speaker equipment

Abstract

A speaker device (100) comprising: a first speaker unit (101); a first cabinet (111); a second speaker unit (102) disposed coaxially with the first speaker unit (101); a second cabinet (121) disposed between the first speaker unit (101) and the second speaker unit (102) and supporting the second speaker unit (102), the second speaker unit (102) being contained in the second cabinet (121); and a resonator (103) disposed between the first speaker unit (101) and the second cabinet (121) and having an opening (131) opening toward a diaphragm of the first speaker unit (101).

Description

Technical Field

[0001] The present invention relates to a speaker device, and more particularly to a speaker device in which a second speaker unit is disposed in front of a first speaker unit.

Background Art

[0002] Conventionally, there has been a so-called coaxial speaker device in which a pair of speaker units are arranged coaxially. In order to adjust the frequency characteristics of such a speaker device, a technique of arranging a Helmholtz resonator between a pair of speaker units has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003] [[ID=Z2]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in order to reduce intermodulation distortion, the structure of a conventional coaxial speaker device becomes complicated, and it has been difficult to effectively reduce intermodulation distortion with a simple structure.

[0005] The present invention is based on the findings discovered as a result of the inventor's intensive experiments and research on the above problems, and aims to provide a speaker device capable of reducing intermodulation distortion with a simple configuration.

Means for Solving the Problems

[0006] To achieve the above objective, one speaker device of the present invention comprises: a first speaker unit; a first cabinet supporting the first speaker unit; a second speaker unit positioned on the sound-radiating side of the first speaker unit and radiating sound in the same direction as the first speaker unit; a second cabinet positioned between the first speaker unit and the second speaker unit and supporting the second speaker unit; and a resonator positioned between the first speaker unit and the second cabinet and having an opening that opens toward the diaphragm of the first speaker unit. [Effects of the Invention]

[0007] According to the present invention, it is possible to adjust the frequency characteristics with a simple configuration and effectively reduce intermodulation distortion and other issues. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing the external appearance of the speaker device in this embodiment. [Figure 2] Figure 2 is a cross-sectional perspective view showing the inside of the speaker device in this embodiment. [Figure 3] Figure 3 is a cross-sectional view showing the speaker unit portion of the speaker device in this embodiment. [Figure 4] Figure 4 is a perspective view showing the resonator and second cabinet in this embodiment, with baffle plates and other components omitted. [Figure 5] Figure 5 is a perspective view showing another example of a resonator (Example 1). [Figure 6] Figure 6 is a perspective view showing another example of a resonator (Example 2). [Figure 7] Figure 7 is a perspective view showing a resonator with a damping cloth attached to the opening. [Figure 8] Figure 8 is a graph showing the effect of the resonator. [Modes for carrying out the invention]

[0009] The following describes embodiments of the speaker device according to the present invention with reference to the drawings. The following embodiments are provided as examples to illustrate the present invention and are not intended to limit it. For example, the shapes, structures, materials, components, relative positional relationships, connection states, numerical values, formulas, the content of each step in the method, and the order of each step shown in the following embodiments are examples and may include content not described below. Furthermore, geometric expressions such as parallel and orthogonal may be used, but these expressions do not indicate mathematical rigor and include substantially acceptable errors and deviations. Similarly, expressions such as simultaneous and identical also include substantially acceptable ranges.

[0010] Furthermore, the drawings are schematic diagrams that have been appropriately emphasized, omitted, or had their proportions adjusted to illustrate the present invention, and therefore do not represent the actual shape, positional relationships, or proportions.

[0011] Furthermore, in the following, multiple inventions may be described comprehensively as a single embodiment. Also, some of the content described below is described as an optional component relating to the present invention.

[0012] Figure 1 is a perspective view showing the external appearance of the speaker device in this embodiment. Figure 2 is a cross-sectional perspective view showing the interior of the speaker device in this embodiment. Figure 3 is a cross-sectional view showing the speaker unit portion of the speaker device in this embodiment.

[0013] As shown in these figures, the speaker device 100 is a speaker in which two speaker units are arranged side by side in the front-to-back direction (X-axis direction in the figures), and comprises a first speaker unit 101, a second speaker unit 102, a first cabinet 111, a second cabinet 121, and a resonator 103.

[0014] The first speaker unit 101 is a speaker designed to be responsible for radiating sounds in a lower frequency range than the second speaker unit 102, and includes a vibration system having a diaphragm 112 and a voice coil 113, a magnetic circuit having a yoke 115, a magnet 116, and a plate 117, and a frame 114 that holds the vibration system and the magnetic circuit.

