JPH05137188A - Speaker system - Google Patents

Abstract

PURPOSE:To provide the inexpensive speaker system where the frequency characteristic is stabilized without extending the length of an acoustic tube. CONSTITUTION:In a speaker system 21, a speaker diaphragm 23 is arranged on the front of a speaker unit 22, and an acoustic tube 24 is arranged on the front of the speaker diaphragm 23. The acoustic tube 24 is so formed that its sectional area is gradually increased from an acoustic tube entrance 25 on the speaker side toward an acoustic tube exit 26 on the opposite side, and a sound absorber 28 is provided on the same axis as the speaker unit 22 in the vicinity of the center of a front end frame 27 of the acoustic tube 24.

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 or an acoustic tube is provided on the front surface of a speaker diaphragm to guide a sound wave generated from the speaker diaphragm to the opening is output as compared with the case where a horn or an acoustic tube is not used. It is widely used because of its advantages such as large sound pressure and the ability to transmit sound in a specific direction.

As shown in FIG. 5, a conventional speaker system 1 includes a speaker unit 2, a speaker diaphragm 3 in front of the speaker unit 2, and a speaker diaphragm 3.
And a horn 4 disposed on the front surface of the. The horn 4 is provided with an opening as a horn entrance 5 on the speaker side and an opening as a horn exit 6 on the opposite speaker side.

The horn 4 is formed such 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 formed in this way, if the length of the horn 4 is sufficiently longer than the wavelength of the band to be reproduced, a flat frequency characteristic can be obtained.

However, with the above-described structure, the length of the horn 4 cannot be set to a sufficient length when incorporated in a device, so that the frequency characteristic has many peak dips as shown in FIG. It was a thing.

Therefore, in order to obtain a flat frequency characteristic with less peak and dip with a shorter horn 4 or an acoustic tube than before, for example, in Japanese Patent Laid-Open No. 63-313998, the front surface of the speaker diaphragm of the speaker unit is disclosed. In FIG. 1, a horn formed of a sound absorbing material is provided. Since the horn is formed such that the sound absorbing material is thin on the horn outlet side and thicker on the horn inlet side, it is difficult to process many horns having the same shape. Since it is arranged on almost the entire surface, there is a problem of increasing the size.

Further, in Japanese Unexamined Patent Publication No. 1-276997, as shown in FIG. 7, an acoustic tube 9 for guiding sound waves is arranged in front of the low-pitched speaker unit 7 and the high-pitched speaker unit 8, and the It is shown that a partition plate 12 having slits 10 and 11 is provided in a portion of the tube 9 that is one-third of the acoustic tube length from the speaker unit side and in the opening portion on the tip side. Slit 1 in the partition plate 12
When 0 and 11 are provided, a part of the sound wave guided to the opening on the side opposite to the speaker unit becomes a reflected wave and is returned to the front surface of the diaphragm of the bass and treble speaker units 7 and 8. In addition, the sound absorbing member 13 arranged inside the acoustic tube 9 absorbs the reflected wave and
It is designed to prevent standing waves from being generated inside.

The back cavity is omitted in FIGS. 5 and 7 described above.

[0009]

However, in the speaker system as described above, variations in characteristics occur or the characteristics are made constant depending on how the sound absorbing material is inserted between the acoustic tube and the partition plate. Therefore, the work becomes complicated and the cost is high. Further, since the bass speaker and the treble speaker are provided in the same horn, the sound wave of the bass speaker may interfere with the treble speaker.

The present invention eliminates the above-mentioned problems, and an object of the present invention is to provide a speaker system which stabilizes frequency characteristics without increasing the length of sound or the like and is inexpensive in cost.

[0011]

The speaker system according to the present invention is a speaker system having an acoustic tube for guiding sound waves to the front surface of the diaphragm of the speaker unit, and the cross-sectional area gradually increases from the acoustic tube inlet to the acoustic tube outlet. And a sound absorbing material arranged in the center of the speaker unit in front of the speaker unit and on the outlet side of the sound tube.

[0012]

In the speaker system having the above structure, the sound wave generated by the diaphragm of the speaker is guided to the acoustic tube outlet, and a reflected wave is generated because the acoustic impedance at the acoustic tube outlet is large. Since this reflected wave is absorbed by the sound absorbing material provided coaxially with the central axis of the speaker unit at the end frame of the acoustic tube outlet, the frequency characteristic becomes flat with few peaks and dips.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 relate to an embodiment of the present invention.
Is a sectional view of the speaker system, and FIG. 2 is a characteristic diagram showing frequency characteristics of the speaker of the present invention.

