Specifications

Digidesign Plug-Ins Guide72
◆ If you have selected multiple regions for pro-
cessing and want to create a new file that con-
nects and consolidates all of these regions
together, choose Create Continuous File from
the File mode pop-up menu.
2 From the Destination Track pop-up, choose
the destination for the replacement audio.
3 Click Process.
Hum Removal
(Macintosh OS 9 Only)
DINR’s Hum Removal module is designed to re-
move many types of harmonic noise from audio
material. It is especially effective on noise such
as AC line hum, light dimmer buzz, generator
noise, guitar pickup noise, fluorescent hum,
passing car drones, and noise from computer
monitor emissions. The Hum Removal plug-in
does this by utilizing a 200-notch comb filter to
remove the individual frequency components—
fundamental and associated harmonics—from
the audio material.
How Hum Removal Works
The Hum Removal module provides harmonic
filters specifically designed to remove harmonic
pitched noise. Harmonic noise is noise that not
only contains a fundamental frequency compo-
nent, as in the 60 Hz component of AC line
noise, but also contains significant components
at the odd or even harmonics of the fundamen-
tal frequency. If you were to remove only the 60
Hz component of AC line noise, you would still
hear significant amounts of noise at 120 Hz (the
second harmonic), 180 Hz (the third harmonic),
and so on.
Harmonic filters will remove not only the fun-
damental frequency they are set to, but also all
odd and even harmonics of that frequency. The
advantage of this type of filter is that it effec-
tively creates hundreds of digital notch filters at
exactly the frequencies needed to remove cer-
tain types of noise.
However, while a harmonic filter is extremely
efficient, it also has drawbacks. The disadvan-
tage of this type of filter is that it can alter the
sound by imparting a ringing or phase canceling
quality to the sound. The harmonic filters used
in the Hum Removal module give you the abil-
ity to choose the best balance between noise re-
duction and the amount of undesired sound al-
teration that occurs.
Hum Removal Parameters
The following section describes the Hum Re-
moval parameters and their use.
BNR AudioSuite does not allow destructive
processing, so the Overwrite Files option is
not available in the File mode pop-up
menu.
Hum Removal is a Macintosh-only plug-in.
It is not compatible with Mac OS X,
Pro Tools version 6.0 and later,
Pro Tools|HD or 24|MIX cards. It requires a
DSP Farm to operate.
Hum Removal