Electrical audio signal processing systems and devices – Including frequency control
Patent
1995-11-21
1997-05-06
Isen, Forester W.
Electrical audio signal processing systems and devices
Including frequency control
381 59, 381103, H03G 500
Patent
active
056278993
ABSTRACT:
A prefilter (5) for an audio system comprising a loudspeaker (1) in a room (2), which corrects both amplitude and phase errors due to the loudspeaker (1) by a linear phase correction filter response and corrects the amplitude response of the room (2) whilst introducing the minimum possible amount of extra phase distortion by employing a minimum phase correction filter stage. A test signal generator (8) generates a signal comprising a periodic frequency sweep with a greater phase repetition period than the frequency repetition period. A microphone (7) positioned at various points in the room (2) measures the audio signal processed by the room (2) and loudspeaker (1), and a coefficient calculator (6) (e.g. a digital signal processor device) derives the signal response of the room and thereby a requisite minimum phase correction to be cascaded with the linear phase correction already calculated for the loudspeaker (1). Filter (5) may comprise the same digital signal processor as the coefficient calculator (6). Applications in high fidelity audio reproduction, and in car stereo reproduction.
REFERENCES:
patent: 4631749 (1986-12-01), Rapaich
patent: 4694498 (1987-09-01), Suzuki et al.
patent: 4769848 (1988-09-01), Eberbach
patent: 4888808 (1989-12-01), Ishikawa et al.
patent: 5023914 (1991-06-01), Arnold
patent: 5168129 (1992-12-01), D'Antonio
patent: 5185801 (1993-02-01), Meyer et al.
patent: 5185805 (1993-02-01), Chiang
patent: 5511129 (1996-04-01), Craven et al.
Journal of the Audio Engineering Society, vol. 37, No. 11, Nov. 1989, New Yourk US pp. 919-926, Kuriyama et al `Adaptive Loudspeaker System`.
Patent Abstracts of Japan, vol. 13, No. 38 (E-709)2/ Jan. 1989 & JP, A, 63 234 699 (Matsushita) 26 Sep. 1988.
IEEE Acoustics, Speech, and Signal Processing Magazine, vol. 36, No. 2, Feb. 1988, New York US pp. 145-152.
Patent Abstracts of Japan, vol. 9, No. 99 (E-311)27 Apr. 1985 & JP, A,59 225 626 (NIPPON) 18 Dec. 1984.
1989 IEEE Int. Symposium on Circuits and Systems Portland 8-11 May 1989; Phuong-Quan Hoang et al pp. 371-374.
Journal of the Audio Engineering Society, vol. 37, Nov. 11, No. 1989, New York US pp. 899-907.
Patent Abstracts of Japan, vol. 13, No. 594 (E-867)27 Dec. 1989 & JP,A,12 048 798 (TOA Tokushu) 4 Oct. 1989.
Craven Peter G.
Gerzon Michael A.
LandOfFree
Compensating filters does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Compensating filters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compensating filters will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2138732