Specifications

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8.1. Wiring to 70V Speakers
See Figure 8-2 on page 30 for wiring.
NOTE: Make sure PCMZPM OUTPUT switch is set to HI PWR. To set the switch, remove the locking plate, place
switch in desired position, and re-secure the locking plate. The locking plate can be rotated to match the switch
setting.
8.2. Wiring to Self-Amplified Speaker or Dedicated Amplifier
See Figure 8-3 on page 31 for wiring.
NOTE: Make sure PCMZPM OUTPUT switch is set to LO PWR. To set the switch, remove the locking plate, place
switch in desired position, and re-secure the locking plate. The locking plate can be rotated to match the switch
setting.
NOTE: The Tip lead of the self-amplified speaker or dedicated amplifier should be connected to the zone's "+"
(positive) terminal and the Ring lead to the zone's "-" (negative) terminal for proper phasing.
8.3. Setting a Zone for Talk Back Operation
Any zone of 70V speakers can be made into a talk back zone that provides hands-free two-way communications
between the zone and the telephone. The Talk back switches at the top of the PCMZPM module (see Figure 8-1) set
the operation mode. During all-call and group zone pages, talk back is inhibited. Talk back operation is not available
in zone modules that are set for LO PWR operation.
Talk back is not advisable in zones that have more than 4 speakers or where the environment is very noisy since both
reduce the clarity of the talk back signal.
Using a second amplifier to provide background music to all zones not being paged is not recommended when talk
back is being used. Bleed through of the background music signal onto the talk back signal can be significant
depending on system wiring.
Use the TALK BACK DELAY and TALK BACK VOLUME controls to adjust for smooth two-way conversations.
NOISE REDUCTION can be set to ON to mute listen background noise when audio activity is low.
8. Zone Speaker Wiring and Setup
ZONE A
ZONE B
ZONE C
OFF ON
TALKBACK
Figure 8-1: Talk Back Switches