and if there is a resonant peak . . . mathematically it must be a multi-pole system. This means that affecting any element changes not only the resonant frequency, but the width and height of the peak (Q), the transition-band slope, and the amount and periodicity of any pass-band ripple.
The difference between 8 and 12 Hz really is very little in the frequency domain - at 1/3-octave it's the same as two adjacent bands on a 31-band EQ. And while the tonearm/cartridge system is indeed multi-order, its filter slope isn't anywhere near steep enough to make much difference in LF response or warp-immunity simply with a change of frequency. Rather, the effect of raising the tonearm mass for a given cartridge usually increases the Q of the filter in addition to lowering the resonant frequency; that is, the resonant peak becomes higher and narrower.
The trade-offs of raising the system Q are the same as for any electrical filter: the "benefits" are that the transition-band (immediately below the resonant frequency) becomes sharper and more selective, and the pass-band (area above the resonant frequency) becomes overall "flatter". The "drawbacks" are that the system becomes dramatically more sensitive to energy imparted at the resonant frequency, the pass-band ripple increases, and increased ringing in the time-domain (impulse) response.
Pragmatically, the main issue will be the extent to which your turntable and environment conduct energy into the tonearm/cartridge system, and at what frequencies. If you're using non-suspended turntables, on sturdy furniture, in a concrete building, then you're probably going to have fewer issues with subsonic resonances, but your system will be more prone to acoustic energy conducted back into the tonearm . . . and a heavier, more rigid tonearm definitely helps to control and dampen this.
But for suspended turntables, springy wooden building structures, heavy support furniture sitting on carpet etc. etc. . . . indeterminately increasing the Q of the tonearm/cartridge system is playing with fire. Each of these additional spring/mass systems can potentially combine to create a condition where the system is extremely sensitive to subsonic and low-bass energy. Many view this as a reason to universally condemn suspended turntables . . . but it's simply a different type of energy to which the system is susceptible, and the trade-off for better immunity to conducted energy within the audio range.
But regardless of the type of turntable design, domicile construction, or support furniture . . . I seem to see fairly regular inquiries on these fora for help to solve the issue of woofer-pumping while playing records. Much of the time the owner has already followed this sort of advice . . .
The best match for ANY cartridge ever made….is simply the very best tonearm you can afford…whatever its Effective Mass
Given that the prime mechanism determining susceptibility to this phenomenon is the tonearm/cartridge resonance envelope . . . the notion that this issue could be avoided simply by spending more money on a "better" tonearm seems a bit unreasonable to me. It's simply far more effective to change to a lower-compliance cartridge, thereby creating a system with a lower-Q resonance envelope at a slightly higher frequency.
Even though there's normally no musical content below 20Hz, there is a variety of noise caused by friction, and the mechanical reality of tracking. What's the amplitude peak of undamped low frequency resonance? What exactly is it that's resonating, your cantilever perhaps? Ever hear of intermodulation distortion?
This is all well documented for decades now. Imperfect equipment and set-up can allow acoustic and mechanical feedback to wreck havoc that is absent with digital.
If low frequency resonance is near the audio band, say 18Hz, then 2nd harmonic intermodulation is 36Hz. This is from The Audio Dictionary: http://books.google.com/books?id=L38MrvScG3gC&pg=PA38&lpg=PA38&dq=low+frequency+resonant+peak+amplitude+in+tonearms&source=bl&ots=L7kNpNUcIL&sig=ux4FxgVPIC1wpe3-WPA3QYKSiYM&hl=en&sa=X&ei=aAQ8VNitOOzbsATX7YLACw&ved=0CDEQ6AEwAw#v=onepage&q=low%20frequency%20resonant%20peak%20amplitude%20in%20tonearms&f=false
I've been a victim of ignoring this issue. I had a very heavy cartridge for a short while, paired with my medium mass arm. The math did not work for this pairing.
I experienced a rumble that I just could not get rid of. To the point of considering building a subsonic rumble filter to cut off the problem. The better solution was to try a different cartridge, which resolved the issue perfectly.
The Equation for Resonant Frequency in a pivoting TA is quite simple. It depends on the total mass of tonearm (tonearm wand + cartridge) M (g) & cart´s compliance C (just quantity of units alone)
F(Hz) = 1000 /(6.28x the square root of MxC) Hz.
The bigger both the M and C are the smaller the F is, the smaller both the bigger the F.
For example let´s use the SME III and its very low mass arm wand 5 g.
For a very compliant SHURE with M 11.6 g and C 30 cu the frequency is 8.5 Hz. For a very stiff Entré-1 with M 10.8 g and C 10 cu the frequency is 15.3 Hz.
The "safe" value for F is 8-12 Hz.
Using a stiff LOMC on a very low mass arm smears sound just under 20 Hz if the vinyl actually contains music in these very low frequencies, of course, and thus doesn´t quite make sense :-/ Using a hyper compliant DENON DL-207 with 50 cu on a medium mass arm leads to tracking issues around 5.5 Hz where pressing faults are serious :_/
What was the fairly purvasive "rumble filter" for on many pre amps, integrated and receivers from the phono dominated era? I have been concerned about this since I have a subwoofer that has no effective lower frequency cut off, volume just trails off gradually at lower frequencies. While this is an asset on digital recordings, The low frequency energy (sounds like a rumble) is so loud on certain records in my collection that it intrudes on the music. This occurs on warped albums and some other recordings with no obvious physical defect. No rumble filter on my current amp. Have been thinking that cartridge/arm matching may be more critically important in this case. Is dawn of more low frequency capable systems brought on by digital sources making this compliance issue more noticeable and problematic for analog reproduction?
I should have said that Grey Research manufactured viscous-damped tonearms, widely used WITH Pickering carts, back in the 50's: (http://www.vinylengine.com/library/gray-research/108-b.shtml)
Cancel my previous Post Davide256.... I've just read some of your other Postings...
Turntables like the Linn and Sota when properly balanced have a suspension resonance point below the audible range of human hearing, vibration from the surface the TT rests on is damped by the suspension above the resonance point.
As to importance, the tonearm is secondary to the turntable. A spring suspension turntable like Linn or Sota with an entry level tonearm will reveal much more than if you buy a better arm but compromise on a non spring suspension turntable.
1) speed accuracy to the point where its musically relevant has been pretty much solved in any TT costing over $300 2) the average stylus pressure is 1.5 gm. The drag of this on a rotating platter assembly of 2000 gms is negligible; the mass equivalent of a tricycle towed behind a truck 3) vibration isolation/damping is what counts...horizontal vibration in the plane of the stylus vibration will suck transients, detail and bass out of your playback
Direct drives are very difficult to isolate vs belt drives
Faith-based 'opinion' will not 'cut' it here...👎 Science-based knowledge and educated thinking is welcome....👍
Halcro, I was trying to make the point that if one knows which arm or arms a cartridge designer used to develop a particular cartridge, he could then perhaps assume that that cartridge/tone arm match is pretty good, at least in the mind of the cartridge designer.
The Shure M97xE had a viscous damped, "dynamic Stabilizer" as well. Pickering and Stanton both had weighted brushes, attached to their stylus assemblies, in an attempt to control movement/resonances, before Shure. Pickering had tonearms that were viscous damped, with the intent of damping resonances, back in the 50's. Some history on damped arms and carts: (http://www.tnt-audio.com/accessories/silicone_damping_e.html) (http://www.technicalaudio.com/pdf/Gordon_Clark_folder/Gray_Research_net_price_list_103_1955.pdf)
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