A high-frequency filter can significantly reduce interference in the high-frequency range above 1.5 kHz, such as resonances, commutation dips, clock frequencies and transients. The stage can be integrated individually in the wall cabinet or as a module in the freestanding cabinet of the multiwave passive. Several high frequency filters can also be connected simultaneously. The size of the filter depends on the level to be compensated. After the filter is switched on, it operates without being controlled and in real time. If required, this can be switched on and off via a signal.