Mixing : Basic Mixing : Signal Routing for Monitoring and Submixing : Discrete Submix Output

Discrete Submix Output
Pro Tools lets you discretely route source audio through a submix. This is preferred for dither or other mastering processing, where you do not want unprocessed audio heard in addition to the processed signals. Use track outputs (not sends) to assign tracks to a bus path for discrete submixing. In this arrangement, the balance of processed and unprocessed signal is controlled by plug-in wet/dry settings.
To create a discrete submix:
1 Set the output of the tracks you want to include in the submix to a stereo bus path.
2 Pan each track.
3 Choose Track > New.
4 Specify the track type (Aux Input) and format (stereo), then click Create.
5 Set the input of the Auxiliary Input to the same bus path to which you assigned all contributing tracks.
6 Set the output of the Auxiliary Input track to your main stereo mix outputs (typically, outputs 1–2).
7 Set the Auxiliary Input Track level.
8 To process the submix, assign a plug-in or hardware insert on the Auxiliary Input.
9 Set the controls of the plug-in. The plug-in Bypass and Wet/Dry controls (if available) determine the amount of effect heard.
The contributing track faders control the balance within the submix. The Auxiliary Input track controls the output levels of all tracks routed to it.
You can apply mix automation to the volume, pan, mute, and send level, send pan, and send mute controls of the Auxiliary Input.
You can also bounce a submix to disk to free up the voices for use by other tracks. See Mixdown for more information.