Specifications

Chapter 3: Pro Tools Concepts 11
Chapter 3: Pro Tools Concepts
This chapter explains the principles and con-
cepts that form the foundation of Pro Tools op-
eration and functionality.
Hard Disk Audio Recording
Tape-based recording is a linear medium—you
need to rewind or fast forward a tape to hear a
particular spot in a recording. To rearrange or re-
peat material in a linear system, you need to re-
record it.
Hard disk recording is a nonlinear (or random ac-
cess) medium—you can go immediately to any
spot in a recording without having to rewind or
fast forward.
Nonlinear systems have several advantages. You
can easily rearrange or repeat parts of a record-
ing by making the hard disk read parts of the re-
cording in a different order and/or multiple
times. In addition, this re-arrangement is non-
destructive, meaning that the original recorded
material is not altered.
Pro Tools is a nonlinear recording system that
lets you rearrange and mix recorded material
nondestructively.
The Digidesign Audio Engine
DAE (or Digidesign Audio Engine) is Digide-
sign’s real-time operating system for digital re-
cording systems. When you install Pro Tools,
DAE is automatically installed on your system.
In the same way that a computer’s operating
system provides the foundation for programs
that run on the computer, DAE provides the
foundation for much of the hard disk recording,
digital signal processing, mix automation, and
MIDI functionality required by Pro Tools and
other products from Digidesign and its Develop-
ment Partners.
The DAE Playback Buffer Size determines the
amount of memory allocated within DAE to
manage disk buffers, which affects system per-
formance. For more information, see “DAE Play-
back Buffer Size” on page 40. The DAE Playback
Buffer Size can be changed in the Playback En-
gine dialog, discussed below.