Re: Harmonics CC tuba


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Posted by Dave on May 24, 2002 at 21:44:46:

In Reply to: Harmonics CC tuba posted by Harmonics on May 24, 2002 at 19:39:58:

First of all, every CC tuba has the same length (roughly. The size of the bell, etc. factors in a bit) Whether you're playing a pea shooter or a Yorkbrunner, it's about the same.

Next, you can't think of the tuba as a slinky or string that has one wave. Really, the tuba has half a wave for the fundamental (i.e. pedal C. C below the staff is the second harmonic. G on the bottom is the third) If you look at a plucked string on a double bass, the ends don't seem to move, while the center moves the most. The biggest movemnt part must line up with the bell of the tuba (metaphorically. Now we're talking about the wave) So it's kind of like half the wave. Then the second partial is 1 1/2, then 2 1/2 etc.

Ok, so to lower the pitch, the wave must be lenghtened. The tuba is lengthend to accomodate this. Thus the essence of valves. As far as where they live, I guess you mean the nodes. When you play the 12th position harmonic on a double bass, you see two of what you had when you plucked it open. So the wave as 2 "widest points" for G (one is at the bell) As far as where exactly these are, that really depends on the wrap of your horn.

Acoustics is far more complex than I can explain in one post, but this should give you some idea. Sorry I didn't really understand the "live" part you your question. Perhaps someone else could clear that up.


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