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Tube of delight!

#1 2011-02-10 06:44:31

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Planar Tone Holes

Planar Tone Holes

Many of you already know that most of my experimental flutes have thin-walled aluminum tubes.  Tone holes in thin-walled tubes have very short effective "chimney height", and yield a bright timbre.  These holes do not change pitch when cross-fingered.  However the timbre is muted by cross-fingering.

Lately I've made a few PVC flutes, which have 0.125" (~3mm) walls.   I've noted that some notes are a bit muted due partly to the greater chimney height.  I'm not cross-fingering, but the result is similar due to the substantial distance to the next open hole.  For example the note E.

It also occurred to me that I could reduce finger pressure to close a hole which was surrounded by a planar surface.   The ball of my finger fits better into the hole.  Try to close a hole on your Shakuhachi with a marble and you'll see it doesn't close.  But of course it will close a hole in a planar surface.

So I modified one of my PVC flutes by milling a planar surface around each fingered hole.  This reduced the chimney height, brightened the timbre and permitted closure with less finger pressure.

This image shows the overall flute.  Like many of my flutes, it has a Delrin head and is tuned in the key of D minor.

http://farm6.static.flickr.com/5258/5432316327_0c608dbf04.jpg

Like all of my flutes, the two lowest holes are not fingered.  They are always open and enhance the timbre of the two lowest notes, D and E.

Here's a closer look at some holes.  The hole on the far right is not fingered.  The others have the planar surrounding surface.

http://farm5.static.flickr.com/4073/5432316333_4208a4ce19.jpg

Below are two pics of the Delrin head.  As I've written before, I like an edge width equal to the ID of the tube. 

The angle at the top which rests on my chin has evolved to become sharper over the past few years.  Two years ago I preferred 65 degrees, which is already sharper than Shakuhachi.  Then I sharpened that to 60 degrees for about two years.  Now, for the past several months I prefer 55 to 57 degrees.

The O-Ring around the head is not acoustic.  It prevents scratching the head when I lay my flute on a hard surface, like my bathroom tile counter.  Do you play in your bathroom?   I like the power!

http://farm6.static.flickr.com/5252/5432316337_ff143226f6.jpg

http://farm6.static.flickr.com/5057/5432316339_f89ece6fa1.jpg

Best regards,

Alan

Last edited by Alan Adler (2011-02-14 06:43:17)

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#2 2011-02-10 17:30:09

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Planar Tone Holes

Very interesting idea. The shorter chimneys would have two main effects. First, they should make the flute brighter and louder, since they would radiate high frequencies better (something like the difference between an old, simple system and Boehm flute). Second, this would raise the cutoff frequency, making the flute able to play higher. But this would change the behavior of the flute in the higher notes, since strange things begin to happen with cross-fingerings when the played frequency begins to approach the cutoff frequency. For instance, there are notes both on the recorder and the shakuhachi in which cross-fingerings actually raise the sounding frequency, instead of lowering it as the some fingerings do in the lower octave. I know that you play your flutes in the lower mode only, so in that case it wouldn't matter, but doing this on the shakuhachi might well make some notes employing cross-fingerings impossible to sound in the kan and dai-kan registers.

It is interesting that you came across the idea of lengthening the flute and adding holes so that the impedances of the lowest notes match more closely those of the notes higher up the tube. A Boehm flute, with very large toneholes, does not really need this, nor does a reverse conical flute like the recorder or shakuhachi (or not as much). But a cylindrical flute with toneholes much smaller than the bore is really in need either of a bell or of some extra holes such as you added to your flute, in order that the lowest notes not sound dull and muted.

Nice work on this flute! You might consider this idea with even larger toneholes, if fingering does not become too difficult. That should brighten the sound even more, but of course it will make intonational adjustments with cross-fingerings increasingly difficult.

Last edited by Toby (2011-02-10 17:30:49)

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#3 2011-02-10 20:04:03

Karmajampa
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From: Aotearoa (NZ)
Registered: 2006-02-12
Posts: 574
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Re: Planar Tone Holes

I have a Xiao, 750mm length, 'F' tuning. It has a bottom section with three pairs of 'tone' holes. Is this what you are also doing ?

