Wide-stage stereo

Stereophonic playback systems are studied to determine the accuracy with which they can reproduce the geometry of the original sound. Sounds were generated in a geometric pattern, recorded, and reproduced over a loudspeaker array. The methods used were similar to those used by Steinberg and Snow in 1933. Using two sound tracks, a derived center playback channel, and corner placement of flanking speakers, geometry plots were made with almost as good accuracy as when observers listened to an actual person speaking at the indicated stations in the geometric array. Since wide speaker spacing was used, corner placement becomes natural. An evaluation of corner speaker placement from the tonal standpoint (as contrasted with the geometric) shows that there is a large increase in quality available by taking advantage of the reflections of the floor and walls. It is shown that corner placement of flanking speakers and use of a derived-channel center speaker affords the best reproduction of geometry as well as tonality.