Waveguide electroacoustical transducing
US5170435A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1992 |
| Grant date | Dec 8, 1992 |
| Priority date | — |
| Expiry date | Mar 2, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2499/13
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A loudspeaker system for radiation into the passenger compartment of a vehicle has one or more elongated acoustic waveguides to efficiently transfer sound pressure energy from a loudspeaker driver outside the compartment into the compartment. Preferred embodiments feature two elongated acoustic waveguides separated by the loudspeaker driver mounted on a hard baffle panel. One waveguide has an effective length of one quarter wavelength at the lowest frequency desired to be reproduced by the loudspeaker driver, and the other waveguide has an effective length three times that of the first waveguide. One or both waveguides may be folded upon itself. The loudspeaker system is driven through circuitry providing reduced system response at frequencies that may cause the deflection of the loudspeaker to exceed its maximum limits. This circuitry includes a high pass filter for transmitting spectral components above the lowest frequency to be reproduced, and a notch filter centered at a frequency where the loudspeaker cone excursion characteristic is a maximum. Another circuit includes boosts the audio spectral components, reduced by the notch filter, into the passenger compartment through an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.