The configuration of the speaker system will be described with reference to FIG. As shown in the figure, the speaker system 21 is
A speaker diaphragm 23 is arranged on the front surface of the speaker unit 22, and an acoustic tube 24 is arranged on the front surface of the speaker diaphragm 23. The acoustic tube 24 is formed such that the cross-sectional area of the acoustic tube 24 gradually increases from the acoustic tube inlet 25 on the speaker side toward the acoustic tube outlet 26 on the opposite speaker side. A sound absorbing material 28 is provided on the central portion of the tip frame 27 of the acoustic tube 24 and on the central axis of the speaker unit 22.

The operation of the speaker system 21 configured as above will be described. The sound wave radiated from the front surface of the diaphragm 23 of the speaker unit 22 is guided to the sound tube outlet 26 through the sound tube 24 and radiated. Then, a reflected wave is generated at the acoustic tube outlet 26 due to a rapid change in acoustic impedance. The reflected wave is absorbed by the sound absorbing material 28 provided on the tip frame 27 of the acoustic tube 24, so that the standing wave inside the acoustic tube 24 is prevented from being generated. As shown in FIG. 2, in the speaker system 21 of the present invention, the sound absorbing material 2 is attached to the tip frame 27 of the acoustic tube 24.
By providing No. 8, flat frequency characteristics with few peak dips are shown.

As described above, the speaker system 21
The position of the sound absorbing material 28 provided in the speaker system 21 is set to one position in the tip frame 27, and the tip frame 2
Since it is set coaxially with the central axis of the speaker unit 22 of No. 7, it is possible to easily attach the sound absorbing material 28 at a predetermined position accurately. As a result, it is possible to stably supply a speaker system having frequency characteristics with few peak dips.

FIG. 3 relates to the second embodiment, (a) is a sectional view of the speaker system, and (b) is a perspective view of the speaker system.

As shown in FIG. 3, the high-pitched speaker unit 31 is arranged at the position of the sound absorbing material 28 provided in the first embodiment, while the high-pitched loudspeaker unit 31 is coaxially arranged behind the high-pitched speaker unit 31. Material 28 is provided. Other configurations are similar to those of the first embodiment.

The operation of the speaker system 21 configured as above will be described. Speaker unit 2
The sound wave radiated from the front surface of the vibrating plate 23 of
Through the acoustic tube outlet 26 and emitted.
A reflected wave is generated at the acoustic tube outlet 26 due to a rapid change in acoustic impedance. This reflected wave is absorbed by the sound absorbing material 28. Further, at this time, the high frequency component of the speaker unit 22 is also cut, so that the acoustic tube 2
Since there is no interference with the high-frequency speaker 31 provided on the front end frame 27 of No. 4, a good speaker system can be obtained. Other operations and effects are similar to those of the first embodiment.

FIG. 4 relates to a modification of the second embodiment,
(A) is a side view of a speaker system, (b) is a top view of a speaker system.

As shown in FIG. 7A, the sound absorbing material 28 of this embodiment is not on the same axis as the speaker unit 22 as in the first and second embodiments, but as shown in FIG. To
It is provided in the space of the first partition plate 32 located in front of the speaker unit 22 at the center of the acoustic tube outlet side 26. Further, a second partition plate 33 is provided behind the first partition plate 32. Other configurations, operations and actions are the same as those in the above-mentioned embodiment.

The partition plates 32 and 33 are preferably mesh plates or mesh members so that the sound absorbing effect is enhanced.

Further, the back cavity is omitted in the drawings of the above-mentioned first embodiment, second embodiment and modification of the second embodiment.

[0024]

As described above, according to the present invention, the reflected wave generated due to the large change in the acoustic impedance at the outlet of the acoustic tube is absorbed by the sound absorbing material provided on the end frame of the acoustic tube. The speaker system can have a flat frequency characteristic with less peak dip.

[Brief description of drawings]

1 and 2 relate to an embodiment of the present invention,
Figure 1 is a sectional view of the speaker system

FIG. 2 is a characteristic diagram showing frequency characteristics of a speaker.

FIG. 3 relates to a second embodiment. (A) is a cross-sectional view showing a schematic configuration of a speaker system (b) is a perspective view of the speaker system

FIG. 4 is a side view illustrating an outline of a speaker system according to a modification of the second embodiment, and FIG. 4B is a plan view illustrating an outline of the speaker system.

FIG. 5 is a schematic configuration diagram of a conventional speaker system.

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

FIG. 7 is a schematic configuration diagram showing an example of a conventional speaker system.

[Explanation of symbols]

 21 ... Speaker System 22 ... Speaker Unit 24 ... Acoustic Tube 26 ... Acoustic Tube Exit 27 ... Tip Frame 28 ... Sound Absorbing Material

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 unit, wherein an acoustic tube having a cross-sectional area gradually increasing from an acoustic tube inlet to an acoustic tube outlet, and in front of the speaker unit. A speaker system, comprising: a sound absorbing material disposed in a central portion on the outlet side of the acoustic tube.