Echo Troubleshooting - Polycom SoundStructure C16 Design Manual

the processing path is selected, the AGC and noise cancellation can be independently enabled for those
channels.
How To Set The Audio Amplifier Default Level?
Installing SoundStructure Devices
This involves setting the proper output level from the SoundStructure device and adjusting the volume of
the amplifier until a good level is heard in the room. Volume adjustments can then be made with the output
fader on the channels connected to the audio amplifier.
How Do I Get More Than One Signal Generator?
SoundStructure devices only support one signal generator per device. If more than one Signal Generator is
required, multiple devices must be linked over OBAM and the signal generators on each of those devices
may be used independently.

Echo Troubleshooting

Many echo problems can be traced to:
1 Check loop-back echo. A matrix cross-point may have been inadvertently unmuted, causing a direct
replica of the audio to be heard remotely.
2 AEC Reference is setup incorrectly (see
reference needs to include ALL the remote audio sources. Any remote audio that is not part of the
reference will hear echo going back to that site.
3 Room gain is too high (see
gain is to provide a better input level to the SoundStructure device and lower the amplifier level.
Others may require a different placement of loudspeakers and microphones.
4 Audio has too much non-linear distortion. If the playback audio is clipping the loudspeaker, the
resulting echo picked up at the microphone can also become nonlinearly distorted. In this case, the
AEC will not adapt to the room echo correctly. One way to resolve this is to lower the amplifier level
or the digital gain inside the SoundStructure of the audio path going to the amplifier output.
The Remote People Hear Echo Of Their Voices From The Local Room
Mute the local microphones and ensure the echo is removed for the remote participants when the local
microphones are muted. Unmute the local microphones and ensure the echo has returned.
If the echo is present when the microphones are unmuted and not there when the local microphones are
muted, it is likely an acoustic echo canceller configuration issue with the local room. If the echo is still there
when the microphones are muted, it is not an acoustic echo issue and may be an issue with wiring or with
routing through the matrix.
Polycom, Inc.
describes the steps to take to ensure a good level to the audio amplifier.
Customizing SoundStructure
Installing SoundStructure
Designs). Note: AEC
Devices). A typical method to reduce the room
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