# Walls of Wind Instruments



## Enthalpy

Hello everyone and everybody!

The topic is debated, but trials let me accept that wall materials influence the sound of wind instruments
scienceforums​Inadequate materials like thin injected plastic make the comparison obvious, hear it there
talkclassical - talkclassical​while good materials differ not so much and matter less than the temperature.

I proposed physical models for this influence, possibly the first ones whose figures make sense, one that involves the elliptic deformation of (thin) walls
scienceforums and followings​an other that considers the bending of the body
scienceforums and followings​one more that models the influence of tube turns
scienceforums and followings​still an other that considers the flare's effect
scienceforums and followings​
Shorting the physics: all my models need mechanical resonances of the body, and their effect compares with the small losses of the air column, not with the air's stiffness. Then, figures can make sense.

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Body bending matters more at long instruments like the contrabass clarinet or the contrabassoon, as more mechanical resonances happen at undesirable frequencies, and they interact more strongly with the air column. The outfashioned *racket construction would alleviate the effect of wall vibrations* radically at low instruments.
wikipedia​because the resonant frequencies of a single-part body increase like its diameter and decrease like its length squared. For instance if a long instrument is folded in 4 in a doubled diameter, and the body length is one-fourth, the resonant frequencies are 32x higher (or if comparing with two body joints, resonances are 8x higher, still wooooow!). Not only fall fewer resonances at sensitive frequencies: the 16x stiffer body vibrates less strongly too.

[Click for full size]








The body must hold together perfectly to increase the stiffness so sharply, hence the displayed single wood part, but wood take years drying and new shapes start at zero. The racket construction should gain so much that maple or even polypropylene (preferably stretched) replace _Dalbergia_. A mock central bore would let dry faster. Or is gluing narrower parts conceivable? Hide glue lasts for centuries at violins. More generally, I hope Vectra and equivalents can replace _Dalbergia_.

Also displayed is metal tubing, for woodwind or brass, where very stiff parts link the tubes. Here pyramids are brazed tangentially to the tubes. Keys can hold there. Tubes farther apart give even more stiffness and the wide turns ease the emission but they must carry some tone holes. The tubes' elliptic deformation remains a worry: braze stiffening rings?

Sliding or replacing the many turns adjusts the air column length at more positions, a less bad means of tuning the pitch of a woodwind.

The rackett construction takes some more wood than separate joints but it lightens the keywork much and offers wood thickness to screws and to tone holes, which I suspect improves the sound of low instruments.

Marc Schaefer, aka Enthalpy


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## fluteman

Enthalpy said:


> Hello everyone and everybody!
> 
> The topic is debated, but trials let me accept that wall materials influence the sound of wind instruments
> scienceforums​Inadequate materials like thin injected plastic make the comparison obvious, hear it there
> talkclassical - talkclassical​while good materials differ not so much and matter less than the temperature.
> 
> I proposed physical models for this influence, possibly the first ones whose figures make sense, one that involves the elliptic deformation of (thin) walls
> scienceforums and followings​an other that considers the bending of the body
> scienceforums and followings​one more that models the influence of tube turns
> scienceforums and followings​still an other that considers the flare's effect
> scienceforums and followings​
> Shorting the physics: all my models need mechanical resonances of the body, and their effect compares with the small losses of the air column, not with the air's stiffness. Then, figures can make sense.
> 
> ==========
> 
> Body bending matters more at long instruments like the contrabass clarinet or the contrabassoon, as more mechanical resonances happen at undesirable frequencies, and they interact more strongly with the air column. The outfashioned *racket construction would alleviate the effect of wall vibrations* radically at low instruments.
> wikipedia​because the resonant frequencies of a single-part body increase like its diameter and decrease like its length squared. For instance if a long instrument is folded in 4 in a doubled diameter, and the body length is one-fourth, the resonant frequencies are 32x higher (or if comparing with two body joints, resonances are 8x higher, still wooooow!). Not only fall fewer resonances at sensitive frequencies: the 16x stiffer body vibrates less strongly too.
> 
> [Click for full size]
> View attachment 161611
> 
> 
> The body must hold together perfectly to increase the stiffness so sharply, hence the displayed single wood part, but wood take years drying and new shapes start at zero. The racket construction should gain so much that maple or even polypropylene (preferably stretched) replace _Dalbergia_. A mock central bore would let dry faster. Or is gluing narrower parts conceivable? Hide glue lasts for centuries at violins. More generally, I hope Vectra and equivalents can replace _Dalbergia_.
> 
> Also displayed is metal tubing, for woodwind or brass, where very stiff parts link the tubes. Here pyramids are brazed tangentially to the tubes. Keys can hold there. Tubes farther apart give even more stiffness and the wide turns ease the emission but they must carry some tone holes. The tubes' elliptic deformation remains a worry: braze stiffening rings?
> 
> Sliding or replacing the many turns adjusts the air column length at more positions, a less bad means of tuning the pitch of a woodwind.
> 
> The rackett construction takes some more wood than separate joints but it lightens the keywork much and offers wood thickness to screws and to tone holes, which I suspect improves the sound of low instruments.
> 
> Marc Schaefer, aka Enthalpy


