WMAS

Wireless Multi-Channel Audio Systems is a wireless broadband audio technology that can combine wireless microphones, instruments, in-ear monitors (IEM) and remote controls into one broadband RF channel. A traditional narrow-band wireless system is limited to a bandwidth of 200 kHz with a maximum power output of 50 mW without a license. As the number of narrow-band systems operating in a local area increases, the power spectral density (PSD) increases, which can cause distortion or interference with nearby systems. The transmitting power of a WMAS is 50 mW, regardless of the number of audio channels being used. WMAS requires a wide band for transmission, 6 MHz in North America or 8 MHz in European countries (the bandwidth of one TV channel in each region). Unlike narrow-band wireless, the 50 mW transmission of a WMAS system is not confined to a 200 kHz band but is spread across the entire 6 MHz (8 MHz in Europe) band. This results in a power spectral density 30 to 40 times lower than a conventional wireless microphone. This reduces the chance of interference from nearby neighbors using the same frequency. The system is bidirectional, meaning it can operate as both a transmitter and receiver simultaneously, allowing, for example, transmitting an instrument signal while at the same time receiving an IEM mix, using one pack worn by a performer. It was introduced by Sennheiser and Shure in 2023.