Kel.


Kia Kaha !

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#4 2011-02-10 20:07:36

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Toby wrote:

"Nice work on this flute! You might consider this idea with even larger toneholes, if fingering does not become too difficult. That should brighten the sound even more, but of course it will make intonational adjustments with cross-fingerings increasingly difficult."

The flute pictured has 0.312" diameter tone holes.  Nearly all of my flutes have 0.375" holes, and a few have 0.5" holes.  I find very little increase in sound beyond 0.375".   Yes, I know Boehm was impressed by Nicholson.  But I've often suspected that Nicholson's power was due more to his skills rather than his large tone holes.

I deliberately made this flute 0.312 because I wanted to explore a slightly "woodier" tone.  Before milling the planar area, the tone was less bright and that was clearly audible and visible on the Syaku Tuner spectrum display.  I liked the sound, but E and A were more muted than I wanted.  I considered enlarging those holes, but was attracted to the ergonomics of planar holes.  Since milling the planes, it sounds about like my metal flutes with .375" holes, and the spectrum looks similar too.

I can feel 0.375" holes more easily than 0.312" holes because my fingers sink slightly into the larger holes.  Thus I may enlarge this flute's holes just to improve the precision of my fingering.  I now play my flutes at least an hour per day - often improvising.  I greatly enjoy it.

Incidentally, Benade is plain wrong in his discussions of cutoff frequency due to a lattice of downstream open holes.  He implies that the lattice dulls the tone.  But everyone who has ever played a flute knows that downstream open holes brighten the tone, and the tone dulls when these holes are closed - as in cross-fingering.

Best,

Alan

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#5 2011-02-10 20:12:16

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Karmajampa wrote:

I have a Xiao, 750mm length, 'F' tuning. It has a bottom section with three pairs of 'tone' holes. Is this what you are also doing ?

Kel.

What happens to the tone when you cover the extra holes with small corks (or a friend's hand)?

Post a picture.

Best,

Alan

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#6 2011-02-10 20:30:56

radi0gnome
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From: Kingston NY
Registered: 2006-12-29
Posts: 1030
Website

Re: Planar Tone Holes

Wow! That's a cool looking instrument. Aside from the two unused holes at the bottom, it looks like there a few more holes, I count a total of 8. Is there a thumb hole? I'm assuming either one of two possibilites, 1) you tuned it to a diatonic scale, or 2) you tuned it like a seven hole shakuhachi with a Bb and Eb hole.

Does it play easier than a standard shakuhachi?


"Now birds record new harmonie, And trees do whistle melodies;
Now everything that nature breeds, Doth clad itself in pleasant weeds."
~ Thomas Watson - England's Helicon ca 1580

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#7 2011-02-10 21:05:00

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

radi0gnome wrote:

Wow! That's a cool looking instrument. Aside from the two unused holes at the bottom, it looks like there a few more holes, I count a total of 8. Is there a thumb hole? I'm assuming either one of two possibilites, 1) you tuned it to a diatonic scale, or 2) you tuned it like a seven hole shakuhachi with a Bb and Eb hole.

Does it play easier than a standard shakuhachi?

Hi radi0gnome,

It sounds like you haven't read some of my earlier posts.

http://www.shakuhachiforum.com/viewtopic.php?id=3360

and

http://www.shakuhachiforum.com/viewtopic.php?id=3373

For me it definitely plays easier than a standard shakuhachi.  I've been developing the head for years and it has become easier to play and prettier in timbre over the years.

The scale is standard D minor
D E F G A (440 hz) Bflat C D (thumbhole)
I have experimented with many scales and enjoy this for improvisation.  This scale also happens to be easy to finger, especially with my offset hole placements.  Some of the scales I've tried are awkward to finger.

Best,

Alan

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#8 2011-02-11 00:27:27

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Planar Tone Holes

Alan, where does Benade say that a tonehole lattice dulls the tone? He specifically talks abouts lattices and I have never seen that sort of statement from him.

