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  2. True for me as well Jim - however some cognitive features might be affected I guess... Best wishes - 🐺
  3. Wolf Molkentin

    FREE REED PHYSICS - 1

    Hi Tom, thank you for straightening that out once again. I would have expected the very highest notes being referred to here, possibly an error while typing? Best wishes - 🐺
  4. Today
  5. Wolf Molkentin

    maintenance for brass reeds

    throughout the same colour and thus not that significant, here‘s a shot of some Wheatstone „brass“ reeds, responsive and rather loud, but nevertheless with the clear bell-like tone (which I‘d hesitate to describe as just being „mellow“) in the higher range I am familiar with from my (very quiet) George Case... possibly true brass here? best wishes - 🐺
  6. ttonon

    maintenance for brass reeds

    Hi David, thanks for the info. I can see the color best I think in the second photo, and I agree that the second and fourth tongues from the left are probably not brass. The third is surely brass. Interesting. Tom
  7. ttonon

    FREE REED PHYSICS - 1

    Johann, you are spreading erroneous ideas. I believe most of us are aware that the sound produced by the Western free reed is not because the reed is coupled to an air column. This is true for the Asian free reed, an entirely different phenomenon. The Western free reed used in concertinas, accordions, harmonicas, bandoneons, etc, are only weakly coupled to the cavity. There are exceptional instances for the highest pitched reeds, and when that happens, the reed has trouble speaking. In other words, coupling to the cavity is detrimental to the tongue vibration. However, the cavity does affect the timbre of the musical tone. I believe that influence can be categorized as reverberation. Another example of reverberation is to put your ear next to a wall in a noisy room, or to play your accordion very near to the corner of a room. Near a wall, the acoustic pressure amplitude is twice that of the wave traveling toward the wall. This must be the case because the reflecting wave must interact with the oncoming wave so that the particle velocity at the wall becomes zero. The wall is a boundary condition. It stops the vibratory air motion that's part of the sound wave, because the air can't go through the wall. Similarly with the cavity. Sound from the reed strikes the walls of the cavity and rebounds, producing a doubled acoustic pressure (oscillatory) amplitude. The dimensions of the cavity are small compared to the wavelengths of the vast majority of the musical frequencies - all except for the very lowest notes. The region of this increased "rebounding" pressure extends throughout the cavity and a little beyond. I know you read my paper describing all this, though others may not be aware of it at: http://www.concertina.org/archive/pica/pica_2005_2/pdf/reed_cavity_design_resonance.pdf Best regards, Tom
  8. ttonon

