JPH0797879B2 - Speaker device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker device in which an acoustic tube for guiding sound waves is arranged on the front surface of a speaker diaphragm.

2. Description of the Related Art A method in which a horn and an acoustic tube are provided on the front surface of a speaker diaphragm and the sound waves generated from the diaphragm are guided to the opening can obtain a larger output sound pressure than when a horn or acoustic tube is not used. Also, it has the advantage that sound can be transmitted in a specific direction, and has been widely used.

Hereinafter, a conventional speaker device using a horn and an acoustic tube will be described with reference to the drawings.

FIG. 6 shows a sectional view of the speaker device. In FIG. 6, 1 is a speaker unit, 2 is a baffle plate on which the speaker unit 1 is mounted, 3 is a rear box provided on the back surface of the speaker unit 1, and 4 is provided on the front surface of the baffle plate 2 on which the speaker unit 1 is mounted. The acoustic tube 5 is a sound guide portion constituted by the acoustic tube 4.

The operation of the speaker device having the horn and the acoustic tube configured as described above will be described below with reference to FIG.
FIG. 7 is a perspective view of the acoustic tube section showing the configuration of the acoustic tube section in a partial sectional view. The hole 6 provided at the center of the baffle plate 2 allows the sound wave radiated from the speaker unit 1 to pass through the acoustic tube 4.
The acoustic tube 4 has a small baffle dimension L1 on the front surface of the speaker unit 1 and a small baffle area. As the acoustic tube 4 approaches the opening of the acoustic tube 4, the acoustic tube opening dimension L2 gradually increases. And the acoustic tube cross-sectional area is increased. If the length L3 of the acoustic tube 4 is sufficiently longer than the wavelength of the reproduction band to be reproduced, the reproduced sound pressure frequency characteristic is flat.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in order to be incorporated in a device with the above-described configuration, it is often not possible to sufficiently lengthen the acoustic tube length, and the acoustic tube opening cross-sectional area is set to the baffle area of the front surface of the speaker unit 1. In many cases, it cannot be taken sufficiently larger than.

For example, FIG. 8 is a perspective view of an acoustic tube portion in which the acoustic tube opening has a long and thin rectangular shape in consideration of incorporation into a device. L4
Indicates the dimensions of the rectangular side of the acoustic tube opening. Compared to the baffle dimension L1 of the speaker unit mounting surface, the acoustic tube opening dimension L4
Is small, even if the area of the acoustic tube opening is larger than the area of the baffle on the front surface of the speaker unit, the sound conducting section 5 often has a structure in which it is once narrowed on the way from the front surface of the speaker unit to the acoustic tube opening. . That is, since the acoustic tube cross-sectional area is once reduced, one acoustic space is formed in the front surface of the speaker unit, and the acoustic tube 4 is attached to the tip of the acoustic space. FIG. 9 shows a reproduced sound pressure frequency characteristic diagram of a speaker device having a horn and an acoustic tube. The characteristic of A in the figure is a characteristic diagram of the speaker device with the conventional horn and the acoustic tube shown in FIG. 6, and the characteristic of B in the figure is the speaker apparatus in the case of the acoustic tube shape shown in FIG. FIG. In the case of the acoustic tube shape shown in FIG. 8,
Since one acoustic space formed on the front surface of the speaker unit acts as the compliance C, the high frequency characteristic is reduced as shown in the characteristic of FIG. 9B, and the acoustic tube length is shortened. The change in the acoustic impedance that occurs at the position becomes large, and a part of the sound wave guided to the opening is generated as a reflected wave inside the acoustic tube, resulting in a characteristic with many peak dips. Further, in the case of the conventional speaker device having the above-mentioned configuration, the high frequency characteristic is reduced, so that it is necessary to use a tweeter in charge of reproducing the sound range as the sound reproducing device.

The present invention solves such a problem, and even in a speaker device having a horn or an acoustic tube whose opening has a long and narrow rectangular shape in consideration of incorporation into a device, a decrease in high frequency characteristics is small, and further An object of the present invention is to provide a speaker device capable of obtaining a flat sound pressure frequency characteristic without a peak dip.

Means for Solving the Problem In order to solve the problem, the present invention arranges an acoustic tube for guiding a sound wave having a long and narrow opening in a front surface of a speaker unit. The area of the front surface is small, and the area increases as it approaches the opening, and the speaker unit is configured to have an elliptical cone-shaped diaphragm.
The speaker unit also has an elliptical shape, and is arranged so that the long side direction of the acoustic tube opening and the long side direction of the elliptical speaker unit coincide with each other, so that the tip opening of the acoustic tube and the diaphragm of the speaker unit. The distance from the surface is different at each point.

Operation With this configuration, an elliptical speaker unit having an elliptical cone-shaped diaphragm is used even in a speaker device having a horn or an acoustic tube whose opening has a long and narrow rectangular shape in consideration of incorporation into a device. At the same time, by adopting a configuration in which the long side direction of the speaker unit and the long side direction of the acoustic tube opening are arranged to coincide with each other, the area of the front surface of the speaker unit can be reduced, so that the compliance C on the front surface of the speaker unit can be reduced. The working acoustic space can be made extremely small, and the area of the sound conducting section can be increased as the distance from the front of the speaker unit to the opening is increased. Therefore, the high frequency characteristics can be maintained without changing the shape of the opening and the length of the horn and the acoustic tube. It is possible to obtain a flat sound pressure frequency characteristic with less decrease in peak dip. Speaker apparatus only, without the need for a combination of tweeters, etc. responsible for range reproduction, so that the satisfactory as an acoustic reproducing apparatus.