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#9 2011-02-11 02:50:10

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Toby wrote:

Alan, where does Benade say that a tonehole lattice dulls the tone? He specifically talks abouts lattices and I have never seen that sort of statement from him.

Hi Toby,

I did not say the he "says" it dull the tone.  I did say he implies that.  See figure 21.3, and the discussion on pages 434 and 435 in "Fundamentals of Musical Acoustics".

Benade takes the opposite (correct) position in "Horns, Strings, and Harmony", pages 228-9.

My good friend Tom Rossing refers to Benade FOMA.  But Rossing hedged on pages 252 of "The Science of Sound" 3rd edition. 

first he wrote,
"... the resonances above the cutoff frequency become very weak." 

then a few lines later he hedged,
"The spectrum measured outside the instrument does not show the same weakening of upper partials, however, because of the greater efficiency of radiation from the open tone holes above the cutoff frequency". 

True, but I wish Tom had flatly stated that open tone holes brighten the timbre, rather than "does not show the same weakening of upper partials".  I discussed this with Tom and he urged me to take it up with a professor in Ohio who has done work on lattices, but that person has never responded to my communications.

Best,

Alan

Last edited by Alan Adler (2011-02-11 02:51:04)

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#10 2011-02-11 06:18:33

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Planar Tone Holes

Alan,

The discussion you refer to is actually speaking about input impedances, and the lack of clear maxima after the cutoff frequency is not analogous to the sound that is radiated into the room. Rossing was not hedging, he was simply stating the fact that there is a clear distinction between the impedance profile inside the bore, which simply shows a relationship between acoustic pressure and acoustic flow at different frequencies for a given bore profile, and the actual spectral content of the sound that is radiated into the room. Radiated sound contains all the partials; how those partials are either reflected or radiated inside the bore is the business of the impedance profile.

BTW I disagree about Nicholson, or at least partly. A lower cutoff frequency limits the maximum achievable dynamic, for a very interesting reason. Consider first that as dynamics increase, the partial content increases as the square of partial order. For instance, blowing harder so that the fundamental is twice as loud increases the power of the second partial by 4x, the 3rd partial be 9x, the 4th by 16x, etc. As long as the peak (impedance minima) exists in the bore, that partial will increase and increase the loudness of the radiated sound. But above the cutoff frequency, the higher partials have no peaks associated with them and create losses, and stronger losses as the player blows harder, effectively limiting the maximum achievable dynamic level. So Nicholson's flute with larger holes and a higher cutoff would have allowed for a stronger dynamic, in addition to a somewhat brighter tone for a given bore profile. You might be interested in this paper:

http://www.phys.unsw.edu.au/jw/reprints … gering.pdf

Did you know that the Nicholson flute had some planar toneholes? Have a look at the picture on this page--the wood of right hand holes was thinned and flattened on top:

http://www.mcgee-flutes.com/Nicholson_on_Tone.htm

Best,
Toby

Last edited by Toby (2011-02-11 06:33:58)

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#11 2011-02-11 07:50:22

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Greetings Toby,

Here is a quote from the Wolfe and Smith paper you linked,

"With larger holes, the increasing cutoff frequency gives a larger number of impedance minima that are in approximately harmonic ratio. This is expected to contribute to the production of notes that are brighter in timbre and louder." 

This says that increasing cutoff frequency brightens the timbre.  Benade teaches that open lattice holes decrease cutoff frequency.  Isn't it reasonable the interpret him as implying that open lattice holes dull timbre?  Furthermore, when teaching about the acoustics of open lattice holes, he is obligated to be clear about how those holes affect the sound of the instrument.  Otherwise, they aren't worth mentioning.

Regarding the planar holes you link, http://www.mcgee-flutes.com/Nicholson_on_Tone.htm

Interesting.

