Theories are great.....
I know of tonearm designers who can convince you that Uni-pivots are theoretically superior to gimballed tonearms....
But hey....they can both work fine.
I know some turntable designers who can convince you that belt-drive high mass turntables are theoretically superior to direct-drive and idlers......
But hey...they can all work just fine.
I know some cartridge designers who can convince you that MC is theoretically superior to MM....
But hey...they can both work fine.
Yep....I just love theories 😎
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As Fleib writes.....which tables have you measured?
This would seem like excellent scientific data and would resolve this argument once and for all.
Could you please list all the tables, arms and cartridges and what they were sitting on Atmasphere? Photos would be good here.
And can you upload the frequency print-outs for each one?
Lastly....how do you discern the different contributions of arm, cartridge, table, drive system, arm support and isolation provisions in the data?
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I'm not sure that the cutting process tests can be transposed to the playback field.
After all.....you use direct drive and linear-tracking arm in the cutting process but you prefer to use belt-drive and pivoted arm for your playback.
Seems counter-intuitive to me......
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Sorry Atmasphere,
I missed the point about the Triplanar and the Technics 1200.
I don't see how attaching the tonearm to the plinth can affect the 'noise'?
Surely the 'noise' is a function of the isolation, the tonearm pod mass, fixity, density and material selection as well as the tonearm rigidity.
There are some who are not fans of the Triplanar with regards to its performance in these areas.....but reaching conclusions about 'noise' when using different tonearms does not seem paticularly scientific nor conclusive.
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I've explained it twice in this thread already. What part of my prior explanations are unclear? The 'noise' is actually introduced when the arm and platter bearings are able to move in different planes and rates. This is what happens when a separate arm pillar is employed.  But what you haven't addressed at all, is a description and photo of the separate arm pillar you employed. You apparently believe that all separate arm pillars are the same regardless of size, weight, construction, density and supports. The only reason an arm pillar can move in different planes and rates is if it is inadequate. And failing your willingness to describe the arm pillar you employed in your tests.....It's apparent it was 'inadequate' for the purpose. |
Pani,
Perhaps you should take note of an audio designer who actually designs and sells tonearms and turntables.....
Someone like Frank Kuzma who makes the 4 Point and Airline tonearms and whose top-of-the-line turntable uses a separate armpod.
I’d be hesitant in calling Frank a fool....
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We found that by installing a brace between the the mount for the platter bearings and the base of the arm that there was further benefit. Now this is illuminating and perhaps needs an explanation from you about what you believe could possibly be 'moving' in your 3/4" solid aluminium plinth? In other words....what did the "brace" fix that was a weakness in the solid aluminium? This is a structural and not a mechanical engineering question and requires a structural engineering answer.... |
Since the cartridge is essentially the interface, its stylus must make up the difference between the motion of the pillar and that of the surface of the platter. "The motion of the pillar"...... There you go again. Nobody is claiming that a "moving pillar" is good but you have simply assumed that ALL pillars move because you yourself have used a 'moving' pillar (which you still refuse to disclose despite my three attempts to wrest it out of you). A properly designed armpod sitting on a well isolated rigid base/shelf/plinth will NOT move despite your ill-informed protestations. If I had an oscilloscope (and knew how to use one)....I would measure the three arms fixed to my Raven plinth and the three mounted on the armpods. It would be interesting to see your arguments if these measurements contradicted your 'theory'.... |
I propose that Ralph be enrolled on the calendar of saints. His restraint is supernatural - a miracle thrice renewed!! Yes indeed...because Ralph can, with the same conviction that he demonstrates his turntable theories....can postulate that OTL valve amplification is the only true path to audio Nirvana....despite the observable distortions. And pray tell us terry9......do you run your amplification using OTL devices? |
The platter and arm must move in the same plane and frequency, should there be any movement at all. Likely this would be airborne induced. That is the most unlikely scenario. Airborne induced vibrations in the platter/tonearm/cartridge synergy are virtually non-existent as the turntable world would have ceased to exist if this were not so. Err...anyone ever go to clubs with DJs playing vinyl at 105dB levels? Structure-borne vibrations are by far the greatest source of distortions in the vinyl playback system. That is why the makers of anti-vibration stands (both active and passive) are successful. These stands have zero effect on air-borne vibrations. Because the induced ’feedback’ is amplified when the volume is increased....most lay people conclude that the ’volume’ has caused the feedback when it is in fact the ’volume’ that simply amplifies the structure-borne feedback which already exists within the particular system. |
If you think air borne vibration is not a problem you are up against the issue of the real world. No matter how dead you think a thing might be, it will always have some motion, some vibration. This is an uneducated assumption. Most people follow this belief but if you had studied acoustics and the science of materials, you would know that materials react to air-borne sound by a mixture of:- - Reflection
