Pseudo Stereo

Since stereo came along, the record industry has been haunted by the bogey of unplanned obsolescence: recordings that were big during the LP decade are now as dated as an automobile with fins. This week RCA Victor started to fight back by announcing the release of ''pseudo stereo"--or, as the record liners prudently euphemize, monophonic recordings with "electronic stereo reprocessing." RCA's first releases: Respighi's Fountains of Rome and Pines of Rome, Moussorgsky-Ravel's Pictures at an Exhibition, Dvorak's Symphony "From the New World", all conducted by Arturo Toscanini.

The sales of Toscanini disks, which once far outdistanced the rest of the classical record field, dropped off sharply after stereo appeared. Alarmed, RCA in 1958 assigned an engineer-composer named Jack Somer. then 23, to see if he could save Toscanini for stereo. It took him two years to produce a recording that sounded convincing and that was not afflicted with such normal recording hazards as "grit, ticks and swish."

Somer's technique is based on the fact that in the usual symphony orchestra, the higher pitched instruments (violins and higher winds) are concentrated on the left, the lower pitched instruments (cellos, bass, brass, tympani) to the right. With a maze of controls he called "the rat's nest," Somer was able to divide a monophonic recording into two separate sound tracks, generally using a high-pass filter to channel the high-frequency violins and winds to the left, a low-pass filter to place the low-frequency instruments to the right. With further gimmicks, such as the adding of reverberation, Somer achieved an effective illusion of true stereo separation.

Not all engineers approve of doctored stereo. Says Columbia's William S. Bachman: "You have a single signal to start with. We don't think there is any honest way to make two out of it. It's like separating mush and milk; once you get them together, you can't get them apart." RCA's Somer concedes that his technique is a compromise: too much separation results in an alteration of the original sound. Moreover, in pseudo stereo "you can spread the sound around the room, but there is no way to get the feeling, as in true stereo, of the proper positioning of the individual instruments." Sharp-eared listeners will detect that the Somerized orchestra has a habit of wandering about the stage: the strings may shift a bit toward center, a trumpeter may wander farther into right field. But most customers are not likely to question the illusion: the gimmicked Toscanini recordings have a luster that their mono counterparts lack.

This file is automatically generated by a robot program, so reader's discretion is required.