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#1 2014-10-23 07:53:09

Adi Pieper
Member
Registered: 2014-10-23
Posts: 3

Ro Kan sharp

Hi, I am in process of building a 1.8 Shakuhachi from a root piece 53.2 cm long. All pitches are pretty close to proper tuning including the Kan pitches with one exception, Ro Kan which is exactly 1/2 note at D# while the lower octave is correct. However Ro Kan is correct if all 5 holes are open, but closing all holes raises it. The bore profile is pretty close to the published profiles. I tried all kinds of spot tuning but cannot lower the Ro Kan pitch to D! Any suggestions?
thanks

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#2 2014-10-24 11:43:16

Mujitsu
Administrator/Flutemaker
From: San Francisco
Registered: 2005-10-05
Posts: 884
Website

Re: Ro Kan sharp

Hi Adi,

Octave issues like this sometimes suggest 1/2 or part of the bore is either too wide or too narrow for the rest. Often, it's easier to identify and fix this issue before the holes are drilled.


Here is some previous discussion on the subject:

http://www.shakuhachiforum.com/viewtopic.php?id=4352

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#3 2014-10-25 00:27:34

Adi Pieper
Member
Registered: 2014-10-23
Posts: 3

Re: Ro Kan sharp

Thanks Mujitsu, I have been reading most of the suggestions on the forum before I posted my problem. Meanwhile I continued tinkering and added material to the half way point, mid flute and lower. I also found that my bottom end was about the same size as the top i.e. 20mm so I reduced it to 18mm as well. The result is that all the lower notes moved up by about 30 cent as well as half the Kan notes but I lost the second half of Kan. So all notes I can play now are still in line with each other except Ro Kahn was still sharp. A tuning beat on the top 1/4 point brought the octaves closer together though, and I will experiment with wet paper but How do I get the upper half of Kan back?

thanks so much

adi

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#4 2014-10-26 13:45:07

Mujitsu
Administrator/Flutemaker
From: San Francisco
Registered: 2005-10-05
Posts: 884
Website

Re: Ro Kan sharp

Adi Pieper wrote:

Thanks Mujitsu, I have been reading most of the suggestions on the forum before I posted my problem. Meanwhile I continued tinkering and added material to the half way point, mid flute and lower. I also found that my bottom end was about the same size as the top i.e. 20mm so I reduced it to 18mm as well. The result is that all the lower notes moved up by about 30 cent as well as half the Kan notes but I lost the second half of Kan. So all notes I can play now are still in line with each other except Ro Kahn was still sharp. A tuning beat on the top 1/4 point brought the octaves closer together though, and I will experiment with wet paper but How do I get the upper half of Kan back?

thanks so much

adi

Adi,

In my experience, when the bore is more than just a subtle adjustment away, it can be very difficult to balance all the variables with a spot tuning approach. It's always possible to fix. But, it can go on in circles forever where one issue is fixed but another is introduced. This can be especially difficult if the holes have already been drilled.   

If you keep going in circles, sometimes it's best to create a jiari shakuhachi. (Which seems like the direction you are heading) That means recreating an established bore profile. Is this the bore profile you are referring to?


http://www.mujitsu.com/images/18.gif

I find it important to pay particular attention to the pivotal changes in the profile. (Around 14cm, 23cm, 36cm and an important one at the choke point at around 46cm. You can slice a pool cue into many wafers of various diameters then connect them to dowels. Instant bore measuring rods.

Of course, all this is easier to tackle if you have many, many shakuhachi under your belt. If not, it's never a bad idea to move on to the next pieces which will likely be more cooperative from the start.

Good luck.

Ken

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#5 2014-12-29 03:19:15

Adi Pieper
Member
Registered: 2014-10-23
Posts: 3

Re: Ro Kan sharp

Thanks Ken,
I spent some time fiddling with the problem, inserting chop sticks etc, finally I got it close to perfect by adding material pretty much in the middle of the flute and narrowing the root end. I now get two octaves pretty much in tune except Ci is a bit sharp in both octaves.
thanks for your advise

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