Wow, thanks for all that. I was beginning to think intelligent comments on this subject were barred from the internet. :lol: Please keep us informed of any further research or experiments.


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## Enthalpy

Happy that you like it, thanks for the encouragement!

Whether the material influences the sound is naturally a controversial topic, because it relies on perception. Also because the effect is small, so it takes some time to notice, and one must search for it. If a flautist just plays 20s music on two instruments, he won't notice any effect of the material.

More listening examples, here oboes of _Dalbergia_ versus plastic, which makes a bigger difference
talkclassical​
The position of most acousticians isn't brilliant. Benade tried decades ago an explanation, the one he thought of failed, so they just claim "can't exist". Science cannot work like this.

Internet isn't worse than real life on that aspect. I heard the same comments that I read on the Web. Plus, some people are interested in claiming "no effect": for instance luthiers who build contrabass clarinets of metal instead of _Dalbergia_.


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## Enthalpy

Here's an example of *rackett-shaped Bb contrabass clarinet*. It reaches written C to sound the contrabassoon's Bb, but is as small as an alto saxophone, its case too.

[Click for full splendor]








The bore extrapolated from the bass clarinet would be 34mm wide as at the Selmer model 28. 32mm (depicted here) and the usefully louder 36mm exist too. Mouthpieces are a mess. The air column is folded in 4 here (the number and positions of the bends aren't thought through) so the body is as short as a soprano clarinet and is wide, hence very stiff as explained previously. If lined maple suffices then, the bare body with 34mm bore weighs 1.3kg, while _Dalbergia *****_ (Bahia rosewood) takes 1.8kg and Vectra 3.0kg.

A metal construction, as shown previously, would make wider turns hosting some tone holes. My stiffeners improve the bending modes, but the elliptic deformation of the thin metal tube remains a worry: add stiffening rings?

I display keys from soprano and bass clarinets to show each hole's function.

Narrow turns and long skewed tone holes let the wood accommodate all tone holes, so a bassoon maker can produce everything. Do bass and contrabass sound better with long tone holes? The U-turns fit butt at the body. A straight bell avoids vibrations and can be of thin metal then. The bocal can make an S to the side to shift the bell away from the musician's sight. Stiffeners (not shown here) should improve the bocal. I suppose metal inserts at the body to fit the bell and bocal extend the range and color the sound.

Many previous ideas apply to this instrument.
stiffeners
electroform bells and bocals
electroform keys
playless long keys
Vectra​
A case can be 66cm long, 42cm wide prior to optimisation, and 18cm thick.

A rackett-shaped contrabassoon seems seducing too. Its air column twice as long should have more bends.

Wishing a nice retirement to Angela,
Marc Schaefer, aka Enthalpy


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## Enthalpy

Wind instruments parts can be electroformed. It's done for some trumpet bells. Some ramblings there and around
scienceforums​The electroformed material isn't as good as when wrought. For instance nickel shows E=100GPa instead of 200GPa. The yield strength and elongation at break too are inferior.

