Subscriber loudspeaker "Echo".

Subscriber loudspeakers.DomesticSince 1961, the Echo subscriber loudspeaker has been produced by the Moscow Electrical Products Plant No. 6. AG is designed to operate in a broadcast wire radio network with a voltage of 30 volts. A special feature of the loudspeaker is a manually set calendar. Input impedance 4800 ohms. The range of reproducible sound frequencies is 160 ... 5000 Hz. Average sound pressure 2.5 bar. The loudspeaker was also produced under the name "EMZ".