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Showing posts with label 199. ΤΗΕ BEST DESIGN FOR AEROPHONE END-BLOWN (WITH FIPPLE) FLUTES COMPARISON OF GERMAN RECORDERS IRISH WHISTLES CHINESE SUCH FLUTES AND QUENAS-LIKE PINQUILO OF ANDES.. Show all posts
Showing posts with label 199. ΤΗΕ BEST DESIGN FOR AEROPHONE END-BLOWN (WITH FIPPLE) FLUTES COMPARISON OF GERMAN RECORDERS IRISH WHISTLES CHINESE SUCH FLUTES AND QUENAS-LIKE PINQUILO OF ANDES.. Show all posts

Sunday, April 14, 2019

199. ΤΗΕ BEST DESIGN FOR AEROPHONE END-BLOWN (WITH FIPPLE) FLUTES.COMPARISON OF GERMAN RECORDERS, IRISH WHISTLES, CHINESE SUCH FLUTES AND QUENAS-LIKE PINQUILO OF ANDES

BEST DESIGN FOR AEROPHONE END-BLOWN (WITH FIPPLE) FLUTES.COMPARISON OF GERMAN RECORDERS, IRISH WHISTLES, CHINESE SUCH FLUTES AND QUENAS-LIKE PINQUILO OF ANDES .
We are accustomed to the traditional design of the aerophone end-blown flutes with fipple , like recorder , by big companies like Hohner , Yamaha etc and we have the illusion that it is an optimal design. This is by far not true.
Some obvious disadvantages of the classical recorders are the next
1) The sound hole of the fipple at the tenor (C4) or even alto (F4) size has very short longitudinal length and in total it is of rather small area, which makes it difficult to make sound at the lowest root note . And when the sound is made we have to blow drastically at lower strength compared to the other notes and it is a sound of very low volume. In addition a little only if we increase the blowing strength it mutates to a note of the next octave which makes in total unstable.
This disantange has been corrected carefully by the Irish low D4 and C4 folk whistles. The sound hole is of greater longitudinal length
2) The holes are of small size which makes a continuous glissandi from say a high note to the same note one octave lower very difficult are almost impossible. Small size holes also give lower sound volume and a bias to higher frequencies, that it is not good for the lowest octave. Small holes are convenient for very fast melodies like Irish reels and Cretan condyles because the are less probabilities of finger covering errors. But such very fast melodies are rather rare in the general context of music.
This disadvantage does not exist say in Incas quenas of Andes folk music , that have large holes which give louder sound and easy sharps-flats and octave glissandi.
This somehow was discovered by Bohm in his modern concert Bohm flute (that is large diameter holes are better ) but because of the keys over them the ability of glissanti and rolling around the holes has been lost. In addition modern analysis for optimal designs has proved that the position of the keys of the modern Bohm concert flute are not really the best as the intuitive linearity of the pitch is lost and there are designs that correct it but they sell such flutes for more than 20,000 dollars!
3) The diameter of the recorder tube is rather small and the ratio total length to average diameter is rather high which is an advantage for the higher octaves but disadvantage for the lower octave and makes mutation to higher harmonics rather unstable. To correct this the recorders have inverse conical diameters and also small barrel-like thicker walls after the sound hole and before the end of the tube. This also makes the total length less. Nevertheless this requires more blowing for the same volume sound, and the perfect sinusoidal harmonic sound is lost . Such smaller average diameters give a sound with bias to higher frequencies and of low volume. The idea to include 3 octaves to the same flute is not really good as only at the first two octaves the playing is easy and symmetric . Better use flutes of different sizes and scales for higher octaves, and keep a smart design for an end-blown flute for only 2 octaves.
Such disadvantages do not exist in Incas quenas that have wider diameters and thus low ratio of length to diameter. Wider diameters will make the higher octaves harder, but that is why they have a thump hole almost at half of the length so that with partial holing of it they ignite the 2nd harmonic and make the second octave easy. Irish whistles do not have such thump hole because they do not need it as they have narrower diameters compared to quenas but larger compared to recorders
4) Besides the thump hole there is an extra hole in recorders , in total 8 holes, which allow for playing to modes of the diatonic scale , the ionian and the dorian, but in overall it is a confusing redantuntly complicated system to play straight and in a minimal way a diatonic scale . The best minimal system of holes to play a diatonic scale is of course only 6 holes in front , which is more or less a universal preference all over the planet (Chinese, Incas, Irish , Greece, Japan, Africa, Scandinavia etc) Irish whistles are a perfect example of it. The next minimal number of holes (to play a diatonic scale) is the 6+1 system with an additional thumb-hole (often called "soul" as it doubles the frequency) and it necessary only when the diameter is rather large (ratio of total length to diameter rather low) which requires partial holing on the thumb to excite the 2nd harmonic and play easily with almost the same blowing strength the 2nd octave.
After these realizations and combining the corrections of such design inefficiency that have already been discovered and implemented by various countries and their folk ethnic music (Irish, Greek, Andes, Chinese, etc)

 In winds there two types of impedance a) the vibration impedance responsible of propagating the vibration from the air column of the mouthpiece to the air column of the tube,and then outside the tube b) The air-flow impedance which is the resistance of the flow of the air. Large bore tubes have reverse effects on the two types of impedance: They increase the vibration impedance because a larger mass of air must vibrate , but they decrease the air-flow impedance because lower flow speeds are necessary to drive the blowing outside the tube compared to thin bore tubes. The air-flow impedance is by far of larger effect on the felt "resistance in playing and producing sound compared to the vibration impedance. 

