These work in very similar way to infrared except that the signal gets sent by radio, not light. Instead of the radiators spreading the signal to the auditorium, the signal is sent out by a radio antenna. It may be that only one is required and it should be in as central a position in the auditorium as possible so that the coverage will reach all the seats.
The quality of the audio input is just as important as with other systems. Try to get a microphone in the mix as well if you can.
There is the same need for the clear information and clear signage, because people have still got to collect headsets.