This buzzing problem just came up today during our matinee show of How to Succeed in Business. At one point there appeared a fairly loud low frequency buzz from one of our speakers. I have checked all personal wireless mics and all other inputs to the board and nothing. I have checked our outputs and still nothing. This is the first time it has happened all season and we have been running this show for almost a week and haven’t had any problems with this up till earlier today. If you need information on what amps and speakers we are using I can provide that later when I can get the exact numbers from them. Any suggestions would be greatly appreciated.