Mujitsu and Tairaku's Shakuhachi BBQ

Ken made a nice one out of Tonkin bamboo.

Tairaku 大楽 wrote:

Ken made a nice one out of Tonkin bamboo.

I had a 2.3 cast bore Tonkin Taimu from Ken. It sounded great.

But, it sounded a lot different than the pure jinashi 2.3 Japanese Madake Taimu I had from him (A very thick piece of bamboo from one of Kodama's harvests). Both were A-flat flutes. Big difference in sound. Tonkin flute had walls 3 to 4mm thick. Japanese Madake flute had walls 8 to 10mm thick, not accounting for the root end which had 20mm walls.

Couldn't have been more different in sound except if one of the flutes were made of thin galvanized steel and the other one made from thick earthenware pipe.

Last edited by Chris Moran (2010-06-01 21:05:08)

Toby wrote:

The thickness of the walls is not significant; the dimensions of the bore and smoothness are the main determinants of the sound.

I suggest we test this statement of yours, Toby.

We (collectively speaking) can stuff you into a 1/2" thick walled culvert and leave you in an abandoned field overnight.

Then the next night leave you stuffed in a 3" thick walled culvert in the same field.

We can stand at the edge of the field and measure the decibels of your screams.

Fair 'nuff?

Chris Moran wrote:

We can stand at the edge of the field and measure the decibels of your screams.

Fair 'nuff?

You sure you've been keepin' up on your meds, Chris?

For me any audible difference in a flute is significant, even if it amounts to only 5%. Talking numbers, maybe not, but it can be the difference between choosing one flute over another. Bamboo itself may not have a sound, but it does react to sound as do most materials. The thinner a material, the more it is affected by sound and or vibration. Does not the sound in a resonating tube react to the vibration that is created within the material of the tube itself, a sort of anti or complementing resonance so to speak? Would not a thinner wall be more subject to this reaction over a thicker one? It may be subtle but it is there, perhaps resulting in more, or less, of an harmonic or overtone? For me it seems to be more audible in Otsu vs. Kan. I can both hear and feel this difference. Of course I can also hear a sonic welder which I am not supposed to be able to do. Having made several thousand flutes of various sorts in different woods with varying densities, wall thicknesses and hole placements, I do not just suspect, I am convinced. Granted some of the sound difference is due to the chimney height at the hole as John mentioned, there is still a difference and it is very much related to wall thickness as well as density of the material being used.

Colyn Petersen wrote:

For me any audible difference in a flute is significant, even if it amounts to only 5%. Talking numbers, maybe not, but it can be the difference between choosing one flute over another. Bamboo itself may not have a sound, but it does react to sound as do most materials. The thinner a material, the more it is affected by sound and or vibration. Does not the sound in a resonating tube react to the vibration that is created within the material of the tube itself, a sort of anti or complementing resonance so to speak? Would not a thinner wall be more subject to this reaction over a thicker one? It may be subtle but it is there, perhaps resulting in more, or less, of an harmonic or overtone? For me it seems to be more audible in Otsu vs. Kan. I can both hear and feel this difference. Of course I can also hear a sonic welder which I am not supposed to be able to do. Having made several thousand flutes of various sorts in different woods with varying densities, wall thicknesses and hole placements, I do not just suspect, I am convinced. Granted some of the sound difference is due to the chimney height at the hole as John mentioned, there is still a difference and it is very much related to wall thickness as well as density of the material being used.

There is no audible difference due to wall thickness, since even the thinnest bamboo only vibrates about a micrometer due to the pressure of the air column. This translates into an addition to the radiated sound of about -40 dB, or .01% of the sound produced by the air column. That is more than totally inaudible. A recent experiment used a metal tube about 1/40 the thickness of a metal flute wall--15 micrometers--and the researchers could not even get it to vibrate significantly at that thickness. In fact to get it to enter breathing mode, in which the walls couple with a playing frequency and sustain the resonance in a way that the vibrations are large and continuing, they actually had to make the tube elliptical in shape. Even then, using an oval tube fifteen thousandths of a millimeter thick, they found that the vibrations had no appreciable effect on the radiated sound:

http://perso.univ-lemans.fr/%7Ejgilbert … ll_vib.pdf

This is totally in agreement with every credible experiment on the subject that has been performed in the past century or so. There is not one which leads anyone to believe that wall materials make any difference at all.

If you claim a physical effect, there must be a physical mechanism to cause it. There is no physical mechanism to cause any change in sound due to the miniscule vibrations of the wall. Further, you could only reliably claim that you find a difference if you are able to completely control all the other variables which are known to cause a difference in sound, the main ones being bore geometry and smoothness. Can you tell me that all your bores are identical to within, let us say, 1/100 of a millimeter throughout? Because that is the level at which significant changes in sound occur. I can supply you with all the math and formulae that explain this, if you wish. Likewise, since 99% of the input energy of a wind instrument is lost at the walls, smoothness plays a very important factor. Were all your walls of identical smoothness?

