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:
Feb. 16, 1982
Filed:
Jan. 04, 1980
Robert W Adams, Medford, MA (US);
Leslie B Tyler, Newtonville, MA (US);
DBX, Inc., Newton, MA (US);
Abstract
An improved equalizing system for modifying an input electrical signal representative of original sound so as to correct for the inherent nonflat frequency response of an audio signal processing apparatus and the acoustic effects of listening environment in which the loudspeaker system of the audio signal processing apparatus may be disposed. The improved equalizing system includes a comparator for comparing the signal energy in each of a plurality of select frequency bands of a predetermined frequency range of the input signal with that of the corresponding signal energy in a like plurality of bands of a like range of a second signal representative of the acoustic output of the loudspeaker system and as a function of the nonflat frequency response and the acoustic effects of the environment. A correction signal representative of the comparison is used to modify the energy within each band of the input signal so as to substantially correct for the nonflat response and the acoustic effects of the environment. In the preferred embodiment, a unique filter arrangement is provided for simultaneously reducing the interaction between adjacent bands and the amount of ripple at the output of the equalizing system.