The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 19, 1978
Filed:
Dec. 27, 1977
Clifford A Henricksen, Yorba Linda, CA (US);
Altec Corporation, Anaheim, CA (US);
Abstract
A method and apparatus for determining the directivity index (DI) and directivity factor (Q) of a loudspeaker is described. A microphone is placed in the throat of a horn-type loudspeaker to measure the acoustical pressure at this point. A second microphone is placed along an extension of a central axis of a loudspeaker at a predetermined distance from the mouth of the loudspeaker to measure the acoustical pressure at this point. The output of each of the microphones is rectified and converted to decibel form. The decibel signal representing acoustical pressure at the throat is subtracted from the signal representing the measured pressure at the predetermined distance. A signal (in decibel form) representing the distance of the second microphone from the mouth of the horn is added to the difference signal and a signal (in decibel form) in accordance with the diameter of the loudspeaker throat is subtracted from the difference signal to provide a signal in accordance with directivity index. From the directivity index a signal in accordance with directivity factor (Q), which is a power ratio, can be derived.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile