Tuba Science

[Dan Schultz]

Hey,.... Please limit yourself to actual facts - not suppositions or opinions.

Not going to be much to write about, then.

[Bandmaster]

Hey,.... Please limit yourself to actual facts - not suppositions or opinions.

Not going to be much to write about, then.

Suppositions and therories can be debated, facts have to be proven. How do you "prove" that the taper is correct or incorrect? So much for the debate....

[Søren]

Thanks Harold. This is my favorite topic.
I asked a couple of questions in a previous tread that have some relevance in this one too.

viewtopic.php?t=13436&highlight=

I have since acquired a program that can make a sound frequency spectrum and tell the amount of the fundamental and overtones in a sound. Just like Mr. Denny has done extremely well on his webpage:

http://www.rickdenney.com/the_tuba_sound.htm

The program that I have is Spectrogram from the following webpage.

http://www.visualizationsoftware.com/gram/gramdl.html

I think that many of the differences in mouthpieces, tubasizes, laquer vs silver and so on could be revealed with doing this simple analysis and then comparing the results.
The problem is now that different microphones and different players would be uncontrollable variables. But if enough people would do this analysis and post the results, I think a general picture would emerge on how different tubas and mouthpieces affect the sound.

As for measuring other parameters such as, intonation differences on tubas with different mouthpieces and response, I do not have any good idea.
But maybe that intonation problems with certain mouthpieces on certain tubas is a consequence of the mouthpiece producing false overtones at certain frequencies.

As I see it, a possibility is that a good mouthpiece is one that produce a nice overtone series at all frequencies. Anybody know something that would conflict with this thesis?

[iiipopes]

Hey,.... Please limit yourself to actual facts - not suppositions or opinions.

Not going to be much to write about, then.

Next Thread....

[Dan Schultz]

....
The problem is now that different microphones and different players would be uncontrollable variables. ...

I really hate to be so negative here, but you have an even bigger problem inasmuch as no two horns are EXACTLY the same.

[Søren]

Well, there are books out there that explain the sonic properties of brassinstruments without any rumor and witchcraft. An excellent example is “Horns, Strings, and Harmonyâ€

[Dan Schultz]

I think that one could study this subject a whole life without writing all about this subject.

I think you are probably correct. There are a few exact principles in accoustics but there are also loads of variables over which you have little or no control. I spent several years working on the design and prototyping of automobile horns. It's true that there are loads of scientific data to support what SHOULD happen under ideal conditions.... BUT the ONLY way to know how a musical instrument will perform is to build a prototype.

[Shockwave]

http://www.chisham.com/tips/bbs/mar2004 ... 67850.html


I did some Fourier analyses the other day of various tubas playing low notes to find the relative amount of fundamental they produce. The purpose was to compare the fundamental output of the same notes on various tubas using false tones and valves. The notes played were C, Ab, and F starting two leger lines below the staff and descending. I used a program called Audacity to record and analyze the sound. The bell of each horn was positioned and oriented identically for each test. These are not absolute measurements, they are only relative since this was done with an uncalibrated mic indoors. A proper test would use a measurement microphone outdoors to eliminate room resonances.

Horn dB@ C Ab F

Conn jumbo sousaphone -3 -7 0

Leyland 5/4 BBb tuba -12 -10 -5

Conn giant Eb -2 -8 -10

E. G. Wright saxhorn w/valves -14 -23 -18

E. G. Wright saxhorn w/false -14 -12 -13

Pan American Eb sousaphone -3 -9 -14

The horns:

Date Model Key Bell dia. Bore # valves

1924 Conn 48K BBb 26 .770 4

1885 Leyland Eclipse BBb 19 .746 3

1924 Conn giant Eb 20 .693 3

1850's E.G. Wright Eb 11 .655 4

1930's Pan Am Eb 24 .625 3


Draw what conclusions you may. My conclusions are as follows:

By using false tones, the Wright gained 11dB on Ab and 5dB on F compared to the same notes played with the 4th valve. A similar study done with the 48k gave me similar results, namely that false tones produce a lot more bass. A difference of 11 dB is an increase in power of around 7 times.

The giant Eb output one decibel more on C and one decibel less on Ab than the jumbo sousaphone.

The Leyland tuba has a beautiful sound, and makes quite strong bass compared to other BBb tubas I've played such as the King 2341 and Conn 20J, but it couldn't keep up with a small Eb sousaphone down to Ab. The low F, strong as it is, was 5 dB below the jumbo sousaphone.

-Eric

[imperialbari]

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[Art Hovey]

Vincent Bach was a good trumpet player, and designed good trumpets. I'm not sure, but I think Dennis Wick is also a trumpet man. I have always been skeptical about applying their backbore conclusions to tubas. If you scale a trumpet backbore up to BBb tuba dimensions it has to be about four times longer, because a tuba is two octaves lower than a trumpet. That makes it almost as long as the entire leadpipe on some tubas! Tubas differ from trumpets in many ways in addition to size. (A trumpet is not a scaled-down tuba, and a tuba is not an overgrown trumpet.)
Instrument designs evolve gradually. We try different things and the ideas that seem to work eventually become incorporated into new designs. -At least that happens with trumpets and trombones. It saddens me to see new manufacturers cranking out duplicates of some of the worst ninteenth-century tubas (for the school market) with no effort to correct even their most obvious flaws.

[LoyalTubist]

Denis Wick is a trombone player.

Agreed. Anyone got some pizza and beer?

[LoyalTubist]

I met Denis Wick in Indonesia. Not too far away, sort of...

I was agreeing about this being a boring post. I am also trying to do some work right now--it's the middle of the afternoon here.

[imperialbari]

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[Rick Denney]

[quote="Søren"]Well, there are books out there that explain the sonic properties of brassinstruments without any rumor and witchcraft. An excellent example is “Horns, Strings, and Harmonyâ€