The RCA Photophone System of Sound Recording and Reproduction for Sound Motion Pictures

The general considerations governing the selection of a sound-on-film recording and reproducing system are analyzed, and the variable width track for recording and the dynamic cone with directional baffle for reproduction are described as best suited for studio and theater applications. The recorders, sound heads for projectors, amplifiers, switching and control devices, power supply, and loud-speaker systems of various types of RCA Photo-phone equipment, are described in detail.