Digi XPress Specifications download pdf (Page 97)

Chapter 6: DigiRack Real-Time TDM and RTAS Plug-ins 91

Using TimeAdjuster for Manual

Delay Compensation

DSP and host-based processing in all digital sys-

tems incurs delay of varying amounts. You can

use the TimeAdjuster TDM plug-in to apply an

exact number of samples of delay to the signal

path of a Pro Tools track to compensate for de-

lay incurred by speciﬁc plug-ins. TimeAdjuster

provides presets for common delay-compensa-

tion 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

the polarity (phase) of one of them, the signals

will be of opposite polarity and cancel each

other out. This technique is convenient for find-

ing the exact delay setting for any plug-in.

To determine the delay of a plug-in by inverting its

signal phase:

1 Place duplicate audio regions on two different

audio tracks and pan them to the center

(mono).

2 Apply the plug-in whose delay you want to

calculate to the ﬁrst track, and a Time Adjuster

plug-in to the second track.

3 With TimeAdjuster, invert the phase.

4 Control-drag (Windows) or Command-drag

(Mac) to ﬁne-tune delay in one sample incre-

ments, or use the up/down arrow keys to change

the delay one sample at a time until the audio

signal disappears.

5 Change the polarity back to normal.

6 Save the TimeAdjuster setting for later use.

Comb-Filter Effect Cancellation

Adjust the delay with the signal in phase until

any comb-filter effects cancel out.

Viewing Channel Delay

Because plug-ins display their delay values in

the channel delay indicators, this can be used as

another method for determining delay compen-

sation.

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.”

1 2 ... 92 93 94 95 96 97 98 99 100 101 102 ... 142 143

Comments to this Manuals

No comments

Digi XPress Specifications Page 97

Comments to this Manuals

Related products and manuals for Networking Digi XPress

Produits connexes et manuels pour Équipement Krohne OPTITEMP LCD-H20 EN