Automix (Am) - Extron electronics DMP 128 User Manual

Automix (AM)

An automixer manages multiple microphone sources, gating or varying input gain
automatically. When properly set, the automixer system will improve use and performance
when multiple mics are in use. The two basic types of automixer include gated and
gain-sharing.
A gated automixer attenuates an input channel when the signal level drops below a
user-defined threshold. DSP Configurator allows the user to divide these automixers into
gating groups. Each gating group is effectively a separate automixer.
A gain sharing automixer sets a maximum room gain and splits this among all open mics,
based on their input levels. While a gain sharing mixer typically has less delay in reacting to a
speaker, gated automixers will normally produce a better noise floor.
The DMP 128 allows the user to choose between a gating automixer and a gain sharing
automixer. When the number of open mics (NOM) is set to zero, the automixer is
gain-sharing. When a NOM value is provided, the automixer is gated.
The DMP 128 uses an automix dialog box to configure the parameters of each channel and
select an AM group.
Automix parameters:
AM Group (Assignment) — Assigns
•
the channel to a gating group.
Selections are 1 through 8.
Default is None.
• Show AM Group Details —
Accesses a dialog box that details
current groups and the parameter
member assignments to each (see
the following section).
• Last Mic Mode On/Off — Prevents
all mics from gating off at the same
time, ensuring there is always one
active mic channel. There are four
possible states:
If not enabled on any mic input, all mics gate off.
•
If enabled on all mics, the last active mic remains on.
•
If enabled on one mic:
•
•
•
If enabled on some but not all mics:
•
•
•
Chairman Mode On/Off — One mic or multiple mics can be set to Chairman under
•
the Gating Priority list. When a chairman mic is gated on, all non-chairman mics are
gated off to the off reduction level.
Current NOM — Displays the selection of the maximum number of mics that may
•
be gated open at any time, per gating group. The setting can be changed using the
AM Groups dialog box. Current NOM range is 1 through 12.
• Gate Threshold — The signal level below which the mic channel gates off and above
which it gates on.
Range is – 60.0 dB to 0.0 dB.
Default is – 50.0 dB.
The enabled mic remains active if it is active when all other mics gate off, or
If the enabled mic is not active, it gates on when all other mics gate off.
If enabled on the last active mic, this mic remains active, or
If not enabled on the last active mic, the first enabled mic in the group gates on.
DMP 128 • Software Control
Gating Threshold
Indicator
Channel Level
(RMS)
Channel Level
Readout
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