Intellimix Dsp; Dsp Best Practices; Acoustic Echo Cancellation - Shure MXA902 Manual

IntelliMix DSP

This device contains IntelliMix digital signal processing blocks that can be applied to the microphone's output. The DSP blocks
include:
• Acoustic echo cancellation (AEC)
• Automatic gain control (AGC)
• Noise reduction
• Compressor
• Delay
To access, go to the IntelliMix tab.

DSP Best Practices

• Apply DSP blocks as needed. Run a test of your system without DSP, and then add processing as needed to fix any is­
sues that you hear in the audio signal.
• Unless you encounter video that lags behind audio, set delay to off.

Acoustic Echo Cancellation

In AV conferencing, a person may hear their voice echo. This happens when a near-end microphone picks up audio from the
room's loudspeakers and sends it back to the far end as echo.
Acoustic echo cancellation (AEC) is a DSP algorithm that gets rid of distracting echo in your microphone signal. AEC identifies
the far­end signal and stops it from being captured by the near­end microphone. During a call, AEC works constantly to opti­
mize processing as long as far-end audio is present. AEC is necessary for clear, uninterrupted calls.
The MXA902 uses the built-in loudspeaker as the AEC reference signal.
Note: If the loudspeaker is off and you still want to use AEC, route the far-end signal you want to cancel to one of the Dante inputs.
AEC Settings
Reference Meter
Use the reference meter to visually verify the reference signal is present. The reference signal should not be clipping.
ERLE
Echo return loss enhancement (ERLE) displays the dB level of signal reduction (the amount of echo being removed). The
ERLE meter generally corresponds to the reference meter.
Reference
The MXA902's reference signal is set to the built­in loudspeaker, which is the sum of the 2 Dante inputs. When the loud­
speaker is on, the reference signal is post-DSP.
Non-Linear Processing
The primary component of the acoustic echo canceller is an adaptive filter. Non-linear processing supplements the adaptive
filter to remove any residual echo caused by acoustic irregularities or changes in the environment. Use the lowest possible
setting that is effective in your room.
Low: Use in rooms with controlled acoustics and minimal echoes. This setting provides the most natural sound for full du­
plex.
Medium: Use in typical rooms as a starting point. If you hear echo artifacts, try using the high setting.
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