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:
Jun. 14, 1983
Filed:
Apr. 20, 1981
John A King, Martinsville, IN (US);
Harman International Industries, Northridge, CA (US);
Abstract
An improved acoustic impedance for a direct radiating dynamic loudspeaker having a natural Q greater than about 1.2, is substantially planar and is positioned in front of and covers the projected frontal radiation area of the diaphragm or cone of the loudspeaker. The acoustic impedance element is supported about its periphery and comprises a fibrous felt material having an air flow resistance in the range of about 50-100 cu. ft. per min. at 0.5 p.s.i. pressure drop, a density in the range of about 6-12 oz. per sq. yd. and a thickness in the range of 0.03-0.09 in. The acoustic impedance element is an air permeable continuous sheet and is comprised substantially entirely of fibers of synthetic materials, such as, for example, polyester, which are relatively impervious to moisture. The Q of the speaker including the damping element is in the range of about 0.75-1.0.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile