Audio mikes that used the cables for signal transmissions have long since been replaced with wireless mikes. Also called Radio mikes, they use radio frequency technology to transmit the audio signals. They are capable of sending signals through FM, AM, UHF, VHF and various digital formats.
The most modern mike sets come equipped with frequency selection modes with which you can set the required frequency without having interference from other transmitters operating at the same frequency band nearby. You are now able to use multiple microphones too at the same time.
The current radio microphones owe their origin to the first original compander microphone that was built by Nady Systems in 1976. He was honored with Emmy award in 1996 in honor of his contribution to the field of technology.
Radio mikes are wireless and hence it is easier for the performers to use them on stage and it is a lot safer too when compared to the wires and cables dangling from wired mikes.
The Radio mikes being wireless have provided freedom of movement and performance to the artists who perform on stage. They can freely move across the stage without having to drag or bother with the cables. The handling staff too need not bother with managing and joining cables etc.
Though Radio mikes are very good, there is yet one disadvantage when it comes to the battery life. The radio batteries tend to get drained out very fast and do not last long. The reason being that the radio microphones use up more power and drain the batteries in no time.
Radio mikes operate within a certain range only. This could be a drawback and you might have to buy higher end equipment to get wider range. Then there is also the risk of disruption of signals due to other equipments being used in the same frequency in near by area.
Many times you will be constrained to use fewer numbers of microphones to be able to retain the clarity and avoid clashing of frequency.