Electrical audio signal processing systems and devices – Including frequency control
Patent
1998-02-05
1999-04-06
Kuntz, Curtis A.
Electrical audio signal processing systems and devices
Including frequency control
381 943, 381 941, 381103, H03G 500, H04R 102
Patent
active
058928332
ABSTRACT:
A multi-band digital gain and equalizer system for receiving and processing an audio signal includes an analog-to-digital converter for converting the audio signal to a digital signal X, a plurality of digital filters, each for processing and selectively amplifying/attenuating a different frequency band of the signal X, to produce an output signal Y.sub.n, in which the waveform of the frequency response is concave downward for the central frequencies of the band and concave upward for the frequencies above and below the central frequencies, a summing circuit for summing the output signals Y.sub.n to produce a resultant digital signal, and a digital-to-analog converter for converting the resultant digital signal to a resultant analog audio signal. The center frequencies of each band processed by a digital filter is separated from adjacent center frequencies of bands processed by other digital filters, by about two octaves. An additional digital filter is provided for processing a frequency band of the signal X which is higher than the frequency bands processed by the plurality of digital filters, to produce an output signal Y.sub.n1 whose waveform of the frequency response is concave upward for the lower frequencies of the band, concave downward for the low to central frequencies of the band, and generally flat for the higher frequencies of the band. The summing circuit sums the output signals Y.sub.n and Y.sub.n1 to produce an output signal whose frequency response is substantially flat, with a "floor" at the low end of the frequencies and a "shelf" at the high end of the frequencies, and with little phase shift.
REFERENCES:
patent: 3846719 (1974-11-01), Dolby
patent: 4359601 (1982-11-01), England
patent: 4661982 (1987-04-01), Kitazato
patent: 4773094 (1988-09-01), Dolby
patent: 4837832 (1989-06-01), Fanshel
patent: 4845758 (1989-07-01), Op de Beek et al.
patent: 4922535 (1990-05-01), Dolby
patent: 5515446 (1996-05-01), Velmer
Valkenburg, "Analog Filter Design," 1982.
Scidmore, "Lecture Notes ECE 341 -Linear Active Circuits," 1982, 1987, 1991.
Greiner, Schoessow, "Design Aspects of Graphic Equalizers," J. Audio Eng. Soc., vol. 31, No.6, Jun. 1983, pp. 394-407.
Jensen Quinn
Maag Clifford
Parker Lance
Barnie Rexford N.
Kuntz Curtis A.
Night Technologies International
LandOfFree
Gain and equalization system and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gain and equalization system and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gain and equalization system and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1378430