12
ENGLISH
Dynamics Processing 101 - Continued
Soft-Knee / Hard-Knee
In order to prevent harsh, unnatural envelopes on compressed signals sophisticated dynamics processors like
the S•com plus feature an SKD (Smart Knee Detector) or automatic knee circuit. The Smart Knee Detector auto-
matically switches from Soft-Knee when the signal is less than 10 dB over Threshold, to Hard-Knee when the sig-
nal is 10db above Threshold. In Soft-Knee mode, there is a gradual effect on gain change, which begins as the
signal approaches the Threshold level. In Hard-Knee mode, gain reduction is linear based on the Threshold and
Ratio controls. Any signal that falls below the Threshold level will be unprocessed.
Noise Gates
Noise gates are used to remove unwanted noise and/or bleed from recorded tracks in the studio or from open
microphones in live sound systems. Noise gates can also be used as a sound effect, most commonly to chop the
end of a reverb let’s say on a snare drum so that the entire snare sound ends just before the beat. The basic
principle of a noise gate is to work as an automatic mute switch. Mute off (Gate Open) when the desired signal is
present and mute on (Gate Closed) when the desired signal is not present. In order to get the gate to work pre-
dictably, it is necessary to set a threshold, or trigger level that will determine when the gate will open. If the sig-
nal is below the trigger the gate will remain closed. When the signal is above the trigger, the gate will trigger
open allowing the desired signal to pass and be heard. Noise gates often have other adjustable controls like
attack, hold, range and release. Many noise gates like the S•com plus use sophisticated circuits to control some
of these parameters automatically.
Downward Expander
The purpose of a well-designed Downward Expander is to increase the perceived dynamic range of a system.
This is accomplished by decreasing the gain during the softer sections, thereby lowering the relative noise floor.
When the signal level is below the desired trigger level, the expander lowers the overall gain by the selected
amount.
Limiter
A Limiter is a specific form of a compressor configured to prevent peaks and for general overload protection. The
S•com plus offers a Limiter section with independent controls designed to work in conjunction with the
Compressor section. The operating range of the Limiter is from 0 to +20dB and when engaged, protects against
signal peaks, overloads and excess modulation in broadcast situations.
Stereo Link Mode
The S•com plus can be configured from dual-mono operation to stereo by using the Stereo Link switch. In Stereo
Link mode, Channel 2 functions are controlled by the settings of Channel 1 with the exception of IN/OUT, KEY
and LIMITER.
Side Chain / External Key
The S•com plus features a side-chain or external Key function. The external Key function is used to externally
process the compressor’s detector circuit. There are many useful applications for processing the detector circuit
including Equalizing for frequency dependent compression, De-Essing - the use of EQ to remove sibilance, and
externally keying off a vocal track for Ducking effects to name a few. Selecting the Key function on S•com plus’
front panel, interrupts the compressors detector path and routes it to the Key Output jack. The Key Input jack
receives the externally processed signal, which will now control the compressor’s detector.
