crystal - Automatic Gain Compensation
The Automatic Gain Compensation (AGC) page provides access to the automix parameters. The number of available automixers is determined by the Power Core license. At maximum capacity, up to 4 independent automix groups can be configured.
Automix
Automix can be enabled for any collection of mono and stereo sources. Once enabled, an internal algorithm monitors the signal power of each channel, and then automatically adjusts the mix levels accordingly. For example, if there are three guests and a host, the algorithm automatically mutes the guest sources while the host is speaking. The feature is ideal for balancing active and inactive microphones, such as in a panel discussion, or creating an automated voice-over.
For each source, there are four parameters:
- Group - assigns the source to an automix group (from 1 to 4).
- AMix - enables (or disables) the automix function. When disabled, the mix level is adjusted manually from the source fader.
- Weight – sets the weighting factor of the source, from +9 to -9 with a default midpoint = 0.
- Speed – sets the "smoothness" of the automixing, in milliseconds (ms).
Sources with a higher weight value get priority in the mix; those with the same weight are mixed equally; those with a lower value get reduced priority. For example, in a panel discussion, you might want to give the host leading the discussion a higher weight value than that of the guests. Or, to create an automated voice-over, adjust the weight of the playout material to a much lower value than that of the voice.
The speed defines how quickly a signal returns to its normal mix level after its gain has been suppressed. A short speed fades signals in and out quickly, but could result in "pumping" if several guests are talking in parallel. A longer speed will be smoother but may generate audible fades in and out. The ideal value depends on the material.
Operation
To access the parameters, press an Access key (on the fader strip) followed by AGC (on the Central Function Keys and/or GUI).
Then adjust the parameters from either the surface or GUI.
On the surface...
There is one page of parameters.
- Turn the Group rotary control to choose the automix group.
- Enable the AMix soft key to turn on the automixing.
- Turn the Weight and Speed rotary controls to adjust the behavior.
On the GUI...
All of the parameters are shown on a single page.
- Press the + and - buttons to choose the automix group.
- Enable the Automixer button to turn on the automixing.
- Touch and drag the Weight and Speed parameter values to adjust the behavior.