What is automixer?

An automixer (automatic microphone mixer) is an audio processing feature that automatically manages the levels of multiple microphones by reducing the gain of those not currently in use. This helps to maintain a clean and intelligible audio mix by minimizing background noise, reducing the risk of feedback, and avoiding phase issues such as comb filtering. Automixers are especially useful in environments where multiple microphones are active simultaneously, such as meeting rooms, courtrooms, or conference settings.

Without an automixer, open microphones continuously pick up ambient sound, which can lead to a poor signal-to-noise ratio, increased chances of feedback, and reduced speech clarity due to overlapping signals. By attenuating unused microphones, automixers improve overall audio quality, apply NOM (Number of Open Microphones) attenuation to control gain, and ensure that only the most relevant microphone is contributing to the output at any given time.

In LUNA series audio matrix processors, the automixer function is designed to intelligently manage and balance multiple microphone inputs in real time. It supports input sources from mic/line, Flex, or Dante channels, making it highly adaptable for a wide range of system configurations.

Each processor supports up to four independent automixer processing blocks, with a maximum of eight input channels per block. This allows users to group and control multiple microphones efficiently within different zones or use cases.

Two types automixing algorithms are available:

Shared Mode (Gain Sharing) – Automatically distributes gain across all active microphones, maintaining a consistent overall level while reducing the gain of inactive channels.

Gated Mode (Gating) – Opens (activates) or mutes microphone channels based on a signal threshold, ensuring that only the microphones currently in use contribute to the mix.

These modes provide flexible tools to ensure clear, feedback-free audio in applications where multiple microphones are used simultaneously.