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. 16, 1986
Filed:
May. 30, 1985
Matthew S Polk, Baltimore, MD (US);
Colin B Campbell, Baltimore, MD (US);
Other;
Abstract
Apparatus for reproducing sound having a realistic ambient field and acoustic image is used in a stereophonic sound reproduction system having a left channel output and a right channel output. A right main speaker and a left main speaker are disposed at right and left main speaker locations, respectively, which are equidistantly spaced from a listening location along a listening axis perpendicular to a line joining the left and right main speakers. A right sub-speaker and a left sub-speaker are respectively disposed at right and left sub-speaker locations equidistantly spaced from the listening location, and further from the listening location than the main speaker. In one particular arrangement each main speaker includes a driver and a tweeter and each sub-speaker includes only a driver. The left and right channel outputs are respectively coupled to the left and right main speakers. A left channel minus right channel difference signal is coupled to the left sub-speaker and a right channel minus left channel difference signal is coupled to the right sub-speaker. In one embodiment, the main and sub-speakers for each channel are respectively incorporated in a common enclosure to fix the spacing therebetween. A technique for determining optimal spacing between the main and sub-speakers and between the various speakers and the listening location is set forth.