Similarly, cast parts are less good than wrought material. The aeronautics industry solved that for cast parts of titanium alloy by *hot isostatic pressing*, where the cast part is heated in silicone under pressure.
wikipedia​Maybe wind instrument alloys too improve that way?

CuZn, CuZnNi, CuNi, AgCu usual for wind instruments have lower solution temperature, annealing temperature, yield strength than TiAlV used in aeroplanes, so I hope the process can be transposed directly. Ni and NiCo may need higher temperatures: use a molten metal instead of silicone maybe? Argon is common too but gases are more dangerous.

This is more general than music instruments.

Marc Schaefer, aka Enthalpy


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## Enthalpy

To avoid dimension changes, conduct the HIP with the part still on or in the mandrel.


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## Enthalpy

Pairs of tone holes have been considered. Deckelmacher described some on Musiktreff.info. And did I see some earlier?

They vent better, useful at the lowest notes of an instrument. As the inductance of wide holes depends on the circumference rather than the area, two smaller cups can be lighter than a large one, good for low saxophones.









I explained the losses created by the body's flexural resonances, there
scienceforums - scienceforums​*If the holes are symmetric, they squeeze these losses*. First as the forces on the body cancel out, and a second time as the volumes due to the body's wobble cancel out too.

The elliptic deformation of the body
scienceforums - scienceforums and more​is 4* worse with symmetric tone holes. 90° would be better against the elliptic deformation but worse against the flexural resonances. Use symmetric holes at a wooden or thick plastic body rather than metal.

As the symmetry acts twice, it remains efficient when not perfect. The holes can have *somewhat different diameters and positions* for a mellower sound
talkclassical​
All this combines nicely at the lowest notes of the bassoon, contrabassoon, bass, contralto and contrabass clarinets.

Marc Schaefer, aka Enthalpy


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## Enthalpy

You all expected it after I lauded the construction
talkclassical​here's a visual impression of a *rackett-inspired contrabassoon*.









The loop plus water key in the bocal keeps the body and the reed dryer. The detachable bell, about as long as the rackett section, gives a nice bassoon look and shrinks the case. Toneholes pairs there may improve
talkclassical​
Register holes all at the rackett section ease the keyworks. Instead, a U-shaped metal tube hosting the register holes would shorten the rackett section and start the bore less narrow. I've drawn the piano hole at its bassoon position, but it seems higher on a contrabassoon.

The short thick body is stiffer. 1.1m isn't much for maple (bowed bass!) nor for Vectra. The first bore tapers from 2 fingers to 1 finger wide, worry? 6 passes would shorten the racket section.

Here most tone holes can be long. All are in wood, so bassoon makers can produce everything. The contrabassoon gives twice as much length as a contrabass clarinet for the bends between the holes. At the bottom, the bigger bend passes below the smaller. Sets of bends of varied lengths can tune the instrument, and quick assembly eases cleaning. A metal bell (not preferred!) should have azimuthal damping stiffeners, say of silver.

Many previous ideas apply to this instrument too.
stiffeners - electroform bells and bocals - electroform keys - playless long keys - Vectra​
Marc Schaefer, aka Enthalpy


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## Enthalpy

A *contrabassoon is clumsy with 6 passes* in a rackett joint. With 4 passes, the height fits a sitting musician and the social status of a contrabass.

(Click to magnify)








The silhouette with 6 passes shows features usable in other designs.

A metal tube, hold firmly at the rackett joint, extends over all register keys so the the bore starts less narrow at the rackett joint.
Stowasser holes at the bell improve hopefully the sound and the emission scienceforums​
The lowest tonehole is doubled and symmetric, it could be less symmetric too
talkclassical​
The curves can be compensated and produced as I suggested there
talkclassical (3 messages)​
Marc Schaefer, aka Enthalpy


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## Enthalpy

We figure better the size of a *rackett-inspired contrabassoon with a musician's silhouette*.









[ContrabassoonRackettCDE.png]

With 4 bores in the rackett joint, the register holes sit better on a metal tube, version C. Then the contrabassoonist can be 1.60m (5'3") tall and the first 1m bore is less narrow.

