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#1 2006-05-14 00:04:55
- evan kubota
- Member
- Registered: 2006-04-10
- Posts: 136
Pitch adjustment, length, node position
In a theoretical model, length and the end effect are the only things that affect the pitch of an end-blown flute. However, as anyone who has actually made one can tell you, the theory has to be bent in real life, so to speak.
My 1.8 non root-end turned out pretty close to the theoretical length - slightly shorter at about 54.2 cm. Non root-ends are easier, though, because you only have to worry about one node for the utaguchi, and the other end falls where it may.
I have some nice-quality culms with the root balls that I'm working with now. One is fairly thick and will probably go to a longer hocchiku. One is already apparently sized nicely for a 1.8. The other is what's giving me a problem - if I keep most of the root end, my choices are either in the 1.6-1.7 range or 2.0-2.1. This isn't a problem, but my question is what techniques can be applied to subtly alter the pitch for a given (fixed) length?
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#2 2006-05-14 12:14:17
Re: Pitch adjustment, length, node position
evan kubota wrote:
This isn't a problem, but my question is what techniques can be applied to subtly alter the pitch for a given (fixed) length?
Evan,
The fundamental pitch can be raised by opening up the bottom end. It can also be flattened by keeping the opening small. This can be helpful if the tonic is slightly sharp or flat. The amount of nodes left in the bore will also influence pitch. Removing most of the nodes makes the bore space larger which flattens pitch. Leaving more of the node will raise the pitch. Hole size and amount of undercutting will also influence pitch. The piece can also be lengthened or shortened with a fixed plug.
All this influences tone color and playability as well. Sometimes, a flute can be 'designed' so efficiently that everything falls in place. Other times, 'overtweaking' turns it into a jumbled mess. Trying to figure out what to do and what not to do keeps it challenging!
Ken
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#3 2006-05-16 23:30:02
- evan kubota
- Member
- Registered: 2006-04-10
- Posts: 136
Re: Pitch adjustment, length, node position
Working on the fundamental of my 2.1. It's 649mm long as far as I can tell (root end is slightly angled) and the initial pitch was closer to B flat than B. It was actually more towards A initially but I decided to enlarge the opening until it tuned to B flat. It's pretty close now but there's not that much room for kari.
As this is a hocchiku and only meant for solo playing, how do you go about producing a flute that is in tune with itself but not necessary absolute pitch? What measurements are followed? In a 'neutral' playing position Ro (B flat) is maybe 10-15 cents flat. I'd have no problems with all the notes being 10-15 cents flat as long as the relative pitch was reasonable. Any suggestions?
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#4 2006-05-17 12:02:58
Re: Pitch adjustment, length, node position
evan kubota wrote:
As this is a hocchiku and only meant for solo playing, how do you go about producing a flute that is in tune with itself but not necessary absolute pitch? What measurements are followed? In a 'neutral' playing position Ro (B flat) is maybe 10-15 cents flat. I'd have no problems with all the notes being 10-15 cents flat as long as the relative pitch was reasonable. Any suggestions?
Evan,
This is a more philosophical response, but I think it's important to realize. I imagine you sense this already, but with tuning, an important thing to be aware of is that nothing exists in a vacuum. Everything you do will influence the pitch of everything you've done before. Envisioning the whole rather than fine tuning one pitch at a time is the key.
For example, Ro will begin to flatten after you open the first hole. Tsu will flatten as you open the second hole, and so on.
Hole placement formulas will get you in the ballpark. From there, you have to take bore width, length and desired hole size into consideration. I like to start with smaller holes, then slowly adjust back and forth as if the flute is a scale and I'm keeping it balanced - never committing too much in any direction.
Carefully examining your tuning mistakes can be very helpful in getting a feel for these concepts. Also, making many, many flutes will slowly develop your tuning strategy.
'holistically,'
Ken
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#5 2006-05-17 16:36:08
Re: Pitch adjustment, length, node position
Mujitsu wrote:
I like to start with smaller holes, then slowly adjust back and forth as if the flute is a scale and I'm keeping it balanced - never committing too much in any direction.
