Specifications

DigiRack Plug-Ins Guide56
TimeAdjuster Controls
Phase Invert Inverts the phase (polarity) of the
input signal. While most Digidesign plug-ins
supply a phase invert button of their own, some
third-party plug-ins may not. Phase inversion is
also useful for performing delay compensation
by tuning unknown delay factors by ear (see
“Using TimeAdjuster for Manual Delay Com-
pensation” on page 56).
Gain Provides up to 24 dB of positive or negative
gain adjustment. This control is useful for alter-
ing the gain of a signal by a large amount in real
time. For example, when you are working with
audio signals that are extremely low level, you
may want to adjust the channel gain to a rea-
sonable working range so that a fader is posi-
tioned at its optimum travel position. Use the
Gain control to make a wide range of gain ad-
justment in real time without having to perma-
nently process the audio files, as you would with
an AudioSuite plug-in.
Delay Provides up to 8192 samples of delay com-
pensation adjustment, or general adjustment of
phase relationships of audio recorded with mul-
tiple microphones, depending on which version
of TimeAdjuster is used. It defaults to a mini-
mum delay of four samples, which is the delay
created by use of the TimeAdjuster plug-in itself.
While phase inversion controls have been used
for many years by engineers as creative tools for
adjustment of frequency response between mul-
tiple microphones, sample-level delay adjust-
ments provide far more control. Creative use of
this control can provide a powerful tool for ad-
justing frequency response and timing relation-
ships between audio signals recorded with mul-
tiple microphones.
Using TimeAdjuster for Manual
Delay Compensation
DSP processing in all digital systems incurs de-
lay of varying amounts. You can use the Time-
Adjuster TDM plug-in to apply an exact number
of samples of delay to the signal path of a
Pro Tools track to compensate for delay incurred
by specific plug-ins. TimeAdjuster provides pre-
sets for common delay-compensation scenarios.
To compensate for several plug-ins in-line, use
the delay times from each settings file as refer-
ences, and add them together to derive the total
delay time.
Alternatively, look up the delay in samples for
the plug-ins you want to compensate for, then
apply the appropriate amount of delay.
To manually compensate for DSP-induced de-
lays, try one of the following methods:
Phase Inversion
If you are working with phase-coherent track
pairs, or tracks recorded with multiple micro-
phones, you can invert the phase to negate the
delay. If you don’t hear any audio when you in-
vert a signal’s phase, you have precisely adjusted
and compensated for the delay. This is because
when you monitor duplicate signals and invert
Some plug-ins (such as Digidesign’s Maxim
and DINR BNR) have different delays at
different sample rates. Refer to the Digide-
sign Plug-Ins Guide for more information
about these plug-ins.
A delay table for DigiRack plug-ins appears
in Appendix B, “DSP Delays Incurred by
TDM Plug-Ins.”