Circuit arrangement for correcting frequency response in accordance with frequency response of a sound field
US4559569A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 1984 |
| Grant date | Dec 17, 1985 |
| Priority date | — |
| Expiry date | Mar 8, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R29/001
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a circuit arrangement for automatically correcting frequency response so as to set a desired frequency response in view of a frequency response of a sound field, a frequency response control circuit is improved such that precise level control at a number of bands is effected with a simple structure. A microcomputer is used to determine the difference between a desired frequency response curve and a frequency response curve obtained by measuring the sound pressure level in a sound field, to which pink noise or the like is emitted through the frequency response control circuit, so as to produce a control signal used in the frequency response control circuit to give a desired frequency response to an audio signal. The frequency response control circuit comprises an amplifier, a plurality of resonance circuits corresponding to the bands, a plurality of variable resistor circuits each including a parallel circuit of a plurality of series circuits of a resistor and an analog switch; and an interface circuit responsive to serial data of the control signal from the microcomputer for controlling the analog switches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.