A summary of a best such design is

THE BEST DESIGN FOR END-BLOWN FLUTES WITH FIPPLES

1) CONSTANT DIAMETER TUBE AS THE GOAL IS OPTIMAL FUNCTIONING AT ONLY TWO OCTAVES AND A PERFECT HARMONIC SINUSOIDAL SOUND
2) MEDIUM TO LARGE DIAMETER OR RATIO OF TOTAL LENGTH TO DIAMETER SO AS TO HAVE A STABLE AND ROBUST SOUND AT THE FIRST OCTAVE WHERE MOST OF THE ACTION IS INTENDED TO TAKE PLACE. THE CHOICES OF INCAS AND ANDES QUENAS AND SLIGHTLY ONLY NARROWER DIAMETER BUT LARGER THAN THE IRISH WHISTLES DIAMETERS IS A GUIDE FOR THIS. THIS RATIO TUBE-LENGTH/BORE INTERNAL DIAMETER SHOULD NOT BE LESS THAN 20 OTHERWISE THE 2ND OCTAVE WILL BE SERIOUSLY OUT OF TUNE IN THE HIGHER NOTES. (THIS IS THE MAIN REASON WHY THE NATIVE AMERICAN INDIAN FLUTES DO NOT PLAY A 2ND OCTAVE AS THE HAVE SUCH RATIO LESS THAN 20 . IF SOMEONE INSISTS IN HAVING THIS RATIO LESS THAN 20, THEN WITH APPROPRIATE MOUTHPIECE (e.g. very narrow layer of air thus very high speed of air falling on the edge of the fipple or fipples with membrane [see post 243] ) HE MIGHT BE TO PLAY A 2ND OCTAVE BUT HE MIGHT ALSO NEED SPECIAL MODIFIED FINGERING. E.G. At about 24 celsius degrees temperature, the speed of sound is 345 meters/second and for the frequency 587.33 of high D, D5 the half-wavelength is 29.37 cm. So a high D5 whistle normally has length 29.37, and the minimum ratio 20 of the pipe-length/bore internal diameter gives a maximum internal diameter for the pipe of 14.68 mm !) CONVERSELY WHISTLES WITH LENGTH/BORE INNER DIAMETER RATIO LARGER THAN 48 WILL HARDLY HAVE A FIRST OCTAVE FROM THE 1ST HARMONIC BUT ONLY 2ND OCTAVE AND HIGHER FROM THE 2ND HARMONIC AND HIGHER. MANY OVERTONE FLUTES LIKE GUJARA WHICH HAS SUCH RATIO 55 BELONG TO THIS CLASS. WE DISCUSS AT THE END OF THIS ARTICLE SUCH CASES OF DIATONIC-OVERTONE WHISTLES. Normally whistles with the intention to play robust and mainly in the first octave should not have L/B ratio larger than 28.
3) LARGE SIZE HOLES. A GUIDE IS THE SIZE OF THE HOLES OF ANDES QUENAS THAT ARE LARGER EVEN COMPARED TO THE IRISH WHISTLES THAT ARE OF COURSE ALREADY OF LARGER HOLES COMPARED THE RECORDERS. THIS ALLOWS FOR EASY SHARPS AND FLATS BY PARTIAL HOLING AND SMOOTH GLISSANDI OF A FULL OCTAVE. THERE IS THOUGH ONE CASE THAT LARGE HOLES ARE NOT THE BEST WHEN VERY FAST MELODIES ARE PLAYED WHERE SMALLER HOLES ARE MORE CONVENIENT NO TO MAKE FINGER-COVERING MISTAKES. BUT SUCH VERY FAST MELODIES ARE RATHER RARE. ALSO TOO LARGE HOLES FOR SOPRANO WHISTLES MAY RESULT IN TO NON-TUNED AND DIFFICULT 2ND OCTAVE.
4) A FIPPLE OF THE TYPE OF IRISH WHISTLES WHICH IS LARGER THAN THE FIPPLES OF RECORDERS CHINESE RECORDERS AND ANDES PINQUILAS. THE SOUND HOLE OF THE FIPPLE SHOULD BE SLIGHTLY ONLY LESS THAN THE SIZE OF THE HOLES ON THE TUBE.
5) IT IS BEST TO HAVE THEM TUNABLE AND WITH AN ABILITY TO CHANGE THE FIPPLE MOUTHPIECE WITH A RIM-BLOWING MOUTHPIECE AS IN QUENAS OR JAPANESE SHAKUHACHI OR CHINESE XIAO FOR VERY SKILLFUL PLAYERS OF RIM-BLOWING MOUTHPIECES WHICH ALLOWS FOR MORE CONTROL FROM THE PLAYER.
6) WE MAY ADOPT THE CHINESE TRICK OF DIZI FLUTES OF AN EXTRA HOLE COVERED PERMANENTLY BY A MEMBRANE E.G. ORDINARY TRANSPARENT OR NOT PLASTIC TAPE, ANYWHERE BETWEEN THE SOUND HOLE AND THE FIRST NOTE HOLE. THIS HOLE IS NOT USED TO PLAY A NOTE BUT ONLY TO MAKE A SPOT OF VERY THING WALL OF THE TUBE WHICH VIBRATES AND MAKES THE OVERALL SOUND MORE SWEET. IN ADDITION IT MAKES THE FIRST OCTAVE MORE STABLE NOT TO MUTATE TO THE 2ND OCTAVE ACCIDENTALLY.

