Polycom EF2201 Brochure & Specs page 35

Vortex Matrix
The cross point matrix in Figure 20
allows the user to map any input to
any output with an arbitrary gain
applied. To set the gain of a cross
point single-click on the cell. To
mute the cross point simply right-
click on it. To set the gain of a
collection of cross points click and
drag to select a rectangular area. A
slider control with a text box will
appear to allow you to change the
Figure 13. Cross point slider view of how input A is used in all the output channels.
gain, select mute/unmute, or, when
working with microphones, allow you
to choose the gated version of the input. The gain of the gated signals should be set to 0dB since the matrix will sum the
automixed signals and use the appropriate weightings of the signals based on the information from the automixer.
To change the gain of an entire row or column you may simply click on the column or row header to see a collection of sliders as
shown in Figure 13. To change gating status, Control-click (hold the control button and left click). To change the automixer
assignment, click on a Mixer column entry.
The R1 and R2 outputs correspond to the echo canceller references Ref 1 and Ref 2. While these outputs are not physical outputs
on the product, they allow you to build the echo canceller reference without stealing physical outputs from the device. In the
example in Figure 20, we used stereo program audio and consequently had a local left output (output 1) and a local right output
(output 2) in the room. The echo canceller reference R1 included both the codec audio (input C), the phone add audio (input PM0)
and a mono sum of the left and right program audio. The program audio is attenuated by 3dB before adding it into the R1 output.
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