2. analog
  3. 1412834749

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
atmasphere's avatar
atmasphere
11,844 posts
 
Many arm manufacturers provide a dubious figure for their arm's Effective Mass whilst a large number provide no figures whatsoever....😷
The cartridge manufacturers simply provide a 'design target' for their compliance figures which can vary significantly from unit to unit....and also possibly changes over time...

'Effective mass' is the combination of the cartridge and arm, as seen in the post from Tonywinsc. As a result an arm manufacturer can't really publish an actual figure, unless they know the mass, compliance and tracking force of the cartridge (since the position of the counterweight will have an effect).

Harry, I don't think you need any more numbers. Take the grills off of your loudspeakers and see how much woofer excursion you are getting. If its a problem- for example if that is how the amplifier power is being gobbled up, you have a problem. If not- maybe you're in the right window.

If the cartridge can track through anything without breakup then you're fine. If not this is something to look at. Some torture tracks:

'Paranoid' by Black Sabbath - Vertigo white label LP (bass energy brings many systems to their knees in a heartbeat)

Village Music of Bulgaria - Nonesuch LP (massed females voices should sound clear)

Verdi Requiem side 1 track 2 - RCA Soria series LP (wide daynamic range with big bass drum whacks)

'Garden of Worm', side two of 'In the Wake of Poseidon' by King Crimson, pink Island LP (heavy Mellotron tracks tend to break up)

All of these recordings should sound really clean and undistorted in any way.

If you can track these without breakup you are in the window.
harold-not-the-barrel
895 posts
 
Bravo Tony `Ö´

Can´t agree more on everything you say.
It is exactly the same what I have experienced over the
decades.
The magic of 10 Hz +/-2.
We must aim exactly there. Everything else is superstition.

The SME III and all series have 2 options to increase mass
on headshell: 2.2 g and 4.4 g metal ballast weights,
very simple method to move the peak area. My SME provides
6.6 g of total extra mass.
http://www.ebay.co.uk/itm/SME-SERIES-309-SERIES-IV-SERIES-V-
4-4-GRAM-METAL-BALLAST-WEIGHT-BRAND-NEW-/141436953524?
hash=item20ee4ca3b4

Additionally, the super rigid titanium-nitride wand has 4
teak ribbons inside wand & is fluid damped outside. SME arms
have very informative sheet for effective mass & frequency
resonance values. SME III is Classic Beauty with fine lines
& gorgeous curves...
like Sophia Loren ~ :^)
Never underestimate damping, it´s the essence.
fleib
1,124 posts
 
Generalizations, half truths, and oversimplification lead to erroneous conclusions even if they work. Rules are made to be broken and it's results that matter. You want to know the resonant frequency of your arm/cart? Buy a test record.

How is it that Halcro can track almost anything with a resonant frequency below the recommended range, magic? It's because his set-up isn't easily excited by acoustic/mechanical impulses and he probably doesn't play severely warped records. They sound like crap anyway, so why?

Resonance doesn't result in near infinite energy out. Even an atomic bomb is finite and we're not converting matter to energy, but the propagation of resonance can be a problem, mimicking oscillation.
Ever see the original Origin Live mod of the Rega arm? They cut two slots along the bottom of the armtube to prevent increased vibration/resonance propagation. The armtube can be sort of like an echo chamber for vibrations.

There are two basic ways to deal with any resonance and vibrations, and the cart will put vibrations into the headshell regardless of resonance. They are damping and dissipation. Over-damping compromises transient response and makes it sound dead, but judiciously applied will mitigate amplitude of resonance and aid tracking. What's the difference between damping and bearing friction? Not much methinks.
Dissipation is channeling energy down the armtube and out, hopefully. The trick is not to have mechanical vibrations go the other way. That's where high quality equipment and set-up comes into play. A well designed table will do this for you if it's set-up right.
Regards,
atmasphere's avatar
atmasphere
11,844 posts
 
^^ the above seems to read as if there is confusion between the resonance of the arm tube with the mechanical resonance of the arm mass combined with the cartridge and its compliance. The two are different.

The adage that rules are made to be broken is in itself a generalization.

The reason the 10Hz target is desirable is not a rule- its a recommendation for best results. If you spend a lot of money on an arm and a cartridge only to have it mistrack by ignoring this recommendation, it is money poorly spent.
harold-not-the-barrel
895 posts
 
Tony, I re-read you statement more closely but don´t agree
about "near infinite energy out", I assume this is a
typing error ? It´s annoying that one can´t edit own posts
shortly afterwards, we all make typing errors occasionally.
Anyway, the Equation is well known for ages and refers only
for the effective mass of wand + cart because the fulcrum
kinda splits the whole moving part (inertia mass) in two
parts. There is another equation for the whole system ? I´m
very curious to study it. Agree otherwise as I wrote.
More to discover