Best regards,

Alan

Last edited by Alan Adler (2011-02-11 08:46:30)

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#12 2011-02-12 02:42:04

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Planar Tone Holes

Alan, you should have a look at the section on brasses and their bells, starting around pg. 399 of FMA. The chart showing the effect on impedances of adding a bell to a piece of pipe is very similar to the figure you refer to, in that adding a bell removes or very much attenuates the higher impedance peaks. So the first point is that the highest impedance peaks are lessened if there is a device present (either a bell or an open tonehole lattice) that radiates the higher frequencies. If they are out in the air, they are not being reflected back up the instrument and thus the impedance peaks for those frequencies are attenuated tot some lesser or greater extent.

The cutoff frequency of the tonehole lattice is the point at which the waves simply ignore any open tonehole and travel all the way down to the end of the bore, but before the cutoff frequency, impedance peaks are shifted in terms of frequency due to the fact that higher frequencies penetrate further into the lattice before being reflected. This apparently has a very important consequence on the timbre of the sound.

You are probably familiar with the concept of "mode-locking". Any periodic wave must have its partials in phase in order to be sustainable. If the higher impedances are not in harmonic relationship, they get pulled into alignment. Actually, the partials all "negotiate" a "regime of oscillation" based on their relative energies and frequencies, and if there is enough "agreement", a completely harmonic note results. But the further the original impedance peak is from a harmonic relationship with the final note frequency, the less it participates in the spectrum of the final note. If we have the first two or three partials in good harmonic relationship, we get a nice strong note, but if the higher partials are out of alignment, they just cannot contribute, and the note is therefore primarily composed of the lower partials and might be plenty strong, but it will also be dull sounding or dark.

Here is what Joe Wolfe has to say in that paper (or another like it), as you point out:

"The increase in cutoff frequency from baroque to classical to modern has important consequences for the sound produced. For most fingerings, the higher f c increased the number of impedance minima that are in nearly harmonic ratios and thus the number of resonances that interact with harmonics of the air jet to produce the spectrum of the note played. For the same note and dynamic level, the sound spectra of the more recent instruments are richer in higher harmonics....This makes them ‘‘brighter’’ in timbre, and also considerably louder, because, for most of the range of the flute, the higher harmonics fall in a range where the ear is more sensitive than it is to the fundamental frequency."

So it is not only a question of radiation, but of changing the impedance profile of the bore in a way that the impedance peaks are more nearly harmonic, as you say. In terms of Benade, I don't seem him saying or implying that open lattice holes decrease cutoff frequency. Each open hole to some extent determines that cutoff frequency depending on its size and its spatial relationship to other open holes in the lattice. For instance, on the classical flute, the holes are of very different sizes. A small first-open tonehole would decrease the cutoff frequency of the lattice, causing the note to be duller as described above. Now if you close that hole (and the hole below is larger), the cutoff frequency of the lattice is raised, and the sound is brightened because the new tube has impedance minima more closely in alignment, again as described above.

One of the great things about the Boehm flute was that with keys, the holes could not only be made larger, but the sizes could be equalized, because the hole sizes no longer needed to be varied in order that their positions be convenient for the fingers. The bassoon still suffers from severe timbral quirks due to the long fingerholes drilled at a bias in order that they be conveniently placed.

The cutoff frequency is a characteristic feature of a tonehole lattice (or even a single tonehole). It defines the point where the mass of air in the tonehole(s) can not be moved by the wave (the ability of waves to do so decreases with frequency) and thus the open tonehole does not even appear open to the wave. Different cutoff frequencies affect the impedances of the tube differently and cause different timbres as described above, but the cutoff frequency is always present and is an integral characteristic of a tonehole or tonehole lattice in relation to a bore.

Last edited by Toby (2011-02-12 02:44:29)

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#13 2011-02-12 05:05:09

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Toby wrote:

"In terms of Benade, I don't seem him saying or implying that open lattice holes decrease cutoff frequency."

