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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…😘
halcro
viridian's avatar
viridian
4,184 posts
 
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.
larryi
1,972 posts
 
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.
boofer
77 posts
 
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.
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