Method and apparatus for measuring characteristics of a loudspeaker
US4209672A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1978 |
| Grant date | Jun 24, 1980 |
| Priority date | — |
| Expiry date | Jul 13, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R29/001
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A loudspeaker and a microphone are arranged in a normal room, the loudspeaker being supplied with an impulse signal. A direct response sound from the loudspeaker and reflected sounds from wall surfaces in three directions of the normal room are converted into a response signal by the microphone. The response signal is A/D-converted, and then Fourier-transformed. The Fourier-transformed response signal is converted into a response signal with an absolute value, and then into a logarithmic response signal. The logarithmic response signal is filtered to eliminate signal components corresponding to the reflected sound. The filtered logarithmic response signal is A/D-converted, and supplied to a recorder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.