A New Sound Reproducing System for Theaters
This paper describes a system for high quality sound reproduction from film in synchronism with the showing of motion pictures in theaters having a seating capacity of 1200 or less. A sound reproducing attachment is mounted upon each standard picture projector and is belt-driven by a common motor unit. The sound reproducing attachment houses a photo-electric cell which converts a light beam intercepted by the film sound track into electrical energy. Suitable preliminary amplifiers mounted upon independent pedestals amplify the output voice frequency energy of the photo-electric cell to a level suitable for further amplification by the main amplifiers. A control cabinet provides for switching and attenuating the sound circuits before being led to the main amplifiers and thence to the loudspeakers.
- Print ISSN
- 0097-5834
- Published
- 1931-02
- Content type
- Original Research
- DOI
- 10.5594/J01520