For the sound reinforcement of halls, auditoriums and buildings, it is not possible to fall back on the classic loudspeaker connection, since the required currents for the many loudspeakers would require a disproportionately thick conductor cross-section. For this reason, the loudspeaker signals from the power amplifiers are transformed to 100 volts and transmitted at this voltage level to the loudspeakers connected in parallel.
In 100 V technology, a transformer is connected in series with each loudspeaker to handle the voltage and impedance matching. The concept is similar to that of power distribution networks. The symmetrical, ground-free signal transmissiontakes place via simple, small-diameter cables. To equalize the volume of individual loudspeakers or loudspeaker groups, the matching transformer downstream of the power amplifier has several taps to which individual loudspeaker groups can be connected.
100 V systems are not fixed to the voltage of 100 volts, they can also have 50 V or 70 V instead of 100 V, as is common in other countries. Other advantages, in addition to the small cable cross-section, are a greater cable length and the parallel connection of the loudspeakers, which makes it possible to expand with additional loudspeakers without much effort.