[0015] The shape (structure) of the first speaker unit is not particularly limited. In the case of this embodiment, the diaphragm 112 included in the first speaker unit 101 is conical (cone type). A dome-shaped cap that bulges forward (the X-side in the figure) is attached to the center of the diaphragm 112.

[0016] The first cabinet 111 is a box-shaped member that supports the first speaker unit 101 at a predetermined position, and has a function of adjusting the vibration of the diaphragm 112 of the first speaker unit 101 in a reverse phase by causing resonance. In the case of this embodiment, the first cabinet 111 houses the first speaker unit 101 inside, and supports the first speaker unit 101 via a first baffle plate 118 that closes the front opening of the first cabinet 111 and a holding member 119. A circular through-hole corresponding to the outer shape of the diaphragm 112 of the first speaker unit 101 is provided in the portion of the first baffle plate 118 facing the first speaker unit 101.

[0017] Note that the shape (structure) of the first cabinet 111 is not particularly limited, and it does not matter whether it is a sealed type or a bass reflex type. Also, the first cabinet 111 may support the first speaker unit 101 using members other than the first baffle plate 118.

[0018] <> The second speaker unit 102 is disposed on the sound emission side of the first speaker unit 101 and is a speaker that emits sound in the same direction as the first speaker unit 101. The second speaker unit 102 is a speaker smaller than the first speaker unit 101 and is designed to be responsible for emitting sound in a higher frequency range than the first speaker unit 101. Similar to the first speaker unit 101, the second speaker unit 102 also has a diaphragm, a voice coil, and a frame, a yoke, a magnet, a plate, etc., but illustration thereof is omitted.

[0019] The direction of the winding axis of the voice coil of the second speaker unit 102 is not particularly limited, but in the case of the present embodiment, it is arranged coaxially with respect to the winding axis of the voice coil 113 of the first speaker unit 101. Further, the second speaker unit 102 is arranged in front of the diaphragm 112 of the first speaker unit 101 (X-side in the figure) so as to emit sound in the same direction as the first speaker unit 101. That is, the speaker device 100 of the present embodiment is a so-called coaxial type speaker device.

[0020] The shape (structure) of the second speaker unit 102 is not particularly limited, but in the case of the present embodiment, a dome-shaped speaker is adopted.

[0021] The second cabinet 121 is a box-shaped member that is disposed between the diaphragm 112 of the first speaker unit 101 and the second speaker unit 102 and supports the second speaker unit 102. The second cabinet rear surface portion 122 of the second cabinet 121 facing the first speaker unit 101 is arranged at a position where it will not interfere even when the diaphragm 112 of the first speaker unit 101 vibrates to emit sound. Thereby, the sound radiated from the diaphragm 112 is effectively radiated outside the baffle plate through the sound path 110.

[0022] In this embodiment, the second cabinet 121 is positioned inside a circular through-hole provided in the first baffle plate 118 and includes a second baffle plate 128 that forms an annular slit 130 between itself and the first baffle plate 118. Note that the slit 130 is not a perfect annular shape, but is divided by a connecting portion 134 that connects the first baffle plate 118 and the second baffle plate 128.

[0023] The slit 130 communicates with the sound path 110 formed between the diaphragm of the first speaker unit 101, the second cabinet 121, and the resonator 103. Sound radiated from the diaphragm 112 of the first speaker unit 101 passes through the sound path 110 and is radiated to the outside through the slit 130.

[0024] In this embodiment, the diameter D of the second baffle plate 128 (see Figure 3) is set to be more than half the wavelength calculated from the low-frequency reproduction limit of the second speaker unit 102. By setting it in this way, it is possible to flatten the overall sound pressure characteristics due to the sound radiated from the slit 130 and the sound radiated from the second speaker unit 102. For example, if the low-frequency reproduction limit is fL = 2000 Hz, the wavelength at 2000 Hz is 344 / 2000 = 170 mm (where 344 is the speed of sound). Therefore, it is desirable that the diameter of the second baffle plate 128 be 85 mm or more, which is half the wavelength.

[0025] Here, the low-frequency reproduction limit frequency is the lowest frequency range that a speaker unit can reproduce. As schematically shown in Figure 5, the low-frequency reproduction limit frequency is the frequency fL at which the sound pressure suddenly drops when the reproduction frequency is lowered.

[0026] Furthermore, the diameter is defined in this specification and in the claims as twice the shortest distance from the point where the axis of the second speaker unit 102 intersects with the surface including the front surface of the second baffle plate 128 to the periphery of the second baffle plate 128.

