JPH05236583A - Speaker system - Google Patents

Abstract

PURPOSE:To provide the speaker system with an excellent frequency characteristic having less peak/dip at a low cost without extending the length of a sound tube. CONSTITUTION:The speaker system 10 consists of a 1st sound tube 30 arranged in front of a speaker 20 and a 2nd sound tube 40 connected to the 1st sound tube 30. The 1st sound tube 30 is formed so that the cross sectional area of the 1st sound tube 30 is gradually reduced from a sound tube entrance port 31 toward a sound tube exit 42, and the 2nd sound tube 40 is formed so that the cross sectional area is gradually increased from a connection part 41 toward the sound tube exit 42. Moreover, a shield plate 32 having a throughhole 34 and a couple of adjustment plates 33 are arranged in the vicinity of the middle of the connection 41 and a couple of partition plates 44 to section the inside of the 2nd sound tube 40 and a sound absorbing member 50 are arranged to the 2nd sound tube 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker system having an acoustic tube for guiding sound waves in front of a speaker.

[0002]

2. Description of the Related Art Conventionally, a method in which a horn and an acoustic tube are provided on the front surface of a speaker diaphragm to guide the sound waves generated from the speaker diaphragm to the opening is compared with the case where the horn and the acoustic tube are not used. It is widely used because of its advantages such as large pressure and the ability to transmit sound in a specific direction.

As shown in FIG. 6, a conventional speaker system 1 is composed of a speaker 2 and a horn 3 arranged in front of the speaker 2. A speaker diaphragm 4 is arranged on the front surface of the speaker 2,
An opening as a horn entrance 5 is provided on the front surface of the speaker diaphragm 4, while an opening as a horn exit 6 is provided on the side opposite to the speaker.

The horn 3 is formed so that the cross-sectional area of the opening gradually increases from the horn inlet 5 toward the horn outlet 6. As for the frequency characteristic of the speaker system 1 thus formed, if the length of the horn 3 is sufficiently longer than the wavelength of the band to be reproduced, good frequency characteristic can be obtained.

However, in the above configuration, when the speaker system 1 is incorporated in, for example, a television set, it is not possible to obtain a sufficient horn length with respect to the wavelength. And a reflected wave is generated, resulting in a frequency characteristic with many peaks and dips as shown in FIG.

Therefore, as shown in FIG.
Japanese Laid-Open Patent Publication No. 13998 proposes a speaker system for obtaining good frequency characteristics with a short horn length and a small amount of peak dips.

The speaker system 1'includes a speaker 2
An acoustic tube 7 is provided on the front surface of the speaker diaphragm 4 of
Inside this acoustic tube 7, a horn 3 ′ formed of a sound absorbing material 8 is arranged. The horn 3'is formed such that the sound absorbing material 8 is thin on the horn outlet 6 side and thick on the horn inlet 5 side.

The back cavity of the speaker 2 is omitted in FIGS. 6 and 8.

[0009]

However, in the speaker system as described above, in order to manufacture a large number of horns formed of the sound absorbing material in the same shape, it is necessary to make the amount and density of the sound absorbing material forming the horn uniform. It was difficult to obtain variations in characteristics. Further, in order to keep this characteristic constant, the work becomes complicated, which is a factor of high cost. Further, the speaker system has been upsized in order to fill the inner circumference of the acoustic tube with a sound absorbing material to form a horn.

The present invention eliminates the above-mentioned problems, and an object of the present invention is to provide a speaker system with stable frequency characteristics at low cost without increasing the length of the acoustic tube.

[0011]

A speaker system according to the present invention is a speaker system having an acoustic tube for guiding sound waves to the front surface of a diaphragm of a speaker, in which the cross-sectional area is gradually reduced from the acoustic tube inlet side to the acoustic tube outlet side. And a second acoustic tube which is connected to the first acoustic tube and whose cross-sectional area is gradually increased from the connecting portion with the first acoustic tube toward the acoustic tube outlet. The first acoustic tube and the second
A shielding plate having a through hole arranged in the center of the connecting portion with the acoustic tube, a pair of adjusting plates extending from the connecting portion toward the acoustic tube inlet at both ends of the shielding plate, and the shielding plate. It is provided with a pair of partition plates arranged at both ends from the connecting portion to the vicinity of the acoustic pipe outlet, and a sound absorbing material arranged at the center of the acoustic pipe outlet and in front of the pair of partition plates.

[0012]

In the speaker system having the above structure, the sound wave generated by the diaphragm of the speaker is radiated by gradually reducing the cross-sectional area toward the outlet side of the acoustic tube and guiding it to the first acoustic tube having the adjusting plate. Reduce impedance disturbance. In addition, the first acoustic tube and the second acoustic tube are shielded by a shield plate having a through hole provided at the tip portions thereof, and a sound absorbing material disposed in front of the pair of partition plates at the center of the acoustic tube outlet. By absorbing the reflected wave inside the tube, the generation of standing wave is suppressed and good frequency characteristics with few peaks and dips are achieved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 relate to an embodiment of the present invention. FIG. 1 is a perspective view showing a schematic configuration by cutting a part of a speaker system, and FIG. 2A is a sectional view of the speaker system of FIG. A top view, (b) is a side view of the speaker system in FIG. 1, and FIG. 3 is a characteristic diagram showing frequency characteristics of the speaker in FIG.

The configuration of the speaker system will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the speaker system 10 includes a speaker 20, a first acoustic tube 30 arranged on the front surface of a diaphragm 21 of the speaker 20, and a first acoustic tube 30 connected to the first acoustic tube 30. And two acoustic tubes 40.

