Proel AMP30XL - Manuale (Pagina 29)

Constant impedance line.
To use this amplifier with a constant impedance line (4Ω), please
connect the COM terminal to the negative post of your speaker, and
connect the 4Ω terminal to the positive post.
− To obtain the best performances, the total speakers impedance
connected to the line, should be equal to the amplifier output
impedance.
− The speakers power sum should not be lower than the amplifier
output power.
− We suggest you to don’t use long cables. Anyhow, for longer
distances application use a thicker cable.
Constant voltage line
If you’re using a constant voltage line, connect either the 25V, 70, or
100V to the “+” side of speaker system, and connect COM to “-“ side
of the speaker.
− Speakers should have a transformer of the same voltage
developed by the amplifier.
− Speakers power sum should not be higher than the amplifier
maximum output power.