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. 17, 1985
Filed:
Nov. 23, 1982
Stig Carlsson, S-117 25 Stockholm, SE;
Other;
Abstract
A loudspeaker is provided for high-quality stereophonic loudspeaker systems intended to be positioned on the floor close to a vertical wall of a room. The aim is to reduce distortion due to that part of the reflected sound which arrives from substantially the same direction as the direct sound. Therefore the sound radiating surfaces and the loudspeaker casing are so arranged that the reflected sound from the floor and the wall arrives substantially in phase with the direct sound up to at least 800 Hz. The loudspeaker has a casing with a side wall (2), a top wall (4) and a bottom wall (6). A loudspeaker unit (7) in the side wall (2) is the sound source for at least the range from 50 to 150 Hz. A loudspeaker unit (9) mounted in a horn-type casing structure close to the bottom wall (6) is the sound source for at least the range from 300 to 800 Hz. A loudspeaker unit (12) located near the rear end of the top wall (4) and facing slantwise forwards towards the side wall (2) is the sound source for the direct sound at higher frequencies. The left-hand and the right-hand loudspeakers form a mirror-image pair. In preferred embodiments the higher-frequency loudspeaker unit (12) co-operates with a horn-type structure (16, 17, 18, 19a, 19b) to avoid reflected sound from the room wall in the mid-range up to about 4 kHz.