ELECTRIC LOUDSPEAKING

Radio Record, Volume I, Issue 25, 6 January 1928, Page 3

ELECTRIC LOUDSPEAKING

NEW BRITISH PRODUCT. It is a commonplace observation that the British radio trade has been beaten on the New Zealand market by the Americatis. Some measure of satisfaction, however, may be gained from the appearance of the British Thomson Ioustcn Co.’s new electric power londspeaker, a demonstration sample of which is on view at the National Electrical and Engineering Co.’s Wellington headquarters. ‘Tis loudspeaker is astonishing in tonal qualities, and its volume can be regulated from a whisper until it conld fill the largest hall in

New Zealand, and at the same time niaintain fidelity in tone. It is a handsome affair resembling in outward appearance a console gramophone of the inost luxurious type, and has a beantiful piano finish. It is operated from either a 110-volt, 230 or 250-volt electric supply line, either direct or alternating current. There is one amplifying valve which takes 450 yolts on the plate. The input goes through a huge transformer, and there are three rectifying valves. The six-inch cone loudspeaker, which, by the way, is invisible, is made of a new material, and is driven by a moving coil floating between the pole pieces of an enormous permanent magnet which is so heavy that it is just about as much as one man could carry. ‘The fluctuations in current from the electric supply line are compensated by a special device. The amount of current consumed while the loudspeaker is operating is about 50 candle-power, or the same as that of one ordinary houserold electric light. A large number of radio listeners haye been treated to demonstrations by this new loudspeaker, which they acclaim as a revelation in reproduction.