In the first acoustic tube 30, the cross-sectional area of the first acoustic tube 30 is directed from the acoustic tube inlet 31 to the tip of the first acoustic tube on the acoustic tube outlet side in order to suppress the disturbance of the radiation impedance. Are formed so that they gradually become smaller. The second acoustic tube 40 that is connected to the first acoustic tube 30 has a cross-sectional area that gradually increases from the connecting portion 41 that is connected to the first acoustic tube tip to the acoustic tube outlet 42. It is formed so that.

Further, the first acoustic tube 30 is provided with a shielding plate 32 having a through hole for guiding a sound wave at a central portion of the connecting portion 41. From both sides of the shielding plate 32 to the acoustic tube entrance 31 side. A pair of adjustment plates 33 are extended, and the adjustment plates 33
By increasing the length of the sound load, the acoustic load is increased.

Further, in the second acoustic tube 40, a pair of partition plates 44 are provided in the vicinity of the acoustic tube outlet 42 side from both sides of the shielding plate 32 arranged so as to be located at the center of the connecting portion 41. A sound absorbing material 50 is disposed in the center of the acoustic tube outlet 42 and in front of the partition plate 44. By changing the size of the through hole 34 of the shield plate 32, the shield plate 32 can suppress the generation of a standing wave due to a reflected wave generated in the acoustic tube. That is, the adjusting plate 33 inside the first acoustic tube 30.
By appropriately setting the length and the area of the through hole 34 of the shield plate 32, it is possible to adjust the acoustic load and change the disturbance of the radiation impedance.

The operation of the speaker system 10 configured as described above will be described. The sound wave radiated from the front surface of the diaphragm 21 of the speaker 20 into the first acoustic tube 30 has a cross-sectional area gradually increasing from the acoustic tube inlet 31 to the acoustic tube outlet 42 side. Increasing the air resistance to the sound pressure in the first acoustic tube 30 by providing the adjusting plate 33 which is formed to be small and has an appropriate size set in the first acoustic tube 30. It is possible to suppress the disturbance of the radiation impedance. Further, the second acoustic sound is provided by the shielding plate 32 having a through hole formed at an appropriate size and arranged at the center of the connecting portion 41 and the sound absorbing material 50 arranged at the center of the acoustic tube outlet 42. By absorbing the reflected wave generated inside the tube 40, the generation of the standing wave is suppressed.

Thus, the speaker system 1 of the present invention
With 0, as shown in FIG. 3, it is possible to obtain frequency characteristics with few peak dips at the acoustic tube outlet 72.

The through holes 34 of the shielding plate 32 may be provided anywhere on the shielding plate, and the number is not limited to one, and a plurality of holes may be provided. Further, in the shielding plate 32, instead of providing the through hole 34, a gap may be provided between the shielding plate 32 and the second acoustic tube 40 or the partition plate 44.

Further, in the speaker system 10, since the sound absorbing material 50 is arranged at the tip of the partition plate 44 at the center of the acoustic tube outlet 42, the sound absorbing material 50 can be easily attached. Further, the first acoustic tube 30 and the second acoustic tube 4
Since 0 can be produced by integral molding, productivity is improved.

Furthermore, the sound absorbing material 50 can be more easily arranged by providing a porous thin plate member or a mesh member having a porosity on the tip side of the partition plate 44. Will be able to.

4 and 5 relate to a modification of this embodiment,
FIG. 4 is a side view of the speaker system, and FIG. 5 is a perspective view of the speaker system.

As shown in FIGS. 4 and 5, the external shape of the speaker system 11 is matched with the internal shape of the television set. Other configurations, operations, and effects are similar to those of the first embodiment.

The back cavity of the speaker 20 is omitted in the drawings of the above-described embodiment and modification.

[0026]

As described above, according to the present invention, it is possible to inexpensively provide a speaker system that stabilizes frequency characteristics without increasing the length of the acoustic tube.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention, and FIG. 1 is a perspective view showing a schematic configuration of a speaker system in a section.

2A is a cross-sectional top view of the speaker system of FIG. 1, and FIG. 2B is a side view of the speaker system of FIG.

FIG. 3 is a characteristic diagram showing frequency characteristics of a speaker.

4 and 5 relate to a modification of the present embodiment, and FIG. 4 is a side view of a speaker system.

FIG. 5 is a perspective view of a speaker system.

6 to 8 relate to a conventional example of the present invention, and FIG. 6 is a side sectional view schematically showing a speaker system.

7 is a characteristic diagram showing frequency characteristics of the speaker system of FIG.

FIG. 8 is a schematic configuration diagram showing an example of a conventional speaker system.

[Explanation of symbols]

 10 ... Speaker system 20 ... Speaker 30 ... 1st acoustic tube 31 ... Acoustic tube inlet 32 ... Shielding plate 33 ... Adjusting plate 36 ... Through hole 40 ... Second acoustic tube 41 ... Connection part 42 ... Acoustic tube outlet 44 ... Partition Plate 50 ... Sound absorbing member

Claims (1)

[Claims] 1. A speaker system having an acoustic tube for guiding sound waves to the front surface of a diaphragm of a speaker, comprising: a first acoustic tube having a cross-sectional area gradually reduced from an acoustic tube inlet side toward an acoustic tube outlet side; A second acoustic tube which is connected to the acoustic tube of (1) and whose cross-sectional area is gradually increased from the connecting portion with the first acoustic tube toward the outlet of the acoustic tube, and the first acoustic tube and the second acoustic tube. A shield plate having a through hole arranged at the center of the connecting portion with the pipe, a pair of adjusting plates extending from the connecting portion toward the acoustic tube entrance direction at both ends of the shielding plate, and at both ends of the shielding plate. A pair of partition plates arranged from the connecting portion to the vicinity of the acoustic tube outlet, and a sound absorbing material arranged in the center of the acoustic tube outlet and in front of the pair of partition plates. Speaker system.