The Arm/Cartridge Matching Myth


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…😘
Convert?fit=crop&h=128&rotate=exif&w=128halcro
You had me in total agreement until your last sentence, which I respectfully disagree with.

We like to focus on things that we can measure, like primary arm/cartrige resonances. But as Halcro points out, these are below the audible band, not that they can't cause problems. Kudos to him for taking on one of the great myths of phonography that gets waaaaayyyy too much attention.

Of greater concern and something that is not easy to measure are the secondary arm and cartridge resonances that are excited by the energy put back into the arm.

These fall well within the audible range and IMHO if resonances in the body of the cartridge are additive to those of the arm you will get a bad match no matter how good the two components are. We have all experienced these strangely bad matches as well as unexpectedly fortuitous matches. And I believe that it is the secondary arm/cartridge resonances that this can be laid at the foot of.

If you doubt this, simply put the stylus in the groove with the turntable off. Gently tap your arm with a pencil. In a perfect world you would hear no sound, but bell-like resonances are quite common, and arm resonances can be both high, and low, Q. It's really not a good thing at all. And it is why IMHO one must carefully match the cartridge to the arm based on experience rather than math.
I would never tap the arm itself when it is in the playing position for fear of over-stressing the cantilever. Instead, tap the record surface near the cartridge. A good table/arm will quickly dampen out the energy imparted into groove that is then fed into the arm--you will hardly hear anything playing through your system if the combination is doing its job correctly.

But,then again, some people actually like the "liveliness" that can be the product of some ringing. So, ultimately it does come down to taste, system matching, some trial and experience. Because one cannot realistically try even a small sampling of possible combinations of arms, tables, cartridges, phonostages, etc., experience certainly does play a big role in winnowing down the field.
I agree with a lot of what Halcro has to say, and I've also tried many tonearm/cartridge combinations and haven't heard horrible results even when the compliance/ resonance formulas were way off. However, I still have copies of Stereo Review magazine from 1979 which DID print graphs about this whole issue, so the topic was written about way back then.
Of greater concern and something that is not easy to measure are the secondary arm and cartridge resonances that are excited by the energy put back into the arm.
An interesting point Viridian…and one that I’ve been wrestling with over five years or so….😖
Many people have mentioned both cartridge resonances and “energy transference” into tonearms over the years…..yet no-one (to my knowledge) has provided any scientific data or evidence to support such claims…?
If cartridge resonances OUTSIDE of the cartridge body really exist (and if they did I can’t help but think this would indicate information loss?)….they would be easily measurable and the data should be available for all the cartridges in the market place…❓
I am unaware of any such data and until some is provided…it seems presumptuous to base an argument or philosophy on this…😵

Energy transference into the tonearm is more easily understood I believe, as it is a purely structural phenomenon….⏄
The tonearm is a counter-weighted propped cantilevered beam as a structural description….
In its neutral balanced state (before any tracking weight is applied)….it is a purely counterweighted cantilever with the total weight of the arm and counterweight transferred vertically through the pivot to the arm bearing.
The stress (or force or reaction) at the headshell in this state is zero…..0️⃣
The bending-moment diagram from this point towards the pivot then increases in a curved catenary slope (because of the arm’s uniformly distributed self weight) until it reaches its maximum bending moment (and shear stress by the way)…at the pivot..😎
Every single stress, bending moment and deflection can be calculated knowing the length of the arm, the material and cross-sectional configuration.
Incidentally….the Resonant Frequency of the tonearm in this ‘balanced’ condition is wayyy below that of the arm on its ‘sprung’ cantilever…😋
Once the VTF is dialed in…the reaction (or force) at the headshell is whatever the VTF is…1.5 Gm-2.0 Gm etc..
From here it becomes less clear cut….😢
There is a constant reaction 1.5 Gm at the headshell as it traverses the record (otherwise VTF would be changing)…but it is a dynamically changing propped cantilever now with the arm moving both sideways and also up and down…😱
If the bearings are truly frictionless…it should induce no extra stresses into the arm other than the ones previously in existence as a propped counterweighted cantilever as far as I can see…😴❓
But it would require a computer run simulation to analyse exactly what was occurring…and the only tonearm manufacturer that has done that to my knowledge is Continuum Audio Labs with their Cobra and Copperhead tonearms…
Beginning with Finite Element Analysis using NASTRAN, PATRAN, and DYTRAN from www.mscsoftware.com finalising in the complex process of Gradient Shape Optimisation using Reshape from www.advea.com. The wand is eggshell thin with special contours and compound curves to “shape” the resonant behavior of the arm. These behaviours are only visible with specialized software tools but clearly audible to experienced listeners.
As it so happens….my Copperhead tonearm is the very best performer with every single one of my cartridges be they high-compliance MMs or low-compliance LOMCs…😘
Very closely behind the Copperhead in matching with multiple cartridge types and designs….are the 35 year-old (high mass) Fidelity Research designed FR-64s/66s and (medium mass) SAEC WE-8000/ST...😍

