EP0429121A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Loudspeaker system comprising a Helmholtz resonator coupled to an acoustic tube
Assignee: Koninklijke Philips NV
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Filing: 1990-11-12
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Granted: —
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Expires: 2010-11-12
Abstract
Abstract The loudspeaker system comprises a housing (1) having therein at least one loudspeaker (3) which divides the volume of the housing into two parts (V₁, V₂). The first volume (V₁) is coupled, via an aperture in the housing (1), to an acoustic tube (5) which comprises damping means (6). The first volume part (V₁) has a smaller volume than the second volume part (V₂). The damping means are in the form of a Helmholtz resonator.
Inventors
- 👤 Joris Adelbert Maria Nieuwendijk
- 👤 Johannes Wilhelmus Theodorus Bax
- 👤 Johannes Josephus Martines Kamphues
- 👤 Frans Alexander Westra
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 17:15
CPC Classifications
H; H04; H04R; H04R5/00; H04R5/02; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2838; H04R1/2846; H04R1/2849; H04R1/227; H04R1/32; H04R1/34; H04R1/345
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
133 words
A loudspeaker system comprising a housing in which at least one acoustic aperture is provided which cooperates with one end of an acoustic tube coupled to the said aperture, which housing comprises a volume which is divided into a first and a second volume part by a loudspeaker arrangement incorporated in the housing and the first volume part is coupled acoustically to the acoustic aperture in the housing, characterized in that the acoustic tube comprises damping means comprising a Helmholtz resonator in the form of a closed volume which is coupled acoustically parallel to the acoustic tube via an aperture, and that the Helmholtz resonator is designed to suppress at least the resonance peak of the lowest frequency in the transmission characteristic of the acoustic tube, in the absence of the Helmholtz resonator.
Claim 2
Dependent Claim
133 words
A loudspeaker system comprising a housing in which at least one acoustic aperture is provided which cooperates with one end of an acoustic tube coupled to the said aperture, which housing comprises a volume which is divided into a first and a second volume part by a loudspeaker arrangement incorporated in the housing and the first volume part is coupled acoustically to the acoustic aperture in the housing, characterized in that the acoustic tube comprises damping means comprising a Helmholtz resonator in the form of a closed volume which is coupled acoustically parallel to the acoustic tube via an aperture, and that the Helmholtz resonator is designed to suppress at least the resonance peak of the lowest frequency in the transmission characteristic of the acoustic tube, in the absence of the Helmholtz resonator.
Claim 3
Dependent Claim
24 words
A loudspeaker system as claimed in Claim 1, characterized in that an acoustically damping material is incorporated in the volume of the Helmholtz resonator.
Claim 4
Dependent Claim
38 words
A loudspeaker system as claimed in Claim 1 or 2, characterized in that the aperture in the volume of the Helmholtz resonator otherwise closed is coupled acoustically to an aperture in the side wall of the acoustic tube.
Claim 5
Dependent Claim
50 words
A loudspeaker system as claimed in Claim 3, characterized in that the aperture in the side wall of the acoustic tube is provided at a distance x from the sound emanating end of the acoustic tube, and that x is a value which lies between 0.03 m and 0.5 m.
Claim 6
Dependent Claim
57 words
A loudspeaker system as claimed in any of the Claims 2 to 4, characterized in that the Helmholtz frequency of the Helmholtz resonator is at least approximately equal to or is higher than the lowest resonance peak in the transmission characteristic of the acoustic tube which would otherwise be formed in the absence of the Helmholtz resonator.
Claim 7
Dependent Claim
44 words
A loudspeaker system as claimed in any of the Claims 2 to 5, characterized in that such an acoustically damping material has been chosen that the Helmholtz resonator has a Q-factor Q H for which it holds that 0.25 ≦ Q H ≦ 2.
Claim 8
Dependent Claim
20 words
A loudspeaker system as claimed in Claim 6, characterized in that Q H is at least approximately equal to 1.
Claim 9
Dependent Claim
52 words
A loudspeaker system as claimed in any of the preceding Claims, characterized in that the area O₁ of the aperture in the side wall of the acoustic tube stands to the surface area O₂ of a perpendicular cross-section of the acoustic tube according to the following equation: 0.25 ≦ O₁/O₂ ≦ 3.
Claim 10
Dependent Claim
23 words
A loudspeaker system as claimed in Claim 8, characterized in that the area O₁ is at least approximately equal to the area O₂.
Claim 11
Dependent Claim
67 words
A loudspeaker system as claimed in any of the preceding Claims, characterized in that the first volume part is coupled acoustically to a second acoustic aperture in the housing, that the said second acoustic aperture cooperates with one end of a second acoustic tube coupled to the said aperture, and that the said second acoustic tube also comprises damping means in the form a of Helmholtz resonator.
Claim 12
Dependent Claim
21 words
A loudspeaker system as claimed in any of the preceding Claims, characterized in that the loudspeaker arrangement comprises two cascade-arranged loudspeakers.
Claim 13
Dependent Claim
55 words
A loudspeaker system as claimed in any of the preceding Claims, characterized in that it is incorporated in a housing of a consumer apparatus, for example, a television set, and that the housing of the loudspeaker system is coupled to the housing of the consumer apparatus via second damping means for realising a vibration damping.
Claim 14
Dependent Claim
31 words
A loudspeaker system as claimed in Claim 12, characterized in that the other end(s) of the acoustic tube(s) is (are) coupled to (an) aperture(s) in the housing of the consumer apparatus.
Claim 15
Dependent Claim
36 words
A loudspeaker system as claimed in Claim 13, characterized in that the other end of an acoustic tube is coupled to the housing of the consumer apparatus via third damping means for realising a vibration damping.
Claim 16
Dependent Claim
43 words
A loudspeaker system as claimed in any of the preceding Claims, characterized in that at least that part of an acoustic tube which is present near the other end has a cross-section which becomes larger in the direction of the said other end.
Claim 17
Dependent Claim
65 words
A loudspeaker system as claimed in any of the preceding Claims, characterized in that the second volume part is coupled acoustically to an acoustic aperture in the housing of the loudspeaker system, that the same acoustic aperture cooperates with one of an acoustic tube coupled to the said aperture, and that the said tube also comprises damping means in the form of a Helmholtz resonator.
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