I was *never* the AV support on any training sessions I've been to. I almost *always* however end up fixing what is wrong with the AV system. Including a presentation by a BOD member in the 350 seat theatre setup that used *gag* BLUETOOTH (Q#$%#$%^#$%) for the microphones.
(Did you know you can use a blackberry 9 series as an audio relay station in bluetooth?)