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:
Apr. 28, 1992
Filed:
Sep. 28, 1990
James J Croft, Seattle, WA (US);
Other;
Abstract
A dipole speaker for use with a multichannel sound reproduction system for producing an acoustical ambience signal. The dipole speaker comprises a transducer which is connected to the sound reproduction system so that it receives a difference signal from between the channels thereof. The transducer may be a unitary loudspeaker or a pair of identical, outward-facing loudspeakers. In response to a difference signal, the transducer generates first and second sound pressure lobes which extend in opposite directions from the dipole speaker, and which are 180 degrees out of phase so that they cancel one another out to produce a null zone which extends in a plane about the speaker. The dipole speaker is used in conjunction with conventional direct-path speakers which are connected to the sound reproduction system. The dipole speaker is positioned in a defined listening area so that the null zone is aligned towards the listener to avoid any sound travelling along a direct path from the speaker to the listener, and the sound pressure lobes are directed towards the walls of the listening area so that the acoustic signal of the dipole speaker is reflected therefrom and arrives at the listener by way of indirect paths. The acoustic signal of the dipole speaker is thus sensed by the listener as arriving from various directions, and its arrival is delayed relative to the arrival of the acoustic output of the direct-path speakers due to the longer lengths of the indirect paths, both of which enhance the ambience of effect of the acoustic output of the dipole speaker.