Sorry to jump in here, Evan... Ken, are you drilling all your pilot holes first, and if so, how small? I've been using pilot holes of about 6mm, but I tend to enlarge each one somewhat into tune before I move up the flute to drill the next. Maybe I'm seeing this as a mistake now, because as I do this my lower holes are probably flattening from where I left them and yet they're already too large to move (enlarge) upward to sharpen things back into balance. I've been trying to end up with 11mm-ish holes (max) on my larger jinashi.
If your technique is balancing a delicate scale, then mine has been more like bouncing a teeter-totter back and forth... 
-Darren.
When it is rainy, I am in the rain. When it is windy, I am in the wind. - Mitsuo Aida
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#6 2006-05-17 18:51:00
- evan kubota
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- Registered: 2006-04-10
- Posts: 136
Re: Pitch adjustment, length, node position
No problem. This is a good question also. I've been trying to work on each hole going up, getting it mostly tuned before adding the others. My first shakuhachi making experience started with small holes at the measured positions, and this was an unmitigated disaster because each required compensation was more than I could achieve later by enlarging the holes.
It seems that wildly divergent recommended positions can be supplied by different formulas and you never know whether it'll be close until you actually drill the hole...
I got it nicely in tune for B flat by removing another 7 mm or so from the root end. Interestingly, the theoretical calculator at jeremy.org says the fundamental should be 243.8 Hz, just under B. The actual pitch at my real length (642 mm) is about 233 Hz, B flat. I guess the hole position recommendations can still be used, since they should scale for the length of the flute?
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#7 2006-05-19 13:06:11
Re: Pitch adjustment, length, node position
dstone wrote:
Mujitsu wrote:
I like to start with smaller holes, then slowly adjust back and forth as if the flute is a scale and I'm keeping it balanced - never committing too much in any direction.
Sorry to jump in here, Evan... Ken, are you drilling all your pilot holes first, and if so, how small?
-Darren.
Darren,
I drill all the holes first, keeping in mind how close to pitch they are. I like to make them pretty close to full size initially - especially the first few holes since they will flatten anyway. The higher holes don't have to be quite as big at first since they require less enlarging to raise the pitch.
There are many ways to go about this. As long as you are aware that previous holes will continue to flatten as you drill new holes, you can devise your own plan to compensate for the pitch change.
Evan,
I use the same hole formula for every flute becasue I'm used to it. Before drilling I take into consideration bore width, degree of taper, wall thickness, etc. From there, I have a good idea which way to cheat when drilling the first hole. Again, all this is relative, so any formula or technique that makes sense to you should do the trick.
Ken
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#8 2006-05-19 14:11:41
- evan kubota
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- Registered: 2006-04-10
- Posts: 136
Re: Pitch adjustment, length, node position
I just finished the holes using the PDF formula - it's tuned quite well. After making all of the holes, B flat was slightly low, so I opened up the end a little bit. It's pretty close to dead on now, and nothing that a little adjustment while playing can't fix.
One question - the formula for non-1.8 flutes gives roughly equal distances between the four top holes, but the numbers for the example 1.8 show different distances (1-2 is 5.6 cm, 2-3 is 5.2 cm, etc). How do you explain this discrepancy? It didn't seem to negatively affect my tuning, in any case (although I think I altered the formula a little bit by scaling up the percent difference between 5.6 and 5.2).
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#9 2006-05-20 12:43:13
Re: Pitch adjustment, length, node position
evan kubota wrote:
One question - the formula for non-1.8 flutes gives roughly equal distances between the four top holes, but the numbers for the example 1.8 show different distances (1-2 is 5.6 cm, 2-3 is 5.2 cm, etc). How do you explain this discrepancy? It didn't seem to negatively affect my tuning, in any case (although I think I altered the formula a little bit by scaling up the percent difference between 5.6 and 5.2).
Evan,
The formulas are taken from different styles of flutes.
There are many variables which influence the location of the holes. All flutes have a different combination of variables. So, a formula taken from one ideal flute often won't match the formula taken from another ideal flute. They are close but not exact. In theory, every jinashi flute has it's own ideal formula. You could simplify this and use a different formula for each style of flute - wide bore, thin bore, thick walled, thin walled, etc. Or, you could stick with one and adjust from there - Whatever simplifies it for you.
I think a good way to reduce the confusion is to get a feel for the physics of the shakuhachi. Then, you'll have a better idea which way to stray from your 'starting point' formula.
Ken
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