LOUD SPEAKER DEVELOPMENT

Hawke's Bay Tribune, Volume XIX, Issue 305, 11 December 1929, Page 10

LOUD SPEAKER DEVELOPMENT

The newly-perfected electrostatic or condenser type loud-speaker, which promises to become a formidable rival to the moving coil instrument for volume and purity of tone appears to be an example of the old saying that there is nothing new under the sun. A recent survey of the world's scientific literature discloses the socalled “singing condenser," first discovered in Europe approximately sixty-six years ago. This was nothing but a lightly- rolled condenser made by placing a paper dialectric between two sheets of tinfoil and using one sheet as an electrode opposed to the other sheet. When an alternating or pulsating voltage was impressed between both electrodes the condenser would give off a musical note dependent upon the frequency of the impressed voltages. Many radio fans have noticed this “ghostly” phenomenon when they disconnected their loud-speaker from the set and the set kept on “playing," . Ithough weakly. They could trace the origin of the sound to the small black box that housed the condenser in the output filter. The reason for the condenser giving off sounds, and the condenser speaker also, lies in the fact that there is a mechanical stress generated between the two bodies of electrodes charged electrically, and as the charges vary, the bodies or electrodes are moved to and fro in accordance with the variations. If the electrodes have any considerable area the sounds that are given off may be of a perceptible order, and a specially con structed device built along these lines might serve as a reproducer for radio reception. Until ■recently, however, few of the condenser speakers were sufficiently efficient or accurate in their reproduction to be very successful commercially. It is said that the reason for this is that no one thought of introducing fhe third element, the flexible dialectric between the two plates or electrodes of the speaker, as is done, by Mr. Colin Kyle, the inventor of the type of condenser speaker which has been named after him. the Kylectron.

When Mr. Kyle. a. former Californian school teacher, who specialised in physics and electricity while in college, began work on reproducers of the cor longer tvpe. he was told bv the wise acres that be was attempting the impossible. That he “accomphshed the impossible" was proved at a recent demonstration in New York hr-’nre a critical audience of several hundred metropolitan radio

Because artirulntion with th" Kvloctron tyne of condenser spon'reis so ne-irlr perfect it ’S sr’-'l to ho an-dicnble +■•> the talking “movies” as well as for home reproduction.