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.
You can use both track outputs and sends to route audio for submixing, depending on whether you want a
discrete or
send and return submix.