GIANT LOUDSPEAKER

Radio Record, Volume I, Issue 39, 13 April 1928, Page 15

GIANT LOUDSPEAKER

New York has a new device which | enables one million people within a radius of one mile to hear one man speaking in an ordinary voice into a telephone. This wonderful loudspeaker is situated at the top of the laboratories of the Bell Telephone Company. An expert, Mr. R. W. King, crossed the Hudson from New York and, about a mile away, spoke into a telephone on the top of a cliff. He said: "Hallo, can you hear me?" and in about five seconds his words came booming back across the harbour. The sound came so suddenly that Mr. King burst into lauzhter, which in a very few seconds also came roaring back again! Although this giant speaker produces such a big volume of sound, the diaphragm is only about the size of a watch. It is made of light aluntinium alloy, thinner than gold leaf, around which is ‘wound a eoil of aluminium wire finer than thread. The voice causes the wire to vibrate and the air chamber between the diaphragm and the mouth of the horn is specially shaped to give a maximum of sound and clarity.