Subscriber loudspeaker "Ob-303".

Subscriber loudspeakers.DomesticSince 1978, the subscriber loudspeaker "Ob-303" has been producing the Novosibirsk plant of low-voltage equipment. Loudspeaker "Ob-303" is designed to reproduce the transmissions of the low-frequency channel of the local wired broadcasting network. The voltage in the transmission line is 30 (or 15) V. The nominal frequency range of sound is 160 ... 6300 Hz. The uneven frequency response is about 15 dB. Average sound pressure 0.23 Pa. The price is 5 rubles.