Why not a Carbon Fiber Contra?

[afugate]

After reading, hearing about, and seeing (at ITF 2019) the Butler Carbon Fiber tenors - and reading forumite 2bobone's comments about his Butler CF Bass and hyperbolic's original question about ergonomics...

It made me wonder about the possibility of using carbon fiber for a contra.

Contras are so stinking heavy and hard on the body. Wouldn't it be great to have one that was half the weight? I suspect it would be prohibitively expensive, but hey, a guy can dream.

--Andy in OKC

[BGuttman]

I suppose it could be done. Do you think they would sell more than the one you will buy?

[afugate]

I suppose it could be done. Do you think they would sell more than the one you will buy?

At today's prices, I'm pretty sure I couldn't afford it, unless I could also drive it or live in it.

--Andy in OKC

[timothy42b]

It's new technology. Give it a few years, it will come down to the price of high end brass.

[Bach5G]

My understanding is that some orchestras now expect the bass trombonist to play contra.

[Mikebmiller]

The tooling and set up to make a contra would be quite expensive. Butler Trombones is still a fairly small company and I think he can sell all the small bore horns that he can make with no problem, so there is really no motivation to do something as complicated as a contra. But I agree that it would be a great option for people that play that beast.

[timothy42b]

They really need a chair/stand like sousaphone players use.

[hyperbolica]

We will get there eventually. I think tuba components will come first, and maybe euphonium bell as well. Marching instruments would be an obvious target due to weight and durability.

3D printing took 20 years to hit mainstream products. The marriage of 3D print and carbon fiber has begun, but its going to take a while to develop. But it won't be hand laid sheets of woven prepreg, it will be more like current glass-filled nylon material. Some components like bells might be able to use custom winding onto a mandrel, but that requires tooling.


https://www.fusion3design.com/fusion3-f ... 90QAvD_BwE

[Tremozl]

I have a Mirafone BBb Contra and it's not much heavier than my Bass Trombone. Don't ask me how. It's remarkably light and well-balanced (the Jinbao BBb Contra is neither.) It didn't take long at all to adjust to the weight increase.

What Carbon Fiber could do is enable even bigger horns to be made with less weight; maybe a BBb Contra with a larger bore, bigger bell section, larger bell throat, maybe even two attachments (FF and GGb triggers.) But the price would probably be absurd.

I haven't handled an F Contra yet so don't know what their weight is, though they tend to have two attachments and a larger bell flare, so depending on the materials it may even be more than the Mirafone.

[EdwardSolomon]

I used to own a Mirafone BB flat contrabass and now am on my second Thein F contra. It is significantly lighter and better balanced. Indeed, I would argue it may even be better balanced than any other trombone I've played. Yes, you feel its weight after a while, but the left hand support helps and it is really arguable whether anyone would take kindly to a carbon fibre instrument in a professional setting, such as an opera house or symphony orchestra.

[LeTromboniste]

It's new technology. Give it a few years, it will come down to the price of high end brass.

You mean the instruments or the materials?

[Tremozl]

I used to own a Mirafone BB flat contrabass and now am on my second Thein F contra. It is significantly lighter and better balanced. Indeed, I would argue it may even be better balanced than any other trombone I've played. Yes, you feel its weight after a while, but the left hand support helps and it is really arguable whether anyone would take kindly to a carbon fibre instrument in a professional setting, such as an opera house or symphony orchestra.

That's good to hear. Yes I imagine the hand rest is a nice touch. I don't personally find the Mirafone heavy enough to require it, but if someone offered me one for free I wouldn't say no. However I had to use a 'peg' (Ergobone) for the Jinbao; they got something seriously wrong with that clone.

[Burgerbob]

I wouldn't mind one, but only if it sounds pretty darn good. My contra is unplayable without an ergobone!

[WGWTR180]

It will be interesting to see where the carbon fiber craze ends up. Lightweight yes! But one horn has already appeared on this Forum for sale and I think more will follow. The few recordings I've heard have been weak in the sound department. However I'll reserve judgement for myself once I've tried a carbon fiber anything.

[Burgerbob]

It will be interesting to see where the carbon fiber craze ends up. Lightweight yes! But one horn has already appeared on this Forum for sale and I think more will follow. The few recordings I've heard have been weak in the sound department. However I'll reserve judgement for myself once I've tried a carbon fiber anything.

My thoughts as well.

[paulyg]

The true strength of carbon fiber is the strength-to-weight, which is only achieved with careful selection of fiber orientation and ply sequence. The 3-D printed material shown above is really just strong plastic, as opposed to a continuous-fiber reinforced plastic, and there is probably a strength difference of 5-10x.

