Sound recording and reproduction systems
US7072474B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 2004 |
| Grant date | Jul 4, 2006 |
| Priority date | — |
| Expiry date | Jun 27, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S2420/01
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Sound recordings are played through a closely-spaced pair of loudspeakers with a predetermined listener position having an included angle of between 6° and 20°, and filter means being employed in creating said sound recordings, the filter means having characteristics such that when the sound recordings are played, the need to provide a virtual imaging filter means at the inputs to the loudspeakers to create virtual sound sources is avoided, the sound recording being such that when played through the loudspeakers a phase difference between vibrations of the two loudspeakers results where the phase difference varies with frequency from low frequencies where the vibrations are substantially out of phase to high frequencies where the vibrations are in phase, the lowest frequency at which the vibrations are in phase being determined approximately by a ringing frequency, f0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.