The Conn Jumbo Sousaphone

[Gongadin]

Congratulations, Roger! Play it well...and really looking forward to a video!

[iiipopes]

What a leak or obstruction does is disrupt an antinode. Go read Schilke's research on the subject, as well as Nick Drozdoff's (1st call NY trumpet player, MF alum, and physics teacher) website and videos that demonstrate how sound really works. It has nothing to do with resistance or flow. I've played both: instruments with leaky tubing and worn valves. Fix the leak or seal up the valves, whether by thicker valve oil or a valve job, and the disruption to the antinode is removed and the note speaks. I stand by my posts.

The only "resistance" is two-fold: 1) the throat of the mouthpiece transitioning to the leadpipe (see Schilke's extensive research on mouthpiece "gap") and 2) the overall efficiency of the horn resonating pitch, known in physics terminology as mechanical impedance. This actually involves a more complex analysis of the design of the entire horn from receiver to bell flare, and the propagation of the terminal node just beyond the bell, and way beyond this thread.

[windshieldbug]

I propose that both sides are correct.

Yes, I know that what you are doing is setting up a standing wave. I did my own anecdotal "smoke" tests years ago to try to visualize the actual airflow speed and volume.

-but-

Even though the airflow is small (or the accepting volume is huge), there is some. I assert that what one feels as "resistance" is the effect of the horn on one's embouchure. The airflow THERE is disrupted if the appropriate frequency is not "locked" in [Including leaks at nodes. The horn can leak in other places and have little or no effect on the production of a note, but THAT note only]. The stronger one's chops, the more the ability to sustain a particular buzz frequency (also known as the ability to blow THROUGH a note). Years ago brass players focused more on the ability to buzz an in-tune note and much less on the adjustment of instrument length.

How about let's tap gloves and come out playing?

[GC]

False tones have a number of legitimate uses in situations where 4th and 5th valves are not available or not the best way to go.

It's much easier to play a pedal B with false tones (2+3 on BBb tuba) than it is to play 1+2+3+4 and pull slides, not that you're likely to need that note any time soon.

When I was learning to play pedal tones in high school, I couldn't hit pedal Bb open, but I could work down to it playing it 1+3. After a while I could hit it fairly easily, but I might have never gotten down to it without the practice with false tones. As my axe was a 3-valve Reynolds sousaphone, false tones were the only way to go.

In college in the early '70's, I owned a really stuffy Meinl-Weston model 25. Its 4th valve combinations below pedal D had so much resistance that I couldn't play Db and C with 4th valve combos, but I could play Db, C, and B strongly and with good tone with false tones.

Sometimes they work, sometimes they don't. When I owned a Cerveny 601 CC for a while, I was totally unable to get any use out of the false tones because they were so far out of tune. Then again, the horn was just too much for my weak lip after a 24-year layoff.

[tuba-tobias]

Hey Roger, pictures!
Either you put up some pictures here ASAP or you'll have to bring the instruments to the Tubajulebord on saturday so I can see them in the flesh.

For you others; Tubajulebord is the annual gathering of tuba and euphonium players here in Norway, first saturday in December. Food of the season (i.e. lutefisk), beer and aquavit is served.

[Dan Schultz]

Hey Roger, pictures!
Either you put up some pictures here ASAP or you'll have to bring the instruments to the Tubajulebord on saturday so I can see them in the flesh.

For you others; Tubajulebord is the annual gathering of tuba and euphonium players here in Norway, first saturday in December. Food of the season (i.e. lutefisk), beer and aquavit is served.

Whether Roger shows up or not.... you've got to post some pictures of that event!