Interesting.
Rules were made to be broken, especially in audio. |
If you get between 8 and 12 Hz you are done. Put the record away until you change cartridges. @mijostyn, so you are saying there is NO difference to the 'sound' within this 8-12Hz Band....? A 50% change is the Resonant Frequency has zero affect on the SOUND...? But when we get to 13Hz (a mere 8% increase over 12Hz).....you will suddenly hear it?! The conclusion from this (if it were true) is that it must be a logarithmic progression and the 'sound' will collapse spectacularly at 14Hz, 15Hz, 16Hz...... This is so easy to scientifically prove, there must be dozens of Phd Theses and 'Peer-Reviewed' White Papers on this very subject...? Unfortunately there is NONE 🧐 Not one....zilch....bupkis....nada. Oh there are plenty of 'Statements', 'Opinions posing as Fact', even 'unsubstantiated claims' by respected tonearm/turntable/cartridge designers....... But not one single Peer-Reviewed Scientific White Paper demonstrating the relationship between Resonant Frequency and SOUND...🤯 You claim to have personal experiences to substantiate your convictions, but so do I.... I have literally tested hundreds of different arm/cartridge combinations using the Shure Audio Obstacle Course Test Record to obtain the 'real' Resonant Frequencies of the Arm/Cartridge combinations (theoretical calculations will NEVER be correct as Compliance is a 'moving target' as is Effective Mass). Now I am NOT saying that there aren't 'differences' in the performances of various cartridges with various arms...🙃 I have spent the last ten years trying to find the 'happy' combinations (see my 'Hear My Cartridges' Thread)..... But the reasons for these differences are multifarious, complex and in many cases.....still unknown to us. The design and material of the Headshell will have significant effects on the sound in almost ALL cases 🤗 I don't aim to convince you (or anyone else) who holds this misunderstood view of the Cartridge/Arm resonant Frequency 'myth'.... Sleep warm and cuddly with your convictions.... A world of great sounds is forever closed to you 👎 For those who have an open mind....you have nothing to lose by just trying it 🙃 Why wrack your brains getting your knickers in a knot over theoretical calculations when it's just so easy to try it and LISTEN...just as Howardalex did with his FR-66S and Shure? Life is too short. Let the music begin.....🎹🎼 |
Despite the lack of scientific evidence available for those making the same claims as Mijostyn.....it rarely prevents them continuing with exactly the same claims.
Their usual segue is to postulate that many things in audio cannot be proven by science.......cable differences, similar amplifier specifications sounding differently, speakers with similar test results sounding differently etc.
Don't be fooled by this disingenuous argument because it is they...the ones making this claim, who are introducing 'science' (Arm/Cartridge Resonance Frequency) to arrive at a conclusion unsupported by that 'science'.
It provoked a 'thought exercise' which leads me to a 'theory' as yet unsupported by scientific evidence.
I predict that any cartridge will have the same Frequency Response Plot Graph regardless of the Arm/Cartridge Resonance it 'sees'.....
This is really sticking my neck out because any electronics technician or even audiophiles with an oscilloscope can very easily prove me wrong here 🤣
A kewpie doll to the first one who does.....👼 |
Imd distortion measurments would be good to add to such an experiment...
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Dear @halcro : I know that if you are or can’t be aware/detect something then and no matter what your belive is that that " thing " tha’s happening just does not exist for you. For several years now and in different threads I already told you that no matters what your room/system impedes ( I don’t want to repeat my in the past wide explanations/facts about. ) that you can be aware not only of this critical " myth " ( as you name it. ) but many other important audio subjects. Please do it a favor ( for the very first time in your life. ) and read very carefully all the different evidences/facts that several gentlemans ( some of them with better knowledge levels that you or me. ) posted in this thread and in others about the issue: https://www.ortofon.com/support/support-hifi/resonance-frequency/ "" compliance is a measure of how springy the suspension is...
