Expander/Gate Controls - Calrec SUMMA User Manual

• Knee: Controls the dB range over which the threshold is active on the incoming signal. With knee set to 'hard', a
signal which exceeds the threshold will instantly have the full gain reduction applied, which leads to a very noticeable
compression. Setting a softer knee 'smooths' the point at which the threshold acts, for example, a 6 dB knee setting
means that the threshold is active over a 6 dB spread leading to a less noticeable compression effect.
FIGURE 3 - COMPRESSOR/LIMITER CONTROLS

Expander/Gate Controls

• Mode: The expander/gate module has a dual mode button for switching between expander and gate functionality.
• Ratio (expander only): Controls the amount of gain reduction applied to the signal. Hard uses a ratio of 2:1, meaning
1 dB of gain reduction is applied for every 1 dB that the signal falls below the threshold, for example, a signal 10 dB
below the threshold will have 10 dB of gain reduction applied. Soft ratio is a variable ratio dependent on the level of
the input signal, the final ratio of 3:1 being applied when the signal drops to 20 dB below the threshold.
• Threshold: The level (dBFS) at which the signal will begin to have its gain affected.
• Depth: Controls the maximum amount of attenuation which can be applied to signals below the threshold.
• Attack: Time taken for the expander/gate takes to open. Short attack times help to preserve natural transient attack
but can result in a 'clicking' sound due to the rapid transition. A long attack time ensures a smoother transition but
some of the transient information will be lost.
• Release: Time taken for the expander/gate to close. Longer release times create a smoother more natural transition.
• Delay (Gate Only):The minimum time the gate will be held open before closing once the threshold is reached.
CALREC
Putting Sound in the Picture
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