Plm6800 - 4-Channel Power Amplifier With Digital Loudspeaker Management - Montarbo PALCO PLUS User Manual

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Two-ohm operation.
Many professional power amplifiers may operate on very low loads and
some of them are specified for continuous operation on 2-ohm loads.
It would therefore seem possible to employ one of these "low-impedance-
capable" amplifiers to drive two parallel-connected RAB1815 subwoofers
(one channel for the two 18", the other for the two 15"), or 4 parallel-
connected RA16 enclosures (one channel for the four LF sections, the other
for the four HF sections).
And, although this is certainly possible, it is not recommended for one or
more of the following reasons:
- 2-ohm operation increases the heat generated by output and power
supply stages, reducing the amplifiers' reliability, making them more prone
to catastrophic failures.
- the high current involved calls for a detailed study of the amplifier-
speaker wiring, and the wiring will inevitably become more complicated
and complex.
- the failure of one amplifier will result in an "out of service" condition
(a dramatic muting) of twice the number of speakers, and this may
compromise the entire performance in course.
- the dynamic range and the damping factor of an amplifier operating
on a very-low-impedance load are significantly reduced, and this may
compromise the exceptional dynamic and transient response of the
PALCOPLUS system.
6.1 PLM6800 powered controller - 4-channel power amplifier with digital
loudspeaker management
The use of the PLM6800 gives a number of important advantages:
- the internal amplifiers' gain and power have been optimized for the
PALCOPLUS system;
- the small size and weight give a great space saving;
- system wiring is simplified beacuse all the required power connectors
®
(Speakon NL4 e NL8) are ready installed on the amplifier's rear panel,
and thus there's no need to fabricate dedicated wiring panels or adapter
cables;
- the 'intelligent' control of the outputs' wiring (the output connectors
are selectively enabled by the digital controller according to the loaded
preset), gives total protection to the speaker's components against wiring
errors.