I'm sitting in our black-box, right next door to the proscenium stage. Let's see, the building was built in 1929, and while the blackbox I'm in was installed only a few years ago, the PA has a few issues I've come to find out about. #1. It's winter in Chicago, which means plenty of static electricity. Every time someone gets zapped, it makes a pop in the PA. I can touch the floor and have the PA snap. #2. The elevators. Nothing like DC falloff current from the old motors leaking somewhere into ground. More of a problem in the proscenium space than the BB.