so a high compliance cartridge has a fairly soft suspension...ie the suspension is easily compressed, it is highly complaint
... if you stick a high compliance cartridge on to a high mass arm..it will generally work...but tracking anything other than a perfectly flat record will cause undamped vibrations in the arm because the suspension is too soft to recover after a warp...or while tracking heavily modulated grooves of high amplitude waves
those vibrations wil affect the stylus’ ability to trace the record groove properly..and unwanted resonances may intrude upon the audible frequencies caused by this mis match...
think of a heavy car on soft suspension springs...when it goes over a bump..it wobbles for a long period of time before it comes to rest...
the opposite applies for a low complaince cartridge and a low mass arm... the low compliance of the cantilver’s suspension (e.g. fairly rigid, does not deflect much under a light mass) added to a low mass arm.(eg less inertia..so requires less force to move it) will lead to mistracking and in some cases an inability to correctly follow a record that is anything other than perfectly flat... also the stylus will struggle to follow the groove without moving the whole arm as well on large modulations in the record...ie bass notes..
same car analogy... light car on stiff springs...meets bump... the car will spend most of its time off the ground when it hits a bump at speed...and the tyres will have trouble following the up and downs of the roads surface because there is not enough mass acting on the stiff suspension ..
its basically a juggling act and you can get away with fairly extreme combinations but ideally you want to settle for a decent mechanical match between the mass of your arm..and how soft or stiff the suspension in your cartridge is...
the effective mass is the mass that the cartridge ’see’s at the end of the tonearm... some arms are heavier in ’mass’ but concentrate that mass near the pivot so the end of the tonearm may have a lower effective mass acting upon the stylus.... think of tapered tonearms...where the mass increases towards the pivot...or arms with heavy bearing assemblies that use a thin tonearm tube...
the balance you aim for basically..is to keep the stylus moving as independently from the arm as possible..without causing any vibration that will feed into the arm and back into the cartridge...ie wobbling... on the other side...you want the stylus to follow the groove as closely as possible without being disturbed (vibrated unecessarily)by warps in the record or losing contact with the groove walls.. ""
""" The thing that can take care of rather large mismatches is tonearm damping. Damping the tonearm´s movements is a key in getting better low frequency stability. ""
dlaloum:
"" any sprung system will have a resonance point at which it moves most easily - energy will tend to get channeled into that frequency resulting in a peak in amplitude.
The mass/springing system of the tonearm, where the only spring is the suspension of the cartridge works in the same way.
Even when the resonant frequency is at the "ideal" frequency of 10Hz, what happens is anything near that frequency will tend to excite the sprung system, and magnify those frequencies.
Test records have tracks of low frequency sweeps - basically a tone at a set level with gradually dropping or increasing frequency usually starting at 3 or 5 Hz and rising to 20Hz or 25Hz.
If you record this track and plot the amplitude to frequency, you will note that it does not reflect a line (as it theoretically should) but shows a marked peak at the resonant frequency. Depending on the arm/cartridge this peak can be anywhere from 2-3db (ok) up to 8db+ (bad).
The peak is not a narrow one, and usually influences frequencies on either side of the maximum point to a lesser extent.
As the RF (resonant frequency) rises it can start to impact on the audible low frequency response of the system - a substantial boost in amplitude at 15Hz as an example can cause huge subwoofer/woofer pumping, sucking up amplifier current, causing intermodulation of the bass frequencies, and generally affecting the sound as a result. (amps being under pressure using up all its grunt moving the woofers ends up losing its sweetness in the high end...) This is one of the reasons golden age phono centric amps often have a subsonic filter!
As the RF drops it starts to approach the frequencies generated by things like footfalls, and other vibrations external to the TT.
If you watch an arm/cartridge at its resonant frequency it clearly starts to "wobble" - there is substantial physical movement.. as it rises the needle will get pulled slightly back, as it drops it will get pushed slightly forward, a form of wow that is seldom considered, but does affect all frequencies reproduced.
Additionally the movement generates vibrations in the entire system which in turn intermodulate with the signal, generating other spurious "noise" (Intermodulation Distortion.).
Also when the RF is triggered, the cartridge movement can cause mistracking - with all of its associated problems, including increased wear and tear on record and stylus!
