User's Manual

Virtual Reference Outputs
The INTERACTPRO allows the user to set up to two Virtual References.
Virtual AEC References allow you to combine multiple audio sources to create a single echo
cancellation reference, such as video conferencing and teleconferencing combined. In these and
some other applications, using virtual AEC references improves AEC performance.
The two virtual references are shown on the far right side of the Matrix.:
Use virtual references when your output to the amplifier contains audio not wanted in the Acoustic
Echo Cancellation Reference, such as local microphones. Route the inputs that contain audio that
needs to be canceled, like "receive from telco" or video codecs, (etc.) to your virtual reference(s).
This gives you the capability to reinforce local microphones into the room and not have them
included in your reference.
Note: If the channels selected for a virtual reference use Processing or Faders, you
should select the processing or fader channel as the virtual reference source. This
provides the AEC process with the most accurate reference for the signal, thereby
providing faster convergence and more accurate AEC performance.
When using virtual references, you must assign an output to that virtual reference in order to track
audio level changes. This output will typically be the output feeding your local room amplifier. If
this is not done correctly, echo may be heard at the far end when level changes are made.
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