What I'd be really curious about is whether carbon fiber is as great a substitute for brass as it is for wood. Careful design of string instruments can very closely approximate the acoustic behavior of wood, despite being lighter...

Unfortunately mass has quite a bit to do with how anything sounds (trombone, violin, airplane wing, ect), so there will always be a trade-off between weight and sounding like a heavier instrument.

[timothy42b]

What I'd be really curious about is whether carbon fiber is as great a substitute for brass as it is for wood. Careful design of string instruments can very closely approximate the acoustic behavior of wood, despite being lighter...

Unfortunately mass has quite a bit to do with how anything sounds (trombone, violin, airplane wing, ect),

Maybe not so much.

With a stringed instrument, sure. The strings are vibration source, coupled to the wood. The enclosed air is essentially driven through a filter.

Brass is a bit different. The lips drive the air column directly; the brass vibrates (mostly) because the air is in contact with it. (I say mostly because there is apparently some mechanical coupling from lips to brass, so there are two sources for the brass component. nevertheless, the brass vibrations do not contribute to room sound.

I suspect the largest effect of the reinforced plastics is just in feedback to the player. The ear is in the near field of bell vibrations, while the audience is far outside.

Once set up you could filament wind bells for almost nothing.

[paulyg]

What I'd be really curious about is whether carbon fiber is as great a substitute for brass as it is for wood. Careful design of string instruments can very closely approximate the acoustic behavior of wood, despite being lighter...

Unfortunately mass has quite a bit to do with how anything sounds (trombone, violin, airplane wing, ect),

Maybe not so much.

With a stringed instrument, sure. The strings are vibration source, coupled to the wood. The enclosed air is essentially driven through a filter.

Brass is a bit different. The lips drive the air column directly; the brass vibrates (mostly) because the air is in contact with it. (I say mostly because there is apparently some mechanical coupling from lips to brass, so there are two sources for the brass component. nevertheless, the brass vibrations do not contribute to room sound.

I suspect the largest effect of the reinforced plastics is just in feedback to the player. The ear is in the near field of bell vibrations, while the audience is far outside.

Once set up you could filament wind bells for almost nothing.

Any conclusion suggesting that the brass does not vibrate or contribute to the timbre is demonstrably false. At low dynamic levels this may be true, but anyone can do an experiment at home to disprove that conclusion broadly. Just play louder and louder until the instrument begins to vibrate in your hand. There you go, the brass is vibrating.

An additional point of contention are the perceived benefits of filament winding. Filament winding is generally used to fabricate parts where the carbon fiber is expected to be stressed in the filament directions- this is most commonly seen in pressure vessels and rocket casings. Filament winding an asymmetric part like a trombone bell, with lots of compound curves, is going to be an absolute nightmare, especially when curing the part. In addition, a trombone bell is not an application requiring the leveraging of the advantages of filament winding- there's negligible hydrostatic pressure on a trombone bell. Filament winding is best used for tanks or casings required to hold dozens or hundreds of atmospheres of internal pressure. Otherwise hand-layup of woven fabric is going to be much more straightforward.

[Mikebmiller]

In the bike world, 20 years ago carbon was rare and expensive. Now is is common and not quite as expensive. With rare exception, just about every bike in the pro peloton these days is carbon fiber.

[afugate]

We will get there eventually. I think tuba components will come first, and maybe euphonium bell as well. Marching instruments would be an obvious target due to weight and durability.

This makes sense.

--Andy in OKC

[afugate]

Good discussion. Thank you to everyone for chiming in. My takeaways...

• It has to sound like a trombone

• It's prohibitively expensive today

• It's more important to have a well-balanced horn than just a light one

• Carbon fiber is still in it's infancy - technology advances will lead to new applications

In short, stay tuned!

--Andy in OKC

[timothy42b]

Any conclusion suggesting that the brass does not vibrate or contribute to the timbre is demonstrably false. At low dynamic levels this may be true, but anyone can do an experiment at home to disprove that conclusion broadly. Just play louder and louder until the instrument begins to vibrate in your hand. There you go, the brass is vibrating.

Of course it vibrates. But that doesn't mean it contributes to the timbre. Nor could it on more than one note, demonstrably.

The air makes it vibrate a tiny amount that can't be detected more than a few inches away. That is arguably within the player's hearing range but not the audience's. Most of the time you can feel it but not hear it. Once it a while you can hear a buzz from a bad solder joint.

Tap your bell with a fingernail. You'll hear a quiet ting. Now compare the force of a tapping finger to the force of vibrating air.

