SPL Channel One 2950, Руководство пользователя

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ON
The first processing module is the de-esser, which removes disturbing sibilants when required.
The de-esser module is activated with the ON button. The S-DETECT LED in the display area
shows that S-sounds are being detected. It is independent from the S-REDUCTION control
and always informs about detected sibilants – attracting your attention to a possible need for
regulation (also see „S-DETECT“ on page 22).
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) the processing is more intensive with extreme S-sound levels than with
those of lower levels. This processing method achieves a consistent level of the remaining
sibilants in the output signal.
SPL De-Esser technology
In contrast to common de-essers based upon compressor techniques the SPL De-Esser makes
use of the phase cancellation principle. It employs filters that process only the reducible
”S-frequencies” but do not interfere with the remainder of the spectrum. The S-frequencies
are detected automatically, the phase is inverted and mixed with the original signal. This
method of operation has distinct advantages 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 average level with the individual 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 certain S-portion
are not processed whereas those that are too loud, or do not effectively contribute to the
sound, are reduced – but the character of the voice remains unchanged.
A further specialty is the integrated Auto Threshold function which makes processing inde-
pendent of the input level. Even when the speaker or singer does not maintain a constant
distance to the microphone, processing is retained at the pre-set S-reduction value.
Conventional systems are dependent on the input level and work more intensively as the
distance to the microphone is reduced. As a result, the SPL De-Esser does not need to be
monitored and re-adjusted permanently to keep processing constant – and it can always be
applied before the compressor, as changing its position would not be an advantage. That is
why an accordant switching function is not necessary.
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Channel One
De-Esser
Control Elements