IMO acoustics at a venue requires a balance of science, art, and experience to be successful. It's impractical to test-fill the space with the anticipated number of warm bodies prior to the performance and to replicate in advance air density, temperature, and humidity.
Two events stick in my memory, with lessons to be learned from each.
The first time I played in front of a microphone was an ear-opener. I have a good sense of balance, as all good musicians have, so I can correctly judge how my volume and projection relates to the rest of the ensemble. On this occasion I was featured soloist in front of the band, and the sound crew insisted on turning up my mic, forcing me to play softer and softer, while they kept turning up my volume, making my sound drown out the band no matter what I did to compensate, including backing away from the mic. During rehearsal I mentioned this to the director, who assured me that everything would be OK when the audience was in the auditorium. Well, come concert time, a good friend of mine recorded the show from the audience, and in spite of me playing from pp to m, guess what?... I drowned out the band! Awkward. I learned to be more assertive about my perception, but the ultimate decision is made by the sound crew. Plus, no matter how much you'd like to dent the rim of the bell of your horn on the thick skulls of some inept AV people, you have to remain diplomatic and fatalistic about the situation, because if you're at odds with them, they can make you sound even worse out of spite.
The other event was a sold out Rodney Dangerfield performance at a vintage local theater, capacity 4500+. My wife and I were in the loge, and when Rodney came on, his words were garbled to the point that we couldn't understand what he was saying. It didn't get better, and when other patrons started complaining too, we went downstairs to the orchestra level, as the laughs were coming from there. Luckily we found standing room before there was no more. The patrons from the loge, mezzanine, box seats, and gallery flooded the lobby and stormed the theater manager's office, demanding refunds. Sooo... the outcome was that the theater refunded approximately half of the money of what could have been a lucrative event, but wasn't, because the sound crew got it really, really wrong. The lesson to be learned here is that even experienced, professional sound crews can be caught out in a venue that was built before acoustics were given the consideration that they receive today.
