The digidesign audio engine, Playback engine dialog – M-AUDIO Pro Tools Recording Studio User Manual
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Pro Tools Reference Guide
8
The Digidesign Audio Engine
The Digidesign Audio Engine (DAE) is Digide-
sign’s real-time operating system for digital au-
dio recording, playback, and processing. When 
you install Pro Tools, DAE is automatically in-
stalled on your system.
In the same way that a computer’s operating sys-
tem provides the foundation for programs that 
run on the computer, DAE provides the founda-
tion for much of the hard disk recording, digital 
signal processing, and mix automation required 
by Pro Tools and other products from Digide-
sign and its Development Partners.
The DAE Playback Buffer Size determines the 
amount of memory DAE allocates to manage 
disk buffers. The DAE Playback Buffer Size can 
be changed in the Playback Engine dialog.
Playback Engine Dialog
Pro Tools lets you adjust the performance of 
your system by changing system settings that 
affect its capacity for processing, playback, and 
recording. These system settings are available 
in the Playback Engine dialog (Setup > Playback 
Engine
).
Pro Tools takes advantage of your computer’s 
host processor for certain tasks and optional 
host-based DSP processing. 
Pro Tools LE uses host (CPU) processing to pro-
vide audio track recording, playback, mixing, 
and effects processing. Both Pro Tools LE and 
Pro Tools HD use host processing to run RTAS
®
(Real-Time AudioSuite) plug-ins for effects pro-
cessing. Performance is determined by your sys-
tem and its Playback Engine settings. 
The Playback Engine dialog lets you set a hard-
ware buffer size and allocate a percentage of 
CPU resources for these tasks.
On Pro Tools|HD systems, you can select the 
number of voices and voiceable tracks for your 
system and its sessions. Voice count choices are 
based on how much DSP processing you want to 
allocate for voicing. 
On Pro Tools|HD systems, the Playback Engine 
dialog is also where you assign dedicated DSP re-
sources for Delay Compensation.
For information on configuring the DAE 
Playback Buffer Size, see “DAE Playback 
Buffer Size” on page 48. 
Playback Engine dialog for Pro Tools|HD system
For more information, see “Configuring 
Pro Tools System Settings” on page 42. See 
also “System Resources” on page 19.
