International photographer (Jan-Dec 1934)

Twenty r he INTERNATIONAL PHOTOGRAPH K k 4pril, 1934 Motion Picture Sound Recording N the previous chapters on monitoring, the genj eral practice of the art was discussed in rather concise form. This final chapter on that subject now brings in some practical aspects of monitoring and explains the change in technique necessan for scoring music. Three-ply veneer is now almost universally used for the walls of motion picture sets. If this thin material is not strongly supported and broken into small panels by thick bracing strips, the resonant frequency of the panels may fall within the range of frequencies that are recorded. Then a loud sound having the same frequency as the resonant frequency of the panels would set them into sympathetic vibration, greatly intensifying the sound and causing distorted sound quality to be recorded. If the monitor man is compelled to work in a set where such a condition exists, his only resort is to keep the microphone at a distance from these "drummy" panels and facing away from them. .houstir Jids Folding baffles made of quilts of sound-absorbing material, such as rock wool, fastened to a suitable framework, are sometimes necessary to reduce the amount of reverberation in a set by adding additional damping. They must be tried at different points until the required effect is obtained, being careful, naturally, that they are out of range of the camera lens. In a similar manner, baffles of hard wood are sometimes used to increase the reverberation in a set that is acoustically "dead." Soft padding, such as Ozite, is usually placed on bare floors to muffle the footfalls of the actors, where such padding will not be in the picture. The monitor man must be alert at all times that extraneous noises, such as the sound of camera gears ("camera noise"), the alternating-current hum from adjacent electric lines, or the scrape of a cable on the Boor during moving shots, do not exist in the sound records he approves. He must watch, too, that he fades in or out with his mixer dials when the cameraman makes a fade in or fade out with the camera. Likewise, if a sound is originating in another room of the set, and the door between that room and the microphone is closed by an actor during a take, the monitor man must turn down the mixer control so that the sound decreases proportionately in volume. Since the rooms are all open on two sides, the actual decrease in sound would hardly be noticeable. Making Orchestrations The scoring of music requires a different technique in monitoring and in placing the microphones than is required for dialogue recording. Scoring is probab!\ the most delicate task the monitor man has to perform, and the one that calls for the greatest natural ability. Just as one microphone has been found to be most satisfactory for recording dialogue, experience has taught monitor men that better recording will result from the use of three microphones for orchestrations. However, as in the case of dialogue recording, there are a few monitor men who still prefer a single microphone for scoring music. The usual practice in making an orchestration is to arrange the orchestra much as if it were on a theatre stage, with the three microphones located where the audience ordinarily would be seated. To emphasize acoustically the stage effect, a backing of hard walls is usually Chapter VIM By Charles Felstead Associate Editor placed behind the orchestra. A heavy rug laid beneath the microphone and a cloth curtain hung behind it, serve to provide the damping normally afforded by the audience. Arranging the Orchestra One form of orchestral arrangement for the scoring of music is illustrated in Figure 1. The same disposition of the instruments is satisfactory whether one, two or three microphones are used for recording. Every monitor man who does orchestrations has his own individual method of seating the musicians ; so the arrangement shown here is given simply as an example of one method. Hard and soft baffles of the screen type are often set up along the edges of the orchestra as an aid in securing the proper effect. The arrangements of the instruments of jazz orchestras and brass bands are somewhat different from that shown. The orchestra is roughh divided into three main groups: the wood-winds and brass-winds, the bass instruments and stringed instruments of the violin type. These groups are arranged on the scoring stage as shown, with the harp and piano placed among the bass instruments. The drums and traps are located at the back beside the cornets because of the intensity of sound produced by these instruments. The three microphones are placed so that there is one in front of each group of instruments. If a single microphone is used, it is placed back farther from the orchestra and to one side of the center so that it favors the stringed instruments, as shown in the illustration. The arrangement for two microphones is a compromise between the microphone settings shown, and the orchestra is divided more nearly into two groups. Individuality Necessary After the initial set-up has been made, it is advisable tor the monitor man to listen to the resulting effect and o , BOPKONE POEITk No. 1 Please mention The International Photographer when corresponding with advertisers.