Motion Picture Herald (Oct-Dec 1932)

24 Better Theatres Section November 19, 1932 MODERN PROJECTION PROJECTION • SOUND REPRODUCTION • ACOUSTICS MEASURING THE QUALITY OF YOUR SOUND By S. K. WOLF A restatement of acoustic values as determinable today, in terms the exhibitor can apply to his own theatre ^here will always be considerable controversy between showmen of different countries as to which offer the most finished entertainment to their fellow citizens. The writer has recently completed a tour of several European countries and is in a position to comment on one aspect of this age-old rivalry. 1 hat aspect concerns the architecture and also the acoustics of European theatres. Generally speaking, theatres in Europe vary in nature to the same extent as do their American counterparts. In large cities like London, Berlin, Vienna and Budapest there exist large motion picture palaces such as we find in our own metropolises. But these are in the way of exceptions to the general rule. During my trip, especially in Central Europe, I was impressed by the almost universal prevalence of small, intimate houses equivalent to our neighborhood theatres. Again, occasionally one would find such oddities as centuries-old convention halls made over into theatres for projecting sound motion pictures. In Venice, Italy, for example, a medieval legitimate theatre frequented by Lucrezia Borgia, was remodeled and adapted to motion pictures! In one respect the European exhibitors seem to have the advantage over their American confreres: Either by chance or by design, the acoustics of their theatres are generally more satisfactory. The result is that while Europeans may not have the variety of entertainment that is available on this side of the water, they are able to present with full mechanical fidelity the material that is at their disposal. One reason why I am led to such a conclusion is the prevalence of small, in timate theatres. Even without elaborate treatment, these are more nearly inherently good in their acoustics. Small theatres are free from "wide open spaces," since they possess a low volume per auditor. As a general rule, the larger the theatre the greater its relative volume. We all know that seating capacity does not increase in proportion to volume, so that our large palatial theatres pay a price for the privilege of being magnificent : they are handicapped by excessive volume. In small theatres the sound is subject to many quick reflections causing rapid dissipation of sound energy. In this way reverberation is reduced. Furthermore, the distances involved are so small that there is less possibility for echoes to interfere with their performance. Large theatres must be designed properly so as to overcome these natural disadvantages. IN EUROPE the small theatre exhibitor, however, is not usually content to rest upon the laurels of the advantages inherent in this type of house. So anxious is he to achieve the utmost in mechanical perfection that one finds the widespread use of velour drapes and other methods of securing good acoustics. They are not satisfied with seeking the best types of sound reproducing equipment, but are willing to take the next step : insuring that the theatre will be an effective acoustic receptor for its entertainment. At the risk of it being considered moralizing, I am adding to these few comments on the situation in Europe a brief discussion on sound and acoustics. They are old subjects, but are worth repeating until all of us know how to evaluate the quality of a sound picture performance. There are three elements involved in the phenomenon of sound : a source of vibrations; a medium, like air to transmit the vibrations to listeners ; and our ears to respond to them and register them on the brain. The elasticity of the air enables it to transmit sound waves, which are a train of alternate compressions and expansions, actual to and fro vibration of the air particles. The number of vibrations per second fixes the pitch ; the intensity of vibration fixes the loudness. The type of mo tion of the air particles determines the character of the sound. In general, sounds may be classified as speech, music and noise. Sounds are recognized as musical when they are composed of tones that have a harmonic relation among themselves. Speech consists of sounds with meaning attached to them. Noise is sound lacking definite musical quality — in fact, usually characterized by disagreeable quality. Sound is a comprehensive term ; it applies to anything that is audible. Since in the theatre we strive for something more than mere audibility, we must differentiate between good and bad sound. Speech and music differ in aim as well as in character. Speech is a means of communication, while music satisfies a less obvious need ; one is practical, the other an art. Accordingly one must be examined on the basis of efficiency, the other for its pleasing quality. The primary consideration with speech is understandability, with tonal quality important though secondary. With music, tonal quality is paramount: it is the reason for different types of instruments— it constitutes what is known as tone color. It is small wonder that sound reproducing equipment must be designed and manufactured with more care than most musical instruments. The equipment must be capable of giving faithful transcriptions of all types of music, from the bass tones of the cello to the high notes of the flute. In one sense, the equipment is all musical instruments. Furthermore, it must act not as a source of all type of music, but of speech and other sounds as well. It must be a faithful, impersonal transcriber, one that does not impose its own idiosyncrasies upon the music it yields. And as a good artist cannot produce the best results with an instrument incapable of matching his art, so do sound pictures depend on the reproducing apparatus. The broadest criterion of good music is that it be easy to listen to. BAD SOUND may be said to be that which fatigues the listener. In the case of speech, if a listener must even slightly strain his nerves to understand, or