Vitaphone - Process

Process

From the perspective of the cast and crew on the sound stage, there was little difference between filming with Vitaphone and a sound-on-film system. In the early years of sound, the noisy cameras and their operators were enclosed in soundproofed booths with small windows made of thick glass. Cables suspended the microphones in fixed positions just above camera range, and sometimes they were hidden behind objects in the scene. The recording machines were usually located in a separate building to completely isolate them from sound stage floor vibrations and other undesirable influences. The audio signal was sent from an on-stage monitoring and control booth to the recording room over a heavy shielded cable. Synchronization was maintained by driving all the cameras and recorders with synchronous electric motors powered from a common source. When music and sound effects were being recorded to accompany existing film footage, the film was projected so that the conductor could synchronize the music with the visual cues and it was the projector, rather than a camera, that was electrically interlocked with the recording machine.

Except for the unusual disc size and speed, the physical record-making process was the same one employed by contemporary record companies to make smaller discs for home use. The recording lathe cut an audio-signal-modulated spiral groove into the polished surface of a thick round slab of wax-like material rotating on a turntable. The wax was much too soft to be played in the usual way, but a specially supported and guided pickup could be used to play it back immediately in order to detect any sound problems that might have gone unnoticed during the filming. If problems were found, the scene could then be re-shot while everything was still in place, minimizing additional expense. Even the lightest playback caused some damage to the wax master, so it was customary to employ two recorders and simultaneously record two waxes, one to play and the other to be sent for processing if that "take" of the scene was approved. At the processing plant the surface of the wax was rendered electrically conductive and electroplated to produce a metal mold or "stamper" with a ridge instead of a groove, and this was used to press hard shellac discs from molten "biscuits" of the raw material.

Because of the universal desirability of an immediate playback capability, even studios using sound-on-film systems employed a wax disc "playback machine" in tandem with their film recorders, as it was impossible to play an optical recording until it had made the round trip to the film processing laboratory.

A Vitaphone-equipped theater had normal projectors which had been furnished with special phonograph turntables and pickups; a fader; an amplifier; and a loudspeaker system. The projectors operated just as motorized silent projectors did, but at a fixed speed of 24 frames per second and mechanically interlocked with the attached turntables. When each projector was threaded, the projectionist would align a start mark on the film with the film gate, then cue up the corresponding soundtrack disc on the turntable, being careful to place the phonograph needle at a point indicated by an arrow scribed on the record's surface. When the projector was started, it rotated the linked turntable and (in theory) automatically kept the record "in sync" (correctly synchronized) with the projected image.

The Vitaphone process made several improvements over previous systems:

• Amplification – The Vitaphone system used electronic amplification based on Lee De Forest's Audion tube. This allowed the sound to be played to a large audience at a comfortable volume. Vitaphone was far from the first sound film system to use this technology, but it had amplifiers and loudspeakers, developed by Western Electric, which were state-of-the-art. Their performance was greatly superior to anything else of the kind then available, including the equipment used by De Forest to present his own Phonofilm sound-on-film exhibitions.
• Fidelity – Contrary to conventional wisdom, neither Vitaphone's ability to fill a theater with an adequate volume of sound nor its success in maintaining synchronization was unprecedented. Léon Gaumont's sound-on-disc films, which were being shown twenty years earlier, were successfully synchronized by the use of electrically interlinked multi-pole synchronous motors, and a pneumatic amplification system more than sufficed to fill Gaumont's 3400-seat flagship theater in Paris with the recorded sound. That sound, however, had to be recorded by the same insensitive non-electronic method introduced by Thomas Edison in 1877, or alternatively by a very crude microphone-based variant which had logistical advantages but did not offer improved fidelity. The resulting sound, however greatly amplified it might be, was tinny and unclear and speech was difficult to understand. The footsteps and other incidental sounds that audiences instinctively expected to hear were missing. It did not sound "natural". The Vitaphone system derived from extensive work on electronically recording and reproducing sound that had been carried out at Western Electric during the first half of the 1920s. Western Electric's engineers had developed a highly sensitive full-frequency-range condenser microphone, capable of capturing a whisper from several feet away, along with the electronic and mechanical equipment necessary to adequately record the audio signal it produced. As a result, the quality of Vitaphone sound in the theater came as a revelation to the audience at its public debut in 1926. It easily and dramatically surpassed anything previously achieved. It even surpassed the sound quality of Western Electric's own sound-on-film system, developed concurrently with the sound-on-disc system but still in the laboratory at that time, because at first the discs yielded better fidelity than an optical sound track.