A well tuned arm/cartridge have the RF positioned where it does the least harm - by keeping it away from footfall/external vibration frequencies, and the resonant frequencies of the TT suspension (usually around 5Hz), keeping it away from the audio range (15Hz+) and if possible keeping its amplitude as small as possible.
Regardless of the final RF, the resonance remains an undesirable aspect of TT technology.
There is a way to control it, it is called damping. Damping can 1) reduce the amplitude of the RF, and 2) slightly shift the peak frequency.
The most common damping is fluid damping using a paddle system in an oil bath attached to the arm - it provides a slight resistance in a frequency sensitive way - the end result can be very effective. (the damping can be internal within the tonearm pivot column, external, it can be done with fluid or electro magnetic servo means...)
As an example, my JVC turntable has a damped arm - running a TK9e cartridge, I measured the resonant frequency at 5.9Hz - this being with the damping disabled.
Enabling the damping "widened" the peak somewhat - going from 5.8Hz to 6.5Hz, but dropped its peak from +4db down to +1db.
The stylus compliance is 31cu, the arm mass calculated out to 23.8g (including cartridge and fixings) - so high mass tonearm with high compliance cartridge - resulting in low RF (much too low).
With damping disabled - the mistracking was relatively obvious - and the system was very very sensitive to anyone walking around the house.
With damping enabled - the mistracking disappeared, and footfall sensitivity although still there, became much much reduced.
This is clearly NOT an ideal setup - I can make it useable with damping - but it will be better if I can lighten the mass by 4g or 5g with a lighter headshell.
And then I can still damp the resulting higher RF....
Some test records have an interesting track that can be used to identify the RF they run the low frequency sweep tone, at the same time as a steady audible tone...
When the arm hits the resonant frequency you clearly hear the tone "warble" - a result of the arm/cartridge movement.
A lesser and more subtle version of this happens when you play a record, and the arm is excited at its RF.
I strongly recommend damped tonearms regardless of the RF... ""
tonywin:
""" Tracking force does not affect the natural frequency of the cartridge/tonearm system- unless you have so much tracking force that the cartridge suspension is bottomed out. You’ll know that is the case if you see a thin ribbon of vinyl curling up behind the needle while playing a record.
Effective Mass is a shortcut for calculating the tonearm/cartridge system natural frequency. Effective mass is really the inertia of the tonearm expressed in grams. That’s because the tonearm is resting on a fulcrum (pivot). The tonearm and counterweight weigh much more than just a few grams. Additionally, the effective mass can vary depending on the position of the counterweight. So a lower mass cartridge will lower the effective mass of the tonearm since the counter weight will be closer to the pivot. I guess the tonearm manufactures provide us with a nominal value. Don’t forget to add the mass of the cartridge, not just the spring rate to the natural frequency calculation.
The only magic about 10Hz +/-2 Hz is that this is the "quiet" area. Below 8 Hz is the range of record warps and footfalls. Above 16 Hz is getting into the range of the music. The tonearm/cartridge system is still responding at 10Hz. Any energy input will make it respond at that frequency. The key is not to have input at 10Hz. This is so the inherent damping of the stylus suspension and any tonearm pivot bearing friction can be effective at keeping the tonearm/cartridge calm. That small amount of damping keeps things under control. If the tonearm system has a response at say 3-5Hz then the resonance- infinite energy out will overwhelm the damping properties and the tonearm will be greatly excited when rising over a record warp. You could certainly not have a problem with a tonearm system response of 5Hz as long as the records are perfectly flat, hole dead center and the turntable well isolated from footfalls.
I had a cartridge/tonearm system at 16 Hz once. It sounded ok but when I looked closely, the stylus was constanltly moving up and down. I rectified the problem by adding a 4 gram mass to the headshell. That dropped the natural frequency to about 10Hz. Everything was steady then.
The danger is that being outside the quiet zone (10Hz +/-) can result in excessive wear or even damage to your cartridge and records- even if it sounds fine. """
fleib:
"" 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... """
timeltel:
""" From 35/40 years back, lots of informative data:
http://www.bostonaudiosociety.org/pdf/bass/BASS-03-04-7501b.pdf
If you’re interested in credentials, Google Lee Phoenix.