[0027] Furthermore, the acoustic characteristics are improved by making the front surfaces of the first baffle plate 118 and the second baffle plate 128 flush. Also, the second baffle plate 128 is integrated with the first baffle plate 118. In other words, the first baffle plate 118 and the second baffle plate 128 are formed by creating a slit 130 that penetrates through the thickness direction in a single sheet of material.

[0028] Figure 4 is a perspective view showing the resonator and the second cabinet with the baffle plate omitted. The resonator 103 is a Helmholtz resonator positioned between the diaphragm 112 of the first speaker unit 101 and the second cabinet 121, and has an opening 131 that opens toward the diaphragm 112 of the first speaker unit 101.

[0029] In this embodiment, the resonator 103 has a resonator back surface 132 on the surface facing the diaphragm 112 of the first speaker unit 101 that conforms to the shape of the diaphragm 112. The opening 131 is provided in the resonator back surface 132. Specifically, the resonator 103 is a part of a hollow frustoconical shape that conforms to the shape of the diaphragm 112 of the first speaker unit 101, divided at multiple points in the radial direction. The portion other than the frustoconical resonator 103 is a dummy part 104 that has a dummy back surface 141 on the surface facing the diaphragm 112 of the first speaker unit 101 that conforms to the shape of the diaphragm 112. The dummy part 104 does not have an opening 131 that opens toward the diaphragm 112 of the first speaker unit 101. Note that the dummy part 104 may be solid instead of hollow.

[0030] In this embodiment, the second cabinet 121 has a second cabinet back surface 122 (see Figure 3) on the surface facing the diaphragm 112 of the first speaker unit 101 that conforms to the shape of the diaphragm 112. The resonator back surface 132, the dummy back surface 141, and the second cabinet back surface 122 are positioned at the limit of their ability to avoid interference even when the diaphragm 112 of the first speaker unit 101 vibrates to radiate sound. The resonator back surface 132, the dummy back surface 141, and the second cabinet back surface 122, along with the diaphragm 112, form a sound path 110 that communicates with the slit 130.

[0031] The resonator 103 forms a resonant space 133 that communicates with the sound path 110 via an opening 131. In this embodiment, the resonant space 133 is composed of a part of the second cabinet 121, a part of the second baffle plate 128, and the resonator back surface 132. The second cabinet 121 and the resonator back surface 132 are formed integrally. The resonator 103 and the dummy part 104 are also formed integrally.

[0032] Although the resonator 103 is described as forming the resonance space 133 together with other components, the resonance space 133 may also be formed by the resonator 103 alone.

[0033] The size of the resonant space 133 formed in a closed state by the resonator 103, and the size of the opening 131, are arbitrarily determined to match the frequency at which the sound passing through the sound path 110 resonates. In this embodiment, the resonant space 133 may not only be a part of a hollow frustoconical shape, but the resonator 103 may also form a resonant space 133 of any shape.

[0034] As described above, the speaker device 100 in this embodiment exhibits the effect of having little change in sound quality depending on the listening position, similar to sound radiated from a point source, and despite its simple structure, it is possible to suppress the generation of intermodulation distortion and radiate high-quality sound.

[0035] In particular, as shown by the solid line in Figure 8, the acoustic resonance peak caused by the slit 130 can be effectively suppressed by the resonator 103.

[0036] Furthermore, by forming the resonator 103 using a portion of the second baffle plate 128 and a portion of the second cabinet 121, it becomes possible to place the resonator 103 in the narrow space between the second baffle plate 128 and the diaphragm 112.

[0037] Furthermore, by positioning the resonator 103 and the second cabinet 121 in front of the sound-radiating side of the first speaker unit 101, and by making the resonator back surface 132, the second cabinet back surface 122, and the dummy back surface 141 conform to the shape of the diaphragm 112, the sound from the first speaker unit 101 can be efficiently guided through the sound path 110, and intermodulation distortion can be effectively suppressed by the resonator 103. As a result, it becomes possible to radiate sound with suppressed distortion from the slit with high efficiency.

[0038] Furthermore, by arranging the first speaker unit 101 and the second speaker unit 102 coaxially, and by having the sound generated by the first speaker unit 101 and radiated from the slit 130 radiate from the second speaker unit 102 at a predetermined distance, the generation of intermodulation distortion is suppressed in addition to the suppression effect of the resonator 103. As a result, it is possible to improve the overall sound quality of the sound radiated from the speaker device 100.

[0039] It should be noted that the present invention is not limited to the embodiments described above. For example, other embodiments of the present invention may be realized by arbitrarily combining the components described herein, or by excluding some of the components. Furthermore, modifications obtained by applying various modifications to the above embodiments that a person skilled in the art could conceive of without departing from the spirit of the present invention, that is, the meaning indicated by the wording in the claims, are also included in the present invention.

