Last week my high school had put on A Midsummer Night's Dream, and I was lucky enough to be doing my first sound designing job for a mainstage show. Our thursday show had went awesome, even our mic girl didn't mess up once. But then came the Friday show. First, it should be said that although I'm normally very good at troubleshooting, I definitely still don't know a lot of the little rules that come along with sound. Like, for instance, that all the recievers should be on the same group. (I think you can all see where this is going.) So, on Friday, apparently everyone in the audience thought it would be cool to leave their cell phones on, even though our director came over the mains before the show started, and told everyone to turn their cell phones off, since they do interfere with the microphone system. Next thing I know, a mic is cutting in and out. Luckily, it's one of the recievers that we have up in the booth, so I look at it and see that it's not getting any reception. We figure, "hey, let's try just holding it out the window." Still no luck. Then, we see that the other mic that's on the same channel as the one that's freaking out on us (hereafter known as mic 3) isn't picking up anything either. During a scene when that mic (4) and 3 aren't being used, we quickly change the channel on 4, give whoever uses 3 a different mic, and just pray to god that the bit players who now have that mic are able to project, in case it doesn't work. (the actual mic display is broken, so we can't ever change that frequency.) The problem with frequencies seem to be over, mic 3 ends up magically picking up again, and 4 goes off without a hitch. After the show, i'm turning off the recievers in the pit (we have mic outputs there, i don't know how any other theatre does it) when i hear someone talkign about how they heard people that weren't onstage during the play. Uh oh. Later, we learn that because of interference from cell phones and the mics all being on different groups, some of them were cancelling each other out or turning them on, even when we didn't touch them on the board. Apparently, at one point someone's mic who was in the drama room (where, truthfully, mics shouldn't even be picked up at ALL) was turned on, and they were cursing too. At this point you'd blame me for not being able to hear that, but even the people in the audience that heard it said that it was very, very low, and it was a techie alumni who told me anyway. Needless to say, the next day all the recievers were magically put on the same group, and we never had interference ever again. Moral of the story: Don't be stupid like me and not know that mics like to play with each other. and tell everyone you know to turn their cell phones off during shows.