sound operators

some advices on stage sound:
using isolating Sennheiser HD-280 headphones because the stage volume can get out of control

This is a problem and it's one that sould be solved. When the stage volume gets out of control, the house sound suffers both acoustically and because the musicians get distracted and aren't playing as well as they could. Headphones aren't the solution, unless everyone is wearing them (which puts the stage volume well under control).

Iroquois, Jackson, Kane, Knox, Lake

Some helpful clues:
Feedback is caused by the mic picking up its own sound from the speaker. This may be because the speaker is facing the mic, or because the sound is bouncing around the walls and stage back into the mic. Sound is made up of many frequencies. This is why feedback sounds like a steady 'tone'. When feedback starts you hear a 'ringing' sound at that frequency, usually enough warning to act fast and pull the level back. If you let it continue it grows to become a shrill tone that can reach maximum PA level if left unchecked. It can be quite effective in clearing the hall!

Champaign, Champaign-Urbana, Chicago, hicago, Collinsville

There are changes in volume levels that occur because of singers/instrumentalists changing instruments, dynamics, etc... stuff that changes even after a thorough sound check.

Mount Carroll, Mount Carroll, Mount Olive, Mount Vernon, Mundelein