Reverb prefix `` Echo ''.
Acoustic systems, passive or active, as well as electro-acoustic units, hearing aids, electric megaphones, intercoms ...Active speaker systemsReverberation prefix "Echo" has been prepared for release since 1966, presumably by the Sarapul plant named after V.I. Ordzhonikidze. The set-top box is a 2 W low-frequency amplifier combined with an acoustic system of two loudspeakers and a spiral installation for reverberation (artificial echo). The set-top box can be used in conjunction with any sound reproducing devices or as a separate bass amplifier with an acoustic system, with or without reverb.