[0040] For example, the speaker device 100 may have multiple resonators 103 with the same resonant frequency, as shown in Figure 5. This makes it possible to enhance the effect of suppressing intermodulation distortion.

[0041] Furthermore, the openings 131 of the multiple resonators 103 may be arranged symmetrically with respect to the plane including the winding axis of the voice coil, which is the direction in which the first speaker unit 101 and the second speaker unit 102 are aligned. This allows the influence of the resonators 103 to be evenly distributed with respect to the diaphragm 112, and suppresses twisting of the diaphragm 112 during operation.

[0042] Furthermore, the speaker device 100 may be equipped with multiple resonators 103 with different resonant frequencies, as shown in Figure 6.

[0043] The resonator 103 may be equipped with a damping member 139. The damping member 139 is a member that amplifies acoustic resistance, and examples include damping cloth and sound-absorbing material. By attaching the damping cloth to cover the opening of the resonator 103 or by placing sound-absorbing material in the resonant space 133, it is possible to control the degree of resonance suppression by the resonant space 133.

[0044] Furthermore, the resonator 103 may be formed separately from the second cabinet 121, the second baffle plate 128, and the like.

[0045] Furthermore, although the diaphragm 112 of the first speaker unit 101 was described as cone-shaped and the diaphragm of the second speaker unit 102 as dome-shaped, the shape of the diaphragm is not particularly limited, and it may also be a flat diaphragm. Also, the shape of the diaphragm is not limited to circular or elliptical, but may also be rectangular.

[0046] Furthermore, although the cabinet and baffle plate have been described separately, they may be a single unit, and the first baffle plate 118 and the second baffle plate 128 may be separate components joined together by connecting members or the like.

[0047] Furthermore, although the first cabinet 111 has been described as an independent enclosure, the first cabinet 111 may be shared with the enclosure of electronic devices such as televisions and computers, or with the structure of mobile objects such as cars and aircraft.

[0048] Furthermore, the speaker device 100 may be used in small, portable playback devices such as headphones or in-ear headphones. [Industrial applicability]

[0049] This invention can be applied to a speaker device 100 that reproduces audio signals such as music. [Explanation of symbols]

[0050] 100 speaker system 101 First speaker unit 102 Second speaker unit 103 Resonator 104 Dummy section 110 Ondo 111 First Cabinet 112 Diaphragm 113 Voice coil 114 frames 115 York 116 Magnets 117 Plate 118 First baffle plate 119 Retaining member 121 Second Cabinet 122 Rear view of the second cabinet 128 Second baffle plate 130 slits 131 Opening 132 Resonator back side 133 Resonance space 134 Connection part 139 Braking member 141 Dummy back side

Claims

1. First speaker unit and A first cabinet supporting the first speaker unit, A second speaker unit is positioned on the sound-emitting side of the first speaker unit and radiates sound in the same direction as the first speaker unit. A second cabinet is positioned between the first speaker unit and the second speaker unit and supports the second speaker unit, A resonator having an opening that opens toward the diaphragm at a position opposite to the diaphragm of the first speaker unit, and positioned between the first speaker unit and the second cabinet, A speaker device equipped with the following features.

2. The first cabinet is equipped with a first baffle plate on the front, The second cabinet includes a second baffle plate positioned inside the through-hole provided in the first baffle plate, forming a slit between itself and the first baffle plate. The speaker device according to claim 1.

3. The resonator has a back surface portion that conforms to the shape of the diaphragm on the surface facing the diaphragm of the first speaker unit. The speaker device according to claim 1 or 2.

4. The surface of the first speaker unit facing the diaphragm is provided with a dummy back surface that conforms to the shape of the diaphragm, The dummy section includes a section that does not have an opening that opens toward the diaphragm of the first speaker unit. The speaker device according to claim 3.

5. The speaker device further comprises a resonator having the same resonant frequency as the aforementioned resonator. The speaker device according to any one of claims 1 to 4.

6. The speaker device further comprises a resonator having a different resonant frequency than the aforementioned resonator. The speaker device according to any one of claims 1 to 5.

7. The openings of the multiple resonators are arranged symmetrically with respect to a plane that includes the direction in which the first speaker unit and the second speaker unit are aligned. The speaker device according to claim 5 or 6.

8. The resonator includes a damping member. The speaker device according to any one of claims 1 to 7.

9. The resonator is It is composed of at least a portion of a region formed by dividing the hollow region that follows the shape of the diaphragm into multiple locations in the radial direction. The speaker device according to any one of claims 1 to 8.

Images