IT SEEMS THAN MANY VERY EXPERIENCED HANDCRAFTED IRISH WHISTLES MAKERS TURN TO SUCH A DESIGN EVEN FOR D5 WHISTLES AND THE PRICES THAT APPEAR ARE FROM THE HIGHEST THAT ONE CAN FIND FOR IRISH WHISTLES.

Greek such flutes that are called souravli in Greece and habioli or thiaboli in Creta had such a design but gradually it was lost by the influence of the German recorders.
I have made plenty many such optimal design end-blown flutes with fipple from PVC. From Bb3 , B3, C4, D4, E4 F4 , A4 F4 Bb4 C5 to D5 .
I have used for the body the designs of Andes quenas with large diameter and large holes 6 front plus 1 thump , while I have used ready-made Irish whistles fipples. The results is a sound and easy playing better than the German recorders , better (deeper and more stable in the first octave ) than the Irish whistles and easier to play compared to Andes quenas. Compared to Irish whistles they have deeper ,louder and more stable sound in the first octave but more difficult sound in the second octave , that is why one must use partial holing by the thump hole to make it adequate easy. Compared to recorders they have a deeper and more bass sound stable and loud first octave and abilities of easy sharps flats and octave glissanti. Compared to Pinquilo of andes (like quenas with fipples) they have more bass sound as the sounding hole of Irish whistles is rather larger than the sounding hole of Bolivian Pinquilo.


The opening of the holes is by the acoustics of the perfect pipe. In other words  The reduction of the length of the  pipe so as to make the sound of pitch higher by one semitone is (1/2)^(1/12)=94.38% shorter. While so as to make sound of pitch one tone higher is (1/2)^(1/6)=89.08% shorter. This means that the distances of the holes become shorter as we go closer to the mouthpiece by a quantitative rule similar to that of the frets in the guitar.
Nevertheless because these calculations are for cutting vertically the pipe, while we just open holes, there should exist a correction to it, and the correction for holes at about a fraction of the  internal diameter of the pipe, is the we make the hole closer to the mouthpiece by about 80%-83% of ID where ID is the internal diameter of the pipe. Probably this empirical correction formula can be refined to one that  the correction is less the higher the pitch of the hole thus a formula like correction=(0.8*ID)/(a*pitch_of_the_hole) , and the coefficient a is again to be empirically found by experiment. Of course in practice we cut the pipe length at the correct initial note and then for the first highest pitch hole we just make a small hole about there (taking in to account the above correction) and then we widen (which means that we raise the pitch) it it till we reach the correct pitch.
 If we want all the holes to be of less diameter as in recorders we start the first (lower pitch) hole closer to the mouthpiece than above estimations and we proceed.   The converse if we want all the holes of larger diameter.
Other practical rules for opening the holes as we move from the lower to the higher pitch holes involve measuring the relative distance  of the holes for tones,semitones, etc that we have opened so far and repeating them by shortening them a  little as we move to higher pitch holes. Or if we already have another flute that we have successfully made and well tuned, we copy the holes distances.

High chimneys in holes (e.g. by thick walls tube or by branched tubes) lower the pitch.

Some flute makers prefer equal distance holes , for the convenience of the fingers, which will mean that the diameter if the holes will become larger as we go closer to the mouth piece. In general the thickness of the pipe plays also a role.
More thick walls pipe more bass the sound and shorter the length and holes closer to the mouthpiece . If we utilize inverse cone pipe, in other words larger diameter closer to the mouthpiece and shorter at the end (as with Clarke whistles ad German recorders) , this will mean shorter length and holes closer to the mouthpiece , but also more blowing.
The size of the sound-hole at the mouthpiece is also very important. It is a good rule to make it (e.g. square or circular) but as a percentage of the size of the internal diameter of the pipe (e.g. circular of diameter 2R equal to the half the internal diameter of the pipe 2R=ID/2 or in general 2R=aID 0<a<1.
 E.g. a=33%-66% A good practical rule for a is to be so that the size of the sound hole is the average size of the finger-holes. The larger the sound hole the higher the pitch, but also the more breathy the sound, good for the first octave but difficult 2nd octave. The shorter the sound hole the lower the pitch , easier 2nd octave but very low volume 1st octave , which easily may jump in an unintended way to the 2nd octave. Also of the sound hole is not rectangular but an orthogonal shape, if the length along the axis of the pipe  is longer than the side vertical to the axis of the pipe, then the sound is more sweet and breathy. If it is conversely  the length along the axis of the pipe  is shorter than the side vertical to the axis of the pipe, then the sound (as it is usually in Yamaha and Hohner recorders and low D Irish whistles ) is more acute like Shakuhachi sound, and the first lower octave is more unstable. E.g. if  the short side of the orthogonal sound hole , parallel to the pipe's axis is r then the vertical longer side is 2r and 2r=ID/2, where ID is the internal diameter of the pipe.
If ones what to have easier 2nd octave than 1st octave, then a square hole not larger than 1/3 of the ID of the tube is a good choice while the finger holes can be larger.

