How about a Lexan tuba??

[bigboymusic]

I'v also owned one of the solid nickel Alex's. First, it was VERY HEAVY. And at 50 years old when I had it, NO DENTS. None. The bell looked like it had just come off the line. It is a tough beast. As far as sound, I don't know about Ted's, but mine never had that 'Alex' sound. You really had to work to get a warm tone. But could it project. The low range was kind of 'Thorish'. Very Hammer like. It was a cool horn, but I'll take my brass 163 anyday (wish I hadn't sold it though.)

[Doug Elliott]

...the main reasons why _______________ are made of _______ is more-or-less because the material is easy to work with and produces satisfactory results.

Fill in the blanks

[jeopardymaster]

Having played my share of fiberglass sousaphones I can think of few prospects less appealing than the opportunity to try a Lexan tuba. And I work for GE.

[Dan Schultz]

..... And I work for GE.

GE does some pretty incredible things with wolfram, Inconel, titanium and such. Maybe they can make us a tuba!

[Dan Schultz]

... Dan, have you ever heard of GE building anything cheap (inexpencive) ???

Since GE sold off some/all of their plastics divisions a while back to SABIC... do they still own the Lexan tradename, jeopardymaster?

Honestly, Brian.... I wish you nothing but success with your project. Someone needs to be thinking 'outside the box'. Tubas have been brass long enough!

Sure, there are hurdles and compromises to be made. I'm think back a few decades ago when business machines went from metal housings to plastic. It took the industry a while to figure out how to overcome EMI/RFI issues.

[Shockwave]

From what I recall of the Schilke material experiments, steel produced a very dull tone and lead produced an extremely bright and metallic tone. That is completely counterintuitive since it is the opposite of the sound of sheets of steel and lead when tapped with a hammer. If you know why the difference in sound occurs, you can take a guess at which materials would be better or worse for brass instrument use.

Why does lead have a bright tone? First, lead is a very weak metal and is much easier to stretch than brass. When a sound wave travels down the lead horn, it exerts pressure that causes the lead tube to expand and contract in a more springy manner than brass. The highest pressure waves are low in frequency and would be lost to vibrations in the metal the most, so the sound becomes very bright though very inefficient. As the frequency of the sound gets higher, the high mass/stiffness ratio of the lead means that inertia of the wall at high frequencies is enough to counteract the springiness of the metal and allows sound waves to travel without loss. Add that together and lead causes a loss of low frequencies and an accentuation of high frequencies compared to brass.

The steel horn is the opposite. It has a higher stiffness than brass, so the lows are accentuated. It has lower mass/stiffness ratio so the highs are reduced. Add those together and you have a dull sounding horn. There is a feedback effect with the lips, so small changes in the sound that reaches the lips from the horn can have a large effect on the sound that is radiated from the business end of the instrument.

As the horn wall is made more stiff through stronger or thicker material, the main benefit is to the medium-low harmonics. The fundamental is limited by the lips, so a thick walled horn can sound more "hooty" and uneven compared to a thin-walled one, though the former is more powerful with a larger dynamic range. Instruments with a naturally weak fundamental like trumpets can produce a bigger sound with thick metal, while instruments with a naturally strong fundamental like tubas produce a fuller sound with thin metal.

What would one expect from different materials given a constant wall stiffness? I made a chart of some materials with their Young's modulus (stiffness) and density, and calculated the ratio of each materials modulus to density and then another ratio relating it to the ratio of brass. The higher the number, the greater the brilliance of the tone.

Lead 8.9
PETG 7.4
Lexan 7.0
Tin 1.8
Silver 1.6
Brass 1.0 (by definition)
Copper 0.94
Nickel Silver 0.83
Oak 0.7 (drum hoop)
Titanium 0.52
Steel 0.50
Aluminum 0.49
Fiberglass 0.45
Carbon Fiber 0.18

The numbers seem to follow the anecdotal reports. Amongst the usual instrument materials, silver is brighter than brass, and nickel silver is darker. Amongst the unusual ones, lead is extremely bright, steel is very dark, and fiberglass is downright dull. However, while a fiberglass trumpet would be unthinkable, I have heard some remarkably good sounds emanate from a fiberglass sousaphone. Maybe some of the other dull sounding materials would make good sounding tubas.

-Eric

[toobagrowl]

We are getting away from the O.P.s Idea. Why not a Laxan tuba ?
Well tooba, the reason a Laxan mouthpiece is as good as it is, is that the mouthpiece is not supposed to
ring at all and instead transmit only the sound within the airstream (the buzz) into the horn. If it rang, it
would lose efficiency and also feedback notes into the player’s mouth. This would make fast articulations
hard if not imposable. So what you call a resonant mouthpiece is actually less resonant, but it's efficiency
makes the horn resonate better.