Filament wound is an easy way to do mass production. It isn't the only way and is way overkill for strength. There is no air pressure within a trombone bell, it's at ambient for all practical purposes. I've installed fiberglass underground fuel tanks that were filament wound, and the ends are deeply curved. I think you could do a bell flare, but you are right it is a geometry problem. I've tried a wet layup on a bell shape myself and that flare isn't easy. You have to go with thin strips and a prepreg filament might be ideal.

[timbone]

My understanding is that some orchestras now expect the bass trombonist to play contra.

Well then the orchestra should buy the instrument. They do it for contrabass clarinets, contrabassoons, etc.

[timbone]

Vibration is everything. For us that is feel (or feedback), energy transmission, response, the most efficient way- with metal. Sure there are folks that can benefit from carbon fibre from a health standpoint. Its interesting that carbon fibre and graphite are popular on the golf circuits. And for the same reason, it does not transmit energy as efficiently as steel shafts. "Feedback" on a golf swing consists of a ball striking the clubhead for about 1/3 to 1/2 milliseconds.

[hornbuilder]

No, the vibration of the metal in an instrument is not essential for tone production. It is after all, being driven. However, it "is" being driven, and there is a resulting effect on the sound emitted by the instrument as a result of the energy that goes towards driving that vibration. Input energy is absorbed by the instrument, amd radiated around the player. This is where weight and mass distribution comes into play.

M

[paulyg]

Tap your bell with a fingernail. You'll hear a quiet ting. Now compare the force of a tapping finger to the force of vibrating air.

You're comparing apples to oranges here- if the deflection of the object in question actually mattered, this false equivalence could get people killed.

Yes, tapping the bell with your fingernail will tell you a lot about its natural frequency (it will dissipate the energy you transferred from your finger by vibrating at its natural frequency). What it won't actually tell you anything about is the frequency response of the bell. The force of vibrating air might actually cause a larger deflection (stronger vibration) at the natural frequency of the bell (or a harmonic, of which there are uncountably many for the complex shape and stress distributions in any given trombone bell) than the fingernail tap.

The whole premise of resonance and structural dynamics comes about because the familiar static relationships between forces and deflections are not valid in certain scenarios. When resonance is achieved, the deflections can be hundreds of times larger than would be expected in the static case for an equivalent force. So, while tapping the bell with your fingernail will tell you a frequency where this effect will occur, it actually tells you nothing about the magnitude of the resulting deflection.

[timothy42b]

Tapping the bell with your fingers is at least a million times the force of the sound wave, that's all I was saying.

Mechanical structures vibrate at the frequencies that are driving them. They have no ability to generate any new ones. This is really basic engineering.

They absorb some tiny amount of energy, more at a resonance frequency, but in no case will a bell deflect enough to change the geometry of the wind column. I think you still fail to understand the mechanism by which a trombone or any wind instrument works: vibration input to a wind column. See Benade et al.

[Burgerbob]

Well, the proof is in the pudding. Different materials respond and sound different, and carbon fiber is far more different than yellow brass is from gold brass or even sterling silver. Whether we understand the mechanism behind that doesn't really matter.

[paulyg]

Tapping the bell with your fingers is at least a million times the force of the sound wave, that's all I was saying.

Mechanical structures vibrate at the frequencies that are driving them. They have no ability to generate any new ones. This is really basic engineering.

They absorb some tiny amount of energy, more at a resonance frequency, but in no case will a bell deflect enough to change the geometry of the wind column. I think you still fail to understand the mechanism by which a trombone or any wind instrument works: vibration input to a wind column. See Benade et al.

You've completely missed my point from my last post. I don't want to get into splitting hairs, but between the fingernail and the air column there isn't a difference in six orders of magnitude. What I was saying is that tapping a bell with your fingernail tells you the frequency of the mode that occurs if you tap the bell with your finger at that spot. It tells you nothing about the amplitude of the oscillations compared to the amplitude of the original displacement, and it's not especially informative when trying to discern the frequency response of the bell when it's driven by the air column instead of your fingertip. Heck, it doesn't even work for your fingernail: tap the bell at the flare, and then behind the bell brace. Different notes!

Thank you for the reminder about "basic engineering." You may need to brush up on your "basic engineering," though, because while on the face of it your statement is correct, it hides just how complex "frequency" and "driving force" aspects of this problem are w.r.t. a trombone bell. The modes of vibration for the trombone bell structure are more similar to those of a drumhead than those of a string or air column (and not all that similar to a drumhead), and analogies to the nicely-worked-out solutions to those eigenvalue problems don't translate too well to something this complex, unless you really understand "basic engineering."

