We organize shows for the school hall which holds 500 people. We had purchased these wireless microphones for the presenters, because they wanted to have their hands free. The quality is excellent and everything went well in the rehearsals. But during the show the audience was loud and we had to start turning up the volume and the gain. Very quickly the microphones reached saturation and went into feedback. Under the feedback threshold they sounded horrible. We therefore recommend them for quiet environments. We now convinced the presenters (they are not really very happy) to use the good olds SM58.