Posted by Bill on April 17, 2002 at 14:22:19:
I have a question about the diaphragm placements for different bore size tubas. One tuba I have is a small bore Eb and it is not necessary to place and hold the diaphragm so high in order to play in tune as it is on a larger bore B & H Imperial EEb (1976). With the latter tuba, it is harder to play the highest notes of the range in tune; they tend to be flat. I tried different size D.Wick mouthpieces and found that the size 4 is easier to play in tune on the Imperial, with a lower height and less effort for the diaphragm. So the mouthpiece plays some role at least.
Does a larger bore tuba require a higher and stronger placement of the diaphragm, or is the Imperial probably just somewhat flat? I may cut it, as others have done.