Altec, Inc.

Mark S Ureda

Clifford A Henricksen

An acoustical transformer or 'phasing plug' for coupling the sound from an annular diaphragm to the throat of a compression-type loudspeaker. The phasing plug in the invention has the general shape of a doubly-truncated cone with an annular surface located on the larger end of the truncated cone and positioned adjacent to the diaphragm. The conical surface of the cone has spaced radial slots or channels formed therein connecting the truncated surfaces of the cone. These channels form air passageways for propagation of sound waves. The walls of the slots or channels are tapered such that the cross-sectional areas of the channels increase from their inlet ends near the speaker diaphragm, towards the outlet ends, positioned at the throat of the horn. The phasing plug provides an improved impedance match between the output of the annular diaphragm and the input of the horn.

Acoustical transformer for compression-type loudspeaker with an annular

A loudspeaker horn has a throat section with a rectangular cross section to which the driver unit is coupled. The throat section has substantially parallel side walls joined together by diverging top and bottom walls. The horn has a rectangular mouth which is formed by a bell section which runs between the throat section and the mouth with an angular divergence corresponding to the desired horn dispersion pattern. If the mouth is made square, equal horizontal and vertical low frequency directivity roll off can be provided. On the other hand, with the speaker of the present invention, various relative horizontal and vertical directivity control can be obtained with different aspect ratios for the mouth. The walls of the bell section may be additionally flared outwardly at a portion thereof near the mouth to provide improved midrange directivity control. The use of planar sides between the throat section and the mouth also makes for an improved directivity pattern.

Growing community of inventors

Woodland Hills, CA, United States of America

Mark S Ureda