That makes sense. My new Kelly mouthpieces are more responsive than my other 'pieces. I know the Kelly Lexan mouthpieces don't really 'resonate', but they sure transmit a resonant sound through the horn. Like you said, it is more efficient - I can hear it on my practice recordings.
I just wondered why there are only Lexan mouthpieces and not Lexan horns, that's all. I thought it would be a good idea. Like Tuba Tinker said: we need to think outside the box.

[toobagrowl]

Lead 8.9
PETG 7.4
Lexan 7.0
Tin 1.8
Silver 1.6
Brass 1.0 (by definition)
Copper 0.94
Nickel Silver 0.83
Oak 0.7 (drum hoop)
Titanium 0.52
Steel 0.50
Aluminum 0.49
Fiberglass 0.45
Carbon Fiber 0.18

The numbers seem to follow the anecdotal reports. Amongst the usual instrument materials, silver is brighter than brass, and nickel silver is darker. Amongst the unusual ones, lead is extremely bright, steel is very dark, and fiberglass is downright dull. However, while a fiberglass trumpet would be unthinkable, I have heard some remarkably good sounds emanate from a fiberglass sousaphone. Maybe some of the other dull sounding materials would make good sounding tubas.

-Eric

Those specs are very interesting. I am amazed to see PETG and Lexan on one end of the scale and Fiberglass and Carbon Fiber on the other end. I would have thought they would all be grouped close together.
I have also heard good sounds from fiberglass sousaphones. Maybe an Aluminum tuba would work? Aluminum is pretty strong and much lighter than brass.

[Rick Denney]

To a large extent, tubas are the way they are because that's the way they always have been. We define good tuba sound on the basis of how they have always been built. Other materials might produce equally or even more pleasing sounds, but they might be different.

But I think the difference is over-rated. I have a Martin tuba made back in the 60's with a brass valve body and a fiberglass body and bell. It sounds like a tuba, and plays like a tuba. It's funky, but I've played brass tubas that were funkier. Any person out front would hear a tuba player play that Martin, and would be fully convinced that they were hearing a tuba. And that's without making other adjustments that might offset or adjust the sound and response of the instrument to steer the material to a particular outcome. There are bright mouthpieces for woofy tubas, and mouthpieces known for their round tones for bright-sounding tubas, for example.

We only think we know the relationship between the material properties, structure (which is the application of those properties), and outcomes. The Kanstul "York" bell is not made from the exact same brass that York used, for example. They adjusted the alloy until they got the same or similar outcomes, after a LOT of experimentation and analysis.

I would expect it to be possible for a plastic tuba to sound like a brass tuba even to a critical ear, though it might need structural details that make it look much different than a typical brass tuba. I won't ever feel like a brass tuba if for no other reason than it will be lighter.

Fiberglass sousaphones were not intended to be particularly light. They were intended to be particularly indestructible. Brass dents too easily, because its yield strength is much lower than its ultimate strength, and to make it reasonable light, it has to be thin. Plastics can be much thicker to provide the same structural stiffness as brass but still be lighter. And hard plastics usually have a yield strength much higher in relation to their ultimate strength, making them far more dent-resistant for a given strength design.

Rick "thinking Chuck Daellenbach sounded like he was playing a tuba with that carbon composite bell" Denney

[J.c. Sherman]

Bloke - the Jupiters are (for better or for worse) resin. Which, of course, makes those damn bells impossible to repair, but cheap to replace.

Echoing Tubatinker's observation, I often tell students and others "Brass is soft; that's why they make brass instruments out of it".

J.c.S.

[opus37]

This question brings up the whole subject of alternate materials for making instruments. One material that holds great promise is carbon fiber composite. Basically, carbon fibers in an epoxy resin matrix. Violins and bows for similar instruments from composites exist today. The reviews on them are incredible. They are extremely light and have very true sound. I know some manufacturers use this material for bells now. Not very popular because it is expensive and comes in black only. This material can be injection molded in very complexed shapes. It is the material used to make many parts on stealth fighter jets. (Also, fishing rods and tennis rackets.) It does work for slides and valves but the rest of the horn could be from this material and it could be engineered, square inch by square inch, to sound perfect. With all that said, why do it? There would have to be an economic advantage to build such an instrument. Right now, with all the wonderful brass and student friendly fiberglass horns out there, the need just does not exist.