What's causing feedback/frequency noise in my microphone while recording in the isolation booth?
I recently got a new shotgun/cardioid microphone for my studio locker. I plan to use it mostly on the road when I travel for voice over work. Normally I use the sennheiser 416 but I wanted a small less expensive mic for traveling. I've tried the mic in different rooms and situations. It's a pretty quiet mic and works fine. Oddly though when I use it in my isolation booth it's picking up frequency low hum noise. The good news here is that it only happens in that one room...but I'm totally stumped as to what's causing it. Inside the booth there are other microphones hanging out. But I've tried to take them out. I tried removing the 416, turned off flouresent light, turned off power source, turned off speakers on other side of glass. Booth is about 4 by 4 feet 7 feet high. Could it just be the booth itself is for some reason causing noise? It's a high end space well built booth and I've never had a issue with other mics in it. Again the mic has no noise when I try it other places...even right outside the booth. So strange. Any ideas are greatly appreciated.