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US 5,261,006 AGranted
Loudspeaker system comprising a helmholtz resonator coupled to an acoustic tube
AssigneeU.S. Philips Corporation
InventorsJoris A. M. Nieuwendijk, Johannes W. T. Bax, Frans A. Westra
Life of this patent
Estimating the term…
Abstract
A loudspeaker system includes a housing (1) having therein at least one loudspeaker (3) which divides the volume of the housing into two parts (V.sub.1, V.sub.2). The first volume (V.sub.1) is coupled, via an aperture in the housing (1), to an acoustic tube (5) which includes a damping element (6). The first volume part (V.sub.1) has a smaller volume than the second volume part (V.sub.2). The damping element is in the form of a Helmholtz resonator.
Claims35
A loudspeaker system comprising:
- a housing which includes at least one acoustic aperture which cooperates with one end of an acoustic tube coupled to 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 with the first volume part 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 in the volume of the Helmoltz resonator, and that the Helmoltz resonator has a Q-factor Q.sub.H, where 0.25.ltoreq.Q.sub.H .ltoreq.2, and is designed to suppress at least the resonance peak of the lowest frequency in the transmission characteristic of the acoustic tube which would otherwise occur in the absence of the Helmoltz resonator.
A loudspeaker system as claimed in claim , wherein Q.sub.H is approximately equal to 1 and the acoustic tube is a relatively long tube having an acoustic transmission characteristic.
A loudspeaker system comprising:
- a housing which includes at least one acoustic aperture which cooperated with one end of an acoustic tube coupled to said aperture, said housing comprising a volume which is divided into a first and a second volume part by a loudspeaker arrangement incorporated in the housing and with the first volume part 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 in a side wall of the tube, 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 which otherwise would occur in the absence of the Helmholtz resonator, wherein the ratio of an area O.sub.1 of the aperture in the side wall of the acoustic tube to a surface area O.sub.2 of a perpendicular cross-section of the acoustic tube is 0.25.ltoreq.O.sub.1 /O.sub.2 .ltoreq.3, and wherein the Helmholtz resonator has a closed volume with an aperture therein acoustically coupled to said aperture in the side wall of the acoustic tube.
A loudspeaker system comprising:
- a housing which comprises a loudspeaker arrangement within the housing and with the housing divided into first and second air chambers wherein the second air chamber is closed and the first air chamber includes at least one acoustic aperture acoustically coupled to one end of a long acoustic tube, a Helmholtz resonator damping device having a closed chamber coupled acoustically in parallel with the acoustic tube via an aperture in the Helmholtz resonator coupled to an aperture in a side wall of the acoustic tube, said aperture in the side wall of the acoustic tube being located at a distance between 0.03 m and 0.5 m from the other end of said acoustic tube, and wherein the Helmholtz frequency of the Helmholtz resonator is equal to or is higher than the lowest resonance peak in the transmission characteristic of the acoustic tube which would otherwise occur in the absence of the Helmholtz resonator.
A loudspeaker system:
- comprising:
- a housing which comprises a loudspeaker arrangement within the housing which divides the housing into first and second air chambers wherein the first air chamber includes at least one acoustic aperture acoustically coupled to one end of an acoustic tube, a Helmholtz resonator damping device having a closed chamber coupled acoustically in parallel with the acoustic tube via an aperture in the Helmholtz resonator coupled to an aperture in a wall of the acoustic tube, wherein the Helmholtz frequency of the Helmholtz resonator is equal to or is higher than the lowest resonance peak in the transmission characteristic of the acoustic tube which would otherwise occur in the absence of the Helmholtz resonator, and the Helmholtz resonator has a Q-factor Q.sub.H, where 0.25.ltoreq.Q.sub.H .ltoreq.2.
A loudspeaker system comprising:
- a housing which comprises a loudspeaker arrangement within the housing which divides the housing into first and second air chambers wherein the first air chamber includes at least one acoustic aperture acoustically coupled to one end of an acoustic tube, a Helmholtz resonator damping device having a closed chamber with an acoustic damping material therein and coupled acoustically in parallel with the acoustic tube via an aperture in the Helmholtz resonator coupled to an aperture in a wall of the acoustic tube, said aperture in the side wall of the acoustic tube being located at a distance X from a sound emitting end of the acoustic tube, where X lies between 0.03 m and 0.5 m, and the ratio of an area O.sub.1 of the aperture in the wall of the acoustic tube to a surface area O.sub.2 of a perpendicular cross-section of the acoustic tube is 0.25.ltoreq.O.sub.1 /O.sub.2 .ltoreq.3, wherein the Helmholtz frequency of the Helmholtz resonator is equal to or is higher than the lowest resonance peak in the transmission characteristic of the acoustic tube which would otherwise occur in the absence of the Helmholtz resonator, and the Helmholtz resonator has a Q-factor Q.sub.H, where 0.25.ltoreq.Q.sub.H .ltoreq.2.
Dependencies are inferred from the claim text.