    FREE REED PHYSICS - 3

    Hi Johann, I believe you're under the mistaken impression that I experimentally measured different reeds that I made. This is not the case. I'm presenting theoretical results from a physical model and mathematical solution. The plots I present are the results of calculations from this analysis. If it helps, I present the geometric parameters I used in these calculations, below' Width of tongue = 3/16 inch Thickness of tongue = 0.010 inch Thickness of plate (shoe) = 0.125 inches Length of steel tongue = 1.4 inches Length of brass tongue (same pitch as steel) = 1.19 inches Length of titanium tongue (same pitch as steel) = 2.77 inches Length of carbon tongue (same pitch as steel) = 2.75 inches Best regards, Tom
  9. I don't just see reeds, I immediately thought specifically of 1950s Wheatstone "screwed down" reeds as in the picture below:
  10. Greetings again to this series showing results of free reed response from an analytical treatment of free reed physics based on a fluid mechanical model. Titanium interests me because it has close to the same ratio of Young’s modulus to density as does steel, but the Young’s modulus and density are each roughly half that of steel. It thus can shed light on the question whether the ratio of these two material properties is all one needs to make a good educated guess about what a given material will sound like when it’s used as tongue material for a free reed. Others have wondered about using titanium as tongue material, and hopefully, the information presented here can assist in evaluating possible rewards from its use. On the acoustic results, to sum up, no, in the case of titanium, there are important influences on harmonic amplitude caused by individual contributions from modulus and density, and the ratio itself cannot describe all key effects. The docx file linked to below presents instructive plots comparing the harmonic amplitudes of titanium and steel. The results are most interesting in that, for low bellows pressure, titanium harmonic amplitudes are in general significantly less than those of steel, suggesting, if these amplitudes translate to the acoustic sound we hear, that titanium should have a mellower or less bright sound than steel. The prediction is that the sound should be even mellower than that of brass, in comparison to steel. However, as bellows pressure increases, this relationship changes, and the titanium harmonic amplitudes become comparable to those of steel, leading to the conclusion that titanium might sound similar to steel at these amplitudes. At the highest bellows pressure, there are a significant number of titanium amplitudes that surpass those of steel. This is the first example I’ve seen where the character of the sound has such a dynamic nature, with markedly different timbre occurring at high bellows pressure. In previous postings in this series, we’ve seen that brass should sound mellower than steel, with the effect increasing with increasing bellows pressure. Here we see similar behavior, only it’s the titanium that becomes bright, starting from a mellow beginning, in comparison to steel. If this is all true (that these harmonic amplitudes translate to the musical tone), I think it would be advantageous for the timbre of the sound to change so much with increasing volume. Such is the case with many other instruments. In general, any aspect of the musical tone that adds complexity to the sound can often be used as an expressive vehicle. Also, the direction of timbre movement with volume - from mellow to bright - is particularly advantageous and natural. Take for example the tenor sax. Low volume notes can be very mellow, with tender association, whereas loud sounds can be plaintive and attention-getting. As with the other documents in this series, the titanium results can be found at: https://app.box.com/folder/79305691686 Best regards, Tom
  11. Yesterday
  12. Jake Middleton-Metcalfe

    FREE REED PHYSICS - 3

    I think Dana Johnson mentioned making an experimental carbon fiber reed once, maybe he will chime in with what he found out by doing it. I have used carbon fiber to make other things in the past but never reeds.
  13. I see tanker ships, but they're sharing perceptual space with English-engineered concertina reeds. 8^) As for "been playing concertina too long"... not possible in my world.
  14. guess I have to plead guilty too, I hardly see anything else but reeeds 🙄
  15. Łukasz Martynowicz

    FREE REED PHYSICS - 1

    Thank you for this link, I saw this discussion a while earlier than this current thread, before I got steadily back on track of who posts what here nowadays, so I missed that it was your post. It is indeed exactly about what I was asking about and is perfectly in line with my position on the topic from years back. Glad to see that someone worked on theory behind it. The reason why I asked about this is simple - this transient period is far more important part of "why and how free reeds generate sound" question than the focus of this thread and there was a long history of discussions about how free reeds work here on this forum completely ignorant about this transient, usually leading to completely false conclusions. Now I'm perfectly satisfied with the scope of your answers and understand, that you have divided your works into separate chunks and hopefully at the end of your journey you will indeed come up with what I would call a complete free reed theory. As to DIX reeds, I must apoogize, after 5 years I misremembered my experiments from back then - I have mixed up effects of various shoe materials vs geometry and scaling. I dug up those a moment ago and Johann is right - they have overall different geometry and scaling than their typical accordion counterparts. If you still want to know more about them here's a link to harmonikas.cz with description and schematics https://www.harmonikas.cz/en/dix-1#obsah
  16. ...when you see a political cartoon in the morning paper and wonder "why are there reeds in the matchbox?"
  17. Wolf Molkentin

    Styles Of Music For Concertina?

    fascinating stuff - and besides, I‘d love to have a concertina with the highest („dog whistle“) notes set for that kind of playing..., would allow for lots of other things too...
  18. Dee746

    Styles Of Music For Concertina?

