| One thing which I believe (there's that "belief" thing again...) is that the heavier horns, and particularly their bells, do not vibrate as much as a lighter horn. This sends more energy out to the audience but may reduce the feedback to the player (thus the "dead" opinion from players that has not generally been borne out by listeners out front). The reduced vibration will also affect the overtone (it's not strictly harmonic) series and thus the sound.
Neither of these is good or bad, but will affect how one plays a heavy horn. I have insufficient experience to judge, but suspect a player must take some time to settle in and obtain his/her sound without as much feedback from the horn. A friend with ears and/or recording setup can probably speed the acclimation process...
Acoustically, from an engineering standpoint, a concrete bell with the same flare as any other material should sound the same out front except for the energy "lost" to the vibrating bell of "lighter weight" horns. The player would get almost no feedback from the horn and would have to have a well-developed sense of his/her sound without that feedback. I suppose a sheet of plastic, or the stand, might reflect some energy back and help out. But, of course, concrete has other, less desirable properties for trumpet players, 'specially weak ones like me... :)
All IMHO, FWIWFM, blah blah blah - Don |