Use output channel strips
By default, a project contains one output channel strip that takes the signal from all the individual tracks in the project. You add additional output channel strips to assign submixes, or to prevent them from being controlled by the master channel strip.
When using output channel strips in this way, you can’t apply any further send effects to the signal flow, as you would using aux channel strips. You can, however, control settings and insert effect plug-ins using the individual controls of the output channel strip.
In some cases, you might want to prevent individual output channel strips from being controlled by the master channel strip—outputs used as send effects to external hardware devices, for example. Simply make such output channel strips solo-safe and they won’t be affected by the master channel strip.
The Insert slots of output channel strips allow signal processing during the mastering process, as well as during normal playback. Typical mastering tools are the compressors, de-essers, and equalizers. Due to technical reasons, you can only use plug-ins that don’t require mono to stereo conversions. In other words, you can use stereo to stereo plug-ins on stereo output channel strips, and mono to mono plug-ins on mono output channel strips. Surround (or multi-mono) versions of plug-ins can be used on mono or stereo output channel strips. Mono to multi-mono variants can be used on mono output channel strips. Stereo to surround, stereo to multi-mono, and true surround versions of plug-ins are accessible in stereo output channel strips.