Signedon graph: Janszen Model I-50 / Direct-Radiator, Electrostatic Loudspeaker / (ca. 1956)
Inscribedon graph: Janszen Model I-50 / Direct-Radiator, Electrostatic Loudspeaker / (ca. 1956) / production model of prototype contains four / "push-pull" units to increase angular cove- / rage. frequency response curve is that of a / single unit.