Flat Second Octave on Parallel bore

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bansuri
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Flat Second Octave on Parallel bore

Post by bansuri »

I have made a few flutes out of ABS plastic pipe and while i can get the first octave to be perfectly in tune, and the first four notes of the second octave are only slightly flat, anything above that the notes are flat by up a semitone.
My D flute is 22mm bore with 2mm wall thickness.
I am not a flute player but trying to learn to play.
I can buy a ready made flute but as a retired person who has time on his hands i enjoy making my own.
Any advice on how to improve the second octave on a plastic parallel bore flute.
Thank you.
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Sedi
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Re: Flat Second Octave on Parallel bore

Post by Sedi »

I use similar tubing -- 1.5 mm wall and 2.2 inner diameter. It works fine. Maybe if you post the size of the holes and the stopper position as well as the size of the embouchure, I can help.
As a rule of thumb -- for a cylindrical bore flute to be in tune (as far as possible -- the C# in the 2nd octave will probably always be a litte flat but you can push it a little to be in tune) -- the stopper needs to be close to the embouchure (closer than on a conical flute), the finger holes should not be too small (the bigger the better -- depending on which fingerings should be used) and the embouchure not too big -- the larger the embouchure, the longer the flute and the closer the stopper needs to be to the embouchure, which will weaken the sound, especially of the low D. I found a 10mm embouchure hole to be pretty good -- but I will try a 9.5 mm on the next one I make.
But with a little experimenting you should be able to get it in tune good enough to even play with others without sounding "out of tune". I use my flutes quite often to play with my wife, who plays accordion, and it is almost perfectly in tune.
I wanted to make a post about the flute and how I did it, but I rarely have the time for lenghty posts these days.
Do you use a lip plate? If not, I would recommend using one, it will much improve the sound -- I use a 2mm thick lip-plate so the total wall thickness at the embouchure is 3.5 mm on my flutes. That improved the sound and response quite a lot.
This is one of the older ones I made -- I have since improved the tuning and design:
https://youtu.be/TneLh3gYmEE
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Re: Flat Second Octave on Parallel bore

Post by bansuri »

Thank you for replying with them useful ideas, my embouchure is 11mm , the stopper is 1 bore diameter away from the embouchure center ie 22mm.
I will measure and post the rest of the hole sizes.
Not sure how to post pictures or if we are allowed to.
Thank you.
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an seanduine
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Re: Flat Second Octave on Parallel bore

Post by an seanduine »

I had the pleasure of meeting a man named Raoul Fajardo.
Raoul patented a method of using an insert into the headpiece to accomplish just what you are seeking. It accomplishes what the Boehm Contraction does.
Google Raoul, The Tipple-Fajardo Wedge, and Doug Tipple.
Robert ´Doug´ Tipple used to post here. Hi Doug!
Read a little more here: https://sites.google.com/site/dougsflut ... jardowedge

Bob
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Sedi
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Re: Flat Second Octave on Parallel bore

Post by Sedi »

bansuri wrote: Sat Apr 10, 2021 9:37 am Thank you for replying with them useful ideas, my embouchure is 11mm , the stopper is 1 bore diameter away from the embouchure center ie 22mm.
I will measure and post the rest of the hole sizes.
Not sure how to post pictures or if we are allowed to.
Thank you.
Ah, thanks. The distance of the stopper is way too far. Try setting it at 15mm or maybe even just as far from the middle of the embouchure as the diameter of the embouchure - that's the rule of thumb for cylindrical flutes (setting it as far away as the bore diameter only works for conical flutes or if you use a boehm taper in the head or the above mentioned Fajardo wedge). So 11mm from the middle of the embouchure. If you reduce the embouchure, you will shorten the overall length of the flute and can then set the stopper a bit farther away from the embouchure. I made a flute today with 9.5 mm embouchure and it's very well in tune. I can measure the distance of the stopper and post it.
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Re: Flat Second Octave on Parallel bore

Post by Sedi »

So I took a few measurements.
On my flute with 11mm embouchure the stopper sits at 11.5 mm. The C# in the 2nd octave is only slightly flat.
On my flute with 9.5mm embouchure -- the stopper sits at roughly 18mm. And it is better in tune than the one with the 11mm embouchure. I do use a lip plate, which also might have an influence. You said, you use 2mm thick tube, mine is only 1.5 mm but with a 2mm lip plate.
Another factor is the top finger hole -- I try to make it fairly big -- mine has 9.5mm, that will improve tuning of the C# in the 2nd octave. But there is a limit to the size as I still want to be able to cross-finger C natural with:
oxx xox
If I make the top hole even bigger, tuning will further improve and the sound will be harder and stronger but I then need oxx xxo for the C natural.
If you are using half-holing for the accidentals you can make the holes as big as you want to -- as long as you can still seal them. The bigger the holes, the louder the flute, the harder the sound (with big enough holes it will sound like a boehm flute) and the better the tuning of the 2nd octave. But for the tuning the top hole and the embouchure in combination with the stopper position are most important.
The issue is -- if you improve the embouchure by just a half millimeter -- it will move quite a bit further up on the tube and the flute will get longer and that will mess up the stopper position and you have to move it much closer to the embouchure, which might weaken the low D and the sound is less strong and "hard".
The air-column is about roughly always the same length. So a slightly smaller embouchure will help a lot. Try reducing it to 10mm or even 9.5mm. Do you use a certain application to calculate the holes?
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Re: Flat Second Octave on Parallel bore

Post by bansuri »

Thank you Bob (an seanduine)
Yes i did know about the wedge but have never got around trying to make one.
I certainly would like to at some stage to try making a flute with a wedge and see
how much it improves the tuning.

