Mujitsu and Tairaku's Shakuhachi BBQ

Karmajampa wrote:

In Karl Abbotts book "Blowing Zen" he refers to the '7 rooms' within the Shakuhachi bore.

Kel,

Just sent you Carl's email address in case you'd like to pick his brain.

Just guessing out loud here... but I wonder if the seven room strategy was developed as
a bore road map by trial and error before Benede's Perturbation W-Curves research?

I used the seven room strategy before being aware of Benede with mixed results. (Probably
due to my own incompetence) Looking at the seven room strategy tips now, some come to the
same conclusions as those found in W-Curve theory. With others I can't find the connection.

Karmajampa wrote:

Thanks guys, I have the Bennaid "Evolution of Wind Instruments", quite a headfull, plod, plod.
However, I do have a mental picture of pressure and flow nodes etc, and the effect of narrowing and widening the bore.

A question arises, What is the influence of the remaining section of the bore below the open hole ? Is the standing wave only active between the blow edge opening and the open note hole, or is something happening in the rest of the bore that influences the sound ?
I would assume something is happening, I think there is an influence on tim bre, for example, I have a Xiao, (don't play if very well) 965mm with a removable lower section, with that section off the upper section which has the finger holes, still plays, the lower section measures 408mm and has three pairs of 'tone' holes.
I think it will give some back pressure and therefore influence the harmonics as the volume of the fundamental is increased.

K.

Good question! It is rather complicated, but I'll try to summarize.

Think of the air in the hole as a little weight, which has to be moved by the wave. This little weight is moved fairly easily by lower frequency waves, but the higher the frequency, the more resistance that air gives, until at a certain frequency, called the cutoff frequency, the wave can't move the air at all, and just continues down the bore as if there was no hole there at all.

In the middle, higher frequencies extend somewhat past the first open hole, making the standing wave increasingly longer (as the pitch rises) than the physical distance to the hole.

Any note is composed of different frequency wavelengths: the fundamental is basically the length of the tube, the first partial 1/2 the length, the second 1/3, etc. Each of these actually terminate at different points in the bore. So, for instance, while the fundamental (one wavelength) reflects near the open hole, the octave (two wavelengths) ends a bit farther before being reflected. Above the cutoff frequency higher partials don't reflect back at all--they just go straight out the end of the flute. A thinner bore, for instance, has more high components because more of the high frequency partials are reflected back from the end to add energy at their frequencies to the "regime of oscillation" of the standing wave.

So when toneholes are small (compared to the bore) and the impedance high, the higher frequency components of the sound are radiated into the air from the lower open tonehole lattice instead of being reflected to reinforce the standing wave. This means that the smaller the toneholes the duller the sound will be, since it will have less high-frequency components. But it also means that cross-fingerings and shadings of toneholes below the first open one have more effect than if the holes were large.

There is a very good paper available on all this, which is, though, a bit tough going at first. If anyone is interested, go to:

http://www.phys.unsw.edu.au/jw/saxacoustics.html

Scroll down to the bottom of the section called "Crossfingering" and click on the link "download a scientific paper".

Here is the intro from that:

"I. INTRODUCTION
The tone holes of woodwind instruments are used to
reduce the effective length of their bore. An open tone hole
provides a low inertance shunt between the bore and the
external radiation field so, at sufficiently low frequency, the
acoustic pressure inside the bore near an open tone hole is
small. Consequently the bore behaves, at low frequencies,
like a simple tube whose end is a little way beyond the first
open tone hole. This extra length or end correction is frequency
dependent: at higher frequencies, the impedance of
the inertive shunt is larger, and so the standing wave in the
bore propagates past the first open tone hole with an increasing
relative amplitude as the frequency increases. As the relative
amplitude of the standing wave propagating beyond the
first open tone hole increases, the length of the end correction
increasingly depends upon whether tone holes further
down the bore are open or closed..."

I think that the extra holes on Chinese flutes have no purpose other than allowing the bamboo to be longer for aesthetic purposes. Acoustically the flute is different from other woodwind instruments and does not need a bell (or lattice of open toneholes) at the end to match the timbre of the lower notes to that of the upper. So a simple cut off end is as good as an extension with extra holes.

Toby

Last edited by Toby (2009-11-18 05:31:45)

Karmajampa wrote:

In Karl Abbotts book "Blowing Zen" he refers to the '7 rooms' within the Shakuhachi bore. He also mentions how to diagnose a few audio problems by opening or narrowing particular rooms.
There is not a lot of explanation as to how and why these rooms have specific influence, as I recall, and can no longer read the text myself, but would appreciate an 'in depth' discussion on this topic by all and sundry, particularly anyone who has used this concept effectively,
I would like to get to know it better. Perhaps we could meet in the bar, Scotch is on me.