The following appears on page 435 of Benade's "Fundamentals of Musical Acoustics" Second Revised Edition:

http://farm6.static.flickr.com/5134/5437901162_7404f92138.jpg

The text on this same page reads,

"..the sound within the woodwind and the way in which it is transmitted out to our ears will be strongly influenced by the presence of the tone-holes cutoff frequency.  We will learn in due course that specifying the cutoff frequency for a woodwind is tantamount to describing almost the whole of its musical personality"

Dear Good Friend Toby,

I know that you love a good debate.  I do not.  I wrote that Benade implied that an open lattice of holes dulls timbre.  You and I agree that it brightens timbre.  However we disagree as to what Benade implied.  Let's simply agree to disagree on what Benade implied.  Let Benade's readers decide for themselves what he implied.

Best,

Alan

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#14 2011-02-12 07:45:13

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Planar Tone Holes

Alan,

That's fine with me. Benade is sometimes very clear and at other times not so clear. I do not believe Benade is in error, only that his explanation is not clear to us in all its implications. Enough said.

BTW, Your Aeropress continues to do an outstanding job with my daily coffee. I find that with a little care I can make each little filter last for about forty pressings. Cleaning takes a matter of seconds. A great device!

Best,
Toby

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#15 2011-02-12 20:58:32

Karmajampa
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From: Aotearoa (NZ)
Registered: 2006-02-12
Posts: 574
Website

Re: Planar Tone Holes

Alan Adler wrote:

Karmajampa wrote:

I have a Xiao, 750mm length, 'F' tuning. It has a bottom section with three pairs of 'tone' holes. Is this what you are also doing ?

Kel.

What happens to the tone when you cover the extra holes with small corks (or a friend's hand)?

Post a picture.

Best,

Alan

Sorry, can't post picture.
Xiao length 960mm, not 750mm.
The additional holes are same diameter as main finger holes.
When I close them with tape the primary change is pitch.

There are three pairs, when I close all three pairs the flute becomes 960mm long, very low note, difficult to get.
when I leave only one of the pairs open I get the pitch change of that length.
The pitch change is in Key.
I can't discern any strong tone change.
When I close only one hole of a pair the pitch is still the same, tone very similar, I need to do a lot more testing or use a spectral analyser  to note any change.
This is an eight finter hole flute, left hand - thumb and three fingers, right hand - four fingers.
It is an end-blown flute, perhaps the Chinese precursor to the Shakuhachi, the blow-edge is quite small, but like the Shakuhachi, you blow directly at the edge. Bore width approximately 18mm.
Made rfrom bamboo.

K.


Kia Kaha !

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#16 2011-02-12 21:37:14

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Hi Karmajampa,

What I meant is what happens when you close the lowest unreachable hole(s), while leaving the highest unreachable hole open?

On my flutes, there are two unreachable holes.  The lowest is there just to brighten the D hole, which is the upper of the two unreachable holes.

The distance to my D hole is about 516 mm.

Tape may not be stiff enough to close a hole.

Best,

Alan

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#17 2011-02-12 22:11:11

Karmajampa
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From: Aotearoa (NZ)
Registered: 2006-02-12
Posts: 574
Website

Re: Planar Tone Holes

Alan Adler wrote:

Hi Karmajampa,

What I meant is what happens when you close the lowest unreachable hole(s), while leaving the highest unreachable hole open?

On my flutes, there are two unreachable holes.  The lowest is there just to brighten the D hole, which is the upper of the two unreachable holes.

The distance to my D hole is about 516 mm.

Tape may not be stiff enough to close a hole.

Best,

Alan

The tape works fine.
I closed the owest unreachable holes, what I get is the pitch of the next open upper hole. Then if I open the next pair of unreachable upper holes I get that pitch, increasing as they are sequentially opened.

I will read up a bit on the Xiao to see if there is any info on this.

A question about the position of your unreachable open holes, are they placed strategically ?
Though it seems to me that you are only adding one additional hole, not the 'D' tuning hole, to influence tone, plus the end of the tube, what happens if you close that ?

K.


Kia Kaha !

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#18 2011-02-12 22:34:14

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Karmajampa wrote:

Though it seems to me that you are only adding one additional hole, not the 'D' tuning hole, to influence tone, plus the end of the tube, what happens if you close that ?

