Adjusting And Verifying Audio; General Rules For Audio - AMX BCS Instruction Manual

Adjusting and Verifying Audio

Adjusting and Verifying Audio
For BCS purposes, adjustments to input audio signals are referred to as digital gain adjustments, while
similar adjustments to output audio signals are referred to as volume adjustments. Not all systems
support digital input gain or digital output volume control. If your system supports these features,
adjustments may be made at any time during normal operation.

General Rules for Audio

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Important: If the level is not specified in a BCS command, the command is executed on the default
level (normally Level 0), which is defined in the configuration file. If the level is omitted and the
BCS command executes on an unexpected level, check the default level in the configuration file
(for systems without a configuration file, check the product documentation).
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Volume is adjusted using any of the following three methods:
Absolute – adjusts volume to a specific decibel level.
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Relative – increases or decreases volume by a specific decibel amount.
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Increment/Decrement – increases or decreases volume a step.
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An output does not need to be routed to adjust the volume; however, it may be helpful to hear
the adjustment.
Audio adjustments can only be executed on a valid level that switches audio signals. If an
audio adjustment is attempted on a level that does not include audio, an error code may be
sent out (see page 41).
For systems where all of the audio channels are not switched on the same level (e.g., an audio
only Optima that routes 8 channels of audio on Level 1 and 16 channels on Level 2), volume
and input gain commands for each of the levels must be entered separately.
Output volume adjustments remain in effect when the output is switched to receive a different
input or is switched on a different level (e.g. from audio only to audio-follow-video).
Specify multiple outputs by including a space between each output number. Specify a range of
outputs by inserting a colon ":" between the first and last numbers of the range.
Enter decibel levels as an integer number representing the desired decibel value multiplied
by 10. For example, +5 dB is entered as 50 and -60.5 dB is entered as -605. (Interpret results
for a volume status command in the same way.)
Do not use leading zeros for gain values in audio commands.
When a muted output is un-muted, the output returns to its previously un-muted volume.
When a Volume command is sent to a muted output, the output is automatically un-muted and
then the volume adjustment is applied. When an input gain command is sent to an input
connected to a muted output, the gain is applied to the input and the output remains muted.
The volume range of an output is determined by the audio board/connector. For a specific
audio volume range, see the specific board/connector documentaion. If the requested volume
change results in a decibel level outside the range specified by the board/connector, the
system responds with "X" indicating that an invalid value was entered.
The total through-system gain (the amount of input gain plus the amount of output gain) for
any input to output routing path is automatically limited by the matrix switcher. (For the value
of through-system gain and other audio specifications, see your matrix switcher's instruction
manual.) If a volume command is entered that exceeds the matrix switcher's specifications,
the command will be accepted (and will be indicated in status results) but will not result in an
audible difference if the dB value entered is outside of the matrix switcher's audio range.
Instruction Manual – BCS Basic Control Structure Protocol