SMALL HORN SPEAKERS

Daily Telegraph (Napier), Volume 58, Issue 244, 15 November 1929, Page 4

SMALL HORN SPEAKERS

IMPROVINGr THE TONE. Wireless reproduction certainJy ma.y not reach its peak of efficiency when it is obtained through the iittle horn-type loud speakers which used to be on the nuirket, and which are stiil employed by many set-ownens, but their performance can be improved by various means. The output strength of a small loud speaker cannot be increased beyond a certain point witliout violent distortion, so increased volume must be ruled oot, together with any attempt to irake tliem reproduce the bass notes niore ioudly. However, rnuoh of the shrillness, rattle and buzz which sometimes accompauies the reproduction given by these instruments can he done away with completely. For instance, the very

simplb expedient of supporting a smalJ horn-type loud speaker on a camera tripod js capable of getting rid of much of the extraneous noise of the receptiou. Another way of improving the tone of a loud speaker is to connect a crystal detectoy in, parallel with the terminals. The crystal deetector tends to filter away any small distortion which may be pi'esent, If, of course, the resistance of the detector is too low, too much of the current will leak across it, and the reception strength of the speaker will certainly not be improved. Ho\yever, if a spare detector of the permanent, ' simi-permanent, or cat's whisker type is handy, a trial of this nature is worth making. , Very often, horn-type loud speakers, big and small alike, give bad tone owing to dirt having collected upon the diapliragm, or to the latter having become rusty The trouble can be prevented from recuring more or less simply by removing the horn, gluing a piec© of thin but tough paper over the stem of the speaker and fastening the horn on again. This will prevent dirt from Teaching the diaphragrfi. If any sligbt diminution in the strength of the reception" is apparent, it can be removed by pricking a few holes with a needle in the paper cover. In most cases, however, no decrease in the reception strength will be noticed. The resting of a small loud speaker upon a sheet of glass, supported npon corks, will go a very long way toward ridding the reception of any objectionable accompaniment of rattle. Such a method of supporting a loud speaker is very useful in those cases in which the instrument j« liabl© to vibration from externa] causes. "Throaty" speakers of the diminutive horn type can generally be cured by wrapping a long strip of flannel around the stem. Tlio appearance of a speaker so trented is certainly not very elegant, even under tlie best. of conditions. but tlio improvcment in tone which the treatment will often effect is notbing sliort of amazing.