Global Module Controls; Dynamics Links; Compressor/Limiter Controls - Calrec SUMMA User Manual

A gate is effectively an extreme version of an expander, with a very high ratio, resulting in the gain of the input signal being
significantly reduced almost immediately as it falls below the threshold. Gates are often used to minimise unwanted audio
content.
Calrec expander/gates have 6dB of built-in hysteresis to avoid unwanted 'chatter' (constant on/off switching) resulting
from an input signal residing on or around the threshold.

Global Module Controls

When looking at a dynamics module, any control situated within the window header affects the whole module, i.e the
compressor/limiter and expander/gate together. This includes the following:
• Each Dynamics module can be inserted either pre EQ, pre fader or post fader. Tap the dynamics position button in
the window header and select an option.
• By default, dynamics modules operate as standalone units. The third button in the window header allows the module
to be put into one of eight Dynamics Links.
• Dynamics modules can be bypassed by tapping the BYPASS toggle switch in the window header.
FIGURE 2 - GLOBAL DYNAMICS CONTROLS

Dynamics Links

Dynamics Links allow multiple audio feeds to have the same dynamics processing applied. When multiple paths'
dynamics modules are set to be part of a Dynamics Link, the amount of gain reduction applied across the link will always
equal that for the signal which is being affected the most. For example, within a Dynamics Link, if one path's signal is
causing 5 dB of gain reduction and another is causing a reduction of 10 dB, all signals within the Dynamics Link will have
a gain reduction of 10 dB applied. When expander/gate units are used within a Dynamics Link and one feed within the
link reaches the threshold level to open the expander/gate, all expander/gates within the link open regardless of the audio
levels of their feeds.

Compressor/Limiter Controls

• Threshold: The level (dBFS) at which the signal will begin to have its gain reduced.
• Ratio: Controls gain reduction once a signal has exceeded the threshold, for example, if the ratio is set at 2:1 and
the signal exceeds the threshold by 4 dBFS, the gain will be reduced so it exceeds the threshold by only 2 dBFS.
When set to 50:1, the compressor is acting as a limiter.
• Make Up Gain: Allows the gain of the whole compressed signal to be increased by up to 20 dB.
• Attack: Time taken to reduce the gain to reach the new compressed level. Short attack times enable the compressor
to catch transients in the audio feed, whereas increasing the attack time will focus the compressor on more long term
level issues, such as level differences across various sections of a program.
• Release: Time taken to remove gain reduction once the signal falls back below the threshold. Short release times
can lead to a 'pulsing' effect, with only audio peaks being compressed. A longer release time will lead to a smoother
effect at the expense of some lower level audio components being compressed.
124 SUMMA
Networked Audio Production System
PROCESSING