With my existing tube length, it dulls the D when I close the unreachable (C#) hole below it.  However if I shorten the tube so that it only extends about an inch below the D, the tone is somewhat restored.  I just prefer the tone with the added hole. 

When I experiment with cross-fingering I find that I can close all the holes below any two consecutive open holes with little effect.  So I surmise that notes are mostly sounding out of the highest open hole, and the hole below it.

My added C# hole just makes D sound out of of two holes as well - just like all the higher notes.  However I often partially block the C# holes with an adjustable sleeve to quiet the D note, which otherwise sometimes sounds too bright.

Best,

Alan

Last edited by Alan Adler (2011-02-12 22:35:31)

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#19 2011-02-12 23:07:35

Karmajampa
Member
From: Aotearoa (NZ)
Registered: 2006-02-12
Posts: 574
Website

Re: Planar Tone Holes

I may not be accurate but from what I recall, your bore is straight and not narrow ?
From my bamboo experience, the wider bore has less influence when cross fingering, though I am open to being corrected.

Also, Toby mentioned you only play in one register, why is this ?

K.
See an image of the Kin Xiao 'F' tuned here http://www.chineseculture.net/guqin/ins … olist.html

Last edited by Karmajampa (2011-02-12 23:36:33)


Kia Kaha !

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#20 2011-02-13 00:48:00

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Karmajampa wrote:

I may not be accurate but from what I recall, your bore is straight and not narrow ?
From my bamboo experience, the wider bore has less influence when cross fingering, though I am open to being corrected.

Also, Toby mentioned you only play in one register, why is this ?

K.
See an image of the Kin Xiao 'F' tuned here http://www.chineseculture.net/guqin/ins … olist.html

All of my flutes are cylindrical (constant) bore.  Tapered bore flutes have lower harmonic content.

Toby and I discovered (when he visited me in Los Altos) that my older flutes which have 6 mm thick walls produce a pitch change when cross-fingered.  My newer flutes, with 1 mm and thinner walls, do not change pitch - but their timbre dulls when cross-fingered.

It's true that I play almost exclusively in the lowest register.  I like the mellow tone.

I had not been aware of the Xiao.  I watched some youtube:

http://www.youtube.com/watch?v=FHthypwRDhg

http://www.youtube.com/watch?v=4-pjlgQh … re=related
pretty visuals

http://www.youtube.com/watch?v=K7FNWUMhT20&NR=1
skilled player

http://www.youtube.com/watch?v=NcK2i6IB … re=related
amazingly long fingers

I'm amused that the top end is square (90 degrees).  As I mentioned earlier in this thread, I've evolved to 55 to 57 degrees. 

From the videos it looked like the blowing edge is in a notch about 7 mm wide, like a Quena.  What is your edge like?

What is the distance from the blowing edge of your Xiao to:
The lowest hole you finger.
Each of the remaining lower holes.

Are you familiar with the Syaku tuner (free, online)?  It displays frequency and spectrum.  What is the frequency of your lowest note?

Best,

Alan

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#21 2011-02-13 02:25:04

Karmajampa
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From: Aotearoa (NZ)
Registered: 2006-02-12
Posts: 574
Website

Re: Planar Tone Holes

Alan, first, I am blind so some of your questions are not so straightforward for me to answer.
I have a 'Chromatic tuner' for Mac that speaks to me, plus a talking tape measure, plus a talking computer - Mac OSX.
However, spectral analysis does not speak !

The Xiao blowing edge is approx 7mm from the end of the flute, there is a 4-5mm groove, the edge is bevelled inside the bore, opposite to our Shakuhachi. So, the straight edge is approx 4-5mm wide.

Full flute length 960mm
bottom pair of unfingered tone holes - 675mm from blowing end.
Next pair - 620mm
Next pair - 587mm, this effectively would be the length of the fundamental.

Lowest finger hole - 498mm - hole 1
Next finger hole - 474mm - hole 2
Hole 3 442mm
hole 4 - 418mm
hole 5 - 360mm
hole 6 - 334mm
hole 7 - 312mm
Thumb - 282mm

I don't yet play it very well, it is a right-hand down flute, I play left-hand down.
As shown, this Xiao has eight holes, others have six.