Open cylindrical tubes resonate at the approximate frequencies:
where n is a positive integer (1, 2, 3...) representing the resonance node, L is the length of the tube and v is the speed of sound in air (which is approximately 343 metres per second [770 mph] at 20 °C [68 °F]).
A more accurate equation considering an end correction is given below:
where d is the diameter of the resonance tube. This equation compensates for the fact that the exact point at which a sound wave is reflecting at an open end is not perfectly at the end section of the tube, but a small distance outside the tube.


A closed tube will have approximate resonances of:
where "n" here is an odd number (1, 3, 5...). This type of tube produces only odd harmonics and has its fundamental frequency an octave lower than that of an open cylinder (that is, half the frequency).
A more accurate equation is given below:
.

We may also copare with  the Helmholtz resonator formula (which applies for ocarinas also )
\[ f = \frac{1}{2 \pi} \sqrt{\frac{p_0 \kappa A}{V_0 \rho l}} \]

where f is the frequency  at a hole, p0 is the pressure and ρ the density ofthe air, while V0 is the volume of the tube till the whole (thus the intenal diameter of the tube is involved) , l is the lenght ofthe tube  till the hole, and A is the total area of the soundhole plus the fingerhole.
where \kappa is just a number, depending on what kind of gas we have. For dry air at 20°C or 68°F, we have \kappa=1.402

See
https://en.wikipedia.org/wiki/Helmholtz_resonance#cite_note-physicsocarinaforest-7
and
https://web.archive.org/web/20130314100538/http://ocarinaforest.com/info/physics/how-ocarinas-work/

There are flutes that behave half like ocarina and half like a tube-flute . E.g.

https://www.youtube.com/watch?time_continue=16&v=Y-HOlxDQQLQ&feature=emb_title


A good question of course is if such ocraina-flute hybrid winds have all harmonics or only the odd number harmonics.

















Since we are discussing here innovative improvements if folk instruments, here area couple of  interesting questions for reed winds.

1) FREE-REED OR FREE-MEMBRANE OR  FIPPLE-AEROPHONES  WITH ALTERNATING OPEN/CLOSE-OPEN TUBE ACOUSTICS WITH BOTH ODD AND EVEN+ODD  HARMONICS ? It is known that by adding a hole (actually a branched pipe) just after the mouthpiece in a closed-open acoustics non-free reed wind (as in Venova of yamaha https://www.youtube.com/watch?v=3XCan3cV76Q) or simple similar versions as the cylisax here https://www.youtube.com/watch?v=J0Ka4M_CvVY&t=95s  and https://www.youtube.com/watch?v=6wa0mPEmJI0  or https://www.youtube.com/watch?v=1B5fTwSC4QQ) the acoustics become open-open having all the odd and even harmonics (overtones)  The question here is, can we apply the same idea for free-reed winds like Bawu , Hulusi etc so that they become from close-open acoustics to open-open acoustics? Could we manufacture such a free-reed open-open pipe acoustics wind? Or alternatively if we use the long and fast increase diameter cone instead of pipe as in the saxophone would we not result to a sound with all the odd and even overtones as with saxophone? Could we manufacture such a free-reed saxophone wind? The same would apply of course if we utilize free-membranes for open-open acoustics instead of free-membranes for cose-open acoustics . All we need to do is to  make sure that the environment of the membrane has environmental air pressure. The reed and membranophone winds with alternating closed-open and open-open acoustics will function for the first octave with the 1st harmonic as closed-open or open-closed tubes and for the 2nd octave again with the 1st harmonic as open-open acoustics! For the reed-instruments like soprillo saxophone this is achieved by a registry hole on the mouthpiece close tthe reed, which converts closed-open acoustics to open-open acoustics. What is remarkable is that even the fipple-aerophones that are considered open-open acoustics can have conversion to alternating close/open-open acoustics! A fipple is normally open,but we can design fipples internal to the tube that are of closed-open acoustics!    ALL THE ABOVE INTRODUCE NEW FAMILIES OF ADVANTAGEOUS WINDS WITH SHORTER HALF LENGTH THAT HAVE NOT BEEN PRODUCED SO FAR ESPECIALLY BY THE INDUSTRIES.

2) FREE-REED OR FREE OR NOT MEMBRANE OPEN-OPEN TUBE ACOUSTICS WITH BOTH ODD AND EVEN HARMONICS. A free wind instrument like Bawu and  Hulusi , or piper (mantouri) the blowing is from around the free-reed therefore the pressure at this end is not of the open air and the acoustics are closed-open pipe acoustic, s with the odd overtones only. But what if we blow from inside the pipe so that the free-reed vibrates at open air  (as in harmonica) ? Would not have then open-open pipe acoustics with all the odd and even overtones? Could we manufacture such a free-reed open-open pipe acoustics wind? Here is a video with an informal experiment from a young anonymous guy, with seemingly free-reed and open-open acoustics as ocarina in plastic bottle https://www.youtube.com/watch?v=hx0CoDQVtvo&fbclid=IwAR3y5VBvxh7QUUvfxXzMVRuvSBEBB01mRsJlXmDRgH-BbuMCHmItY2EliH8

On the other hand if for a cane-reed instrument like clarinet the opening of a registry hole very close the the mouthpiece converts it to a  reed-instrument with open-open acoustics (like Venova or Soprillo Sax) , then applying it to have permanently open-open acoustics we have easier fingering for the 2nd octave (6+1 holes) like quenas by using 1st and 2nd harmonics (overtones) instead of only the 1st harmonic. Why not then design and make such open-open acoustics reed-instruments? 

