Shure SCM410 Manual page 22

Shure Incorporated
FIGURE 10: INHIBITING GATING FOR UNWANTED SOUNDS
Loudspeaker Muting
Some applications require a loudspeaker to be placed near each talker to provide audio reinforcement, or to per-
mit telephone conversation or conference monitoring. Each loudspeaker can cause feedback unless it is automati-
cally switched off when the talker near it speaks. To provide this function, connect the GATE OUT terminal of each
channel to a separate loudspeaker muting relay (See Figure 11). Recommended relays are Radio Shack 275-248,
Omron G2R-14-DC12 (Digi-Key number Z745-ND), Potter & Brumfield R10-E1Y2-V185 (Newark number 45F106),
or equivalent.
Note: A diode across each relay coil is required to suppress inductive voltage spikes which may damage the
SCM410. An existing sound system using 24-volt relays can be used with the SCM410 without modification if the
relay coil current draw is under 500 mA.
FIGURE 11: LOUDSPEAKER MUTING
Filibuster Mode
Normally, when several people talk, each microphone gates on so that no speech is missed. In "filibuster" mode, a
microphone remains gated on until the talker pauses long enough for that microphone to gate off. No other micro-
phone can gate on until that microphone gates off. This prevents talkers from being interrupted.
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