Acoustical transformer for compression-type loudspeaker with an annular diaphragm
US4325456A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 10, 1980 |
| Grant date | Apr 20, 1982 |
| Priority date | — |
| Expiry date | Oct 10, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R1/30
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An acoustical transformer or "phasing plug" for coupling the sound from an annular diaphragm to the throat of a compression-type loudspeaker. The phasing plug in the invention has the general shape of a doubly-truncated cone with an annular surface located on the larger end of the truncated cone and positioned adjacent to the diaphragm. The conical surface of the cone has spaced radial slots or channels formed therein connecting the truncated surfaces of the cone. These channels form air passageways for propagation of sound waves. The walls of the slots or channels are tapered such that the cross-sectional areas of the channels increase from their inlet ends near the speaker diaphragm, towards the outlet ends, positioned at the throat of the horn. The phasing plug provides an improved impedance match between the output of the annular diaphragm and the input of the horn.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.