Extron electronics DMP 128 User Manual page 49

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 <Enter>.
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 gain structure setup 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. Detailed descriptions of the AEC dialog
components are 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.
Meters
• ERL – the ratio in dB between the signal at the reference and the signal at the AEC
channel input. When ERL is a positive number, the signal level at the AEC channel input
is lower than the signal at the selected reference (0 to +15 dB is desirable).
• ERLE – the amount in dB of potential echo signal that the AEC algorithm, not including
NLP processing, is cancelling.
• TER – the sum of ERL + ERLE, in dB.
DMP 128 • Software Control 43