8
Basic Operation
Overview
Basic operation of the AR-DM2-B Audio Monitor involves selecting an input module as the audio source, using the LED
bar graphs to visually monitor signal levels, and choosing a mode in which to monitor audio through the stereo speakers.
The user can switch between up to four installed I/O modules, each providing up to 16 channels of audio. The LED bar
graphs will then display VU/PPM levels for each audio channel from the selected input module. Finally, audio channels
from the selected module can then be monitored through the stereo speakers in a variety of ways: Any single channel can
be monitored in mono, any channel pair can be monitored in stereo, and any group of eight channels can be down-mixed
to stereo using a variety of configurations.
Selecting an Input Module
The
SRC
switch is used to select the source module from which to monitor audio.
•
Module slots are identified with numbers 1-4, from left to right when facing the rear panel of the audio monitor.
•
Only the selected module’s channel inputs can be monitored simultaneously. Audio channels from different input
modules cannot be monitored at the same time.
Loop-through outputs and dedicated output modules however will
function at all times regardless of the selected module.
See module specifications for details.
•
If the
SRC
switch is set to a module slot where an output module or no module is present, no audio will be visible on
the meters or audible from the speakers.
•
Each module location retains exclusive settings – Channel selections and mix configurations are saved separately
for each module (1-4) when switching modules. Settings are only reset once the module is removed from the audio
monitor.
Volume
,
Balance
, and
Mute
settings are common to all modules.
LED Bar Graphs
The
LED bar graphs
display signal level information for each audio channel.
Once an input module is selected using the
SRC
switch, the LED bar graphs immediately begin displaying signal level
information for up to 16 channels of audio, depending on the number of channels available from the module. The bar
graph for each channel will function even if that channel is not selected for monitoring through the stereo speakers as
described in the
Audio Monitoring
section.
The LED bar graphs have the following functions:
VU/PPM Signal Level
Each 20-segment LED bar graph represents the full scale of dynamic range of the audio monitor (-66dBFS to 0dBFS).
Signal level is simultaneously displayed in two ways. Signal level is shown in Volume Units – the average volume of
the signal – reflecting the perceive loudness of the signal. The bar graphs also function as Peak Program Meters,
indicating signal peaks by displaying a single red LED at the peak level with a slow decay time.
Digital Audio Signal Presence
Unlike analog audio signals, digital audio signals contain a constant bit stream even when the audio content is silent.
Such bit stream presence during silence is indicated by red illumination of the first LED segment of the corresponding
channel’s bar graph. This feature is useful in differentiating between an accidentally disconnected cable from silence in
the audio programming. This feature is not available for analog audio inputs.
Note:
If a channel pair contains a DOLBY encoded signal, the corresponding LED bar graphs will not show a signal level.
DOLBY signal presence is indicated by the illumination of the blue LED below each channel pair. See the
DOLBY
Encoded Signals
section on
page 13
for more information.
