Specifications

Digidesign Plug-Ins Guide74
In order for Hum Removal to learn the audio sig-
nal from live inputs, Pro Tools must be in play-
back mode.
Signal Present LED Lit when an audio signal is
received.
Using Hum Removal
As in the BNR module, you must have Hum Re-
moval learn the target noise in an audio track.
To learn the noise, the Hum Removal module
sweeps through the material’s frequency spec-
trum, scanning the noise to find the most prom-
inent frequency characteristic of the audio sig-
nal. When this is completed, it automatically
configures itself for maximum hum removal by
setting its center frequency parameter to the
fundamental frequency of the most prominent
hum.
Before You Begin
Before you start using Hum Removal, think
about the nature of the noise and where it is lo-
cated. Is it on a single track, or several tracks? Is
it a single type of noise, or several different
types? The answers to these questions will affect
how you use Hum Removal.
If there is a single type of hum on a track, insert
the Hum Removal plug-in onto the track. Solo
the track to make it easier hear as you remove
the noise. If a single track contains different
types of noise, you may need to use more than
one DINR insert to remove the other types of
noise. If multiple tracks contain the same noise,
you may want to bus them all to an auxiliary in-
put so you can use a single DINR plug-in insert.
This will minimize the amount of DSP you use.
To use Hum Removal:
1 Click the Inserts pop-up on the track with the
noise and select Hum Removal. The Hum Re-
moval window appears.
2 In the Edit window, select the portion of the
track where the hum is strongest—ideally, a seg-
ment with as little of the desired signal as possi-
ble. This will make it easier for the Hum
Removal module to accurately analyze the hum.
If the track contains a segment comprised of
hum only, select that portion.
3 Begin audio playback, and in the Hum Re-
moval window, click the Learn button. The
plug-in samples the first 50 milliseconds of the
selected audio and searches for the most promi-
nent hum frequency.
– or –
Locate and identify hum on the fly, during play-
back, using the Hum Removal module’s Learn
Last Audio mode. To do this, Option-click (Mac-
intosh) or Alt-click (Windows) the Learn button.
Begin playback, and when you hear the hum
that you want to identify, click Learn a second
time. The plug-in will identify the hum based
on the 50 milliseconds of audio immediately
preceding the second click.
4 Adjust the Cut Level slider to increase or de-
crease the degree to which the hum frequency is
cut.
Although the Hum Removal module automati-
cally sets the Cut Level to maximum hum re-
moval, you may still want to adjust this param-
eter to minimize any undesired side-effects. To
compare the audio with and without noise re-
duction, click the Bypass button.
5 Fine tune the hum removal by adjusting the
Threshold, Attack, and Release sliders.