The acoustic systems were developed by the well-known Swedish designer Ole Mirsch. His company "Ole Mirch AB" produced acoustics of the OM series.
Mirsch OM 21 dual-band system. Perless speakers and first-order filters (6dB) are installed in it. Acoustics work well with both transistor and tube amplifiers. There are no genre preferences. Classical music, acoustic jazz, rock and even electronic music are played well.
Specifications:
The maximum power is 35Watts
Frequency range 50-20,000 Hz
Resistance 8 Ohms
The graphs of the measurements of their parameters are pasted on the back walls of the speakers.