What advice can you give on playing consistently loud, but all the while maintaining control and avoiding cracks, such as in a piece by Mahler or Bruckner?
Dale Clevenger's answer:
We play so many "big" pieces which require good quality loud playing that we sometimes take for granted this necessary "technique". The fact is that, by far, most students and professionals never play or are asked to play at the decibel levels that we routinely play. In my master classes and lessons I demonstrate the wide varity of dynamics needed in the CSO, (and other major orchestras) from "ppp" to "fff". Usually, I get comments like, "crude, hard, crass, or raucous". After hearing really close then from a long distance, the comments are quite different...."big, good loud, full, exciting, a revelation, etc".
Having said all this, I still have not addressed the method of practice one needs to be able to play "good loud". Any subject related to performing on a brass instrument that requires great stamina, could be compared to running a marathon (26.2 miles). It cannot be done without a lot of systematic, disiplined and incremental study/practice. It should start sooner than later, age-wise. A very good example of this method of practice would be the Singer "Embouchure Building" book in the Heavy Routine section. Read the script! It's important! Do not expect over-night results. Typically, several weeks or months would be more realistic. Lots of trial and error and experimentation as to your mouthpiece placement, pressure and muscle/facial tension. The primary rule is: quality, quality, and quality. Good luck.