By your logic I should be able to duplicate the internal features of any given trombone in a block of granite, and have anyone walk up, buzz into this monolith, and not be able to tell a difference from any brass trombone, because the geometry of the air column is all that matters. This hypothesis is yours to test- I wouldn't bother, though. By the way, I took a look at Benade's work... it's wonderful, but there is nothing about dynamic coupling of the instrument to either the air column or the frequency source (embouchure). In fact, I even found a paper on nonlinear extensions of wind instrument theory, and it steers clear of any discussion of the dynamics of the instrument structure. This simply isn't an area that has been studied- but just because "fixed boundaries of the air column" is a standard assumption in academic papers on acoustics, that doesn't mean it's true or valid all the time.

Trombone bells (and the rest of the trombone corpus) amplify component frequencies of the buzz (and junk from the oral cavity, throat, and bronchi) outside the harmonics of the air column. There, I said it: the shape of the air column isn't all that matters (brace locations, anyone?). This is why trombones made of different things sound different, this is why people sound different on different trombones with the same mouthpiece, and it's why nobody with a set of microphones and an oscilloscope can honestly say that they've defined what makes a beautiful sound. There's art in making a beautiful sound, and there's art in making a trombone that can sound beautiful. Science hasn't quite caught up yet.

[GBP]

http://la.trompette.free.fr/Smith/IOA/material.htm

https://pdfs.semanticscholar.org/db0c/ ... 84bba2.pdf

Researchers can’t seem to agree either.

[timothy42b]

Well, the proof is in the pudding. Different materials respond and sound different, and carbon fiber is far more different than yellow brass is from gold brass or even sterling silver. Whether we understand the mechanism behind that doesn't really matter.

True, nobody has proposed a mechanism that is in any way convincing.

Empirical evidence - well, the more carefully you design an experiment, the more the effect disappears. The scientist says that's because it doesn't exist, the musician says that's because that's not how we play in instrument in real life.

I used to have an open mind, until the definitive experiment was done: the production of the pBone. The bell is not just inexpensive, it's cheap, thin injection mold plastic. And it sounds like brass. Maybe not like a high quality instrument of brass, but clearly within the spectrum of trombone.

If you and I played 3Bs side to side in a room, listeners at the other end could clearly identify us. Same is true if we played pBones. There would be no doubt who was playing.

On the other hand, if you played both trombones, and I played both, probably they could not tell which horns we are playing at greater than chance. The difference between players is larger than between materials.

[Burgerbob]

Well, of course the player is the largest aspect. No one is debating that at all.

Telling different horns apart? I've done it a lot, recently, with great players. It's immediately obvious, even with two horns of the same make.

[Schlitz]

.

[Burgerbob]

Y’all know that Snorsworthy is out there in the stix waiting for you......

Oh boy. I hope not... He's taken to Facebook as of late.

[norbie2018]

Y’all know that Snorsworthy is out there in the stix waiting for you......

Oh boy. I hope not... He's taken to Facebook as of late.

Ok, I need to ask: who's Snorsworthy?

[BGuttman]

Steve Norsworthy was a trombone player / egomaniac on The Trombone Forum. He thought he was God's gift to trombones. His ego made him unwelcome.

[GBP]

Well, of course the player is the largest aspect. No one is debating that at all.

Telling different horns apart? I've done it a lot, recently, with great players. It's immediately obvious, even with two horns of the same make.

Here is the rub in all that; Why do they sound different? Is material, design how the mouthpiece reacts to the design of each instrument. How about how the person reacts to each instrument. There are so many variables that it would be difficult to say why. Also, comparing two instruments is a 1 in two chance. Was it repeated enough times to discount the 50/50 chance?

[Burgerbob]

well, the horns sound different... There are variables, but, again, that's not really the debate. Even my two Corp bells sound quite different played by the same person.

[GBP]

well, the horns sound different... There are variables, but, again, that's not really the debate. Even my two Corp bells sound quite different played by the same person.

Well, the proof is in the pudding. Different materials respond and sound different, and carbon fiber is far more different than yellow brass is from gold brass or even sterling silver. Whether we understand the mechanism behind that doesn't really matter.

If two bells of the same material and design sound different, maybe material doesn’t matter as much. Maybe it is more about construction. Point I am making is currently, we don’t know for sure why.

[norbie2018]

Steve Norsworthy was a trombone player / egomaniac on The Trombone Forum. He thought he was God's gift to trombones. His ego made him unwelcome.

Got it. Thanks!

[timothy42b]

Y’all know that Snorsworthy is out there in the stix waiting for you......

Oh boy. I hope not... He's taken to Facebook as of late.

And Tubenet.