terraplane8bob,
Another point to consider. Trumpets project the most of all the brass. They project in a very directional manner, maximum straight to the audience. The conductor may be off axis and may not get the full beamy energy of the trumpet. That's the reason the podium could be softer than the direct beam to a significant audience distance. It is the loudest instrument, esp in the upper midrange 3-4 kHz where the human ear is most sensitive. When I heard the trumpet beaming to me at midhall center, it was loud and brilliant. But softer instruments like strings and woodwinds are lost in midhall compared to the stage or 1st row. Even the other brass instruments are way softer than the trumpet--the trombone projects at a lower angle than the trumpet, the French horn projects behind to the floor, and the tuba vertically. All these softer instruments get diffused away the more distance their sound has to travel. But the trumpet is like a directional megaphone.
My Audiostatic 240 electrostatic panel is straight and highly directional. Heard straight on axis, it transmits the purest sound that way, without HF rolloff. I don't mind keeping my head aligned straight, to get the beamed sound from the left and right with full toe-in. All other electrostatics have curved panels, and give flawed off axis sound in a multitude of directions, with resultant time smearing. This is what happens with all distant seats in the hall. Only the trumpet survives the distance-induced time smearing.