Low Impedance Systems; Operation - Adastra RM series User Manual

A 100V line speaker system can comprise of many speakers connected together. The determining
factor for how many speakers can be used on a single amplifier is the power rating. For most
purposes, it is advised to connect as many speakers as needed with a combined wattage of no more
than 90% of the amplifier's output power rating.
The terminals of a 100V speaker are connected to a transformer and in some cases, this transformer
may be "tapped" for different power ratings. These tappings can be used to adjust the wattage (and
output volume) of each speaker in the system to help achieve the ideal total power of the system for
the amplifier.
Speaker switching zones (RM240SB only)
The RM240SB has 4 separate terminals for 100V speakers. Any 100V speakers connected to the
terminals labelled ZONE 1/ ZONE 2 / ZONE 3 / ZONE 4 (+) and COM (-) will be governed by 4 front
panel speaker switches (e.g. a speaker connected to ZONE 1 and COM will only work if Zone 1 is
selected on the front panel)
There is also a switch labelled "ALL" on the front panel which enables zones 1 to 4 all at once.

Low impedance systems

Alternatively, the RM series amplifiers can provide an output for a single 8Ω speaker by connecting
the "8Ω" terminal (16) to the positive (+) speaker connection and "COM" terminal (15) to the
negative (-) speaker connection.
It is important to ensure that the speaker load is no less than 8Ω and that the power handling of the
speaker is equal to or greater than the output power of the amplifier. Do not use 8Ω and 100V at the
same time.

Operation

When all connections to the amplifier are made, turn all rotary controls down and switch on the
power (11) and a power "ON" LED will illuminate.
Turn BASS and TREBLE controls to the 12 o'clock position (pointing straight up) and turn the
MASTER rotary control (9) up part way for testing.
Ensure a signal is being fed to one of the line inputs 2, 3, 4 or 5 and gradually increase the volume
control for that channel until the output is heard through the speakers.
Turn up the MASTER to the maximum required volume level and reduce the channel volume control
if necessary.
Repeat this process for any other line inputs connected to channels 2, 3, 4 or 5.
Note: If a line input is not connected to an RM series mixer-amplifier, the initial test can be made
using the built-in media player. See the "Media player" section for instructions.
Both the media player output and LINE 5 input are governed by the LN5/USB volume control.
RM Series User Manual