Audio signal reproduction apparatus
US5784476A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1997 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Sep 19, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2420/01
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Audio signal reproduction apparatus, for example, an in-car entertainment system, includes a number of audio signal sources (I--I to I-N) which are selected by means of a selector (2) and fed to an AGC circuit (4) before being applied to an amplifier (6) and loudspeaker (7). The AGC circuit (4) includes an amplitude analyzer (42) and a low-pass filter (43) to produce an output signal (44) which controls the gain of an amplifier (41). The arrangement is such that the AGC circuit only causes a gain change when the audio signal lies outside a predetermined amplitude band for a given minimum time period. Thus only long "too loud" or "too soft" passages cause a gain change and transients pass through the arrangement without causing a gain change.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.