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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…😘
128x128halcro
halcro's avatar
halcro OP
2,664 posts
 
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
atmasphere's avatar
atmasphere
11,861 posts
 
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.
pryso
1,939 posts
 
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?
almarg's avatar
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almarg
9,670 posts
 
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
in_shore's avatar
in_shore
596 posts
 
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
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