Polycom EF2201 Brochure & Specs page 24

Output
From
From Matrix
Gain
Matrix
Level
Figure 10. The signal chain feeding the output.
Line Outputs 1-8, A-D
All 12 outputs on the EF2280 (or 8 outputs on the EF2241) operate in an identical fashion. The line level output signals appear at
the rear panel mini Phoenix™ connector (3.5mm spacing). As shown in
gain or attenuation, NOM attenuation, followed by the output filtering, signal delay, and signal mute and then conversion from a
digital signal to a balanced analog audio signal. When viewing the output signal meter on the Vortex front panel or via the
Conference Composer software, the output meter shows the signal level just prior to conversion to an analog signal at the D/A
converter.
The user can apply up to 20 dB of gain and as much as 100 dB of attenuation (the range is +20 to -100). This allows the user to
interface to external equipment that may not support a 0dBu nominal level.
The NOM attenuation, if enabled, will compensate for the number of open microphones (NOM) that are assigned to that particular
output by applying an attenuation of
This keeps the overall gain of the signal constant and helps eliminate acoustic feedback in sound reinforcement applications. A
unique feature of the Vortex is that the NOM attenuation is computed for each of the 12 outputs and can be different for each
output depending on what microphones are mapped to that particular output.
The outputs of the Vortex are line level with a nominal level of 0dBu with a maximum value of +20dBu. Output gain or attenuation
adjustment is possible on a per channel basis.
22
NOM
PEQ
Atten.
On Off
Parameters
10 log ( NOM )
. Please note that NOM attenuation is computed on a per output basis.
10
Delay Mute
On Off
the output processing consists of an arbitrary user
Figure 10
-
Outputs 1 to 8
D/A
-
and A to D
-