6.16: Wireless Mics

Wireless Microphones

Wireless microphones, also known as radio mics, FM mics, transmitter mics, or cordless mics, allow performers, speakers, and broadcasters to move freely without being tethered by cables.

Wireless systems work by converting the microphone’s signal into a radio frequency transmission. This is sent to a receiver, which outputs the audio directly to a mixing console or audio interface.

• A standard wired microphone can be converted into a wireless mic by attaching a transmitter to its rear, allowing it to transmit wirelessly.
• Handheld wireless microphones have a built-in transmitter within the mic body.
• Miniature and headset microphones typically connect to a bodypack transmitter, which clips to the belt or pocket and transmits the signal wirelessly.

Wireless microphones can operate over a wide range, from about 100 feet to as far as 2,500 feet, depending on the system’s power, frequency band, and environment.

Interference Considerations

One of the challenges of wireless systems is transmission interference. Wireless mics share frequency ranges with other radio devices, and crowded RF environments (such as concerts, broadcasts, or urban areas) can lead to dropouts, noise, or signal loss. Professional-grade wireless systems often include frequency agility, diversity reception, and encryption to reduce interference and ensure reliable performance.