Here is an photo of a memraphone which normally it would have a closed-open tube acoustics but with a long chimney right after the mouthpiece it becomes open-open accoyutsics with all the odd and even harmonics compared for example with the standard mebraphone clariphons (like the claricano here https://www.youtube.com/watch?v=64Uy7BQHMgg ) with closed open acoustics. The sound is more open and closer to saxophone rather than  closer to clarinet. The straight branch is so as to blow while the curved is as in the case of yamaha Venova, to create open-open acoustics.






3) SINGLE TUBE RIM-BLOWING OPEN-CLOSE  ACOUSTIC DIATONIC WINDS? It is known that the pan-flute as rim-blowing winds has a very nice breathy sound closer to the human voice, compared to a concert flute, and that the pipes of it are closed to the end so that acoustics are open-closed pipe acoustics with the odd only overtones. What if we design a pan-flute with a single only pipe and rim-blowing like a quena , and instead of holes we put mechanical valves that change the pipe length by closing the pipe at particular height so that all the required notes and pitches are produced? Would it not such a  rim-blowing single pipe open-closed pipe acoustics wind be easier to play at least for one or two octaves? It could also be a sliding wind with a slit and a moving bottom, as long as the part of the slit is always covered, or it could be sliding wind with a second pipe moving in it.

4)AEROPHONE WITH FIPPLE  TRUMPETS? AEROPHONE DIDGERIDOOS(FUJARAS)  WITH TRUMPET ACOUSTICS.
LONG TUBE AEROPHONES (CHROMATIC/HARMONIC WINDS)  WITH FIPPLE ,SIMILAR TO FUJARAS/DIDGERIDOOS, TRUMPETS AND BRASS WINDS (ratio 80< Length/Bore and about equal 125 as in trumpets ) ?
It is known that many  long tube winds have been invented with cane reeds (like  coils either double reeds  https://www.youtube.com/watch?v=QwPgiVCVxEA or single reed like Mr curly of Lindsay Polak https://www.youtube.com/watch?v=Iu60MwpMiow ) or lips-reeds in trumpets and other brass winds. But what if the same acoustics are used for aerophone winds with fipples? Fujara and didgeridoos are simplistic  cases of them with close air acoustics at the side of the mouth but they can be rendered to open-open acoustics with fipples. Such winds have not been elaborated in the same way with valves etc as the brass lips-reeds winds.

The fujaras that are know if they have large bore inner diameter and thus length/bore ratio less than 80 will not belong to the acoustic and musical effect described here (sliding whistle over a desne scale of higher harmonics)
Examples of Fujaras
https://www.youtube.com/watch?v=y8Wzb3tLPCs

I made one such aerophone didgeridoo from a 97 cm long PVC pipe with inner diameter 12mm (thus Length/bore ratio= 970/12=80.83) and with a fipple from a Sweet tone Clarke whistle C5. I opened 4 holes above the middle of the tube (corresponding to the 2nd harmonic) that as in the trumpet keys give an increase of the tone by 1 semitone by 2 by 3 and by 4 semitones (one more key than trumpets) .The action is mainly on the 6th and 5th octave. The base not is F5.
Then I made a 2nd one. I made this 2nd   aerophone didgeridoo from a 172 cm long PVC pipe with inner diameter 16.5 mm (thus Length/bore ratio= 172/1,65=104.24) and with a fipple from a generation whistle at Bb . I did not opened holes as the variation of pitch was relatively easy and desne in the harmonics.The action is mainly on the 6th  and 5th octave. The base not is G5.
These winds should not be confused with the Mosenos that are similarly long and with a fipple but they still play at the 1st 2 harmonics with small Length/bore ratio compared to 80.

More experiments that are not irrelevant by Nikolas Brass



https://www.youtube.com/watch?v=oKnK5h_y3pg


5) LONG CHIMNEY (BRANCHE TUBE) IN LOW AND BASS WHISTLES TO LOWER THE TOTAL LENGTH AND MAKE THEM EASIER  FOR FINGERING

The idea (and patent) of Yamaha with a long chimney or brach-tube just after the mouthpiece and of about 2/3 of bore size compared to main tube was so as to convert close-open acoustics (with odd only harmonics ) to open-open (with both odd and even harmonics). But it has another effect too: It lowers the total length of the tube. This technique applied to low and bass whistles will make them of considerably shorter length . This will make the covering of  the holes with the fingers a lot easier . Even the "pipers grip"might not be necessary now.
In  the next photo we see a  D4 clariphon (chalumeaux) with along chimney which converts it from closed-open acoustics to open-open acoustics. Nevertheless the same technique will make a Low D4 whistles with a fipple a lot shorter!



