Posted by js on August 31, 2002 at 18:15:09:
This is a phenomenon that I hear when many "good" tuba players perform technical solos:
Often, when an angular melodic line suddenly dips to an isolated note well below the staff (a low note that is  not  marked louder  nor  accented), I hear "tah-tah-tah-tah-  BLATT  tah-tah-tah, etc. (the  blatt  being the sudden low note).  Let's us (I'm quite hard on myself about this - being a personal pet peeve) tuba [and bass trombone] folk try  not  to do this when performing solos, unless marked that way on the written page.
Tubas and bass trombones (the instruments themselves) "love" to make very resonant low sounds.  They are built to do this.  Often, some of the "best" tubas and bass trombones resonate more easily in the low range than in their "middle" ranges.  As I encourage myself to listen to my tendencies and those of my instrument, I encourage others.