Pro Tools 101_ An Introduction to Pro Tools 11 ( PDFDrive )

Source: Avid ® .
Sub Time Scale
The Sub Time Scale in a Pro Tools session is set to Samples by default,
meaning that Timeline locations are represented as sample-based values,
relative to the start point of the session. The Sub Time Scale provides a
convenient secondary timing reference.
Like the Main Time Scale, the Sub Time Scale can be set to Bars|Beats,
Minutes:Seconds, Time Code, Feet+Frames, or Samples. To display the Sub
Time Scale in the Edit menu, select SHOW SUB COUNTER from the Main Time
Scale pop-up menu. To set the Sub Time Scale, select the desired timebase
from the Sub Time Scale pop-up menu.
Figure 2.36 Sub Time Scale pop-up menu
Source: Avid ® .
Ruler Display Options