- Absorption (as heat)
- Transmission (passing directly through)
It is only when sound pressure of a sufficient volume (and that's important) at a material's Resonant Frequency occurs...that the material can 'vibrate'. You do know of course that the Resonant Frequency of most tonearm/cartridge combinations is 6-15 Hz and this is well below the frequency reproduction ability of all commercial loudspeakers and almost all subwoofers as well? It in only in this frequency band that any vibration of the tonearm/cartridge can be observed. There is no 'alternate' vibration phenomena unless you can direct us to the relevant scientific papers? For the heavier plinth and platter components of the turntable system, a resonant frequency in the order of 2-6 Hz may apply. You seem to use the term 'vibrate' as if somehow it were a different genus to 'resonate'? Not only is your understanding of air-borne sound transmission and vibration factually inaccurate, it is logically impossible. Were it true....every increase in the volume dial would degrade the sound. Let me repeat that.... If air-borne sound pressure is a problem in the turntable playback system, then every increase in volume would of necessity degrade the sound. Now there are many out there who will exclaim that this is indeed the case with their systems but as I explained previously...they are hearing the effects of structure-borne feedback...AMPLIFIED. There are tens of millions of turntable systems where turning up the volume is heard to IMPROVE the sound quality noticeably. |
Now here is a serious new turntable... http://www.analogplanet.com/content/dietrich-brakemeirs-apolyt-turntable-aims-be-worlds-finest-and-m...Dietrich knows a thing or two about turntables, arms and cartridges. And gosh....what are those? They look like tonearm pods and did he say in the interview that the tops of the pods are totally isolated from the plinth and structure? Just like the famed Continuum Caliburn turntable with its arm support divorced from the platter bearing support via suspension cables and bottom magnets. They are obviously all mad....😱 |
Accoustical excitation at frequencies other than the materials resonant frequency will result in NO vibration in the material, regardless of the energy level of this excitation? "Acoustical excitation"....? I'm unfamiliar with that term in the scientific sense. Can you please explain its meaning? As I stated, acoustic theory as I studied it, related to materials science and air-borne sound transmission accepts that there are only three  physical observable factors. - Reflection
- Absorption
- Transmission
Apart from the sub-atomic level at which some say everything is vibrating.....a material cannot vibrate unless its resonant frequency/frequencies are excited. And even then it may not be noticeable or destructive unless the amplitude (volume) is sufficient. That is why the famed 'myth' of the glass of wine/water being made to shatter when a singer hits the resonant frequency has only been scientifically observed when the volume was increased to 115dB if I recall correctly? |
Under circumstances where we fire sound at a material.....
Are you saying that the material will ONLY vibrate at its resonance frequency, assuming that this frequency is present in the sound?
If any other sound frequency is used there will be NO vibration in the material? This with any energy level in the sound? Correct....unless you define the transmission of sound through the material as caused by vibrating molecules. During Sound Transmission Testing of walls for apartment buildings, we test at all frequencies from 20Hz to 20,000Hz at SPL up to 100dB. The resonant frequencies of all masonry and combination plasterboard/stud/insulation fall well below the audio band and no vibrations are detected. Glass walls of certain sizes and thicknesses can be induced to vibrate at their resonant frequencies (20-30Hz) at high SPLs. |
Haha...
Yes Chris, I remember that from years ago.
Everyone can try that test.
Just place your mouth close to the cartridge while playing a record and yell at the cartridge/tonearm.
If airborne sound waves are ever going to be heard it should be under this test.....
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Halcro
Can you please explain how we can hear and clearly understand someone talking on the other side of a closed window?
Horrid music, which sounds like a broken washing machine, coming thru the walls of my sons bedroom? Err...perhaps you should read my post again? Or does "Transmission" not mean the same thing in New Zealand? |
If air-borne sound pressure is a problem in the turntable playback system, then every increase in volume would of necessity degrade the sound.
Correct. The defence rests....😎 |
The airborne stuff, by comparison, is relatively inconsequential IMHO. Correct Geoff.. It is unimportant whether the vibration is occurring at a resonant frequency or not- its vibration either way- just more of it if its at a resonant frequency. It really doesn’t matter much to me if people wish to create a fantasy parallel universe in which the laws of physics, evidence and data don’t exist. Audiophiles are renowned for indulging in such shenanigans. But when some, proffer nonsense as ’fact’ without a skerick of scientific evidence and insist that we swallow it as gospel.....it begins to matter. |
We do agree on this point. We both recognize that air borne vibration can be a problem. No we don't.... I pointed out that:- If air-borne sound pressure is a problem in the turntable playback system, then every increase in volume would of necessity degrade the sound. You said that was correct.... You then contradict yourself by writing:- The result is it is quite impervious to the volume level in the room; even at 110 db the sound is still very relaxed. The two statements are logically incompatible. No amount of plinth dampening will avoid the effects of air-borne sound waves on the vinyl, cartridge, stylus and tonearm. The fact that you and many others can listen to vinyl played back at excessive volumes demonstrates conclusively that air-borne sound waves have no effects on the turntable system. |
