Projection engineering (Sept 1929-Nov 1930)

Page 42 Projection Engineering, September, 1929 ability to reach such sound levels extends the range of musical expression, and carries an impression of power. Why else do we build giant organs, organize choruses of hundreds of voices, bands of fifty pieces, and orchestras of a hundred or more instruments? It will be argued that the large orchestra is necessary to afford the desired variety of instruments and to give proper balance. But if there are several instruments of each kind, this explanation can hardly stand. Still less do such reasons apply to the two hundred voice chorus. A quartet, or for some compositions a sextet, can carry all the parts, afford the full range of voice qualities, and can be controlled and blended more perfectly than a larger number of voices. There is, of course, a psychological factor in favor of the large orchestra or chorus, but the primary purpose is to produce a great volume of sound. Altered Sound Quality The multiplication of sound sources results inevitably in a change of sound quality, the wave shape from the multiple source being more complex. With the best of tuning, two different instruments playing the same note will produce more or less rapid beats. With a large number of instruments playing the same note, each will beat with all the others, and the result is rapid and rather irregular fluctuations in intensity during the playing of each note. Whether the net effect is pleasing to the ear is perhaps a matter of taste. Those who prefer the complex tones would probably describe them as "richer." Those who like the simpler tones would speak of them as "mellow" or "smooth" and find, relatively, a certain harshness in the complex tones. Heretofore we have had no choice but to accept the complex wave and the tonal qualities which it carries, whenever we have wanted great sound volume. The two factors have gone hand in hand. With the new tool at our disposal, the high power sound reproducing device, we can control volume and tone quality independently, and can have the smooth and mellow tones of the small group or single instrument at any volume. There is thus a new freedom given to musical expression. The quality resulting from blowing or bowing strongly can be reproduced softly as desired, or the quality of an instrument played softly may fill the auditorium. Still more important is the advantage to be gained in the rendering of vocal selections. Every voice changes in quality according as the person sings loudly or softly, and the change is certainly in the direction of an impairment in quality as the loudness approaches the point where strain and effort are present. The forced voice gives no pleasure and is likely to result in permanent injury. We seek the world over for the rare combination of great power, pleasing voice quality, and sufficient musical appreciation and training to use the voice with artistic effect. But there are thousands of singers who have all of the requirements except power, and whose voices may even surpass those of their more celebrated brothers or sisters in richness and fineness. These voices are now made available in the theatre and auditorium as well as in the parlor. All singers may use their voices at more natural levels, and the smooth round tones of the soft or subdued voice may be heard with ease in all parts of the house. Amplifying a Whisper Certain difficulties are encountered in the attempt to magnify the voices of singers actually present on the stage, and the full advantage of electrical sound production cannot perhaps be realized under these conditions. But where music is recorded and then reproduced the new factors will become of great importance. Already the alteration of sound levels possible with electrical phonograph recording and reproduction has been utilized to produce records of a type that has been quite popular, namely, the "whispering" tenor solo. The microphone is placed very close to the singer, who speaks and sings in a voice little above a whisper. On the higher notes the voice becomes nearly a falsetto. The reproduction is many times louder than the original, and the effect is of a voice of very unusual quality. Those who listen probably do not often realize the discrepancy in loudness, and might not like it so well if they did. We have so long been seeking naturalness in reproduction that unnaturalness is thought of as a fault, even though it may have been brought about for a purpose and with pleasing effect. Although a large orchestra is looked upon as the finest that can be provided in musical entertainment, it may be predicted that where recorded music is used, the aim in general will not be to give the best possible imitation of the large orchestra (although this can be done with remarkable success when desired), but to render in whatever volume is wanted the simpler music of a small orchestra, with single instruments instead of groups of instruments carrying melodies. Balance is not dependent on the use of the proper number of instruments of each kind, but can be controlled by the positions of the players relative to the microphone. The Orchestra of the Future Let us venture another prediction, farther probably from early fulfillment. The orchestra of the future will make extensive use of electrical sound producing devices. One of the most important applications will be to accentuate the tones of certain instruments in order that a single instrument may carry a melody, or to give the effects of accompanied solos without subduing the entire remainder of the orchestra. Again new tone qualities are obtainable by electrical means. For example, let us suppose that an electrical sound pickup is located within the instrument whose tones are to be magnified. The character of the tones will vary with location and also with the design of the electrical pickup or microphone. Instruments which are not at present loud enough to be useful, except in the softer passages of the composition, will be made useful for the loud passages as well. With such electrical assistance as has been suggested, the orchestra of the future will be able to produce many effects not now possible. ONE TEN-THOUSANDTH OF AN INCH IS IMPORTANT IN "TALKIE" MAKING THE first sound picture or talking movie designed especially for purposes of military instruction was completed recently and shown before a representative group of military and naval officials. The film was made at the Infantry School at Fort Benning, Georgia. It is a result largely of the Western Electric Company's experimental work and production methods. One of the "most difficult of all production tasks," to quote the company's statement, was placed before the Hawthorne organization of the Western Electric Company by the enthusiastic public reception of the talking pictures. More than $500,000 worth of the most modern machine equipment had to be bought and especially adapted to this project. A heavy production schedule was set up. The tool room was geared up to capacity for turning out the required tools. A storeroom covering 6,500 square feet of floor space was built in record time for the storage of material, process parts and apparatus. Accuracy and precision were the basic features in the planning. One ten-thousandth part of an inch was a familiar item. The finest work was necessary in the manufacturing processes entailed in making the new condenser type transmitter (the microphone used in recording for the talking pictures). One small disc, a part of the transmitter, must be ground until its; surface is exactly flat — microscopically flat. To test this flatness a quartz disc is used. By placing this disc on top of the other disc, a patchwork of light rays broken into spectrum rays is seen. If this patchwork of light rays does not have a certain design then there is something out about the flatness of the manufactured disc. Dust-proof rooms are used for transmitter assembly. Dust, any speck of it, in this instrument, would be fatal. Glass cabinets, with all the moisture exhausted, contain the parts which are assembled in the cabinet. The workmen place their wrists through rubber sleeves fixed to the cabinet in order to assemble the parts. Executives Service Bulletin.