Polycom Vortex EF2280 Reference Manual page 36

Automixer
Parameters
V EF2280 Reference Manual
ORTEX
The following parameters configure how the EF2280 automatic microphone
mixer operates. Parameters include the following: Decay Time, Hold Time,
Camera Gating Threshold, Chairman Mode, Chairman Mic, Last Mic On Mode,
Last Mic Number, Local Max NOM, Global Max NOM, Off Attenuation, Thresh-
old Type, Gating Mode, Gate Ratio, Manual Threshold, and Microphone Prior-
ity.
Signal Level
Channel turns on
when signal level
is above gate ratio
Channel ON
G R
ATE ATIO
Channel OFF
Ambient Level
Figure 24. Off Attenuation, Hold Time, Gate Ratio, and Decay Time.
Global Settings.
Decay Time. Decay time is the amount of time the microphone audio
takes to ramp down to the Off Attenuation level after Hold Time. Decay
Time values range from 0 to 5000 msec. The default value is 1000 msec.
Hold Time. This is the amount of time the microphone stays On after the
energy in the channel drops below the gating threshold. The default value
is 500 msec. The range is 1 to 5000 msec. Microphone channels gating
On and Off too frequently during short pauses in speech might be the
result of setting the Hold Time too low while too many microphones gat-
ing on at the same time may be the result of Hold Time values that are
too high.
Camera Gating Threshold. Specifies the hold time for camera gating
information. Camera gating information can be used to position a camera
by using the gating info and a camera positioning system.
Mixer Settings.
Bus Mixer. This command is used to assign one of the two internal auto-
mixers to one of the EF Bus automixer groups. For example, consider
three Vortex devices each of which has 4 microphones assigned to Auto-
mixer 1 and 4 microphones assigned to Automixer 2. Now, if each of
these devices sets their Automixer 1 to use Bus Mixer 5 for example, then
the three automixers (one from each device) will work as a single auto-
mixer containing 12 (3 x 4) microphones. Setting Bus Mixer to 0 means
that the automixer is not grouped on the EF Bus and the automixers
operate independently.
Chairman Mode. Enables or disables Chairman Mode for the specified
automixer.
Chairman Mic. Sets the Chairman Microphone for the specified auto-
mixer.
Last Mic On Mode. Sets "Last Mic On" mode for the specified automixer.
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