Troubleshooting Audio; Audio Format Support On Enova Dgx Boards - AMX Enova DGX 100 Series Hardware Reference Manual

Troubleshooting Audio

Before troubleshooting audio, it helps to understand how the system handles EDID information.
The source reads and adapts to the pre-loaded EDID on the board's input connector.
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The factory default EDID is set to support 2 channel L-PCM audio. This EDID can be modified by using one of the
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methods described under "Possible Solutions" on the following page.

Audio Format Support on Enova DGX Boards

The following table indicates which audio formats are supported by specific Enova DGX boards.
Audio Format Support on Enova DGX Boards
Audio Format
2 Channel L-PCM
6 Channel L-PCM
8 Channel L-PCM
Dolby Digital
DTS
Dolby TrueHD
DTS-HD Master
IMPORTANT: Because signals are routed through HDMI, DVI, DXLink Twisted Pair, and DXLink Fiber Boards which feature
SmartScale Technology, they normally produce a quality image. If the installation has special scaling, EDID, or HDCP
requirements, see page 140.
Problem
The default EDID for input boards only supports 2 channel
L-PCM audio. If a sources chooses to ignore this EDID and send
a format that is not in the EDID, the audio may not pass
through the Enova DGX 100 Series Switcher at all or it may be
distorted.
To present other types of audio formats to the source, a
different EDID must be loaded. If after changing the EDID on
the input board, the audio is still distorted or is not present on
the destination device, then the device may not be capable
of supporting the requested audio format with the newly
loaded EDID setting. In this case, a standard EDID (2 Channel
L-PCM) should be used and the sources set up to only pass the
type of audio that the downstream destination devices can
handle.
The AMX EDID Library is available at www.amx.com (search
for EDID Library).
Audio not present or intermittent with good video.
A likely cause is that 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.
Enova Digital Media Switchers - Hardware Reference Manual
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* Dolby Digital and DTS support up to 48 kHz, 5.1 channels.
** ASB Boards support 1 down-mix input channel.
Solution
Checking for Support: One way to check if a destination supports a
particular type of audio format is to capture the EDID using the System
Configuration interface's Save EDID function and then paste the data
from the .edid file into an EDID reader program (e.g.,
www.edidreader.com).
If you encounter audio problems, we recommend trying the following
solution:
Use the EDID Save and Load functionality in the System Configuration
interface (see page 141) to read the EDID from the destination device
and to write it to the HDMI input on the Enova DGX Switcher.
Change either the audio format to non-HBRA or change the video
format to a format that does not use reduced blanking.
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DVI Input & Output Boards
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