We are asked which mics used in live situations provide the least amount of feedback. The following are some things to think about regarding this issue.
One of the easiest ways to reduce feedback is to move the microphone closer to the desired sound source. So, if you’re the engineer, make sure that your stage mics are appropriately placed on amps, drums, singers, etc. Additionally, using a directional microphone (cardioid, supercardioid, etc.) will typically increase the amount of gain before feedback due to the focus of a polar pattern that doesn’t pick up as much stage noise (monitors, amps, etc). Also, remember that an “open” mic that is not being used directly is simply inviting feedback. If not directly, then as a result of allowing more unwanted sounds to get into the mix, which requires desired mics to be turned up more, so reduce the number of open microphones from the mixing position. Finally, try to keep microphones and loudspeakers as far away from each other as possible.
Proper implementation of the above techniques will go a long way towards eliminating feedback in your sound system.