A Peep Behind the Scenes

Radio Record, Volume III, Issue 45, 23 May 1930, Page 7

A Peep Behind the Scenes

--eo BY installing a small but complete sound film plant at the Chilton House School, Island Bay, Wellington, on Wednesday last, Mr. McCutcheon, chief engineer, Western Blectrie Co., entertained and interested about 150 residents of the district. The films were virtually a peep behind the scenes, for they portrayed in a novel manner many of the principles of sound, and incidentally of radio, that were the basis of the talkies. Basing the operation of the talkies on a cartoon, "How Mute Found His Voice," those gathered were shown by sound and sight how the idea of the sound track was worked up in the Western laboratories. "Talkie," a personified strip of sound film, took "Mute’-his silent prototype-by a2 questionable way into the laboratory, where he was shown by Dr. Western the way "Talkie" had found his voice. There were the two plants-one well known to radio and the other the recording camera plant.

Part of the former is to be found in every radio home-the amplifier, the microphone is similar to that used in the studios, but the photo-electric cell, although of radio origin, is, not yet fully known to all and sundry. The moving cartoons showed hor’ the two impressions are made, both on separate film, and how the two are printed out on the final positive. The picture was interpolated by a song from "Talkie," and Dr. Western took his silent friend along the track taken by the voice. Mute finally found his voice, and with "Talkie" joined in a rousing farewell. The cartoon was a base for the following film, "Some of the Characteristics of Sound." Much as might be written on the subject. of frequencies, frequency ranges, tone, pitch, and amplitude, it remains for a film such as this to make things quite clear. An oscillator, and four instruments, served té show how characteristics of tone

depend on the number and strength of the overtones. Beside the flat and colourless note of the oscillator, ’cello, flute, violin, piano, and voice stood out in pleasant contrast. ; A note of 50 cycles-how often does the reader of everyday radio literature hear this phrase? Yet it means little to him other than a deep note; but in this film the oscillator was tuned from 50 to 6000 cycles, and as the whine left the screen, we who were present knew something more of sound than we had before. To see the sound waves slowed up to-visible speed was another feature of this unusual film, and those fortunate enough to be present undoubtedly knew something more of sound than they had done before. At one stage certain frequencies were cut off from the recording microphone, and one was transplanted in the radio of a few years ago, which unhappily still obtains in some of the poorer instruments. In "Scenes Behind the Scenes" at Hollywood and the other film cities of the States, we were shown how the talkie industry has been meant a literal recreation of the industry of moving picture production. Hverywhere

there are large sound-prool studios, several acres in extent. Judging from the huge doors, the places are veritable prisons in their magnitude. And this is necessary to keep extraneous noises from the microphones. Apparently dozens are required to produce, photograph, and sound record a modern film. The photographers are housed in glass cases to prevent the sound of the motors being picked up by the microphone, The days are certainly gone when the director shouted his comments at the artists and the camera men danced round, turning the handle that recorded the moving picture. This is the electrical age when this mighty force can do almost all things but create. The evening at Chilton House concluded with supper and dancing, provided by the talkie amplifier and a gramophone.