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This invention relates to apparatus for reproducing sound and particularly to an improved diaphragm or amplifier adapted for use with phonographs or other similar machines. The usual reproducing diaphragm is of considerable size. When sounds are reproduced by such a diaphragm additional audible notes or overtones are developed which depend in a general way upon the size, shape, and material of the diaphragm. Other overtones represent the natural frequency of the horn, box or air chamber with which the diaphragm is associated. These overtones alter the character of the sound reproduced by the diaphragm and detract from its quality. It is the general object of our invention to provide a novel form of sound reproducing apparatus by the use of which these objectionably overtones may be avoided and by which the purity and clearness of the original sound may be closely reproduced. In the preferred embodiment of our invention we employ a sound reproducing device comprising a large number of relatively small vibrating elements. The natural notes or overtones of these small vibrating elements and their associated air chambers, if any, are so high that they are not audible to the human ear.
- Robert Goddard
reproducing sound, apmplifiers, phonographs, phonograph amplifiers
Goddard, Robert, "Sound-Reproducing Device" (1926). WPI Patents Collection. 31.