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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
 
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....👍
Ag insider logo xs@2x
knownothing
1,615 posts
 
What was the fairly purvasive "rumble filter" for on many pre amps, integrated and receivers from the phono dominated era? I have been concerned about this since I have a subwoofer that has no effective lower frequency cut off, volume just trails off gradually at lower frequencies. While this is an asset on digital recordings, The low frequency energy (sounds like a rumble) is so loud on certain records in my collection that it intrudes on the music. This occurs on warped albums and some other recordings with no obvious physical defect. No rumble filter on my current amp. Have been thinking that cartridge/arm matching may be more critically important in this case. Is dawn of more low frequency capable systems brought on by digital sources making this compliance issue more noticeable and problematic for analog reproduction?

kn
harold-not-the-barrel
895 posts
 
Good evening

The Equation for Resonant Frequency in a pivoting TA is quite simple.
It depends on the total mass of tonearm (tonearm wand + cartridge) M (g) & cart´s compliance C (just quantity of units alone)

F(Hz) = 1000 /(6.28x the square root of MxC) Hz.

The bigger both the M and C are the smaller the F is, the smaller both the bigger the F.

For example let´s use the SME III and its very low mass arm wand 5 g.

For a very compliant SHURE with M 11.6 g and C 30 cu the frequency is 8.5 Hz.
For a very stiff Entré-1 with M 10.8 g and C 10 cu the frequency is 15.3 Hz.

The "safe" value for F is 8-12 Hz.

Using a stiff LOMC on a very low mass arm smears sound just under 20 Hz if the vinyl actually contains music in these very low frequencies, of course, and thus doesn´t quite make sense :-/
Using a hyper compliant DENON DL-207 with 50 cu on a medium mass arm leads to tracking issues around 5.5 Hz where pressing faults are serious :_/
ptmconsulting
1,000 posts
 
I've been a victim of ignoring this issue. I had a very heavy cartridge for a short while, paired with my medium mass arm. The math did not work for this pairing.

I experienced a rumble that I just could not get rid of. To the point of considering building a subsonic rumble filter to cut off the problem. The better solution was to try a different cartridge, which resolved the issue perfectly.

Yes, it does matter.
fleib
1,124 posts
 
Even though there's normally no musical content below 20Hz, there is a variety of noise caused by friction, and the mechanical reality of tracking.
What's the amplitude peak of undamped low frequency resonance? What exactly is it that's resonating, your cantilever perhaps? Ever hear of intermodulation distortion?

This is all well documented for decades now. Imperfect equipment and set-up can allow acoustic and mechanical feedback to wreck havoc that is absent with digital.

If low frequency resonance is near the audio band, say 18Hz, then 2nd harmonic intermodulation is 36Hz.
This is from The Audio Dictionary:
http://books.google.com/books?id=L38MrvScG3gC&pg=PA38&lpg=PA38&dq=low+frequency+resonant+peak+amplitude+in+tonearms&source=bl&ots=L7kNpNUcIL&sig=ux4FxgVPIC1wpe3-WPA3QYKSiYM&hl=en&sa=X&ei=aAQ8VNitOOzbsATX7YLACw&ved=0CDEQ6AEwAw#v=onepage&q=low%20frequency%20resonant%20peak%20amplitude%20in%20tonearms&f=false

Regards,
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