2.6.4 Speaker Volume Control
Speaker Volume Control requires use of the Cooper Wheelock SP-SVC module. The Supervised
Volume Control (SP-SVC) allows manual volume setting for telephone paging and background
music for a specific speaker or speaker zone. The selected adjustment will not affect the volume
setting of emergency prerecorded messages or live microphone usage. Refer to the Cooper Whee-
lock Safepath SP-SVC Installation Instructions (P/N: P84598) for more information.
SP-SVC terminal layout
Only one (1) SP-SVC can be installed per audio zone; however, multiple speakers can be
controlled by the same speaker volume control override output.
All fixed volume speakers must be placed before the SP-SVC in the speaker circuit. Any
speakers placed after the SP-SVC module will be able to be attenuated.
An end-of-line resistor (ELR) must be installed on the last speaker connected to the SP-SVC.
Attach wires according to the label on the terminal block. The DC input/output terminals are
interchangeable. If the SP-SVC is the last unit in the Speaker Volume Control Override circuit,
then an ELR must be installed.
The maximum wire impedance between devices must not exceed 35 ohms.
Emergency Command Center Manual — P/N LS10001-000FL-E:G 5/3/2016
4.7K, 1/2W ELR
TB23 on ECC-50/100
main control board
Figure 2.18 Speaker Volume Control Wiring
From preceding volume control module
or override output (on main board)
To next volume control module or ELR
From audio output or preceding
speaker (fixed volume)
To next speaker (variable volume)
Fixed Volume Speakers
15K, 1W ELR