Posted by Klaus on April 09, 2002 at 19:37:26:
In Reply to: Intonation... posted by Out of tune on April 09, 2002 at 18:16:48:
The odd notes, that you have experienced, are the one we all experience on large conical brasses. Maybe not the very same note names, but at any rate the same positions in the partial system, whether our instrumenst are pitched in GG, BBb, CC, Eb, F, G, or Bb.
If you had a past on trombone or horn, you would have gotten accustomed to thinking in tubelengths. To be adjusted by hand slide or by hand position respectively (Gunther Schuller is my Guru on hand positioning).
The same approach can be taken on large conical brasses. If you have a 5 valve CC with the 5th as a long whole step, one of your problem notes, the Eb can be fingered:
2: which is the flat one
23: which would tend sharp
14: which might be right on, but with a brittle attack
45: which might be slightly flat, also with a brittle attack
134, 345, and 12345 also should render something close to an Eb. All with a not so reliable attack.
I have tried these fingerings in various instrumental contexts. And invariably have come up with the two first ones being the only useful ones. To know which one to use, you have to analyse the musical context. The extremely short version is, that if the Eb is a dominant seven in an F7 chord, then use 2. If the D# is the major third in the tonic B natural chord, then use 2. If the D# is the leading note in E major then use 23 (and 3 for E).
When I tested a Besson 983 Eb, I was told, that if I used anything larger than a Denis Wick #3, then I would play way flat. I found the DW #1 better sounding, and had to pull the tuning slide very far to reach an A=440 equivalent of pitch.
The only situations, where I have skewed octaves badly, have been when I played bassbone or euph on large tuba mouthpieces. The sound and range was good, the tuning and intonation were useless.
My often stated mouthpiece philosophy is to find the largest possible generic cup diameter combined with a voluminous cup shape. My preference for my US style Eb and BBb basses is a funnel shaped profile. The throat has not to be of the maximal dimension. Open up the backbore as barrel shaped as possible (I have limited tool options). That includes shortening the cylindrical length of the throat from the backbore side.
In my not so humble opinion this approach gives a good combination providing leverage for a strong embouchure matched with a wide and warm air supply.
But be prepared for the full load of Hell's capacity of glowing coal coming down right on your sinning head, if you do not practise a lot, or if you have a bad day physically. Your spectre of main problems will shift from intonation and range to neat and clean articulation in lower dynamics.
Just my (pre-)senile points of view