Audio-Technica's System 9 is a four-channel frequency-agile wireless system designed to provide rock-solid performance along with easy setup and clear, natural sound quality. Featuring sleek, stackable, contemporary styling, System 9 is available in handheld, headworn, guitar, lavalier and body-pack configurations. The system offers four compatible user-switchable VHF channels (169.505, 170.245, 171.045, and 171.905 MHz).

Each System 9 configuration includes the ATW-R900a receiver and either a body-pack transmitter or handheld microphone/transmitter. The ATW-R900a is a non-diversity, single-channel receiver with advanced dipole antenna design for extended operating range, which improves operation by providing a ground element in addition to the usual signal element. The ATW-R900a also offers volume control along with AF Peak, RF and Power indicator lights.