Diaphram etc
I'm not sure that diaphram usage can have more or less "potential"...
As I said, get yourself a copy of the book which explains quite a lot. It also includes a medical case study, i.e. a doctor who was also a trumpet player wanted to see if the diaphram of a professional trumpet player was any different from an amateur.... the results ...
Quote
".... it seems a misnomer to refer to diaphragmatic breathing and development of the diaphragm muscle as the key to support of the trumpet player's wind power. Certainly, it is unlikely that the thin sheath that the diaphragm is can be hypertrophied and strengthened in a way similar to the large voluntarily-controlled skelital muscles. With this in mind, it would seem more reasonable to place emphasis on the student's ability to raise the anterior chest, thereby increasing its volume and develop the muscular power necessary to bring about the squeezing action of the musculature mentioned, and to gain full control over these muscles' function. This data would seem to have far-reaching import, not only for trumpet players, but wind players of all types as well as vocalists."
In Howard Snells book, "The Trumpet", the word Diaphram doesn't even appear in the sections on breathing... in fact, at my lessons when I asked him about breathing, his reply was ".. breath normaly, plus a bit more..."...
Quote
"... Good posture, a clear concept of sound and a general musicality, are the bases from which I teach. Undue emphasis (i.e. interference) on particular physical processes of the body may produce a momentary effect of improvement, but will certainly not be of lasting benefit. The effect will be to add extra tension to the player. Interference through seemingly precise verbal instructions - to do this or that with this or that - is both unnecessary and potentially harmful. "
I think that some teachers use the "diaphram" issue as something tangiable to grab on to. E.g. Use your diaphram instructions etc... what they really should be doing is telling the student to make a bigger sound, take a deep breath.. as soon as the diaphram is mentioned, the wheels fall off so to speak, and the student will forever be searching for way of improving their diaphram use. Tell them to improve their sound by breathing deeply , breathing in tempo, exhaling in tempo prior to inhaling in tempo (the Carmaine Caruso Method ) etc.. and focus on Sound rather than a part of the breathing apperatus that can't be directly controlled.
just my 2 cents!