Speaker system

• US 6,002,781 A
• Filed: 07/19/1995
• Issued: 12/14/1999
• Est. Priority Date: 02/24/1993
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Honda, Kazuki, Takayama, Satoshi
• Primary Examiner(s): LE, HUYEN D
• Application Number:
  US08/504,145
• Time in Patent Office: 1,609 Days
• Field of Search: 381/337, 381/338, 381/345, 381/349, 381/351, 381/FOR 140, 381/FOR 141, 381/FOR 146, 381/353, 381/348, 181/156, 181/185, 181/186, 181/187, 181/189, 181/196, 181/197, 181/199
• US Class Current: 381/338
• CPC Class Codes: H04R 1/2857 for loudspeaker transducers

Abstract

A speaker system comprises an acoustic tube with one end coupled to the back side of the speaker unit and the other end released to a sound field space through an opening window, and at least one air chamber disposed along the acoustic tube. The cross sectional area of the air chamber is larger than the cross sectional area of the acoustic tube, and the cross sectional area of the opening window is smaller than the cross sectional area of the acoustic tube. Therefore, the air chamber forms an acoustic filter so that the higher resonance frequency components in medium and high frequency region caused in the acoustic tube may not be radiated from the opening window, and formation of peaks and bottoms of frequency characteristic due to interference with the sound radiated from the front side of the speaker is prevented. The opening window of a small cross sectional area lowers the resonance frequency of the acoustic tube. Alternatively, the speaker system comprises an acoustic tube with one end coupled to the back side of the speaker unit and the other end released to a sound field space through an opening window, and at least one air chamber disposed along the acoustic tube. The cross sectional area of the air chamber is larger than the cross sectional area of the acoustic tube, and the cross sectional area of the opening window is smaller than the cross sectional area of the acoustic tube. The branch chamber possessing different route lengths causes a phase difference in the acoustic tube to cancel the resonance in the acoustic tube, so that formation of peaks and bottoms in the frequency characteristic may be prevented. An acoustic tube with one end closed and other end coupled to the front side of the speaker, suppresses the amplitude of the diagram of the speaker under low frequency region and the generation of abnormal sound such as speaker bottom beat phenomenon.

Claims

1. A speaker system comprising:

a speaker unit having a front side and a back side,

an acoustic tube with one end coupled to the speaker unit and the other end having an opening window, said acoustic tube having a cross sectional area and said opening window having a cross section area,

the back side of the speaker extending into the acoustic tube, and

at least one air chamber which is a low pass filter situated directly between the end of the acoustic tube coupled to the speaker unit and the end having an opening window so that air flows between the one end and the other end of the acoustic tube via the air chamber, wherein the air chamber has a cross sectional area which is larger than the cross sectional area of the acoustic tube, and the cross sectional area of the opening window is smaller than the cross sectional area of the acoustic tube.

2. A speaker system according to claim 1, wherein a listener hears sound coming from both said speaker unit and said opening window.

3. A speaker system comprising:

a speaker unit having a front side and a back side, the front side of the speaker coupled to an enclosed space,

an acoustic tube with one end coupled to the speaker unit and the other end having an opening window, said acoustic tube having a cross sectional area and the opening window having a cross sectional area,

the back side of the speaker extending into the acoustic tube, and

at least one air chamber directly situated between the end of the acoustic tube coupled to the speaker unit and the end having an opening window so that air flows between the one end and the other end of the acoustic tube via the air chamber, wherein the air chamber has a cross sectional area which is larger than the cross sectional area of the acoustic tube, and the cross sectional area of the opening window is smaller than the cross sectional area of the acoustic tube.

4. A speaker system according to claim 3, wherein said air chamber is a low pass filter.

5. A speaker system according to claim 3, wherein a listener hears sound coming from both said speaker unit and said opening window.

6. A speaker system comprising:

a speaker unit having a front side and a back side,

an acoustic tube with one end having an opening window, the back side of the speaker extending into the acoustic tube, said acoustic tube having a cross sectional area and the opening window having a cross sectional area, and

at least one air chamber which is a low pass filter and a bypass chamber situated between the end of the acoustic tube having the opening window and the back side of said speaker extending into said acoustic tube so that air flows between the one end and the other end of the acoustic tube via the air chamber, wherein the air chamber has a cross sectional area which is larger than the cross sectional area of the acoustic tube, the cross sectional area of the opening window is smaller than the cross sectional area of the acoustic tube, and the bypass chamber includes a bypass route extending from one location on the acoustic tube to another location on the acoustic tube.

7. The speaker system of claim 6 further including a further bypass route, said bypass route and said further bypass route having different lengths.

8. A speaker system according to claim 6, wherein a listener hears sound coming from both said speaker unit and said opening window.

9. A speaker system comprising:

a speaker unit having a front side and a back side, the front side of the speaker coupled to an enclosed space,

an acoustic tube with one end having an opening window, the back side of the speaker extending into the acoustic tube, said acoustic tube having a cross sectional area and said opening window having a cross sectional area, and

at least one air chamber and a bypass chamber are disposed between the end of the acoustic tube having an opening window and the back side of said speaker extending into said acoustic tube so that air flows between the one end and the other end of the acoustic tube via the air chamber, said at least one air chamber having a cross sectional area which is larger than the cross sectional area of the acoustic tube, the cross sectional area of the opening window is smaller than the cross sectional area of the acoustic tube, and the bypass chamber includes a bypass route extending from one location on the acoustic tube to another location on the acoustic tube.

10. The speaker system of claim 9 further including a further bypass route, said bypass route and said further bypass route having different lengths.

11. A speaker system according to claim 9, wherein said air chamber is a low pass filer.

12. A speaker system according to claim 9, wherein a listener hears sound coming from both said speaker unit and said opening window.