User Manual

Acoustic Echo Canceller (AEC)
MRX Designer User Guide
47
2 [NR] button
This is an on/off switch for the noise reduction function which removes steady-state
noise such as produced by a projector or air conditioner in the local location. We
recommend that you leave this on.
3 [THRESHOLD] knob
When applying noise reduction, noise that exceeds the Threshold level is attenuated
down to the level specified by Threshold.
4 Level meters
These show the input/output levels and information related to acoustic echo.
• [IN] level meter
Shows the input level from the mic.
•[REF] level meter
Shows the input level from Reference.
• [OUT] level meter
Shows the output level from AEC.
• [ERL] level meter
Shows the ratio between the “Reference input” and the “echo amount included in the
mic input detected by AEC.”
In general, an ideal setup will have ERL (Echo Return Loss) in an approximate range
between 0 dB and –16 dB. If this is higher than 0 dB, the mic input level might be
too high or the mic and speaker might be too close. If this is lower than –16 dB, the
mic input level might be too low.
• [ERLE] level meter
Shows the amount of acoustic echo in dB units that was removed from the mic input
as a result of AEC learning. If the echo is being removed correctly, a negative value
is shown.
• [TER] level meter
Shows the amount of acoustic echo in dB units that was ultimately removed.
5 [RESET] button
Click this button to reset the information that AEC learned.
6 Port text box
Shows the port name. You can double-click the name and edit it.