Specifications

DigiRack Plug-ins Guide14
Dither Controls
Bit Resolution
Use this pop-up menu to choose one of three
possible resolutions for the Dither processing.
Set this control to the maximum bit resolution
of your destination.
16-bit Recommended for output to digital de-
vices with a maximum resolution of 16 bits,
such as DAT and CD recorders.
18-bit Recommended for output to digital de-
vices with a maximum resolution of 18 bits.
20-bit Recommended for output to digital de-
vices that support a full 20-bit recording data
path, such the Sony PCM-9000 optical master-
ing recorder, or the Alesis ADAT XT 20. Use this
setting for output to analog devices if you are us-
ing a 20-bit audio interface, such as the
882|20 I/O audio interface. The 20-bit setting
can also be used for output to digital effects de-
vices that support 20-bit input and output, since
it provides for a lower noise floor and greater dy-
namic range when mixing 20-bit signals directly
into Pro Tools.
Noise Shaping
Noise shaping can further improve audio perfor-
mance and reduce perceived noise inherent in
dithered audio. Noise shaping uses filtering to
shift noise away from frequencies in the middle
of the audio spectrum (around 4 kHz), where
the human ear is most sensitive.
The Noise Shaping button engages or disengages
Noise shaping. Noise shaping is on when the
button is highlighted in blue.
The DigiRack Dither plug-in only provides
eight channels of uncorrelated dithering
noise. If DigiRack Dither is used on more
than eight tracks, the dithering noise begins
to repeat and dither performance is im-
paired. For example, if two Quad DigiRack
Dithers are used, both Quad instances of
Dither will have all of their dither noise un-
correlated. However, any additional in-
stances of the Dither plug-in will begin to
repeat the dithering noise.