Characteristics of Film Reproducer Systems

An analysis of sound-picture reproducing-system characteristics, including electrical and acoustical response data collected in the interest of determining the possibilities involved in obtaining an average characteristic for reproducing various film products with uniform response over several combinations of loud speaker equipment. With the aid of a curve tracer having a long-persistent cathode-ray screen, a photographic record was made of the characteristics, starting with various forms and amounts of equalization and exploring their relationship to the power-handling capacity of amplifiers. Following through the system, this record shows the characteristics of dividing networks under various conditions of load, and finally the acoustical response curves taken for comparison of the loud speaker equipments under study. — The measurements of loud speaker combinations included various types of units, both permanent-magnet and energized, low-frequency horns ranging from open back baffles to folded horns with specially designed rear-loading compartment, and high-frequency multicellular horns of various configurations and constructional details. — After establishing the natural characteristics of the various equipments involved, careful listening tests were made over an extended period with samples of commercial prints and other recordings. A description follows of the difficulties and problems involved in an effort to obtain one overall characteristic, which would give satisfactory reproduction for all types of material. The final results are shown, with a short discussion of the methods for duplication in other equipment combinations, and conclude with recommendations for future designs and ratings.

Print ISSN

0097-5834

Published

1939-02

Content type

Original Research

DOI

10.5594/J14641