On the other hand Viridian….I agree with Larryi’s advice to never tap on the arm when in the playing position….😰
Apart from possible damage to the cantilever as he points out….dynamic (or impact) loading on a material bears little relationship to the transfer of sound waves propagated through structure or air and thence into the material…👎
In architecture…when we test a wall for its sound-proofing properties or a theatre wall for its reverberant characteristics…we never ‘hit’ it with any implement..👀
In acoustic theory….sound is propagated through materials by Reflection, Transmission and Absorption and the amount of each of these is able to be calculated by the materials’ properties and thicknesses and the frequencies and SPL (volume) of the sound.
When designing a parquet timber or tile or stone clad floor for minimizing the ‘impact’ sound of stiletto footsteps…..different design solutions are required…😕

What we all seem to agree on though…. Boofer included….is that the notorious arm/cartridge Resonant Frequency Calculator is no indication of a tonearm’s ‘matching’ ability to a cartridge….😎✋
Very interesting Halcro. Thanks for the post.

I suppose another approach is to try to find out which arms the cartridge designers used while developing your cartridge. Then you would at least get closer to what those designers like.

The problem is that there is the whole rest of the system and even the room that plays a role in the overall sound and that will certainly be different from one's own set up.

I have not read anywhere which arms Lyra uses to develop its cartridges, but I did read that the AirTight Supreme was in part developed on an SME arm, for instance.
I would only place upper and lower limits on Halcro's proposition; it would not be a great idea to use a very high mass tonearm with a very high compliance cartridge, simply because of the resulting flexing of a very compliant cantilever which might cause physical damage, never mind resonance. Let say, an ADC XLM with an FR66S.
I would only place upper and lower limits on Halcro's proposition; it would not be a great idea to use a very high mass tonearm with a very high compliance cartridge, simply because of the resulting flexing of a very compliant cantilever which might cause physical damage, never mind resonance. Let say, an ADC XLM with an FR66S.
That's interesting.....I've never heard of anyone destroying a cantilever with a high-mass arm...😱❓
I understand how confusing it must be for most audiophiles to understand esoteric structural principles....😴
In normal playing conditions....the cartridge has no idea about the tonearm's Effective Mass...😎
The only 'mass' it sees is the VTF of 1.5Gm...😛
When I balance my six arms to 'neutral' (before applying VTF)....they ALL pivot freely when pushed towards the spindle....despite their differing Effective Masses 👍
Imagine a huge tonearm weighing two tons on perfectly frictionless pivots..👀
You could easily push it with one finger to start it pivoting...👅
The problem comes when you try to STOP it once it is pivoting...😵
It is only THEN that the Effective Mass becomes an issue...😱
So it is only a change in RELATIVE movement which brings into play Effective Mass...hence its role in the UP and DOWN movement of tracking a warp...☺️
If you play a record with a seriously off-centre hole...you will notice the tonearm moving back and forth while it tracks the groove...😫
This again will bring into play the Effective Mass...👀

So the only times Effective Mass plays a role is when playing a warped or off-centre record...😏
At all other times....the 'mass' that the stylus and cantilever sees is the VTF...😘
I suppose another approach is to try to find out which arms the cartridge designers used while developing your cartridge. Then you would at least get closer to what those designers like.
I'm not sure about this Peterayer.....❓
If I were designing a tonearm, I'd want to test it with as many different cartridges (and TYPES of cartridges) as I could..😎
However...I suspect that nowadays most designers of high-end arms test them predominantly with MC cartridges as they believe that most buyers will be using this type of cartridge....😢
A well-known and much-aclaimed tonearm I once owned....sounded fine with LOMCs yet performed poorly with every MM I tried...😩⁉️
In fact the interesting discovery with my many arms and cartridges......was that the poor arms were exposed...not with different LOMC cartridges...but with different MM cartridges...😵❓
So the common audiophile belief that LOMCs require better arms than MMs...is simply another myth IMO...👀😎❓
Stylus compliance is what matters... mechanically the same as matching shocks on a car. As an extreme example, the light weight Grace 707 tonearm creates interesting wow and flutter effects matched with inexpensive stiff suspension Grado cartridges with any record the slightest out of round. And heavy tonearms with highly compliant cartridges easily bottom out on records that are not perfectly flat.