Starting on pg. 9, the practical Peter Prichard; "We really don’t know quite what we’re doing in this industry":
http://www.bostonaudiosociety.org/pdf/bass/BASS-04-08-7605b.pdf
Sources of resonance excitation: "The vibration input to the pickup (both signal and warp) is represented by the constant current generator exciting the circuit. The motion of the stylus assembly is modeled by the current in the CR branch, which shows that the circuit is a high-pass filter, with a resonant peak at the corner frequency."
http://shure.custhelp.com/app/answers/detail/a_id/4072#PhonoArmDamping ""
atmasphere:
""" 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. ""
kirkus:
"" 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. Hi Halcro . . . I think the main conceptual problem here is that the resonant frequency is only one parameter that’s descriptive of the tonearm/cartridge resonance envelope. Keep in mind that the tonearm/cartridge combination is a mechanical high-pass filter, and if there is a resonant peak . . . mathematically it must be a multi-pole system. This means that affecting any element changes not only the resonant frequency, but the width and height of the peak (Q), the transition-band slope, and the amount and periodicity of any pass-band ripple.
The difference between 8 and 12 Hz really is very little in the frequency domain - at 1/3-octave it’s the same as two adjacent bands on a 31-band EQ. And while the tonearm/cartridge system is indeed multi-order, its filter slope isn’t anywhere near steep enough to make much difference in LF response or warp-immunity simply with a change of frequency. Rather, the effect of raising the tonearm mass for a given cartridge usually increases the Q of the filter in addition to lowering the resonant frequency; that is, the resonant peak becomes higher and narrower.
The trade-offs of raising the system Q are the same as for any electrical filter: the "benefits" are that the transition-band (immediately below the resonant frequency) becomes sharper and more selective, and the pass-band (area above the resonant frequency) becomes overall "flatter". The "drawbacks" are that the system becomes dramatically more sensitive to energy imparted at the resonant frequency, the pass-band ripple increases, and increased ringing in the time-domain (impulse) response.
Pragmatically, the main issue will be the extent to which your turntable and environment conduct energy into the tonearm/cartridge system, and at what frequencies. If you’re using non-suspended turntables, on sturdy furniture, in a concrete building, then you’re probably going to have fewer issues with subsonic resonances, but your system will be more prone to acoustic energy conducted back into the tonearm . . . and a heavier, more rigid tonearm definitely helps to control and dampen this.
But for suspended turntables, springy wooden building structures, heavy support furniture sitting on carpet etc. etc. . . . indeterminately increasing the Q of the tonearm/cartridge system is playing with fire. Each of these additional spring/mass systems can potentially combine to create a condition where the system is extremely sensitive to subsonic and low-bass energy. Many view this as a reason to universally condemn suspended turntables . . . but it’s simply a different type of energy to which the system is susceptible, and the trade-off for better immunity to conducted energy within the audio range.
But regardless of the type of turntable design, domicile construction, or support furniture . . . I seem to see fairly regular inquiries on these fora for help to solve the issue of woofer-pumping while playing records. Much of the time the owner has already followed this sort of advice . . .The best match for ANY cartridge ever made….is simply the very best tonearm you can afford…whatever its Effective Mass Given that the prime mechanism determining susceptibility to this phenomenon is the tonearm/cartridge resonance envelope . . . the notion that this issue could be avoided simply by spending more money on a "better" tonearm seems a bit unreasonable to me. It’s simply far more effective to change to a lower-compliance cartridge, thereby creating a system with a lower-Q resonance envelope at a slightly higher frequency. """
If after you read it all those excellent information you still think that because yo just can’t be aware of that issue does not exist and is only a " myth " then you have a big big personal problem.
Btw, @mijostyn is rigth.
Think for a moment how could be that several knowledge gentlemans/audiophiles are wrong and only you are rigth? ? ! ! How????? What did you learn all those years from the day started this thread? ? What? ?
Regards and enjoy the MUSIC NOT DISTORTIONS,
R. |