With 6 bores and its register holes at the rackett joint, the version D doesn't look so clumsy, or I get used to it. It's taller than the bassoons, but less nicely than version C. The case for D is easier to carry than for C, and much easier than present contrabassoons. Maybe I try some bore arrangements, later.

A version E, not displayed, could have 6 bores and the register holes on a metal tube, with a shorter bell and a bottom fairing that improves the aspect and is removed for transport. Easier first bore, smaller case.

The short wide rackett joint is acoustically better, symmetric (or nearly) tone holes at the bell shall reduce the vibrations there, and the keys shorter than at present contrabassoons and sitting on a single joint must be more stable. The metal tubes should be stiffened, damped, and if carrying register holes, they should hold firmly at the wood. The bocal's shape should clear the musician's view.

I like the aspect telling "I am a lower bassoon".

Marc Schaefer, aka Enthalpy


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## Enthalpy

Here are *arrangements of 6 bores for a rackett-inspired contrabassoon*, version D or E.

Here all bores are parallel, good for precision.
Front fingers move keys at front bores, thumbs at rear bores (mainly).
The bends between bores are shorter than local semitones. But can all toneholes sit on wood?









[ContrabassoonRackettDEBore.png]

At left, the rackett joint is thin enough for the hands. At right, the thinner sides carry the keys, and hand rests are needed.

Finding these arrangements took me long as bitmaps. CAD shouldn't help much. I suggest balsa cones that represent the bores and walls, and a string with colour marks at the desired toneholes positions.

I like the quick end opening at my bassoon to clean and dry the bores. Each rackett end could usefully group all bends as one quickly removed part.

Marc Schaefer, aka Enthalpy


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## Enthalpy

After 1200h praticising, *I would still adopt immediately and learn a bassoon with a better system*. More flautists, clarinettists... may also switch to an easier bassoon.

Bassoons have keys closed at rest below the main closed-to-open transition. They cause most emission difficulties, needing extra key movements. The Boehm flute opens at least two adjacent holes at the main transition, better. It also gives flexibility to upper register fingerings. So that's why a professional bassoonist wanted me to invent a *bassoon with flute system*.

_I do not write_ "big tone holes at theoretical positions" because this fails at the bassoon. But narrow long holes may need other fingerings for the third register.

Flute fingerings could apply, perhaps even the bassoon joints be kept. While the left fore fingers go down to to G on the flute, they would reach C as usual on the bassoon, but the index opens the F and no register hole, while the freed left thumb operates the register holes, and the second register starts at F# with the pinkies. The right index to ring fingers would play B down to G. Separable joints must move Eb with the right index as on the clarinet (add maybe the trill key at left ring finger) and transmit the flute's "E" mechanism ("A" on the bassoon) too. The Brossa or Brossa-Schaefer key can't be missing
May 19, 2018 - May 13, 2021 - May 16, 2021 on scienceforums​
The many lower notes are more subjective. As the excellent Boehm clarinet does, I'd move 3 cups (open at rest, though) by the right and left pinkies: this reaches E, the last hole on the boot. Holding the left pinkie touchpieces on the boot lets them protrude - or lower the left hand or raise the instrument.

Then the right thumb can close 3 cups open at rest to reach C# (all on the bass joint hence with transmissions or protruding keys) and the left thumb 3 more to reach Bb.

Though, I hate the flute's F# at right ring finger and the right pinkie pressing for most notes. Since the bassoon's holes are wider apart than a bore width, and if this doesn't hamper the third register, the right middle finder could close a second hole near to the ring finger's hole, and the ring finger close a second hole near to the pinkie's hole, as the flute does at left hand. The better Boehm *clarinet fingerings would apply to the bassoon* on the first register, with the second octaviated and the third still unknown. These are also saxophone fingerings, just better.

==========

While these systems may seduce flautists and clarinettists, I strongly *prefer my systems with even or with piano-like fingerings*
scienceforums - scienceforums​as the system with even fingerings is simpler to build, and both systems are easier to play and more versatile.


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## Enthalpy

The proposed rackett-shaped Bb contrabass clarinet and contrabassoon
contrabass clarinet - contrabassoon and around​should benefit from *curves that host tone holes* in the wood, there
curves with tone holes​


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