Creating a Submix
A submix is created by routing multiple audio sources to a common bus or output path. This “submixes” the sources to a single path that can be returned to an Auxiliary Input, where the submix can be processed with plug-ins or external effects processors.
Audio is routed to a submix by assigning any combination of sends and track output to available bus or output paths.
When routing mono signals with internal mix busses, be sure to use mono busses rather than splitting stereo busses. Since Pro Tools | First keeps stereo busses phase aligned, splitting stereo busses can result in inaccurate delay compensation.