Build Your Echo Canceller Reference - Polycom Vortex EF2280 Reference Manual

Customize Setting
for Your Particular
Application
B Y E
UILD OUR CHO
If your system does
NOT have sound
reinforcement,
If your system has
sound
reinforcement,
© Polycom, Inc.
The following sections will describe customizing parameters on the EF2280 for your
particular application if you are not using Preset 0.
C R
ANCELLER EFERENCE
The acoustic echo canceller (AEC) reference should generally contain exactly the
same audio signals as what is coming out of your loudspeaker(s), since the signal out-
put from the loudspeaker is what is then picked up by the room's microphones caus-
ing acoustic echo. Note that this statement is a general statement. Conditions for this
being true follow:
• The AEC reference should contain exactly the same audio as the loudspeaker
output: all far end audio, audio from the phone add, program audio, etc.
• If your system contains stereo inputs and outputs, the reference must contain a
mix of both stereo inputs. For example, if your VCR audio is in stereo, the refer-
ence should contain both the left and right signals each attenuated by 3 dB, as
well as any other audio that is going to your loudspeaker.
• If you are using crosspoint gains in the loudspeaker mix, apply the same gains to
the signals in your reference.
• Do NOT mix your room microphones into the reference, but include all other
audio (program audio, remote audio, phone audio, etc.).
• An exception to this rule is when you use one EF2280 split to operate indepen-
dently in two rooms. If the two rooms communicate with each other (along with
communicating via codec and the phone line), the reference in the first room
must contain the microphones from the second room and vice versa. See Figure
11 below.
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NTEGRATING THE
17 V
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EF2280 Reference Manual