Operating instructions

G-2
This caused a dilemma for soundtrack recordists. Should the tracks be
recorded to take advantage of the improved speakers, or should they be
prepared to sound best on the many older installations already in place?
Given that it was impractical to release two versions of a given title, the
only alternative was to tailor soundtracks to the older speakers. The
result was to ignore the improved high-frequency response of the
newer, better units.
To forestall compatibility problems, in the late 1930s a de facto
standardization set in, the theater playback response that today is
called the “Academy” characteristic. Theater owners knew what to
expect from the films, and therefore what equipment to install. Directors
and sound recordists knew what to expect from theater sound systems,
and thus what kind of soundtracks to prepare. The result was a system
of sound recording and playback that made it possible for just about any
film to sound acceptable in any theater in the world. It was also a
system, however, without the flexibility to incorporate improvements
beyond the limitations that existed in the 1930s.
Even with these limitations, for years optical film sound provided
higher quality sound than home phonographs and radios. But by the
late 1960s and early 1970s, superior hi-fi stereo systems had been
installed in so many homes that a significant and influential proportion
of the moviegoing public was used to better sound at home than could
be heard in the theater.
Magnetic Sound
In the 1950s, a new method of putting sound on film was introduced as
an alternative to the optical soundtrack. After the picture is printed,
narrow stripes of iron oxide material similar to the coating on magnetic
recording tape are applied to the film. The sound is then recorded on the
magnetic stripes in real time. In the theater, the film is played back on
projectors equipped with magnetic heads, similar to those on a tape
recorder, mounted in a special soundhead assembly called a “penthouse.”
Magnetic sound was a significant step forward, and at its best provided
much improved fidelity over the conventional optical soundtrack.
Magnetic sound also permitted the multiple tracks required by
stereophonic sound. The voice of an actor appearing to the left, center,
or right of the picture could be heard coming from speakers located at
the left, center, or right of the new wide screens also being introduced
at this time. Music took on a new dimension of realism, and special
sound effects could emanate from the rear or sides of the theater. The
two main magnetic systems adopted were Twentieth Century Fox’s
four-track 35 mm CinemaScope system introduced for The Robe, and the
six-track Todd-AO system first used for such 70 mm films as Oklahoma!
and Around The World in 80 Days.