Speco Technologies PL-120SA - Manual (Page 6)

6
SPEAKER IMPEDANCES:
Speaker terminal taps for 70V constant line voltage are provided on the rear panel of the unit. To
connect the power output directly to a speaker or PA horn or a combination of speakers and/or PA
horns, connect to the COM and L and R tap on the terminal strip. Be sure the speaker(s) or PA
horn(s) is capable of handling a reasonable power output from the amplifier or permanent damage to
the speaker(s) or PA horn(s) may result. Also, be careful not to overload the amplifier with too many
speakers or PA horns. If it is desired to use a number and variety of speakers, the speakers must be
arranged in various series or parallel arrays to provide proper impedance matching. 70V constant line
voltage must be used (parallel connection only). If you are not familiar with impedance matching,
consult a professional installer or technician for advice. If 70V constant line voltages are used, a line
matching transformer must be used with each speaker. Again do not overload or use incompatible
speakers. Line transformers are the preferred method for multi-speaker installation.
CABLE REQUIREMENTS
Output cabling need not be shielded in most cases and should be of sufficient gauge to minimize
losses due to the resistance of the wire over long runs (insertion loss). Cable thinner than 18
gauge is not recommended. Long runs require 16 gauge or heavier.
In some cases, where the output cable is run in close proximity to unshielded intercom cables,
electrical cables, radio transmission antennas or other sources of interference, or when the
amplifier is being used for paging from a telephone system, the amplifier may require shielded
output cabling to prevent audio feedback or interference.
PRIORITY PAGE: THE AMPLIFIER FEATURES A VOICE ACTIVATED PRIORITY PAGE CIRCUIT
AND AUTOMATICALLY MUTES ALL PROGRAM MATERIAL (TUNER/TAPE/CD,ETC.) FROM THE
AMPLIFIERS OUTPUT, AND PERMITS MIC 1 AND THE TELEPHONE INPUT TO
OVERRIDE FOR PAGING ANNOUNCEMENTS.
TELEPHONE LINE: A TELEPHONE LINE INPUT OF 600 OHM IS PROVIDED.
THERE ARE MANY OTHER FEATURES OFFERED. PLEASE READ MANUAL COMPLETELY.
WHENEVER IN DOUBT ABOUT INSTALLATION, CONSULT WITH A PROFESSIONAL
INSTALLER OR TECHNICIAN OR PERSONAL INJURY, DAMAGE TO THIS AMPLIFIER
AND/OR SPEAKERS MAY RESULT AND YOUR WARRANTY MAY BE VOIDED.