Mujitsu and Tairaku's Shakuhachi BBQ

Taldaran · 2009-12-18 22:34:57

In response to a post in the flutemaking section, (the general discussion is about whether the flute material makes any difference to the sound), a question was asked if the body of the shakuhachi actually vibrates, or whether we only perceive vibration through our bare fingertips touching the vibrating column of air.

Take some tape (blue painters tape works great-leaves no residue) and cover all the holes of your shakuhachi and blow RO while lightly cradling the flute in your hands, fingertips no where near the holes, or just letting the flute lay in the webs of your thumbs, fingers not even touching.

Does your shakuhachi actually vibrate?

Last edited by Taldaran (2009-12-18 22:36:08)

edosan · 2009-12-19 00:29:15

It should be stipulated that:

• The fingers holding the flute should not touch the tape where it covers the holes.

If this is the case, I feel no vibration in the bamboo, even blowing a brutal honking Ro-otsu in my bathtub; a very reverberant place.

I have an Ichijo 1.8 that has thick walls, and a 21.5mm bore at the blown end.

Get near or on a taped hole: planty of vibration.

Last edited by edosan (2009-12-19 00:31:51)

Toby · 2009-12-19 02:54:02

Here's an interesting note along those lines. Some researchers did quite sensitive tests of body vibrations in trumpets, using laser interferometry. They did find some vibrations, but they were caused not by the air column, but by the player's vibrating lips pressing against the mouthpiece. Brass bells do vibrate quite significantly for certain structural reasons, but not other parts of the body.

Toby

Taldaran · 2009-12-19 06:54:05

That's amazing that you feel no vibration.

I feel vibration from all of mine. Some much more than others. From the different sized jinashi I have made (1.5 to 3.0) as well as the very dense David Brown 1.8 in tiger myrtle.

As I stated in my post, my finger tips were no where near the taped holes, and I even tried it cradled it in the webs of my thumbs. No contact at all with my fingers

I'm curious to see what other forumites experience when they try it.

Glenn Swann · 2009-12-19 08:29:48

of course, you could also just play normally, without tape, and ask a non-shakuhachi friend who has no particular bias toward the answer see if he/she can feel vibration on the body of the flute. (especially interesting if done in bathtub...).

edosan · 2009-12-19 10:40:12

Taldaran wrote:
That's amazing that you feel no vibration.

The miniscule vibration you may feel is likely from the resonance generated by the air stream right at the blowing edge,
which is nowhere near what you feel when you are actually covering the holes with fingers and playing in the normal manner.

In any case neither 'vibration' is enough to produce any actual sound, and I have to pay very careful attention to feel even that
tiny residual amount coming from the blowing edge.

Regarding any 'vibration detection' bona fides on my part: I played the guitar, a lot, for 25 years, and I built, modified, repaired and
restored acoustic and electric guitars—anything with frets, actually—for 20 years. Felt some sound-generating vibration on a fairly
regular basis...

Glenn Swann · 2009-12-19 11:24:07

having neither tape nor friend handy, i just played RE one handed and checked with the free hand-
very clear feeling of vibration between blowing edge and #4 hole, near end, and on underside. not as strong as on fingerholes, but close. distinctly bigger vibrations on self-made bare-bamboo chinese madake 2.4 than ji-ari 1.8, but consistently there.
at any rate, if the column of air is vibrating and creating sound, how could that NOT resonate into the walls? couldn't it be A and B, not a distinct either/or?

Toby · 2009-12-31 08:22:12

Yes, there is a bit of vibration, but it is really tiny. Compare this to the vibration that you feel when blowing over the top of a PET bottle. That latter is the kind of vibration that was excited in the tests of thin, elliptical metal tubes, and which did not change the spectrum of the radiated sound as mentioned in the tests by the French researchers. Backus measured the vibration of clarinet walls at one micrometer, giving a sound radiated by the walls at a level 10000x below that of the air column. This is not perceptible in the very best of cases.

Toby

Mujitsu and Tairaku's Shakuhachi BBQ

#1 2009-12-18 22:34:57

An interesting experiment for you to try!

#2 2009-12-19 00:29:15

Re: An interesting experiment for you to try!

#3 2009-12-19 02:54:02

Re: An interesting experiment for you to try!

#4 2009-12-19 06:54:05

Re: An interesting experiment for you to try!

#5 2009-12-19 08:29:48

Re: An interesting experiment for you to try!

#6 2009-12-19 10:40:12

Re: An interesting experiment for you to try!

Taldaran wrote:

#7 2009-12-19 11:24:07

Re: An interesting experiment for you to try!

#8 2009-12-31 08:22:12

Re: An interesting experiment for you to try!

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