Projector for film with two sound tracks - both synchronously running sound signals are amplified with one intensity reduced by other

摘要

The second sound track on the film runs synchronously with the first. Both sound signals are amplified, and one signal intensity is reduced by the other sound track. Acoustic signal volume in one sound track is controlled by a control signal in the other. These control signals are recorded in the second track by themselves, or in addition to other sound signals. The sound heads (4, 5) pick up the acoustic information from the magnetic tracks (2, 3) carried by the film (1). The switch (6) preferable fitted to a microphone, enables a control signal lying outside the frequencies of the sound tracks to be conveyed from the generator (7) to the second track (3).