The Arm/Cartridge Matching Myth

Halcro, my post is not about tone arm designers. It is about cartridge designers.

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...❓👀

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....😜

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,

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

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.

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...👀😎❓

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 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.

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.

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 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.

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.