What is a Master Bus?

A master bus is the final signal path in a mixing system where all audio channels are combined before being sent to the main output. It represents the complete mix of all tracks in a recording or live sound setup.

In a digital audio workstation or mixing console, every channel and subgroup typically routes to the master bus. This bus collects the combined signals from vocals, instruments, and effects to produce the final stereo or multichannel output.

Audio engineers often apply processing such as EQ, compression, limiting, or mastering effects on the master bus to refine the overall sound of the mix. Adjustments made at this stage affect the entire mix rather than individual tracks.