ASB Audio Switching Boards
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Enova Digital Media Switchers - Hardware Reference Manual
Routing the down-mix Input
The down-mix input is selected from the available audio inputs and is routed the same as any other audio input to any or
all outputs (for general switching and configuration instructions, including the down-mix input, see page 130).
down-mix SEND_COMMANDs
The down-mixed audio input uses a subset of the SEND_COMMANDs available for Audio Switching Boards (see below). For
details on each of the SEND_COMMANDs that work with the down-mixed audio input, see the Audio Input
SEND_COMMAND section on page 231.
AUDIN_STATUS
AUDIN_GAIN
AUDIN_STEREO
AUDIN_COMPRESSION
AUDIN_COMPRESSION_ATTACK
AUDIN_COMPRESSION_RELEASE
AUDIN_COMPRESSION_RATIO
AUDIN_COMPRESSION_THRESH
NOTE:
To negate a down-mix command, reroute the switch.
Audio Switching Board Troubleshooting
If the audio is not present or is not at the expected destination:
You may need to re-wire to a different connector (see the section on "Audio Routing Capability" on page 171).
Check to be sure all the "Rules for System Setup" on page 164 have been followed.
Verify that the Audio Switching Board is seated correctly by removing and re-seating (see page 266) and then
test/check the board’s functionality again.
If audio signal output format (2 channel L-PCM) is different than the required output format:
You may route one input to any or all outputs as Dolby TrueHD, Dolby Digital, DTS-HD Master Audio, DTS, or 2 CH
through 8 CH L-PCM format by selecting that input as the down-mix Input (see page 130).
- or -
You may change the output format by disabling the extraction/insertion of the signal by Audio Switching Boards
and allow the input signal to be passed through the system as embedded audio on a video signal (see page 143).
If audio buzzes when connected to a balanced audio input device:
Wire the Audio Switching Board (ASB) connector as follows (see wiring example on the right in FIG. 80 on
page 170):
ASB L+ to device L+
ASB R+ to device R+
ASB ground not connected
ASB R- to device R-
Jumper from ASB R- to ASB L-
If down-mixed audio is not present or is intermittent with good video:
A signal containing both video and audio must have space for both signal portions. The audio signal portion lies in
the blanked portion of the video signal. High Bit Rate Audio (HBRA) requires a larger than normal space in the
blanked area of the signal. Video formats with reduced blanking normally provide enough space for audio
signals. In a signal that combines a video format with reduced blanking and HBRA, the HBRA signal is truncated
and can present as either no audio or as problematic audio (static, clicking, absent, etc.). While Enova DGX
hardware supports both HBRA and reduced blanking video formats, these formats do not necessarily work with
one another.
To resolve the issue, change either the audio format to non-HBRA or change the video format to a format that
does not use reduced blanking.
If the Audio Switching Board defaults to "Embedded" rather than "Switched" audio:
Audio Switching Boards default to Switched audio but, if the system was upgraded from Enova DGX 8/16/32/64 to
100 Series and then power cycled prior to insertion of ASB boards, the system may not recognize the correct
default state.
To resolve this issue, open the System Configuration interface and toggle the Audio Routing to its correct setting
(see page 171).