These innovations notwithstanding, the Vitaphone process lost the early format war with sound-on-film processes for many reasons:

• Distribution – Vitaphone records had to be distributed along with film prints, and shipping the records required a whole infrastructure apart from the already-existing film distribution system. The records would start to suffer from audible wear after an estimated 20 playings (a check box system on the label was used to keep count) and were then supposed to be replaced with a fresh set. Damage and breakage were inherent dangers, so a spare set of discs was usually kept on hand, further adding to the costs.
• Synchronization – Vitaphone was vulnerable to severe synchronization problems, famously spoofed in MGM's 1952 musical Singin' in the Rain. If a record was improperly cued up, it would start out of sync with the picture and the projectionist would have to try to manually acquire sync. If the wrong record had been cued up there was no realistic option but to pause the show for a few minutes while swapping in the correct disc, resetting everything and starting that reel again. If the film print became damaged and was not precisely repaired, the relationship between the record and the print would be thrown off, also causing a loss of sync. Vitaphone projectors had special levers and linkages to advance and retard sync, but only within certain limits. Scrupulous care and attention were demanded from the projectionist. In the absence of human error and the occasional malfunction that can befall any complicated machine, the Vitaphone system worked as intended, but when a problem did occur it could be an embarrassing disaster.
• Editing – A phonograph record cannot be physically edited, and this significantly limited the creative potential of Vitaphone films. Warner Brothers went to great expense to develop a highly complex phonograph-based dubbing system, using synchronous motors and Strowger switch-triggered playback phonographs. Multiple source discs would be carefully cued up, then parts of each in turn were dubbed to a new master disc. The cutting of the new wax master could not be paused, so each playback turntable had to be started at just the right moment and each signal switched to the recorder at just the right moment. The system actually worked, but imprecisely enough that the reel of film typically required some adjustment by adding a few frames here and removing a few there in order to conform it to the disc of edited sound. This discouraged frequent changes of scene in the film and the lively pace that they created. Not only was editing sound on disc a nightmare for the editor, but it was increasingly obvious to everyone that while the system sufficed for musical shorts and a synchronized musical accompaniment for otherwise silent films (the only applications originally planned) it was no way to make a feature-length film with "live" sound. By the middle of 1931, Warner Brothers-First National had thrown in the towel and was recording and editing optical sound on film, like all the other studios, and only then dubbing the completed soundtrack to discs for use with the Vitaphone projection system.
• Fidelity versus Sound-on-Film – The fidelity of sound-on-film processes was improved considerably after the early work by Lee De Forest on his Phonofilm system and that of his former associate Theodore Case on what eventually became the Fox Movietone system, introduced in 1927. The De Forest and Case-Fox systems used variable-density soundtracks, but the variable-area soundtrack used by RCA Photophone, introduced in 1928, eventually predominated. Although the fidelity of optical sound never quite caught up with ongoing improvements in disc recording technology, for practical purposes the early quality advantage of discs had been overcome within a few years.

After the improvement of the competing sound-on-film systems, Vitaphone's disadvantages led to its retirement early in the sound era. Warner Brothers and First National stopped recording directly to disc and switched to Photophone sound-on-film recording. Warner Brothers had to publicly concede that Vitaphone was being retired, but put a positive spin on it by announcing that Warner films would now be available in both sound-on-film and sound-on-disc versions. Thus, instead of making a grudging admission that its technology had become obsolete, Warner Brothers purported to be doing the entire movie industry a favor.

A significant number of theater owners, who had invested heavily in Vitaphone equipment only a short time before, were financially unable or unwilling to replace their sound-on-disc-only equipment. Their continuing need for discs compelled most Hollywood studios to prepare sets of soundtrack discs for their new films, made by dubbing from the optical soundtracks, and supply them as required. This practice continued, although on an ever-dwindling scale, into the mid-1930s.