K.


Kia Kaha !

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#22 2011-02-13 03:10:37

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Hello Karmajampa,

Thank you for the details of your Xiao.

Your description of the blowing notch is not far from a Quena.  I tried making a Quena style head.  Although I like my wide blowing edges for their rich tone, I thought a narrow Quena style might be easier to play.  However for me it was harder to play, and of course the tone was not anywhere near as rich.

From the tone hole dimensions you provided, I would guess that your lowest note is D (approx 294 Hz).  I would also guess that if the Xiao was sawed off at approximately 600 mm, there would be little or no change in tone.

Best regards,

Alan

PS  I visited New Zealand in 1973.  A lovely country full of lovely people.

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#23 2011-02-13 04:02:15

Karmajampa
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From: Aotearoa (NZ)
Registered: 2006-02-12
Posts: 574
Website

Re: Planar Tone Holes

Close, the bottom note is C 263Hz

I too prefer the wider edge, but that will be influenced by not a lot of Xiao practice.

K.


Kia Kaha !

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#24 2011-02-14 03:04:31

Alan Adler
Member
From: Los Altos, California
Registered: 2009-02-16
Posts: 78

Re: Planar Tone Holes

Notes A, G, and E were slightly muted relative to the other notes because each of their holes had a relatively long distance to the next lower hole. 

So I enlarged these three from 0.31" to 0.38".   That brightened them just enough to yield a more uniform timbre over the range. 

I offset the hole centers .025" downward to maintain tune.  That still permitted fully covering the old hole with the new.

Here's an annotated version of the earlier pic.  Because it's the old pic, the holes depicted here are the original diameter.  But you can see which holes I enlarged.

http://farm6.static.flickr.com/5020/5443123433_a3b3328d12.jpg

Best,

Alan

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#25 2011-02-14 03:22:42

Toby
Shakuhachi Scientist
From: out somewhere circling the sun
Registered: 2008-03-15
Posts: 405

Re: Planar Tone Holes

Alan Adler wrote:

Karmajampa wrote:

Though it seems to me that you are only adding one additional hole, not the 'D' tuning hole, to influence tone, plus the end of the tube, what happens if you close that ?

With my existing tube length, it dulls the D when I close the unreachable (C#) hole below it.  However if I shorten the tube so that it only extends about an inch below the D, the tone is somewhat restored.  I just prefer the tone with the added hole. 

When I experiment with cross-fingering I find that I can close all the holes below any two consecutive open holes with little effect.  So I surmise that notes are mostly sounding out of the highest open hole, and the hole below it.

My added C# hole just makes D sound out of of two holes as well - just like all the higher notes.  However I often partially block the C# holes with an adjustable sleeve to quiet the D note, which otherwise sometimes sounds too bright.

Best,

Alan

Hi Alan,

End corrections increase with frequency, so while in the low octave most of the sound energy radiates from the first (and to a lesser extent second) open hole, higher frequencies penetrate further down. This means that a cross-fingering that simply dulls a lower note can change the pitch significantly when the note is overblown to the second mode. If you play always in the lowest mode, you can play with hole sizes without much worry, but if cross-fingerings are used in the second or third octave to create diatonic notes, things can get tricky.

Sometimes, as with simple flutes and recorders, cross-fingerings can actually raise the pitch (as in 2nd mode Bb and C). Notes like 2nd mode F# and G# require holes of the right size for cross-fingerings to sound them in pitch. This applies also to the quena and xiao.

Because flutes are very poor in high harmonics, they really don't need a bell or extra holes at the end to match the quality of the lowest notes with those of the rest of the flute. But one often sees these extra holes on Asian flutes, especially Thai and Chinese instruments. I believe they are there mostly for aesthetic reasons. For example, dizi sideblown flutes often extend well past the embouchure hole and are also extended at the foot with up to four or five holes, sometimes making the flute twice its sounding length. Often ornaments are hung from the end, like the banners on medieval horns.

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