6) WHISTLE WITH A MEMBRANE  REED ON THE FIPPLE WHICH REDUCES THE VIBRATION IMPEDANCE.
It is possible to have a reed on the soundhole of the fipple of a whistle! For this the sound hole must be larger, and then cover the extra part with a plastic or other material membrane reed. It could also be a cane reed. The vibration of the air which is vertical to the surface of the membrane will set in vibration the membrane-reed also which will influence the color and quality of the sound.  This idea exist also in the dizi chinese flutes, but they put the membrane not on the soundhole but on an extra hole just after the mouthpiece. It adds to the sound of the flute the sound of the membrane which vibrates as the air flows parallel to it. I used a membrane-reed from a white balloon, and actually I put it in double sheet as it was the balloon before inflating. It has to be well stretched and fixed on the fipple by tape. In the photo we see an example on a wooden-plastic Fipple of a Low D4 whistle with thin wall aluminum body of inner diameter 25 mm . The open sound hole that is left, has ratio of transverse to longitudinal sides 2:1.  The area that the membrane-reed covers is about double the uncovered one (Uncovered : 10mm*5mm Covered about 10mm*10mm ) Before the balloon reed, the fipple had large sound hole with very breathy sound and difficult 2nd octave. After the balloon reed the sound hole become 10mm*5mm and the low octave acquired very clear (not breathy) and soft sweet sound, while the 2nd octave acquired again very clear (not breathy) and loud melo sound,and somehow it is  more pleasant and easy to play in the higher octave than in the lower as is the case with the concert Bohm flute too.  This suggest happier melodies that star in the 2nd octave move in the low 1st octave and finally end again in the 2nd octave as in the upper registry whistles (see below THE UPPER REGISTRY WHISTLES (28< Length / bore ID ratio  <48) FOR HAPPIER MELODIES ) . The overall result was a substantial improvement of the sound and easier playing response of the whistle.  Suddenly this cheap Low D4 whistle become the best sounding and playing Low D4 whistle among many other expensive ones that I have! The material of the reed influences the color of the sound. I did not try it but I assume that if I would put a cane reed from say an alto sax cane reed, the sound would be more woody. Obviously this can apply also to soprano C5 and D5 whistles and might allow rather wide bore such whistles (more than 14 mm)  to have easier , clear and loud 2nd octave, even if the Length/bore ratio is less than 20.
 In winds there two types of impedance a) the vibration impedance responsible of propagating the vibration from the air column of the mouthpiece to the air column of the tube,and then outside the tube b) The air-flow impedance which is the resistance of the flow of the air. Large bore tubes have reverse effects on the two types of impedance: They increase the vibration impedance because a larger mass of air must vibrate , but they decrease the air-flow impedance because lower flow speeds are necessary to drive the blowing outside the tube compared to thin bore tubes. The air-flow impedance is by far of larger effect on the felt "resistance in playing and producing sound compared to the vibration impedance. The membrane on the fipple does not affect much the air-flow impedance but lessents the vibration impedance.




TWO  OTHER CLASSES OF AEROPHONE WINDS WITH FIPPLE

A) THE UPPER REGISTRY WHISTLES (28< Length / bore ID ratio  <48) FOR HAPPIER MELODIES
In  this category belongs also the concert flute (especially if we substitute the upper head join with a fipple) Its ratio L/B=33. Other traditional flutes in this category are many recorders and also it is the Ney if we adopt a fipple instead of rim-blowing and also the kaval flutes too. Such types of  flutes and whistles are designed for happier music and melodies where we start at the higher registry (octave) we may move to the lower registry (octave) and we end the melody in the higher registry (octave_ again. Such whistles when blowing normally they play directly to the 2nd registry (octave) while when we want to play to the lower 1st registry (octave) we have to underblow carefully. This is  the inverse with the standard whistles that when we blow normally they play in the 1st registry and in order to play in the 2nd registry we must overblow.
In the next picture we see two such whistles one in D4 and one in C4 with L/B ratios respectively the D4  55cm/1.65cm=33.33
and the C4 63cm/1.65cm= 38.18

I have made on more in F4 with L/B ratio equal to 47.5cm/1.2 cm=39.58


B) THE  DIATONIC AND CHROMATIC OVERTONE WHISTLES (48< Length / bore ID ratio <80 ) FOR CHORD ARPEGGIOS AT EACH HOLE.
These whistles are relatively unknown and I am not aware of any traditional flute in this category. The closest traditional flutes are the overtone flutes but they do not have many holes for a diatonic or other scale. This flutes have the peculiar characteristic that they are so long and with thin tupe (L/B ratio above 48) that when blowing or even under-blowing they cannot lay the 1str harmonic registry (octave). They only play with the 2nd or higher harmonics. They have more than 8 harmonics that sound easily with blowing softer or stronger. These flutes are a combination of the traditional overtone flutes and the standard diatonic flutes like irish whistles. As far as it is  concerned the acoustics relevant to the L/B ratio (which is between 48 and 80  ) , they are in between the trumpet acoustics with ratio around 125 and classical flutes and whistles with ratio between 16 to 48.
They play with less than half action  "horizontally" with their holes as diatonic scale (e.g. 2 octaves) and more than half action  "vertically" at each hole more than 8 overtones (3 ,4 octaves) that are essentially arpeggios of major chords (up to the 7nth harmonic).  Up to the 10 harmonic, the overtones of each hole belong to the scale (with the exception of the 7nth harmonic which makes the arpeggio , that of a major chord with  7nth). The playing is best when it is improvisational. It is nice to play a melodic theme and be able to play also over each note of it the arpeggio of  power-chord or major chord. The overall range of such flute is considerably larger than the standard whistles. The fipple sound hole is preferably smaller than the usual to help the higher overtones.Such winds are so much so as to read an existing  written melody from musical notes and play but a melody inside you to improvise and meditate .

