Subscriber loudspeaker `` Sound ''.

Subscriber loudspeakers.DomesticSince 1956, the subscriber loudspeaker "Sound" has been producing the Izhevsk Radio Plant. AG `` Sound '' was produced both for operation in a radio broadcasting network with a voltage of 30 volts, and for the Moscow city radio network, with a voltage of 15 volts. There is no other data on the loudspeaker yet.