Finally, there is the wild card: human perception based on expectation. It has been reliably shown that expert flute players who were convinced that they could consistently tell the difference between flutes in different materials, to the point where they could describe the differences, found themselves absolutely unable to tell the difference when visual, tactile and weight clues were removed. In a separate experiment, ten top professional trombonists testing bells (again, which they felt sure they could identify by sound) were unable in double-blind testing to tell them apart, even though those bells actually did differ in sound radiation by 2 dB at the position of the player's ears. This is enough to be perceptible, but not one of those trombonists could tell those bells apart.

This subject is endlessly debated, and everybody is convinced that wall thickness and/or density makes a difference, but this is all untrue: any sound differences are due to either difference in bore geometry, smoothness, or player belief leading to expectation leading to differences in performance leading to perception reinforcing belief...

FWIW,
Toby

Last edited by Toby (2010-06-04 12:57:56)

One simple way of getting a 'real' world feel for at least part what Toby's talking about here is to take a bunch of your shakuhachi and tape all the holes up, each with a couple of layers of masking or blue tape, then play a hearty Ro on each of them, keeping your fingers OFF the taped holes (for now).

You will feel virtually NO vibration in your fingertips when you do this, on any of your flutes. I've tried it; I didn't. Then play a Ro with your fingers over the taped holes.

You'll feel some slight vibration at your fingertips (as you do when normally playing the flute), and that is caused by the resonating air column in
the bore and hole chimney pressing against the tape.

Any vibration you may feel on the outside of the flute when the holes are taped is MINISCULE in terms of creating any audible sound itself, or affecting the sound created by the resonating bore. You don't even feel all that much at the taped holes.

edosan wrote:

Any vibration you may feel on the outside of the flute when the holes are taped is MINISCULE in terms of creating any audible sound itself, or affecting the sound created by the resonating bore.

My offer is open to you, as well as Toby, for being a principle test subject.

For those who are still open to learning on this subject, I think it would be instructive to read John Coltman's classic double-blind experiment on the subject of the effect (subjective and objective) of wall materials. Go to:

https://ccrma.stanford.edu/marl/Coltman/Papers.html

1.06 Effect of material on flute tone quality.

Afterward read:

1.08 Material used in flute construction

This contains his response to his own Chris Moran-type interlocutor.

Amazing how this touches nerves, isn't it?

Bert Pimentel has summed up the subject very well here. No math needed...

http://www.bretpimentel.com/does-materi … -to-agree/

Finally:

http://findarticles.com/p/articles/mi_q … n21295745/

Instead of trying to kill the messenger bringing bad news, doubters are urged to read these papers and engage in constructive debate on the points contained therein.

Toby

"A fable, the more remarkable since it is always discussed, is that the material of which a wind instrument is made has an influence on the sound of the same; that this is not so rests on incontrovertible acoustical laws, about which there should be absolutely no more discussion."

--Arthur H. Benade, 1981

(Benade received the Acoustical Society of America's Silver Medal (for musical acoustics) and its Gold Medal (for overall excellence in acoustics). He served as the Acoustical Society's Vice President and also chaired its Technical Committee on Musical Acoustics. He was a President of the Catgut Acoustical Society; a member of the Technical Advisory Committee of Pierre Boulez's Institut de Recherche et Coordination Acoustique/Musique in Paris; an advisor to the Dayton C. Miller Collection of Flutes at the Library of Congress; and an Honorary Member of the National Association of Band Instrument Repair Technicians. His many talks before scientific, educational, and musical organizations in the USA and Europe included a series in Stockholm sponsored by the Swedish Royal Academy of Music and the Plenary Session Lecture in Musical Acoustics at the 9th International Congress on Acoustics in Madrid.)

Jon Kypros wrote:

I was thinking why not make a single PVC flute and then double or triple it up, that is if you can get several pieces of PVC to fit into one another like a telescope.

Good idea. But that would only really prove about PVC. Bamboo might be different. I have a flute by Koga which has clearly been sanded down so the walls are thinner than normal. It is a good sounding flute but I would characterize the sound as thin. I don't know of course what it sounded like before they did that.

Chris Moran wrote:

edosan wrote:

There is no doable 'test', because in order to do one, you'd need two shakuhachi with identical bores, but different wall thicknesses (and you'd need to assume identical bamboo density as well).

Got any of those layin' around for the test, X?

The test I was referring to was the one stuffing either you or Toby into different thicknesses of drain pipe. I think that's doable.

Absolutely doable, and the method of choice for so many down through the centuries for finding truth.

Toby

"Eppur si muove..."
      --Galileo Galilei

Last edited by Toby (2010-06-05 01:24:05)

edosan wrote:

There is no doable 'test', because in order to do one, you'd need two shakuhachi with identical bores, but different wall thicknesses (and you'd need to assume identical bamboo density as well).

All kidding aside (which is hard to do when your opponent is bare-breasted and wearing lederhosen):

You seem to differ from Toby when it comes to density? That's significant. Toby's argument doesn't address density, from my reading, only "smoothness." If you argue that two pieces of bamboo have to be the same density you're making the argument for the other side of the debate.