Polycom EF2201 Brochure & Specs page 47

Figure 23. The full matrix creating zone outputs 1 and 3 on EF2280:00.
Similarly we will attenuate the Zone 4 microphones 9dB for output to Zone 3. This attenuation is performed by setting the cross
point gain of XB1 to sub-matrix output XM2 to –9dB. In the main matrix for Vortex EF2280:00 we will sum WM2 and XM2 to form
the local Zone 3 output.
The full main matrix for Vortex EF2280:00 is shown in Figure 26Error! Reference source not found.. In this figure, the local
microphones (Zone 1 and Zone 2 microphone inputs 1-8), the Zone 3 microphones (WM0), and the Zone 4 microphones (XM0) are
summed and sent to the codec on output A and are placed on the bus to be sent to the Phone interface (an EF2201 in this example)
which also take the four zones of microphone audio off the bus and create a sum of these signals before sending it to the
telephone line. The output for Zone 1 (output 1 on EF2280:00) consists of the codec, the phone add (from PM0), the microphones
from Zone 2 attenuated by 9dB (WM1 from Figure 28), the microphones from Zone 3 attenuated by 6dB (attenuated in the main
matrix), and the microphones from Zone 4 attenuated by 3dB (attenuated in the sub-matrix XM1 as shown in Figure 28). The output
in Zone 3 (Vortex EF2280:00 Output 2) consists of the codec audio, the phone add audio, the microphones from Zone 1 attenuated
by 6dB (attenuated in the main matrix), the microphones from Zone 2 attenuated by 9dB (attenuated in the sub-matrix WM2 in
Figure 28), the microphones from Zone 4 attenuated by 9dB (attenuated in the sub-matrix XM2 in Figure 28). NOM attenuation is
enabled for outputs 1, 2, and output A so the appropriate output attenuation (based on the number of open microphones from all
the Zones) will be applied.
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