The fujaras that are known if they have large bore inner diameter and thus length/bore ratio less than 80 will also belong to the acoustic and musical effect described here if made by smaller size bore and thus also shorter length (thus maybe not bass flutes). The fujaras use to have only 3 holes at the diatonic 4-chord in semitones 2-2-1. E.g. if the root is C3, then the holes give the notes D3-E3-F3 but at the 3rd harmonic G4 they will give the notes  A , B , C  thus eventually all the diatonic scale. Similarly if we open 5 holes chromatically in semitones 1-1-1-1 as in the style of valves of trumpet,  for the first harmonic it would be C#3-D3-D#3-E3-F3, the 3rd harmonic will give on the same holes G#, A , Bb, B, C , thus eventually all the 12-note chromatic scale
Examples of Fujaras
https://www.youtube.com/watch?v=y8Wzb3tLPCs

See also

https://www.youtube.com/watch?v=qzOLO5YHL9Q


The general rule to make an overtone whistle say in X base tone (e.g. C5, G4, D4, C4 etc) is to utilize the same bore inner diameter size with the ordinary whostre but about double the length. This is expected in general to give the Length/Bore ratio between 48 and 80. The resulting whistle is an overtone whistle that the basic tone (one octave lower than the corresponding whistle tone) cannot be played in the instrument , but the next octave (2nd Harmonic) is playable which is the original whistles root note.  Furthermore if we want a diatonic overtone whistle we utilize only 3 holes (the  lower pitch 3 holes if it would be an ordinary whistle) If the length is very long (for alto or low whistles) we "coil" the tube with turns and rounds as in t he brass wind instruments.  If we want a chromatic such overtone whistle we simple fill-up the gaps of the 3-holes of the diatonic overtones whistle as above with all their sharps or flats getting so 5 holes in the same area , which is about the lower 1/3 of the tupe. In thsi way with the 2nd and 3rd overtone we have all the 7-notes diatonic scale or all the 12-notes chromatic scale.  
In the next picture I made from 16 mm bore  (inner diameter 12 mm) PVC and sweet tone Clarke whistles mouthpieces (fipples of D5 and C5 ) two such "magical" diatonic overtone whistles in D5 and C5 (although the length is as if of Low D4 and C4).The have respectively L/B ratios the D5 57/1.2=47.5 and the C5 64cm/1.2cm=53.33
They have 6+1 holes, but if we seal with a tape all except the highest 3, as in Fujara, we still have with the 1st and 3rd harmonic all the 7 notes of the diatonic scale.



In the next photo we see  a C5 and aF5 overtone diatonic whistles only 3 holes are opened and suffice for a full 7-notes diatonic scale even only with the 2nd and 3rd harmonic.


Here is a bass in Bb3 diatonic from PVC of 32mm external diameter ,  of length about 148.2 cm (the same length with a Bb4 trumpet) , again with only 3 holes. In semitone intervals 2-2-1 or in notes Bb3 C4  D4 Eb4 . That is all it is necessary for a 7notes scale because it already starts with the 2n harmonic (due to the double than normal length)   and the 3rd harmonic gives in the same octave and on the same 3 holes  the the notes  F4-G4-A4-Bb4 thus all the Bb3 7-notes major scale. As it is a bass one, it falls in the category of Fujara. The high pitch ones I call overtone whistles. By changing the last part of the coil-tubes with another of appropriate length and holing we may have more roots on the same upper body.



In the next 2 photo we see a  C5 full chromatic overtone whistle that utilizes practically the 2nd and 3rd harmonic and with the 5 holes to give the chromatic half octave C5 C5# D5 D#5 E5 F5 F#5 with the 2nd harmonic and with the 3rd harmonic to give on the same holes the G5  G#5 A5 A#5 B5 C5 C#5 gives thsu a full chromatic 12 notes octave. The 1s tharmonic  is hardly listened or of sound it is fused with the 2nd harmonic due to the membrane fipple (see post 243) and gives to this part of the 5th octave a more bass sound. It is made again by PVC tube of external diameter 25 mm. The lenghth to bore ratio Length/bore=34 , thus strictly speaking an upper registry whistle (see post 199 ) rather than an overtone whistle. That is why it does not give more than the 3rd harmonic. The idea is the same with the trumpet and the valves that produce 5 notes each a semitone away from the previous. We see 7 holes in the front (there is not thump hole) but the highest pitch hole is a tuning hole for C5, thus 6 holes covered 3+3 by the two hands. These 5 notes that divide a 5th (laso a 4th) give the concept of ancient Greek 4-chords and 5-chords as basic building block for an octave scale. If we close that tuning hole too it will give a Bb4 note as in aC4 Ney. The whistle as it has a breathy harsh sound due to the membrane fipple sounds almost exactly like a C4 Ney flute (which normally is rim blowing ) and if we exclude the 1st harmonic of the Ney is identical with what the Ney is playing (of course the semitones are in the equal tempered scale rather than deviating scale)



