Apple Logic Pro X - Manual (Page 857)

Chapter 25 Preferences, project settings, and key commands 857
Input preferences
Input preferences are only available when Additional Surround Options is selected in
Advanced preferences.
•
Surround Show As pop-up menu: Sets the surround format. The choice you make automatically
updates the remaining pop-up menus in the Input pane.
•
Surround Initialize buttons: Choose between the default setup of Logic Pro, the ITU
(International Telecommunications Union) standard, and the WG-4 standard.