Embodiments Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals as those in FIGS. 6 to 9 indicate the same parts.

FIG. 4 is a perspective view of the acoustic tube portion in one embodiment of the present invention. In FIG. 4, 7 is a baffle plate for attaching an elliptical speaker unit having a hole for guiding a sound wave radiated from the speaker unit to the acoustic tube 4, and 5 is a sound guide part for guiding a sound wave having a rectangular opening. The area of the sound guide portion 5 is small on the front surface of the speaker unit, and the area increases as it approaches the opening. FIG. 5 is a front view showing a state in which the elliptical speaker unit 8 is attached to the baffle plate 7 which constitutes the acoustic tube portion of the present invention shown in FIG.

The operation of the speaker device having the acoustic tube portion of the present invention configured as described above will be described with reference to FIGS. 1 to 3.

FIG. 1 shows an acoustic tube portion according to an embodiment of the present invention,
FIG. 2 is a cross-sectional view of an open rear speaker device, FIG.
FIG. 3 is a diaphragm cross-sectional view showing a diaphragm shape of an elliptical speaker unit composed of the cone-shaped diaphragm shown in FIG. 3, taken along line XX, and FIG. 3 is an elliptical speaker unit composed of the cone-shaped diaphragm. 3 is a cross-sectional view of the diaphragm, showing the section along line YY.

In the speaker device of FIG. 1, the shape of the diaphragm 9 of the elliptical speaker unit 8 attached to the baffle plate 7 is different from the long side direction to the short side direction as shown in FIGS. 2 and 3. Further, by arranging so that the long side direction of the opening of the acoustic tube 4 and the long side direction of the elliptical speaker unit 8 are aligned, the standing wave generated inside the acoustic tube 4 is suppressed. And a flat sound pressure frequency characteristic with few peak dips can be obtained. Further, particularly by using the elliptical speaker unit 8, it is possible to increase the radiation area of the sound conducting portion 5 as the front surface of the elliptical speaker unit 8 approaches the opening, and the elliptical speaker unit 8 has a larger emission area. The acoustic space acting as the compliance C can be reduced, and further, unlike the axially symmetric shape of the diaphragm of the conventional round speaker unit, the respective surfaces constituting the diaphragm 9 are different from the long side direction to the short side direction. In addition to obtaining the sound pressure frequency characteristic with little decrease in the high frequency characteristic, there is also an effect that there is little reduction in the directivity characteristic on the left and right in the long side direction of the opening.

As described above, according to the present embodiment, the elliptical speaker unit 8 is provided with the acoustic tube 4 configured such that the front surface of the speaker unit has a small area and the area increases as it approaches the opening. The sound wave can be naturally guided to the opening of the tube 4 without resistance, flat characteristics can be obtained even in a high frequency region, and a speaker device with high clarity can be realized.

In one embodiment, FIG. 1 is an open rear type,
It goes without saying that the same effect can be obtained even when the speaker device is of the closed-back type and the bass reflex type.

EFFECTS OF THE INVENTION As described above, according to the present invention, an acoustic tube for guiding a sound wave having a rectangular opening is arranged on the front surface of the speaker unit. And an arrangement in which the speaker unit has an elliptical shape and the long side direction of the acoustic tube opening and the long side direction of the elliptical speaker unit coincide with each other. By doing so, even in a speaker device in which the acoustic tube opening has a long and narrow rectangular acoustic tube in consideration of incorporation into a device, the acoustic space that acts as the compliance C on the front surface of the speaker unit can be reduced, and from the front surface of the speaker unit. Since the area of the sound conducting section can be naturally increased without resistance as it approaches the opening, there is little decrease in high frequency characteristics and peak A flat sound pressure frequency characteristic with little increase is obtained,
Consequently, it is possible to obtain an effect that a speaker device with good clarity can be obtained without using a tweeter or the like together.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rear open speaker device provided with an acoustic tube according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a diaphragm shape in the long side direction of an elliptical speaker unit. Is a cross-sectional view showing the shape of a diaphragm in the short side direction of an elliptical speaker unit, FIG. 4 is a perspective view of an acoustic tube portion according to one embodiment of the present invention, and FIG. 5 is a acoustic tube portion according to one embodiment of the present invention. A front view, FIG. 6 is a cross-sectional view of a speaker device having a conventional horn and an acoustic tube, and FIG. 7 is a partial cross-sectional view of the configuration of the conventional acoustic tube shown in FIG. FIG. 8 is a perspective view of a conventional acoustic tube portion in which the acoustic tube opening has a long and thin rectangular shape, and FIG. 9 is a characteristic diagram of a speaker device having a horn and an acoustic tube. 4 ... Acoustic tube, 5 ... Sound conducting part, 7 ... Baffle plate, 8 ...
... Elliptical speaker unit, 9 ... Diaphragm.

Claims (1)

[Claims] 1. An elliptical speaker unit has a front surface on which an acoustic tube for guiding a sound wave having a long and narrow opening is arranged. The acoustic tube has a small area on the front surface of the elliptical speaker unit. The elliptical speaker unit is configured to have an elliptical cone-shaped diaphragm so that the area increases as it approaches, and the long side direction of the acoustic tube opening and the long side direction of the elliptical speaker unit. A speaker device in which the distance between the tip opening of the acoustic tube and the diaphragm surface of the elliptical speaker unit is different at each point by arranging so as to match.