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Extron Electronics DMP 128 User Guide User Manual

Page 47

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When using an output channel as a reference, the reference point is post volume control;
therefore, changes to the listening volume in the room affects the AEC gain structure (see

AEC Dialog

, below). If you have an output channel on the DMP 128 that is not being

used, you can isolate the reference channel from the channel being used for volume
control by routing reference signals to the unused output channel.
If you do want the reference signal to track with changes in listening volume, and want
more control over the actual reference level:

1.

Route the far end signal to both the amplifier output and the virtual (unused) output.

2.

Create a group master control that contains the amplifier output and virtual output.
Set soft limits for the group master control, as desired.

3.

Set optimal level for the amplified output. Set optimal level for virtual output. Relative
levels between both settings will be maintained by using the group master control.

aEc configuration

To insert and configure an AEC processor:

1.

Insert an AEC processor on the desired input channel using one of the following
methods:

Double-click the AEC (filter) block in the DSP Configurator workspace.

Right-click the AEC block to open the context menu and select Insert AEC.

Click the AEC block to select it (or use the arrow keys to navigate to the AEC
block) and press .

2.

Double-click the AEC processor to open it. Open the Select Reference

drop-down list and select a reference.

3.

Click Bypass to disengage bypass. The AEC processor is now operational.

aEc Dialog

The AEC dialog contains a number of meters and indicator LEDs that are essential for
setting up gain structure and monitoring activity. The AEC reference must be selected
from a list, otherwise the echo canceller will not work. Noise
Cancellation, part of the AEC processor, is selected and adjusted
here. A detailed description of the AEC dialog components is
included below.

activity LEDs

Far – lights when activity is detected from the remote site.

Near – lights when activity is detected from the local site.

Update – lights when the AEC is updating, converging, or

reconverging.

DMP 128 • Software Control

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