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4.2 Front and rear panel
5. START-UP
This speaker-system must only be connected with an appropriate power amplifier. The amplifier power must
correspond with the speaker-system power. An amplifier with too little power can also destroy a speaker-
system with a higher power range.
5.1 Choosing an appropriate power amplifier
Before starting with the installation, you must clarify how many speaker-systems you would like to install in
the room.
In order to increase the sound pressure level two speaker-system pairs should be connected with the power
amplifier. Please note that the impedance is only half the value when you connect two speaker-systems with
one channel of the power amplifier. Please make sure that the power amplifier is qualified for this operation
mode.
When connecting further speaker-system pairs (e.g. 3 pairs) to the same power amplifier, the impedance
lowers even further. You must always make sure that the power amplifier is qualified for the new impedance.
If the impedance of the speaker-system is lower than the lowest allowed amplifier impedance, the amplifier
and the speaker-systems may be damaged.
Furthermore, you must define the operation mode for your system. If the power amplifier is to be used in
stereo-mode, the power is lower as in e.g. mono bridged mode.
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Suitable power amplifiers:
OMNITRONIC P-125 Amplifier, 2x65W/4Ohm
No. 10451105
OMNITRONIC P-250 Amplifier, 2x125W/4 Ohm
No. 10451110
OMNITRONIC P-500 Amplifier ,2x250W/4 Ohm
No. 10451130
The following descriptions refer to OMNITRONIC power amplifiers. You may also use other appropriate
power amplifiers.
5.2 Operation modes
Stereo operation
Normal operation mode of an amplifier, in which every channel gets its own signal. The most commonly used
mode of amplifiers is stereo-operation at 4 Ohms. Make sure that the operation-mode-switch is correctly set.
Calculation number of speakers – impedance
E.g. 1 speaker à 8 Ohm = 8 Ohm
2 speakers à 8 Ohm = 4 Ohm (parallel)
2 speakers à 8 Ohm = 16 Ohm (in line)
3 speakers à 8 Ohm = 2.66 Ohm (parallel), only for amplifiers capable of handling 2 Ohms
2 speakers à 8 Ohm = 24 Ohm (in line)
4 speakers à 8 Ohm = 2 Ohm (parallel), only for amplifiers capable of handling 2 Ohms
N.B.:
The input-impedance of the speaker-systems should at least be the same or even higher than the output-
impedance of the amplifier.
Parallel operation
Possibility to run the amplifier in mono-mode, i.e. via one input channel. In parallel operation mode, the
voltage remains the same, the current is doubled. Consequently, the output impedance is limited to the
minimum value of one individual channel.
Connect the input signal to the input-plug CH-1.
Make sure that the amplifier is disconnected from the mains before you set the operation-mode-switch to
parallel.
Bridge the red pole sockets of Output Channel 1 and Output Channel 2.
Connect your speakers to the Speaker-socket Output CH-1.
Caution!
Before switching on your amplifier, please refer to the explanations under Operation.
Adjust the level with the gain-control CH-1 on the frontpanel.
Bridging
Possibility to run the amplifier in mono-mode, i.e. via one input channel. In bridged operation mode, the
current remains the same, the voltage is doubled. Consequently, the output impedance is doubled.
For stereo-operation, 2 amplifiers are needed.
Connect the input signal to the input-plug CH-1 on the rearpanel.
Make sure that the amplifier is disconnected from the mains before you set the operation-mode-switch on the
frontpanel to Bridge.
Connect your speakers to the red Speaker-socket Mono Bridged.
Caution!
Before switching on your amplifier, please refer to the explanations under Operation.
Adjust the level with the gain-control CH-1 on the frontpanel.
Choosing appropriate connection cables
The speaker-system must only be connected via a sufficiently dimensioned cable. Too thin cables lead to
cable heatup or enormous power loss and loss in sound-quality.
For all speaker-systems up to 400 Watts, we recommend a cable diameter of 2.5 mm², for all other speaker-
cables 4 mm².
A high damping factor of your amplifier supplies a clear sound reproduction. Unnecessarily long and thin
cables will influence the damping factor and thus the low frequencies in a negative way. In order to
