Ioan R. Allen

Apparatus for reproducing motion picture film photographic sound-tracks to correct reproduction errors and reduce noise

Apparatus for reproducing motion picture photographic (optical) sound-tracks is disclosed in which significant information regarding track placement, slit illumination, azimuth and impulse noise is derived by dynamically processing and comparing the signals obtained by reading each half of a bilateral sound-track. In a further embodiment a pair of detector elements monitors the septum between two tracks in order to detect lateral film misalignment.

Are movies too loud

Over the past few years, the subject of movies getting louder has generated increasing concern within the film production community. In addition, it has become commonplace for moviegoers to claim that movies are too loud. Many theatres now project films at an audio fader setting below the calibration setting that would match that in the dubbing theatre, presumably because of audience complaints. The following material discusses some of the issues that can be described as sound-track loudness. What is a measure of loudness for a movie? Why do theatres turn the sound down? Have new sound formats (Dolby SR and more recently the digital formats, Dolby SR.D, Sony SDDS, and DTS) exacerbated the perceived loudness problem? This paper describes an investigation aimed at defining perceived long-term sound-track loudness with a meter reading, and some data are presented.

Stereophonic motion picture photographic sound-tracks compatible with different sound projection formats and record and playback apparatus therefore

Discrete four-channel photographic (optical) motion picture sound-tracks are disclosed that are compatible with existing monophonic and stereo variable area (SVA) theatre projection equipment. Six track and four track embodiments are disclosed. In the four track embodiments 4-4-4 matrix encoding is employed in producing the sound-track. Apparatus for recording and reproducing the compatible four-channel sound-tracks are also disclosed.

Motion picture theatre electro‐acoustic characteristics

The playback of Dolby Stereo films requires significantly improved electrical and electro‐acoustic characteristics in the cinema if the full capabilities of the soundtracks are to be realized. The finished result can extend both the high and low frequency perceived cut‐off frequencies by at least an octave. Some 2000 theatres have now installed new playback equipment. The paper describes typical theatre characteristics before modification, and the techniques necessary to achieve the desired electroacoustic response, now defined in ANSI Standard 2969. The possiblity of further improvements is discussed, within the confines of existing theatre technical personnel and test equipment.