K.

Hi Kel, I'm a 106th and Broadway. There's Jazz club, SMOKE, on the corner...

I first tried Carl's 7 Rooms Theory around 1996. Man it was a mind*&$#. I put it away for a few years and when I started taking shakuhachi lessons, I came back to. It made more sense then, but it was still a little abstract as you are discovering. Then, I went to Japan and really got into Spot Tuning. It should be mentioned that this theory and approach is for a modern fabricated bore 1.8 instrument.

Because of your posting, I went to look at the Carl's book again. I saw that he had a remedy for a bubbly Otsu no Ro and I happened have a flute with that issue so I tried his recommendation to work on Room #3. I dropped in a tiny tuning bead and at the bottom of Room #3 the Ro became much more unstable. But, as I pulled the bead up near the top of the 5cm room Ro improved greatly.  I wasn't fully satisfied with the balance and knowing that there is more than one way to skin a cat, I decided to poke around. Next, I looked for the second biggest issue with the flute, which was a weak Kan no Ro. So I preceded to checked the Kan no Ro pressure points I learned about from a visit with John Neptune. It turned out that both points made Ro less bubbly, but the bottom one near Tsu also made Kan no Ro better. In my blissful state of having made some rather quick and successful discoveries I went to the third issue, which was a weak Tsu. From experience, I know that the Choke Point, where Rooms #6 and #7 meet, often affects Tsu and Tsu meri.

The tape on the middle of the top indicates the best spot. It had the most positive affect on all three issues - fixed the bubbly ro, strengthened Kan no Ro and gave Tsu more "room" and volume. Today, I successfully killed three birds with one stone! I'll back track tomorrow to see if I can adjust the balance of each issue some more.




I think Carl's Theory may have come from experience based on the specs of one bore. His remedies may work but every handmade shakuhachi is different due to the maker's degree of taper and location of choke point. His book provides a good starting point to explore bore issues but the practice will be challenging for the beginner.  I recommend getting familiar with John's pressure points chart as I think it is more helpful for the intuitive maker. Understanding both can only be a good thing.

Shakuhachi making is a combination of science and art. Science takes you to the gate and art takes you through it. 

Heres' something David Duncavage wrote me me a while back:
   

David Duncavage wrote:

"In traditional shakuhachi making, much of the mechanics (bending, utaguchi insertion, nakatsugi, hole drilling, root shaving….) can be learned fairly quickly by anyone who is reasonably skilled at basic craftsmanship.  But the bottom line is “birthing the sound”.  There is a sound in each bamboo that we strive to release.  In order to do this, you need to play reasonably well I believe.  In fact, that was the first bit of advice Tom Deaver gave me well over twenty years ago.  An equally important part has to do with ones spirituality I believe.  Yes, being trained in physics and engineering, I understand that the sound is a result of fundamental principles of acoustics.  But no human made measuring device can equal what happens when our basic senses become at rest within the dimension of the spirit.  Yes, through the advances of modern science and technology we can “see” deep into the world of quantum mechanics, make incredibly complicated integrated circuits like the Pentium chips, and see evidence of the Big Bang in galaxies flying away from us at difficult to comprehend speeds.  But measure the “holistic warmth” of a tsu sound, measure or gauge why some sounds from a particular piece of bamboo resonate in the chest of one person and not another … science may have a way to explain it, and perhaps point to it, perhaps measure part of it.  But give one a solid roadmap to recreate it in a naturally varying medium like bamboo?   I think not.  Ultimately, it comes down to the craftsperson working with the bamboo in a spirit of gratefulness that “sets the stage” for the bamboo to sing its song.  I always tell people who bought a flute from me that the flute is incomplete without a player.  The last step in making a great shakuhachi is the person who plays it. - David Duncavage, September, 2007

Single malt please

I wrote a brief email to Karl Abbott asking if he could add to the use and background of the 7 rooms.
He replied that he has not made a Shakuhachi in over 30+ years, he got the information regarding the Rooms from a book he read while in Japan but did not use it himself and only made flutes for himself and stopped once he got one he liked.

I will get the Room information up here to look at in a bit more detail.
So, meantime, lets' sip the bottle and go blow some.

K.

Last edited by Karmajampa (2009-11-19 13:01:50)

Karmajampa wrote:

He replied that he has not made a Shakuhachi in over 30+ years, he got the information regarding the Rooms from a book he read while in Japan but did not use it himself and only made flutes for himself and stopped once he got one he liked.

Classic "non-wheel reinvention". Oh, the irony
Carl is a very wise man!

Tairaku wrote:

Have you watched him on "Wife Swap"?

I don't own or watch tv, but it sounds pretty bad. Maybe Carl should've kept on 'filing za root' in a bamboo sort of way!