The Arm/Cartridge Matching Myth

Hi Kirkus,

Many thanks for your thoughtful Post (as usual).....and it has made me realise how wrong I am about the importance (or lack thereof) of the Arm/Cartridge Resonance…..😲❗️
I’m really kicking myself now because I’ve done a great deal of thought and study on the subject of Structure-Borne Feedback as it relates to Audio and yet…..because I fortunately don’t suffer from it myself…..I completely ignored its possible relationship to the Arm/Cartridge Resonance…😅❓

As I have written many times previously….EVERY suspended floor structure….be it timber, steel or concrete…..is under stress.
At points of maximum bending and deflection…this stress induces low subsonic frequencies which can be so severe in certain cases…that vibrations may even be felt....🔊
Contrary to popular belief…..a suspended reinforced concrete slab can often be worse than a suspended timber floor, especially in modern high-rise apartment buildings which commonly use thin prestressed, post-tensioned slabs with little standard steel reinforcing…😱
The subsonic frequencies in most suspended floor systems are commonly in the order of 2-5Hz and vary in location and intensity on an individual basis. In other words….no two audiophiles are experiencing exactly the same conditions….but ALL audiophiles with a turntable located on a suspended floor are living with a vibrating ‘singing’ demon under their feet….👿
Normal equipment racks are of little use against these types of subsonic frequencies and ‘cures’ like rubber, sorbothane and air-bladders may ameliorate some aspects to the detriment of others…😕
Only the expensive ‘active’ acoustic stands developed for electron microscopes (like Minus K) which utilise ‘tuned’ springs along with mass plates designed to handle exactly those frequencies 2-5Hz, will be effective on a suspended floor system…..😃
The best floor of all….❓
A reinforced concrete slab on the ground….which is what I have…👀😍
If you don’t have this luxury…mount your turntable on a shelf fixed to a wall which sits on its own footing. A masonry wall is preferable to a timber-framed wall, as a masonry wall will not support ‘tension’ whilst a framed wall will. Remember…’tension’ equals ‘stress’ equals ‘noise’.
If you can’t use a wall-mounted shelf…then try to locate your turntable as close to an external wall as possible. The middle of any floor span has the most stress and deflection….😖

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.
If your floor is producing 2Hz…then 4Hz, 8Hz and 16Hz are the harmonics.
If your floor is producing 3Hz…then 6Hz, 12Hz and 24Hz are the harmonics.
If your floor is producing 4Hz…then 8Hz and 16Hz are the harmonics….and so on..
The common silent woofer-pumping many complain of, seems again indicative of the Resonant Frequency activating the woofers...🔊

This is why I suspect, changing cartridges or headshells or adding mass or damping to the tonearm often ‘solve’ the problem….❓
You are simply shifting your resonant frequency ‘out’ of the feedback harmonics…..👀
You are not ELIMINATING the problem….😞
You are DODGING the problem….😜
If you have this problem.….you could never have 2 turntables, 6 tonearms and 40 headshells and cartridges (as I have) without experiencing a single feedback problem…❓

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 general opinion is, that it is fine when the result is between 8-12.
It is overrated and I don't give much for it. Today you have different materials in the Arms (Steel, Aluminum, Wood, Titan etc. etc.). There are also different Tonearm geometries out there, some have less distortions at the beginning, some more in the inner grooves, most audiophiles think, when they buy an "Arm" then it is done perfect in every way but I think, that's the mistake of their audiophile life. Did no one ask why some arms are straight and some not? And why? (the straight ones are cheeper to make and need no knowledge...) and what the arch angle is good for? .....
These materials all have different resonances. Next, you have different kind of bearings (from construction and from design). these differences can be huge.Or, is the Arm a rigid design or not, what's with the energy transfer?
How fast is this one? Does it even exist, or does the Arm save it to a momentum and starts to vibrate on its own and reflects this back into the tracking process...long story short: does it allow fast transient transmission?
Back to life
I have (and had) combinations which have been between 9.7 -10.0- 10.4
Nearly super (from that Theory) but I was amazed that some carts performed MUCH better in Arms where the "calculation" showed different datas.
This calculation is more or less a help but after all I don't give a dime for it. A good designed tonearm is much more important.
I wrote several times about that when I made my comparisons with my Arms and Datas and the result was always the same, the best quality Arms worked best with a lot of cartridges at superior level.
And other Arms only with a few ones.
Btw. Cartridge Design does not stop with compliance. Their reaction with a tonearm can be totally different, but you will never read something about that. The best cartridge is a sold cartridge and based on that you will also find the general "recommendation" about loading: 100 Ω 47kΩ :-)
Example: Lyra Titan / Olympos are superior from sonics in top Arms only (energy transfer via Headshell into the Arm), when used in Arms with cheap bearings or bad geometry you get an analytical sound which is not a pleasure to listen to.
But let's not forget: All has to go through a Phonostage and that one can change the results also. Or, even more audible, internal turntable vibrations (Bearing, Belt, Motor(s), Platter, Suspension ...), in my personal opinion, I think, they degrade the possible maximum from sonics more than anything else.

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

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.

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?