User manual

Parallel connection
The impedances are divided.
The 4 x 16Ω speakers can be connected to an
amplifier that manages 4Ω connections.
Series connection
The impedances are added up.
The 4 x 4Ω speakers can be connected to an
amplifier that manages 16Ω connections.
CONNECTION MODES
Constant impedance speaker systems
Constant impedance outputs are generally used in the case of lines with a small
number of speakers having a certain power and being placed at a minimum distance
from the amplifier. Speaker connection will be a combination of connection in parallel
and series connection, so to bring loudspeakers total impedance to a value which is
not critical for the amplifier. In the series connection the positive lug shall be
connected to the negative lug of the following speaker. In the connection with
constant impedance it is always recommended that speakers total power is higher
than the power supplied by the amplifier.
If in the connection with constant impedance the volume of one or more speakers
needed to be set independently or also if any speaker needed to be switched off, the
use of attenuators keeping impedance constant is required.
In the series connection, whatever the impedance of each speaker, the total
impedance results from the sum of all the impedances. Anyway, using sound
speakers with equal impedance and power is recommended.
SPEAKERS CONNECTION
The loudspeakers connected in parallel to amplifier's output will make system
expansion easier, if required, by simply shunting from any of the previously installed
speakers. Similarly, the loudspeakers which are not necessary anymore can be
removed. Matching the "phase" is necessary both in the connection of each speaker
to its own transformer and in the connection in parallel of the speakers.
Constant voltage speaker systems
Using the following formula: P=V²/Z with V being 100/70V and Z being speaker's
transformer primary impedance any power applied to each speaker can be
calculated. If, instead, you know the voltage (100V/70V) and the rated power (or
powers) of the transformer and you want to calculate transformer impedance, the
following formula applies: Z=V²/P.
SPEAKERS CONNECTION
This connection system implies that each speaker is equipped with its own line
transformer. The amplifier shall be equipped with 100V / 70V constant voltage
outputs.
All the constant voltage outputs (100V/70V) of a single amplifier can be connected at
the same time, provided that amplifier's rated power remains equal or higher to the
sum of the power of all the speakers installed on each output line.
18
BEFORE 5 speakers were connected to the system for a total of
55W. The selected amplifier was 60W.
AFTER Speakers were added and removed from the system.
The total requested power is now 87W.
In this case it is sufficient to change the amplifier,
but the system (in terms of cables) will remain unaltered.
com
15W 10W
10W10W
10W
100V
60W
Amplifier
com
15W 10W 10W 6W
6W10W20W10W
100V
100W
Total = 16Ω
4Ω 4Ω 4Ω 4Ω
Total = 4Ω
16Ω 16Ω 16Ω16Ω
Amplifier