Patent EP0295641A2 successfully refreshed from Google Patents.
EP0295641A2
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EP
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Loudspeaker system
Assignee: Panasonic Holdings Corp
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Filing: 1988-06-15
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Granted: —
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Expires: 2008-06-15
Abstract
Abstract A loudspeaker system which comprises a loudspeaker unit for radiating a first sound, a horn unit having a throat coupled to the back of the loudspeaker for radiating a second sound, and an acoustic filter provided in the horn for causing an acoustic impedance of the horn unit to be discontinuous. When the minimum frequency of cyclic dales of the sound pressure observed in the characteristic curves of a sound pressure of a composite of the first and second sounds as a result of a phase delay brought about by the length of the horn unit is expressed by fd, a primary harmonic resonance can be produced between the loudspeaker unit and the acoustic filter which is similar to that produced by a straight acoustic tube having its opposite ends closed, thereby to render the frequency of the primary resonance to be generally equal to the frequency fd.
Inventors
- 👤 Syuji Saiki
- 👤 Kazue Sato
- 👤 Kazuki Honda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 20:14
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2853; H04R1/2857; H04R1/2861; H04R1/2865; H04R1/283; H04R1/2834
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
155 words
A loudspeaker system which comprises a loudspeaker unit for radiating a first sound, a horn unit having a throat coupled to the back of the loudspeaker for radiating a second sound, and an acoustic filter provided in the horn for causing an acoustic impedance of the horn unit to be discontinuous, whereby in a characteristic curve of a sound pressure induced by a composite of the first and second sounds, and when the minimum frequency of cyclic dales of the sound pressure observed in the characteristic curves as a result of a phase delay brought about by the length of the horn unit is expressed by fd, a primary harmonic resonance can be produced between the loudspeaker unit and the acoustic filter which is similar to that produced by a straight acoustic tube having its opposite ends closed, thereby to render the frequency of the primary resonance to be generally equal to the frequency fd.
Claim 2
Dependent Claim
155 words
A loudspeaker system which comprises a loudspeaker unit for radiating a first sound, a horn unit having a throat coupled to the back of the loudspeaker for radiating a second sound, and an acoustic filter provided in the horn for causing an acoustic impedance of the horn unit to be discontinuous, whereby in a characteristic curve of a sound pressure induced by a composite of the first and second sounds, and when the minimum frequency of cyclic dales of the sound pressure observed in the characteristic curves as a result of a phase delay brought about by the length of the horn unit is expressed by fd, a primary harmonic resonance can be produced between the loudspeaker unit and the acoustic filter which is similar to that produced by a straight acoustic tube having its opposite ends closed, thereby to render the frequency of the primary resonance to be generally equal to the frequency fd.
Claim 3
Dependent Claim
39 words
The loudspeaker system as claimed in Claim 1, wherein the acoustic filter is disposed at a position spaced from the throat of the horn unit a distance generally equal to one half of the wavelength of the frequency fd.
Claim 4
Dependent Claim
30 words
The loudspeaker system as claimed in Claim 1, wherein a portion of the horn unit adjacent the throat thereof is comprised of a plurality of horn sections of different lengths.
Claim 5
Dependent Claim
22 words
The loudspeaker system as claimed in Claim 3, wherein the acoustic filter is disposed within the opposite portion of the horn unit.
Claim 6
Dependent Claim
57 words
The loudspeaker system as claimed in Claim 3, wherein, when the respective lengths of the horn sections of different length are expressed by L1 and L2 and the length of said other portion of the horn unit is expressed by L3, the ratio of (L1 + L3)/(L2 + L3) is within the range of 1.1 to 2.
Claim 7
Dependent Claim
28 words
The loudspeaker system as claimed in Claim 1, wherein the acoustic filter is constituted by a throat having a cross-sectional area smaller than that of the horn unit.
Claim 8
Dependent Claim
49 words
The loudspeaker system as claimed in Claim 1, wherein the acoustic filter is a drone cone which comprises a shielding plate operable to acoustically shield the interior of the horn unit and a vibratory plate supported by a suspension and disposed at a central portion of the shielding plate.
References Cited (Backward Citations)
No citation records indexed.
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