GUIDE TO INSTALLATION AND OPERATION
FRS-3901 |
25
No Signal Delay:
The period for which signal must be continuously absent before an alarm can be triggered can be
adjusted from 3 to 255 seconds in preset steps: 3, 5, 7, 10, 15, 20, 30, 40, 50, 60, 90, 120, 180, 210, 240, 255 sec.
The default value is set to 15 seconds.
5.5.4 Downmix
This tab provides resources to control the downmix of a “5.1 channel” surround-sound audio signal into an LtRt or
LoRo stereo pair. The 5.1 terminology refers to six discrete audio channels, with the low frequency effect (LFE)
channel of limited bandwidth designated as the “.1” channel. The downmix can be done using any of the 32 audio
channels processed by the audio processor using the Input Channels controls in the interface.
Input Channels:
Use the 6 pulldowns to select the source channels for the downmix process.
Downmix:
Operating Mode: Use the pulldown list to select the downmix
operating mode:
•
OFF: Downmix is disabled. Output channels pass
through unchanged.
•
Manual: Downmix follows the downmix parameters
manually configured by the user.
•
Follow Metadata: Downmix follows the downmix
parameters of the Metadata.
Level Normalization: use the pulldown to select the type of
normalization to be applied on the downmix output level.
•
OFF: Downmix output level is not normalized. Clipping
may occur depending on the input channel levels
and the selected mix levels.
•
Level A: Downmix output level is normalized based on
the applied mix levels to provide a uniform output
over the range of mix levels available. Clipping
will never occur, even with full scale input
channels and mix levels.
•
Level B: Downmix output level is normalized based on
the channel configuration to provide a uniform
output loudness between 3/2 and 2/0 programs.
Downmixing a 3/2 program produces a loudness
attenuation compared to the same program in
2/0 at the same input loudness. To provide a
uniform output loudness, a loudness attenuation is applied only on 2/0 programs. If the operating mode is
Follow Metadata,
the channel configuration is given by the Dolby Digital coding mode parameter in the
metadata. If the operating mode is
Manual,
the channel configuration is given by the selected mix levels:
a 2/0 channel configuration is achieved by setting Center, Surround, and LFE Mix Levels to
Mute
. Any
other combination of mix levels is assumed to be a 3/2 channel configuration. Level-B normalization also
includes Level-A normalization, based on the applied mix levels. Clipping will never occur, even with full
scale input channels and mix levels.
•
This selection is not available when
Oper. Mode
is OFF.
Figure 5-15 Audio Processing - Downmix
