Grass Valley AMX-3981 2014 - Manual (Page 101)

GUIDE TO INSTALLATION AND OPERATION
AMX-3981 | 95
Presets
The Preset pulldown allows the JA-ALC module to be configured for this program according to a set of stored values.
There are:
• Five user-accessible registers that can be saved and recalled
• Four factory supplied read-only registers
The user can edit the label text for the five user-accessible registers
The presets hold values for the parameters that are set in the Advanced tab for each program.
• The available controls are described in the next section
• The contents of the read-only :Factory” presets are listed there (page 97)
6.6.4 ALC PGMx Configuration
For each program, the ALC parameters can be adjusted to obtain the desired behavior. This block diagram shows the
processing stages in the signal path:
View the Audio Modules / PGMx / Advanced tab to access the available controls.
6.6.4.1 Input Gain
An input gain stage is available in front of the ALC to compensate for
programs having an input loudness out of the ALC tracking range (very
low or very high input loudness). The input gain ranges from -20 dB to +
20 dB, in steps of 1 dB.
6.6.4.2 Leveler
The figure illustrates the transfer function and the parameters that can
be adjusted.
Target loudness - Operating Level
• Target loudness sets the desired output loudness in LKFS
according to ITU-R BS.1770. Level Magic continuously fits, as
closely as possible, the average loudness to the target
loudness.
• Operating Level sets the desired output level in dBFS. Level
Magic continuously fits as close as possible the average level
to the operating level. However, the high-dynamic audio
material can cause small deviations from the operating level.
Note: High-dynamic range audio material can cause small deviations
from the target loudness or operating level.
Figure 6.24 JA-ALC - ALC configuration