Simulated stereo from a monaural source sound reproduction system
US4308424A · kind A · utility
Inventor
Key dates
| Filing date | Apr 14, 1980 |
| Grant date | Dec 29, 1981 |
| Priority date | — |
| Expiry date | Apr 14, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S5/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A source of monaural sound such as a radio receiver or record player provides an audio signal which is fed along parallel paths to a like number of speakers. In one or more paths there is a control which imparts amplification or gain to the signal. In the other path, however, a frequency dependent amplitude variation and phase delay means is interposed in the circuit. It is the purpose of this means to vary the amplitude response of that signal to introduce a bass boost of about a factor of two and a treble cut of about a factor of ten and to vary the phase shift of that signal to introduce from about a 180.degree. to about 225.degree. phase lag to the monaural signal, the amplitude response and phase lag being a function of the frequency of the signal, to impart a simulated stereo effect to the sound as heard from the plurality of speakers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.