Busses
A track is connected to a bus. A bus allows you to mix multiple audio tracks into a
single signal. An output bus is typically connected to a hardware audio output on your
computer or audio interface. Without busses, only one track could be connected to a
physical audio output at a time, requiring you to have as many physical audio outputs
as you had tracks.
For example, if you have a sequence with eight audio tracks, you can assign the output
of each track to the same bus. That bus mixes the eight audio signals together and
sends the combined signal to a hardware audio output so you can hear all eight tracks
on a single speaker.
Each bus typically corresponds to a hardware output, so busses and hardware outputs
are usually synonymous. However, you can also use output busses to group track
outputs together for mixing and grouped export. Busses can be mono or stereo and
can be connected to one or two hardware outputs, respectively.
Note: Busses in Final Cut Pro are used for routing tracks to hardware audio outputs or
for automatic stereo downmixing. You cannot create send or auxiliary busses as you
would in other audio applications.