The Audio-Technica AT-MX351 is a professional automatic mixer designed to manage multiple microphones in conferencing, courtroom, council chamber, and performance environments. Its primary function is to intelligently control the gain of up to five microphone channels, automatically opening only the microphones in use while muting or reducing the gain of inactive ones. This process, known as gating, helps to reduce overall background noise, minimize feedback, and improve system gain before feedback, resulting in clearer audio intelligibility without requiring constant manual adjustment by an operator.

The mixer employs Audio-Technica’s proprietary Adaptive Threshold Sensing technology, which sets individual channel thresholds based on the ambient noise level of the room, ensuring consistent and natural operation. Each channel features independent level controls, LED indicators for signal and gate status, and a priority override function that allows a designated channel (such as a chairman’s microphone) to remain open or to duck the levels of other channels. The unit sums all active channels to a balanced stereo or mono output for connection to a sound system, recorder, or broadcast console.

Housed in a compact half-rack metal chassis, the AT-MX351 is designed for easy integration into fixed installation racks or portable setups. It operates on standard phantom power supplied from a connected mixing console or an external power supply, simplifying installation. By automating the management of multiple open microphones, this mixer provides a reliable and effective solution for enhancing speech clarity and system stability in multi-participant audio environments.