Speaker Impedances - Speco P-30FACC Instruction Manual

For 25V and 70V CONSTANT VOLTAGE LINE CONNECTIONS
(refer to figure 4).
IMPORTANT NOTICE: When the 25V and 70V constant line voltages are used, a line
HOW TO CONNECT LINE MATCHING TRANSFORMERS IN PARALLEL
ALWAYS CONNECT LINE TRANSFORMERS IN PARALLEL

SPEAKER IMPEDANCES:

Speaker impedance taps for 4, 8 and 16 Ohm speakers are provided on a terminal strip on the rear
panel of the unit. Also, outputs for 25V and 70V constant line voltage are provided. To connect the
power output directly to a speaker or PA horn or a combination of speakers and/or PA horns which
have a resulting voice coil impedance of 4,8 or 16 Ohm, connect to the COM and the proper
impedance 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 or the 25V or 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 the 25V or 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.
matching transformer must be used with each speaker. All
transformers must be connected in parallel.
(25 VOLT LINE OR 70 VOLT LINE)
NEVER CONNECT LINE TRANSFORMERS IN SERIES
25V Transf.
Jumper positions for
70V
70V or 25V selection.
25V
FIGURE 4
10
70V Transf.