So if you have a collection of treasures that are less than perfect LP's, matching compliance to mass does matter.
Halcro wrote- "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…"

I've been into audio slightly longer- and I can't disagree more- maybe I read
different stuff but arm mass and stylus compliance and resonant frequency
were a well noted topic. I was urged not to buy a particular cartridge by a
local hifi shop as I was told its compliance was too high for the tone arm on
my Kenwood table.

There was a company- I don't recall who it was, that made a device that
attached to a head she'll that damped tone arm resonances (a small piston
device thatvattached to the headshell and made contact with the LP- who
made that?). Let's also look at the damper on the Shure V15 type 4- also
their to address this issue. Then there's this 1973 article.
http://www.aes.org/e-lib/browse.cfm?elib=1950http://www.aes.org/e-
lib/browse.cfm?elib=1950
Hi Henry,
I would like to underline a couple of things,
1-
for some reason I believe tangential arms are more sensitive to res-freq than pivot arms, perhaps because the cantilever also has to support the burden of the lateral mass ?? I'm not sure. As I noted elsewere it was an amazing improvement in sound quality when I rised the res-freq from about 5Hz to 9,5Hz, in my old T3F.
2-
I do agree with those than think the cantilever will overflex with too low res-freq.

3-
Finally, what about speakers ? I personally cannot listen to to closed-box speakers. I prefer panels or OB desings like Siegfried Linkwitz & John Kreskovsky.
Electronicaly EQ-subs are not possible to be used when res freq goes under 6Hz, even if LP is perfect as the mere touch of the stylus in the first 5mm will send the woofers to bottoming ... but not only. When I had the Apogee Full Range the woofer-panel went into crazy/over excursion even if the Krell Elec-XO did not used any EQ. OTOH when you stick to the righ res-freq. nothing bad happens.

Regards,
Stylus compliance is what matters... mechanically the same as matching shocks on a car.
Welcome Davide256...😆
As the first contributor to this Thread who does not agree with it....it would be beneficial if you could provide some mathematical or scientific arguments to counter those I have proposed...❓👀
Oh...and the analogy with "shocks on a car" is inaccurate unless you happen to run your cartridge's VTF at 14Gm....⁉️
But then again....a car does not have an 'Effective Mass'...😎
What it weighs is what it weighs....😜
Greetings Zavato...✋
I could not get your Link to work unfortunately.....😢

I think we did read different magazines....❓👀
In Australia we had access in the late '70s and early '80s to British magazines like Hi Fi Answers and Hi Fi Choice...and in the mid '80s onward, we could buy TAS and then later still...Stereophile...😍
I may be wrong...but I can't recall reading about this subject in those magazines during those early years...❓👀
Halcro, my post is not about tone arm designers. It is about cartridge designers.
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)
Sorry Peterayer...my bad...😴
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.
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....👍
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)
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?

kn
Good evening

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 :_/
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.

Yes, it does matter.
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

Regards,
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.
*******🎓*******
Halcro, Hi Fi News has been measuring secondary resonances in tonearms for decades:

http://www.sme.ltd.uk/content/Series-IV-Tonearm--Hi-Fi-1544.shtml

what is harder to quantify is the interaction between resonances in a specific cartridge and arm. However both will certainly have resonant signatures and it is not a very large leap of faith to believe that those resonances can interact.
Zavato,

"a small piston device that attached to the headshell and made contact with the LP- who made that?"

I remember those and believe they were sold by Discwasher.

Now everyone can sleep tonight. ;^)
10-13-14: In_shore
*******🎓*******
+1.

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.

Thanks, Kirk. Good to see you posting again.

Best,
-- Al
Ditto ... Kirk.

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.
@Pryso- Something like this? ( http://www.freepatentsonline.com/4151998.pdf ) ( http://www.ebay.com/itm/DiscTraker-Tone-Arm-Cartridge-Damper-RARE-with-all-parts-and-instructions-/191373090757?pt=LH_DefaultDomain_0&hash=item2c8eb99fc5 )
Regards, Zavato/Pryso: Disctracker, I believe.

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.

Peace,
Pryso- I think you're right- discwasher
DiscTracker. Rodman99999 beat me to it.

Peace
(again),
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!
Hi Kirkus,

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….❓
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.
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...😊❓

Regards
Henry
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.
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?
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.

Best regards,
-- Al
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.

Profound effect
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.

This is how threads get off track
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.
@Zavato- You said that, even though you don't need one now; you still want a Disctracker. The one on eBay is still available.
Hi Ralph,
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...😍
Thanks Al,
I knew that you would be able to explain this so that even a dummy (me) would get it....😬❓
And I got it.....😜❗️

Regards
Henry
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'....❓👀
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.

kn
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.
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.