    You probably already know about this, but I also found a a copy of the Decca 78 recording from 1936 by Raphael of "Doena" at archives.org. https://archive.org/details/78_doena_raphael-worlds-greatest-artist-of-the-concertina-leo-lefleur_gbia0050199b
  19. I'd like to replace the straps on my Lachenal anglo 20B and am curious what the original strap pattern and colour would've been when new?
  20. Johann

    FREE REED PHYSICS - 3

    Hi Tom, the complete test condition described. How did yo make the reed? Dimensions off the reeds. that were compared. Johann
  21. Johann

    FREE REED PHYSICS - 3

    I personal think it is a waste of time to to make reeds with Carbon (CFK) it is impossible to bend a carbon reed to set it correctly. This is important it is not enough to be able to sand the reed. And i personally would not like to do the job with this carbon dust. I did use carbon sheet material for some time not for rees but oherer parts.
  22. ttonon

    FREE REED PHYSICS - 3

    Hi Johann, what's the confusion? What would you like to know? Tom
  23. Johann

    FREE REED PHYSICS - 3

    Tom this is a bit to less info how you set up the test condition.
  24. Greetings. In my first post in this series, I forgot to mention the fact that in the comparison plots between brass and steel, the tongue lengths are adjusted so that the brass and steel vibration has the same frequency. In my second post comparing carbon and steel, the two tongues have equal length, and in this post, I give results for carbon and steel tongue lengths having the same frequency. The amazing thing in this comparison is that the carbon normalized harmonics are enormously larger than those for steel. I honestly didn’t expect such dramatic results. And they show large difference even for the smallest bellows pressure. For me, this increases my curiosity over what a carbon fiber reed tongue would sound like. Notice also the dominance of the 5th harmonic over the 4th, for all but the lowest bellows pressures. I've noticed before the contentious battle between these two harmonics, and here it's well displayed. The docx file for this case is the same: https://app.box.com/folder/79305691686 Best regards, Tom
  25. ttonon

    FREE REED PHYSICS - 1

    Hi Lukasz, please read the following post so that you can get up to date on these details: Not quite. The analysis behind these posts contains a physical model for the forces acting on the tongue, a mathematical representation of that model, and a solution that is periodic. The method of solution admits only periodic solutions. A solution that starts from rest is not periodic. This is a common practice in the theory of vibrations and in applied mathematics. Right now, I'm not interested in a transient solution starting from zero initial conditions, which I believe would be more complex than the one I've done, and may not even be amenable to analytic techniques, as opposed to the numerical techniques now in vogue, of course because of necessity and the availability of fast computers. No it shouldn't, because this is an analysis of solely the tongue vibration. Hopefully I can use this model and apply it to a coupled chamber, but that's something for the future. Can you please explain what DIX reeds are, and maybe give us a picture? Is it similar to the HOPV (High Output Piccolo Voice) technology? Best regards, Tom
  26. Johann

    FREE REED PHYSICS - 1

    We never cover all aspects, main difference of DIX is the fact that the reed gup or precision is less narrow. A tighter fit of tongues to frame results always in more higher overtones. I only can speak off acordeon DIX reeds the have in average shorter tongues on the comparable tone of modern reeds. Less stiff, thinner frames and geometrie is also different. All of this different dimensions have effects. Some or all have effects on overtone including modes, but the main difference is the reduced precision. Still if we copy old DIX as good as possible the never sound exactly the same. It is really difficult to copy old reedsets. If we only would need to know the type of steel and the dimensions then it should be possible but it isn't possible to copy this way. Even if we also copy the shaping the sound not quite equal. Most modern copies are to tight in fitting, so the sound brighter. But there are other factors what makes it difficult to copy DIX or other reedsets. Tom is right that modes do contribute to timbre but we are far away of calculating reed sound by setting up reed material and dimensions and stiffness. I agree that reeds made of different material do sound different because we have to use different length for the same pitch what results in a different mix of modes and overtones. I also disagree that carbon would be a good material for reed tongues. Carbon conbund is difficult to machine not easy. We also don't know how carbon compound behaves over longtime.
  27. Łukasz Martynowicz

    FREE REED PHYSICS - 1

    I know that resonance and coupling matter in case of chamber layout - I was merely stating the fact, that Tom's work does not include (or it hasn't been clearly stated, that it does) chamber geometry and tongue geometry (as you more broadly point out). And with DIX reeds I don't think it's related to resonance, but to minutia of airflow around the tongue in the initial stage of agitation, restricting development of higher modes of vibration, and I brought this up as an extreme case of reed/shoe geometry influence on the tone - DIX reeds are just a tiny variation on otherwise classic accordion reed design - trapezoid tongue in non-tapered opening.
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