[Dixielandjazz] More on Vitaphone

[Stephen G Barbone]

How Vitaphone Worked

A Vitaphone-equipped theater used normal projectors equipped with a  
special turntable and reproducer, a fader, an amplifier, and  
loudspeaker system. The projectors operated as normal motorized silent  
projectors would, but also provided a mechanical interlock with an  
attached phonograph turntable. When the projector was threaded, the  
projectionist would align a start mark on the film with the picture  
gate, and would at the same time place a phonograph record on the  
turntable, being careful to align the phonograph needle with an arrow  
scribed on the record's surface.
When the projector rolled, the phonograph turned at a fixed rate, and  
(theoretically) played sound in sync with the film passing the picture  
gate simultaneously. Unlike the prevailing speed of 78revolutions per  
minute for phonograph discs, Vitaphone discs were played at 33-1/3  
r.p.m., and the normal spacing of the grooves was compressed further  
together in order to increase the playing time to match the 11-minute  
maximum running time of a reel of film. Also, unlike most phonograph  
discs, the needle on Vitaphone records moved from the inside of the  
disc to the outside.
The Vitaphone process made several improvements over previous systems:
Amplification - The Vitaphone system was one of the first to use  
electronic amplification, using Lee De Forest's Audion tube. This  
allowed the sound of the phonograph to be played to a large audience  
at a comfortable volume.
Fidelity - In the early days, Vitaphone had superior fidelity to sound- 
on-film processes, particularly at both low and high frequencies.  
Phonographs also had superior dynamic range, on the first few playings.
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. Additionally, the  
records would wear out after an estimated 20 screenings (a checkbox  
system on the record indicated the number of plays), and had to be  
replaced. This consumed even more distribution overhead. Damage and  
breakage were also inherent dangers.
Synchronization - Vitaphone had severe and notorious synchronization  
problems, some of which were covered in a few hilarious scenes in  
MGM's Singin' in the Rain starring Gene Kelly. If a record skipped, it  
would fall out of sync with the picture, and the projectionist would  
have to manually restore sync. Additionally, if the film print became  
damaged and was not precisely repaired, the length relationship  
between the record and the print could be lost, also causing a loss of  
sync. The Vitaphone projectors had special levers and linkages to  
advance and retard sync, but it required the continual attention of  
the operator, and this was impractical. The system for aligning start  
marks on film and start marks on records was far from exact.