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…😘
128x128halcro
As I've repeated numerous times......I was moved to begin this Thread, not to disparage the science behind the topic......but because after 40 years in Audio, and the last 12 years testing and listening to hundreds of arm/cartridge combinations.....my ACTUAL experiences could not match what the 'science' was predicting 🤔When I say this.....I don't mean that it was a 50:50 proposition so that the science worked in so FEW cases that I could live it 🤗I mean:-
  • I NEVER had a cartridge 'jump' from the groove
  • I NEVER had visible woofer pumping
  • I NEVER had audible mistracking
  • I NEVER had over-bloated bass
  • I NEVER had 'missing' bass (unless the cartridge was deficient)
Good science requires 100% applicability and predictability.Bad science should still provide (at the very least) a majority applicability 🎯When the 'science' provides zero correlation to the listening experience of even one shmuck (like me)....it needs to be questioned.
Propitiously......this LINK landed in my Emails last night and deserves a reading (complete with the graphs, and Test results which aren't included in the following quote.

This is the second post in the series on low frequency interaction between the tonearm and the cartridge.
In our previous post, we've formulated The Plan, and done the first bullet point: measured the Ortofon/Jelco combo from 5 Hz to 20 kHz, and put it all on two charts. What the measurements showed was a bit removed from what the calculations suggested.

Today, it's time for the second part of The Plan:
Make sure our test rig is working fine and is picking up both high and low frequency resonances. We'll measure the low frequency set with it, and superimpose it over the usual 20Hz-20kHz sweep.2Change the cartridge to the one with different compliance, and see what the effect on the low frequency resonance would be.3See what the low frequency content of the usual LPs looks like. We'll use some nearly unplayable LPs from our collection to try and get the effects of warps and excentricity.4Do the analysis of the data and see if there are some recommendations to be made on matching tonearms and cartridges.The Setup
In addition to the Ortofon SL-15E that we've employed in the previous post, we will use our old acquaintance the Denon DL-103. Its compliance is specified at 51065⋅10−6 cm/dyne (5 µm/mN). This fits well with the required downforce of 2.5 gram. Unlike many other cartridges, there's no doubt that Denon's suspension is actually quite stiff.
And to give an opposite perspective, a Shure M97xE. While it is shown with its brush down, all our measurements were done with the brush up and the downforce correspondingly decreased.

Shure specifies the compliance at 2510625⋅10−6 cm/dyne, but it's probably much higher. Various moving magnet Audio Technicas are specified as having 40 (!), and Shure definitely has a much softer suspension. The lower required downforce (less than a gram for Shure versus 1.8-2.2 g for ATs) supports this.

The MeasurementsThe accepted formula gives us 12 Hz resonant frequency for the Denon.
So if we take it at face value and plot Denon and Ortofon low frequency resonances together, we should get something like this.

Of course, the amplitudes might be different, and the curves would not be so neat and unbroken. But we definitely would see the frequency peaks, and we would see the frequency shift. The resonant peak must shift in frequency.

I've zoomed the charts on the 5-25 Hz area and made the X axis linear.
And what do we have in reality?
That doesn't look like shift at all. Maybe the vertical resonance would?
We see the change in amplitude all right, but the frequency shift is missing. This does not look much like resonant behaviour.


Extraordinary findings require extraordinary evidence, right? So let's see if using the Shure would result in the shift in the frequency of the resonant peak. Remember, specified lateral compliance of Shure is the same as Ortofon's, but we expect it to be higher. So our peak should be similar with the blue trace's, or slightly to the left. Right?
You can argue that the 6 Hz hump is the peak we're looking for, but this is splitting hairs. The main difference is in the lower overall motion, not in some particular frequency.


For completeness, here's the vertical comparison chart with Shure included.
What did we discover today?Looks like the low frequency behaviour of the cartridge/tonearm combination is shaped more by Newton's third law than by the compliance resonance. Modern cartridges (meaning all those built in the last 60 years or so) have too much suspension damping and non-linearity for the resonances to dominate.

I would stop at this today, leaving conclusions proper until the last post in the series. This is heady stuff, and I fully expect some people to become very upset.

Besides, we are not done yet. So far, we're only studying the motion that is excited by the artificial test signals. What would happen when we expose our combinations to actual real life records? That's the topic for the next post.

I'm not claiming 'victory' as a result of this single publication.....but I AM claiming 'vindication' in QUESTIONING the premise contained in this Thread.
Thanks again Professor.....but a lot of time has passed since I responded to Kirkus’ Post and I would like to clarify my thoughts since that time.

I also really want to address the points brought up by Dover, Thom and Chris as they are important.....however this will still have to wait as I need to prepare for this evening’s dinner party which will include the attendances of my Luncheon Buddies (and their spouses) 🍽

Conversation will of course be appropriate for the female company....although after even more whisky......it can become quite loud and raunchy 🤪
Henry
I haven’t participated in this thread except at the end, when I was commenting on another posters findings. So if you could kindly give me some slack.

I have a question for you going back to your OP.

You said.

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.

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IMO - Hearing "Resonant Frequency" change, "empirically" in Audiophiledom, requires sticking to the golden rule of making only one change at a time, and keeping, everything else the same.

The Resonant Frequency is the result of combined materials in our audio kit. Anyone disagree ?

The most obvious action we can take - that comes to mind - to prove or dis-prove your Resonant Frequency claim is to just change out the armtube of your tonearm....... into a different material.

Did you attempt this Henry ?

Have you owned and tried / do you own tonearms, with the capability to change out the armtube material ?

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My Empirical Findings

You know of my reference tonearm Henry, but for the others reading benefit here; I use a custom build ET 2.5 and it comes from the factory with optional armtubes to deal with different cartridges /compliance’s, and to keep the Resonant Frequency manageable.

In this link

https://photos.app.goo.gl/pgs7qXyF2f4miwLWA

one can see the MAG wand - Magnesium on top and the Carbon Fiber wand on the bottom. There is also an all aluminum wand.

Mag - stiff compliance (high resonant carts) - MC
Carbon Fiber - middle of the road - works with stiff and higher compliance carts. All around performer.
Aluminum - meant for the higher compliance carts - MM - lower resonance.

Let me say before I forget that IMO - all vintage MM’s have stiffened suspensions which makes their Resonant Frequency - not what it says in their user manual - it would be higher.

Think of the sound you get from a stiff and a less stiff tuning fork.

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Empirical Findings - good enough for me.

My Magnesium wand is intended for a stiff Cart - high resonant -Like an MC.
If I put a high compliance MM cart on the Mag wand, the sound becomes quite strident. Keeping the MM on the Aluminum or CF wand works well.  The fact that there is a "sound" change to me, just by changing out the armtube, proves to me, we are dealing with a Resonant Frequency change.

This has been one of my findings.

Cheers Chris

ct, I'm not in a bad mood at all. I just don't tolerate idiocy. People who know me know that I do not manipulate the truth and don't pull punches.
I prefer Islay scotch. Lagavulin will due:)
So lets see, by your logic, regarding any mechanical system subject to user perception, ignore the dynamic (moving) parts interaction and get the best platform you can find??
That's equivalent to having a set of tires and shocks/springs you got from your grandpa's garage, and then deciding to put those excellent parts on the best car you can find. 
Do you seriously think the subjective results are likely to be better than maybe acceptable?
You may not have experienced a problem, but I and many others have. Your analysis and conclusions are ignorant and worse silly.