Re: Advice for dealing with singers who wander out in front of the PA
Gates are handy to keep stray sounds out of mics that aren't being used. If set up correctly, they are wonderful assistants to the board operator. Of course, pulling down the slider of an unused mic will do the same thing. It won't help a bit with your feedback situation, and if the gate kicks open for whatever reason, it can result in instant feedback without warning if the mic is in a position where feedback could occur.
Compressors make getting into feedback WORSE on many occasions. When the artist is singing, the compressor is pulling down the gain. However, when they stop, the gain goes back up, and feedback can occur at that point. If they were singing their heart out and walked in front of the speaker, it may be fine, but when they stop to take a breath, the gain goes up and feedback city. Without a compressor, the artist has to adjust their singing volume, but at least the mic level is consistent, so you have less surprises.