Polycom Vortex EF2241, Application Note

Page: 49 / 77

You may connect either the left or the right channel of the auxiliary line level output to
the Vortex device. Any audio that is sent from the far side will be monaural.
Please follow our instructions for wiring the Vortex device to the codec. Failure to do so
may induce noise into the signals sent and received from the codec.
3.
Raise the gain on the appropriate Input of the Vortex device to +10 dB.
4.
Lower the gain on the appropriate Output of the Vortex device to -10 dB.
It is important to set the gain structure correctly so that you don't clip the input audio
stage of the codec and that the Vortex device gets a good signal to perform processing
with. The nominal input and output of the codec is .3 V rms. The nominal input and
output of the Vortex device is .775 V rms. This equates to a difference of 8.24 dB between
the two nominal levels. For simplicity, you may round that value to 10 dB.
E
NABLING THE
VSX 7000
TO WORK WITH A
V
ORTEX
D
EVICE
We recommend that the firmware version of the VSX 7000 be updated to at least 7.0 or
higher because the internal VSX 7000 echo canceller can be disabled.
1.
Connect a monitor to the video output of the codec.
2.
Go to System, Admin Settings, Audio Settings, and select N
EXT
for Page 2. Select the A
UDIO
M
IXER
option for the Line Input that is connected to the Vortex device. Select O
FF
for the Echo Canceller
option. Select Monitor-Far Site Audio for the Line Output. For both settings, leave the L
EVEL
settings at 5.
3.
Disable the loudspeaker that is built-in to the VSX console. Go to System, Admin Settings, Audio
Settings, and select N
EXT
, N
EXT
for Page 3. Select O
FF
for M
IDRANGE
S
PEAKER
. Depending on the
type of loudspeakers you are using, you may want to lower and/or disable the Subwoofer. Make
those changes in the S
UBWOOFER
S
PEAKER
and S
UBWOOFER
O
FFSET
sections.
4.
Once that is completed, make sure that the Input to the Vortex device is assigned to the
appropriate AEC Reference signal.
49