The Exhibitor (Nov 1938-May 1939)

BM-22 BETTER MANAGEMENT DEVELOPMENTS Behind the Scenes in The Equipment Field No. 2 of a Series 1 1 NEW RCA MI-9050 SOUNDHEAD OFFERS KNOWN STANDARDS, NEW REFINEMENTS Hard upon Better Management’s discussion last month of "The New in Sound, Projection, and Mechanical Equipment, based on the recommendations of the Academy of Motion Picture Arts and Sciences, comes this week the announcement from the RCA Victor Division of the RCA Manufacturing Company, Inc., of the debut of its new soundhead, to be known as the MI-90 50. Announcement of the equipment came this week from Homer B. Snook, reproducer sales manager for RCA Photophone, with technical description from M. J. Yahr, Photophone Sales. Appreciative of the fact that good sound in a theatre is, perhaps, the operator’s greatest problem, and that it is, at the same time, the most severely technical of all problems of management, the Editors of Better Management feel that they can do no better than allow Photophone tell you of the new mechanism. MODEL MI-9 0 5 0. The new "streamlined” RCA Photophone soundhead for motion picture projection embodies more than a score of neur advances. A shock-proof drive for the famed RCA rotary stabilizer, a double switch exciter lamp are among the improvements. "First and foremost, we feel that the introduction of the newly designed MI-90 50 soundhead will create an entirely new conception of soundhead mechanisms for exhibitors. In this soundhead, we have combined all of the engineering research and field experience which we have had during the last 10 years with such mechanisms in order to produce one which incorporated features and refinements always considered to be essential, as well as a number of new ones which we feel will add still further to the sturdiness and dependability of the well-known rotary stabilizer type of head. "A few of the outstanding features are the following: "1. The famous 'rotary stabilizer’ assures absolute constant film speed (passed the scanning lamp). "2. 'Shock-proof’ drive further eliminates mechanical disturbances. "3. Reversible exciter lamp socket. "4. Pre-focused exciter lamps. "5. Micrometric gear mesh adjustment. "6. High quality ball-bearings throughout. "7. Interchangeable drive motor equipped with flywheel for improved starting characteristc. "8. Gear drive throughout; no chains or belts. "9. Oil-proof optical system, with positive focus adjustment. "10. Positive oil drainage system. "11. Scientific placement of film driving elements and white painted interior to facilitate threading. "12. Stabilizer and optical parts cushion mounted to eliminate vibration. "13. Hermetically sealed rotary stabilizer oil case. "14. Positive action pad rollers and large film strippers. "15. Hold-back sprocket to prevent take-up jerks. "16. No stationary surfaces to damage film. "17. Quickly adaptable to installation of parts for 'push-pull’ operation. "18. Integral gear box assembly. "19. Totally enclosed case. "20. Modernly styled. "In explanation of the so-called shock-proof drive, our engineers have designed the gear train in such a way was mechanically to isolate the constant-speed sprocket shaft from the remaining gear train and drive apparatus. This means that back lash and other irregularities which may b: present in the projector drive train can not be transmitted readily to the constant-speed sprocket. The net result is a still further elimination of the irregularities of film movement, which irregularities are normally responsible for various forms of distortion in sound reproduction. "Amplifiers are usually considered as the second important link in the chain of sound-reproducing apparatus. In our new line of amplifiers, primarily the thought has been to provide the exhibitor with a unit having true high-fidelity range and adequate reserve power, so that the newest type of high-range prints now being produced in Hollywood could be used without any danger of distortion or over-load. "It is of especial interest to note that the trade, generally, has come to recognize adequate amplifier reserve power as being of the greatest importance. This is true since the esthetic value of sound is considerably affected by the relative loudness of the sound, as well as the trueness of the pitch or over-load. "Without this reserve power it would be practically impossible to reproduce loud passages, especially of musical selections, with the result that the dramatic value would be spoiled. "RCA has built into the amplifier systems standby features which will allow the show to be carried on in the event of the failure of any one of the components of the system. Provision has been made for quick and ready checking of all tubes by means of a meter and switch. This check can be carried on while the equipment is in operation. "The amplifier apparatus is mounted in a modernly styled rack, eliminating unsightly and costly inner-apparatus wiring. "Recognizing that theatre apparatus is subjected to conditions not normally encountered elsewhere, the equipment has been designed so that all parts are quickly accessible and, what is more important, they are rated very conservatively to assure extremely long life. This same idea has even been used in the voltage ratings for the vacuum tubes. "The third important portion of the equipment is the stage speaker complement. Here we are using the well-known two-way speaker system, which consists essentially of a cellular high-frequency horn, equipped with one or two highly efficient driver units. "The cellular construction of the horn gives an even spread of the sound throughout the auditorium without unduly concentrating the sound in any one portion of the auditorium. "The bass notes are reproduced through a system employing either one or two large folded wooden baffles, equipped with highly efficient dynamic speaker units. "The entire speaker complement will handle a tremendous volume of sound without distorting or rattling. Even here, provision has been mad: for emergency in the event of failure of the high frequency unit by a switching arrangement, which allows all of the sound to be reproduced over the low-frequency baffle system. This feature is controllable from the booth. BEAUTY’S UTILITY. RCA Photophone’s new amplifier rack was designed by John Vassos, Lynn Brodton, industrial artists. Trim, compact, the cabinet provides easy access to all parts of the amplifiers for checking or the making of repairs. "Provision has been included in these equipments for rapid changeover of sound from any projector station. High quality 'mercury’ type switches are used for fading purposes. Complete front-wall volume control is provided so that the projectionist does not have to walk to the amplifier rack for this purpose.” Readers of Better Management will eagerly await the show-room inspection of this equipment, the demonstration from an actual installation. January 18, 19)9