SPL 9945, User Manual

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11
Operation
De-Esser
On
The first module behind the pre-amplifier stage is the De-Esser, which imme-
diately removes disturbing S-sounds when required. The De-Esser module is
activated when the button is on. The S-Detect. LED in the display will show
that S-sounds are being detected regardless of the selected S-Reduction
value, in other words even when the button is switched off detection is still
shown in the display.
S-Reduction
With the S-Reduction control you can determine the intensity of S-sound
reduction. Because processing is undertaken from comparison with the
level of the entire frequency spectrum ( see next section ”Technical informa-
tion ...”) the processing is more intensive with extreme S-sound levels than
with those of lower levels. After processing the output signal has a consi-
stent S-sound level.
Technical information regarding the De-Esser
In contrast to common de-essers that influence a frequency band of about 2
octaves with compressor techniques the Auto-Dynamic De-Esser utilizes
filters that process only the reducible ”S-frequencies” but do not interfere
with the remainder of the spectrum.The S-frequencies that lie in the unplea-
sant range are automatically recognized, the phase is inverted and mixed
with the original signal. In this manner the disturbing frequency is quenched
and the hissing noise reduced. This method of operation has distinct advan-
tages because it is unobtrusive and helps retain the original tonal quality.
Compressor-typical side effects such as lisping or nasal tones do not occur.
Finally its operation is as simple as pulling on the hand brake.
The reduction is accomplished by comparing the entire level with the indi-
vidual S-sounds: the De-Esser functions only when the S-noise level exceeds
the average level of the entire frequency spectrum. This means for example
that original S-sounds with a determinate S-portion are not processed
whereas those that are too loud, or do not effectively contribute to the
sound, are reduced – the character of the voice remains unchanged.
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