Radio today (Jan-Mar 1939)

in the direction of the horn. Also a single horn can be heard a couple blocks away at the sides and the rear, because of sound reflections. Since chimes are instantaneous in nature, a speaker with a 30-watt voice coil dissipation will easily handle the output of a 50-watt amplifier. This applies to both recorded and amplified chimes. So for church tower chime installations the rule seems to be 50 watts power for each speaker of 30 watts capacity. Generally one to three speakers are used. Average reverberation So far no mention of the reverberation time on auditoriums has been made. For outdoor installations reverberation is not a problem. Inside installations should take reverberation into account. But for the chart given, only an average of all conditions found is possible. In practically every instance, the chart will give power requirements that are on the high side. But this is a desirable condition, for it is poor policy to run an amplifier at its maximum output — a certain amount of power should be kept in reserve for peak requirements. PRESENT "SOUND" OUTLETS AND THEIR PROBLEMS Editor, Radio Today: On numerous occasions I have been asked to express my views on the position of the radio jobber in the Sound industry today. I hope that the following comment will prove of more than usual interest to your readers. It is common knowledge that the radio jobber is gradually losing his heretofore enviable position in the Sound Industry. In the interests of the radio trade at large, I would like to present my view's on present-day Sound merchandising. Criticisms and suggestions are specifically invited. Public is "wise" Members of the public today are "discount wise." They insist upon buying from sources which they believe are in the best position to distribute their requirements at the lowest possible prices. Further, it is apparent that presentday outlets for sound equipment do not differentiate between types of customers. Servicemen, industrial engineers, night-club owners and unclassified P. A. users, are all treated in exactly the same fashion. Anyone purchasing a sound system from a mail-order house buys at the dealer's price. In an effort to compete with these mail-order houses, parts jobbers are following this same procedure The mail-order house sells principally through the medium of its catalogue and local sales offices. Anyone desiring a sound system is sold at the catalogue price. Prices in general are lower, for the simple reason that a company of this type normally sells for cash. Further, its operating overhead is lower and the turnover greater. First, the major portion of equipment sold by mail-order companies is bought by the ultimate consumer. S'econd, a considerable amount is purchased by individuals, who are able to sell this same equipment at a price higher than the mail-order resale. This is (possible because the customers of these individuals know absolutely nothing about the trade and have no reason whatsoever to investigate this aspect of the business. The third type of customer which is common to all sales agencies, is the party who buys for rental purposes only. In this case it doesn't matter who sells the equipment so long as it is satisfactory for this work. In most instances, the party who buys for rental work knows the trade well enough to purchase equipment at the lowest possible prices. (Continued on page 50) CHART FOR DETERMINING THE NUMBER OF ACOUSTICAL SOUND WATTS REQUIRED To calculate the amplifier output required, the sound (acoustical) watts must first be determined for the room size, calculated by referring to curve for the noise level encountered. Then using the efficiency of loud speaker, electrical power is determined. February, 1939 15