A trumpet that the sound is produced by the lips is a  lips-reed wind with closed-open acoustics that normally have only odd number harmonics (overtones) . Nevertheless because of the gradual cone at the end, as with the saxophone  eventually because of a complicated phenomenon of acoustics  both odd and even number of overtones. Still strictly speaking an aerophone is not producing the sound from a reed, but by a fipple or rim blowing. A modern trumpet at Bb was tube length of 1.482 m and is producing 8 overtones, the first is not possible to play so from 2nd to 8th are C4 G4 C5 E5 G5 A5 C6. These 7 notes are essentially part of an arpeggio of the C major chord with 7nth within 2 octaves. The keys-valves allow for 6 more series of such harmonics each one a semitone lower. 

So what if the same acoustics are derived as aerophone winds with fipples? Fujara and didgeridoos are simplistic  cases of them with close air acoustics at the side of the mouth but they can be rendered to open-open acoustics with fipples. Such winds have not been elaborated in the same way with valves etc as the brass lips-reeds winds.


The fujaras that are know if they have large bore inner diameter and thus length/bore ratio less than 80 will not belong to the acoustic and musical effect described here (sliding whistle over a desne scale of higher harmonics)
Examples of Fujaras
https://www.youtube.com/watch?v=y8Wzb3tLPCs

I made one such aerophone trumpet from a 97 cm long PVC pipe with inner diameter 12mm (thus Length/bore ratio= 970/12=80.83) and with a fipple from a Sweet tone Clarke whistle C5. I opened 4 holes above the middle of the tube (corresponding to the 2nd harmonic) that as in the trumpet keys give an increase of the tone by 1 semitone by 2 by 3 and by 4 semitones (one more key than trumpets) .The action is mainly on the 6th and 5th octave. The base not is F5.


As 2nd version o the holes we open a hole at the 2/3 of the length (corrected higher by above 80% of the more diameter) which corresponds the 3rd harmonic and two holes  that give sequentially 2 semitones above it. And we also we mark the middle of the tube (that would correspond to  thump hole giving the roo one octave higher, thus 2nd harmonic) but we do not open a hole there, we only open again 3 holes that give sequentially 1 tone  1  semitone and 1 semitone above it. In this setting of 5 holes (3+2) we incorporate almost the natural minor, the double harmonic minor and the harmonic minor in the main octave (which contains the 1-3-1 semitones pattern and has 5# and 2# in place of 5 and 2. The harmonic minor has only 5# in place of 5 and 2 while the natural minor has 5 and 2 ) which is chromatic feeling that complements the strongly harmonic feeling of the arpeggio of the major chord of each hole as higher harmonics). Strictly speaking the holes scale is the parachromatic Byzantine which is in semitones 1-2-3-2-1-1-3 (in steps of  F major it is 5, 5# 6, 1, 2, 2# 3 5).When we open all the lower 3 holes a major 3rd interval appears , while of we open only the upper two holes a minor 3rd interval appears. Alternating these two we get nice harmony.

Then I made a 2nd one which feels even better (because the ratio is higher 104 and the bore larger) without holes  . I made this 2nd   aerophone didgeridoo from a 172 cm long PVC pipe with inner diameter 16.5 mm (thus Length/bore ratio= 172/1,65=104.24) and with a fipple from a generation whistle at Bb . I did not opened holes as the variation of pitch was relatively easy and desne in the harmonics.The action is mainly on the 6th  and 5th octave. The base note is G5.

These winds should not be confused with the Mosenos that are similarly long and with a fipple but they still play at the 1st and 2 harmonics mainly with small Length/bore ratio (e.g. 20) compared to 80.

The most important characteristic of these aerophone trumpet, winds are

1) They need not be bass , but on octaves from 7nth to 4th etc
2) The sound is not really one note but rather like a chord with many hidden harmonics
3) They must have very high Length/bore ratio above 80 and preferably around 125
4) They behave in the pitch of the sound like sliding whistles with a continuum of pitches but not entirely on all frequencies but on a dense grid of harmonics (certainly more than 12 chromatic notes in the octave) 
5) They are very satisfying in playing like natural human whistling but unlike it or unlike the violin without frets, the harmonics give a natural scale of "frets"  that the pitch falls in it which is very harmonic to listen . It is so because the relative change o the pitch is determined always by harmonics.
6) The harmonics are very easy to obtain not by overblowing (as in standard overtone whistles)  but by simple blowing even under-blowing. 
7) Holes are not necessary for hem. Only if the Length/bore ratio is much less than 125, e.g. 80 then 4 choles (reachable by the hands) at equal pitch distances of one semitone are adequate to help small chromatic changes of 1, 2 3 or 4 semitones (in trumpets the 3 keys help for 1,2 and 3 semitones). The reason that 4 semitones is added is because  a  sequence of alternating minor-major thirds gives chords on every 3 notes.
8) Such winds are so much so as to read an existing  written melody from musical notes and play but a melody inside you to improvise and meditate .


More experiments that are not irrelevant by Nikolas Brass