Sedi,
I have pushed in the cork by 5mm so that its 18mm from centre of embouchure and i was surprised how much improvement it makes.
Will make another flute with 10mm embouchure and move the holes down by a couple of mm to make the holes bigger.
I use Mark Shepards percentage method of placing the holes, 43% 50% 58% 68% 73% 83% which seems to give good results.
I have used the calculator method as well but calculated holes sizes don't always work, i prefer to start with a small hole and keep enlarging
it until i get the correct pitch.
Still trying to work out how to post a photo on this page.
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Re: Flat Second Octave on Parallel bore

Post by Tunborough »

bansuri wrote: Mon Apr 12, 2021 11:06 am Thank you Bob (an seanduine)
Yes i did know about the wedge but have never got around trying to make one.
I certainly would like to at some stage to try making a flute with a wedge and see
how much it improves the tuning.
I suggest you also check out this thread on the cylindrical headjoint insert: viewtopic.php?f=2&t=107840&start=30. I suspect a stepped cylindrical insert can balance the octaves at least as well as a wedge, with less impact on the tone colour.
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Re: Flat Second Octave on Parallel bore

Post by Sedi »

That might work better than a wedge. I thought the wedge changes the tone too much and weakens it. But I never spent enough time to perfect it. I also used a "tuning rod" on some models, like on a German marching band flute -- the Sandner "Zauberflöte".
Very useful link btw. thanks. I remember the discussion but haven't yet read the PDF -- which I will now do.

I still think that a completely cylindrical flute is a valid design.
The one I made last (I was constantly tweaking the design for at least a year now, since starting to make wind instruments in 2015 -- first with a quena-style instrument, later whistles then flutes) has a C# in the 2nd octave that is just about 8 cents flat (compared to 1st octave C#) according to my RTT app, when I play it normally without any effort to "blow it in tune".
But I played ocarina for a long time and compared to the tuning issues of ocarinas the tuning problem of a cylindrical flute is a non-issue. So I might just unconsciously "blow it in tune".
I wanted to make a lengthy post (including a video and screenshots of the RTT app) to present it in the forum but I just don't seem to find the time. When I have a little time on the weekend -- I mostly spend it to make another flute :D . I also made them chromatic so that most of the cross-fingerings of a baroque flute work on it. In combination with a few half-holings -- I increased the lowest hole to be able to half-hole it with good results. It looks a bit like an asymetrical monstrosity however because of the hole sizes :D .
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Re: Flat Second Octave on Parallel bore

Post by an seanduine »

Bansuri, you will find an impressive discussion regarding parallel flute design acoustics here: viewtopic.php?f=2&t=107840&p=1212419
The entire thread is well worth the read.

Bob
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Re: Flat Second Octave on Parallel bore

Post by bansuri »

Thank you for all the useful information.
Are there any pictures or diagrams of a "stepped cylindrical insert" , how it fits and what size.
The "tuning rod" on the German marching band flute -- the Sandner "Zauberflöte". is interesting.
Another interesting discovery on the forum is the conical spike protruding from the face of the stopper and pointing down the bore, something
worth trying out.
Thank you gentlemen for your replies, much appreciated.
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Re: Flat Second Octave on Parallel bore

Post by Tunborough »

bansuri wrote: Thu Apr 15, 2021 12:08 pmAre there any pictures or diagrams of a "stepped cylindrical insert" , how it fits and what size.
Aye, there's the rub. To my knowledge, it's been tried in only one flute, which Terry McGee crafted from orange conduit, and a whistle that Hans described in a companion thread. The dimensions described in those threads are a place to start. You can try whatever you have to hand that's around 0.5 to 1.0 mm thick that you can form into a cylinder and slide into your head joint.
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Re: Flat Second Octave on Parallel bore

Post by Narzog »

I've only made whistles sofar, but mine I'm able to play the second octave in tune by pushing it into tune. By this, I mean the second octave notes, especially the higher ones, when you break into second octave, will be very flat. but you can push it harder and it will go into tune. So its just as the notes get higher I blow extra hard, which does feel natural with some practice. And its consistent, the higher the note the harder you blow. This style tuning also usually gives a good oxx ooo, and is how whistles like Generation are tuned. I use the Bracker calculator online for hole spacing and dimensions and its worked very well. Although you will want to tweak the last hole / hole sizes for low whistles. The calculator pretty much gives you identical dimensions to a generation, but on a low whistle the last hole is just too big, and on big bore the holes can be too big and need to be made smaller. You can also tune it so that the higher notes dont need push to be in tune (just make them sharper), and you blow the lower notes weaker to make them not go sharp. This is how Burke whistles are tuned, which makes them extra easy to paly in tune (at least this is how I feel like my Burke works). At the cost of a sharp oxx ooo. Maybe flutes work differently than whistles but I thought that whistles are just a flute that the embouchure is done for you by a fipple so I'd think that this should all work with a flute.
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Re: Flat Second Octave on Parallel bore

Post by bansuri »

https://imgpile.com/i/76waUM
https://imgpile.com/i/76wei4
Not sure if this will work but this is a picture of my home made flute. which i shall experiment with
adding the various tuning devices discussed here to bring the second octave more into tune.
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