The Arm/Cartridge Matching Myth

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….😎✋

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.

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...❓👀

Sorry Peterayer...my bad...😴

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....👍

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….❓

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

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'....❓👀

Nice Post Tonywinsc....👍
Thank you..😘

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...❓👀

Thank you to all who have contributed here....😍

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...😘❓🎶

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 Tony,

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.

For this to occur...a 16Hz tone had to be created either on the record, by the warp or off-centre disc...or via structure-borne feedback..❓👀
If your arm is 'moving'....you have a problem...😱
If your arm is not moving up and down or from side to side....whatever your Resonant Frequency may be....you don't have a problem and there will be no excessive wear on the stylus...😃🎶

Ralph,

The FR-66 is not a "very high-mass" tone arm- although its on the high side for sure, but not 'very' high.

I think you are mistaken....👀❓
The FR-64s is listed on Vinyl Engine with an Effective Mass of 35Gm..so a figure of 40 Gm for the FR-66s is quite believable...❓😱
I've trawled through the Data Base on Vinyl Engine and can find no arm ever made that comes even close to these figures...😫❗️
Here are the highest masses of tonearms I could find on the Database:-
SME Series V...Mass=10/11
SME 3012R=14
VPI JMW Memorial 9 Signature=9.5
Zeta=16
Technics EPA250=14
Roksan Artemiz/Tabriz=9
Linn Ittok LVII=13.5
Dynavector DV501=25

Here are the Compliance figures for some of the cartridges I have used on the FR-66s:-
Shure V15 Type III Compliance...22.5
Signet TK7SU....30x 10-6cm/Dyne
Acutex LPM 312 III STR....24
Acutex LPM 420 STR...42
Empire 4000D III....30

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?

I've never thought about this before....and now you've got me thinking about this....❗️😱
STOP....⭕️🔙❌🚫

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