Grass Valley AMX-3981 2014 - Manual (Page 38)

GUIDE TO INSTALLATION AND OPERATION
32 | AMX-3981
A85 ITU BS.1770 -24 10 sec LKFS
ARIB TR-B32 -24 3 sec LKFS
Enable Loudness Monitoring turns ON the ALC input and output loudness monitoring for all programs.
5.5.2 PGM1-8 tabs
Loudness monitoring
When turned ON, the loudness meters display the program
input loudness (before ALC processing), the dynamic
correction applied by the ALC, the ALC limiter correction,
and the program output loudness (after ALC processing).
The input and output loudness are given in LUFS or LKFS,
depending on the modes selected in the Config tab.
Loudness meters are integrated over a “sliding-window”
period which is also mode-dependent.
Dynamic and limiter corrections are always given in dB.
Each correction meter is integrated over a period of 250
milliseconds.
ALC Presets
Three factory presets for the ALC are available to cover most
broadcast applications.
• Factory Light – The ALC applies low dynamic range
compression on the audio program content. The overall
response time is relatively slow, which reduces the ALC
ability to tightly follow the target output loudness. Using
this preset, the program content will sound a little more
dense, while keeping most of the original program
dynamic range.
• Factory Standard – The ALC applies moderate dynamic range compression on the audio program content. The
overall response time is also moderate, which allows the ALC to follow the target output loudness quite well. This
preset is well-suited for most types of audio content. It is the factory preset loaded when loading the card default
parameters.
• Factory Heavy – The ALC applies high dynamic range compression on the audio program content. The overall
response time is relatively fast, which improves the ALC ability to tightly follow the target output loudness. Using
this preset, the program output content will sound much more dense, less dynamic.
Five user presets are also available to save and load custom configurations of the ALC. These presets are labeled
ALC 1 to 5 but the user can edit the preset names via the “Edit Labels” button.
We STRONGLY recommend starting with the ALC factory preset (Light, Standard, Heavy) that is closest to the
desired objective, then fine tuning it to reach the desired goal. This will minimize the troubles that will likely be
encountered as many adjustments interact.
ALC Bypass
Checking this box bypasses the ALC program processing, and the input channels pass through to the output
unaltered.
Figure 5.22 Miranda ALC – PGM1, 2, 3, …, 8 tab