Specifications

DigiRack Plug-Ins Guide10
Delay in Digital Signal
Processing
DSP processing in digital audio systems incurs
signal delay of varying amounts. Such delays
can vary from as short as few samples to as long
as several hundred samples, depending on the
type of processing applied.
If you have recorded an instrument on multiple
tracks using multiple microphones (a drum kit
for example) and process the different tracks
with different plug-ins, the tracks may go out of
phase. You will then need to compensate for
these delays to avoid phase cancellation prob-
lems.
Compensating for Delay
Use the following methods, as available, to com-
pensate for processing delay.
Delay Compensation
(Pro Tools|HD Systems with Pro Tools 6.4 and
Higher Only)
Use Delay Compensation to automatically cal-
culate and compensate for processing delay. For
more information on Delay Compensation, see
the Pro Tools Reference Guide.
TimeAdjuster
(TDM Systems Only)
You can compensate for TDM plug-in-induced
delays by using the TimeAdjuster plug-in. This
plug-in lets you apply a specific number of sam-
ples of delay to the signal path of a Pro Tools
track. TimeAdjuster provides settings files that
apply the correct compensation time in samples
for delay introduced by one or more plug-ins.
See “TimeAdjuster” on page 77 for more infor-
mation about the TimeAdjuster plug-in.
Manual Delay Compensation
You can manually compensate for processing
delay by first calculating the amount of delay on
each track, and then nudging other track’s play-
lists later or earlier in time. This method is useful
when Delay Compensation is unavailable, or
when you want to conserve DSP resources.
See Appendix B, “DSP Delays Incurred by
TDM Plug-Ins” for information on delays
inherent in specific DigiRack TDM plug-
ins. See the
Pro Tools Reference Guide for a
guide to calculating DSP-induced delays.
For information about TimeAdjuster in
Delay Compensation sessions, see the
Pro Tools Reference Guide.
You can also compensate for offsets in-
curred by processing delays by using the
same plug-ins on all tracks.