Chicago Symphony - plays as loud as the do because the acoustics at podium. Brass does not sound as loud at podium.
Acoustics can effect sound, tuning and matching of sound.
Finest quality of tone in the midrange leads to better quality at loud and soft dynamics. Motivation of player influences sound, tuning matching most. Air does not become stale it becomes blocked by pressure at throat. Continue long tone. Lip as a buzzing unit rather than a resistance unit.