Sonnox Oxford SuprEsser User Manual
Page 28
4.2 Advanced Screen Controls
4 DESCRIPTION OF CONTROLS
LEVEL TRACKING Section
AUTO IN Button
This controls the mode of the threshold functionality. In ‘Auto-Level- Tracking’ mode
(ie. with the IN button selected), the compressor’s trigger threshold follows the
general level of the wide input signal, and the THRESHOLD fader adjusts the
threshold relative to that general signal level. If you want the same relative level of
gain reduction for a quiet sound as for a loud sound (for example, in each case you
want 6dB of gain reduction relative to the general signal level), then use
Auto-Level-Tracking mode, and set the THRESHOLD fader 6dB lower than the
peaks shown on the graph.
In ‘Absolute’ mode (ie. with the IN button not selected), the THRESHOLD fader
controls the absolute level of the compressor’s trigger threshold — so if it is set to
-10dB, signals over that level will trigger gain reduction.
DAMPING Touch Pad
In ‘Auto-Level-Tracking’ mode, this controls the time constant used for following the
general level of the wide input signal. In other words, the smaller the damping value
is, the more quickly the threshold level will rise or fall to a new level; the larger the
value, the more stable the threshold value.
Generally speaking, you want to have the largest value possible consistent with the
material you are working with. For general dialogue or vocals, a larger value will be
adequate because there is not so much variation in general signal level. For a
speaker who rapidly changes from mumbling to shouting, then a smaller constant
will be required for the compressor to adapt quickly enough.
The algorithm used to implement ‘Auto-Level-Tracking’ responds more quickly to
rises in the input level, and more slowly to drops in level. This means that the plug-in
will tend to under-gain-reduce when the level drops rapidly, and minimise
over-gain-reduction when the level rises rapidly. This helps to compensate for the
nature of vocals and speech in which the troublesome sounds often leap out of
silence.