JP4482291B2 - Speaker device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a speaker device that is used particularly for low-frequency reproduction when sound is reproduced by an audio device.
[0002]
[Prior art]
Conventionally, in a speaker device, various techniques have been developed for low-frequency reproduction (see, for example, Non-Patent Document 1). In the low sound range, when the speaker unit is used alone, the sound of opposite phases radiated from both the front and back surfaces of the diaphragm is mixed and interferes with each other, canceling each other and reducing the sound pressure. Assuming that the effective vibration radius of the speaker is a, the frequency at which the wavelength λ of the sound wave becomes 2 × π × a becomes a cutoff frequency that decreases by −3 dB, and decreases at a rate of −6 dB / oct. Sound pressure drop due to interference can be avoided by enclosing the back side of the diaphragm with an enclosure. However, the air in the enclosure acts as a spring and resonates with the mass of a vibration system such as a diaphragm, making it difficult to reproduce a frequency lower than the resonance frequency. In order to reproduce bass with constant sound pressure, it is generally advantageous that the effective vibration radius a is large. However, since the internal volume Vc of the enclosure is proportional to the fourth power of the effective vibration radius a of the speaker unit under the condition that the resonance frequency is constant, if a speaker unit having a large-diameter diaphragm is used, a large enclosure is required. .
[0003]
When a small-diameter speaker unit is used, the enclosure can be downsized. However, in order to obtain a sound pressure comparable to that of a large-diameter speaker, the amplitude becomes large. When the amplitude of the diaphragm of the speaker unit increases, the vibration is transmitted to other parts of the speaker unit, and further, the vibration is also transmitted to the enclosure, so that sound is easily emitted from other parts than the diaphragm. In order to prevent sound emission from parts other than the diaphragm, the applicant of the present application can divide a relatively small volume speaker box used as an enclosure into the first half and the second half, and provide an opening in the first half for comparison. A speaker system is disclosed in which an acoustic radiation portion of a small-diameter speaker unit is connected via a buffer material and the speaker unit is supported inside a speaker box (see, for example, Patent Document 1). The speaker unit is directly supported by a stand whose tip is inserted into the interior of the speaker box from the connection portion between the first half and the second half of the speaker box, or is supported by a weight that functions as a virtual ground, and the drive unit of the speaker unit, etc. The vibration generated in the speaker box is not easily transmitted to the speaker box.
[0004]
[Patent Document 1]
JP 2001-285974 A (FIG. 1)
[Non-Patent Document 1]
Supervised by Tamon Saeki, “New Edition Speaker & Enclosure Encyclopedia” Seikodo Shinkosha Co., Ltd., May 28, 1999, p. 72-129
[0005]
[Problems to be solved by the invention]
Although the speaker system disclosed in Patent Document 1 is intended for reproduction in the full range from the low range to the high range, it cannot be so large due to the use of the stand, and the reproduction of the low range is not possible. There is a limit about. For the reproduction of the low sound range, a commercialized larger speaker system is not sufficient, and a 3D system or a 5.1 channel system for adding a subwoofer for low sound reproduction is also used. Since these subwoofers have low directivity at low frequencies, only one subwoofer is used in many cases.
[0006]
Since the speaker system disclosed in Patent Document 1 is aimed at reproduction with a small size and high sound quality, it is not preferable to use a very large speaker system even if subwoofers are combined. If the diameter of the diaphragm is reduced and the mass is increased, reproduction in the low sound range is possible even when combined with a speaker box having a relatively small volume. However, the low frequency range reproduced from such a speaker system tends to be heavy and lacks a sense of speed.
[0007]
An object of the present invention is to provide a speaker device capable of low-speed sound reproduction with a sense of speed even in a small size.
[0008]
[Means for Solving the Problems]
The present invention is diaphragm and a driving unit, have rows sound reproduction by reciprocally vibrating the diaphragm back and forth by the drive unit which is arranged behind the diaphragm, the direction after the front is vertical A speaker unit installed as follows :
On the front side of the front Symbol diaphragm, the disposed with a gap so as not to contact at the maximum amplitude from the diaphragm surface, the surface on the side facing the diaphragm surface of the diaphragm covers the entire surface of the diaphragm has a shape along the three-dimensional shape, the surface of the side facing the front Kifu rotation plate surface, the gap at the periphery compared to the gap definitive in the center of the diaphragm is stronger than the peripheral portion is expanded A front load having a shape larger than the mass of air added to the diaphragm ,
A weight disposed behind the drive unit, having a mass that becomes a virtual ground with respect to the speaker unit, and a weight that supports the speaker unit via the drive unit;
A speaker box that houses the speaker unit and the weight and supports the weight via a cushioning material, the front load so that a common axis of the front load and the speaker unit is in a vertical direction. And a speaker box for supporting the speaker .
[0009]
According to the present invention, the speaker unit includes a diaphragm and a drive unit, and performs sound reproduction by reciprocally vibrating the diaphragm back and forth by a drive unit disposed behind the diaphragm. On the front side of the diaphragm, the front loading is arranged with a gap so as not to contact at maximum amplitude, et al or the diaphragm surface. Front loading has a three-dimensional shape along the shape of the vibration rotation plate in together when cover the entire surface of the rotation plate vibration surface of the side facing the diaphragm surface, a large mass compared to the mass of air that is added to the diaphragm Therefore, the vibration transmitted from the front surface of the diaphragm to the air with the vibration of the diaphragm is reflected on the surface of the front load and returned to the diaphragm. For the diaphragm, this corresponds to an increase in the resistance of air, which is a medium for sound radiation, and vibration is performed with an equivalently large mass added. Even if the mass of the diaphragm itself is not increased, the mass as the vibration system is increased, so that the reproduction up to the low frequency range is possible. Since there is no increase in the mass of the diaphragm itself, bass reproduction with a sense of speed is possible in terms of hearing.
Further, in the present invention, the surface on the side where the front load faces the diaphragm surface of the speaker unit has a shape in which the gap is enlarged in the peripheral portion compared to the central portion having strength compared to the peripheral portion. The load applied to the center of the relatively strong diaphragm can be increased, the load applied to the periphery of the diaphragm can be reduced, and the air layer between the diaphragm and the front load can be easily moved in and out. be able to.
[0011]
In addition, behind the driving unit of the speaker unit, a weight having a virtual grounding with respect to the speaker unit and supporting the speaker unit via the driving unit is disposed, so that the diaphragm is air Even if the reaction force is received, the vibration is absorbed by the weight and the transmission of vibrations to the surroundings can be reduced, and the sound quality can be prevented from being deteriorated by the surrounding vibrations .
[0017]
Further, the front loading and the speaker unit may be common axis such that the vertical direction, supported lifting is Runode, even if the mass of the front loading and the speaker unit is increased, easily supported. Even if a weight is added to the back of the speaker unit, it can be arranged along the vertical axis and supported easily.
[0019]
In addition , since the speaker unit and the weight behind the speaker unit are supported in the speaker box so that the direction in which the diaphragm is driven by the speaker unit is vertical, the speaker unit or weight having a large mass for low sound reproduction is used. Can be easily supported. Since the directivity of the reproduced sound is lost in the low sound range, the reproduced sound can be heard with sufficient sound quality even when the speaker unit is oriented vertically.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 shows a schematic configuration of a main portion of the speaker apparatus 1 the invention shall be the premise. The speaker device 1 includes a front load 2 and a speaker unit 3. The speaker unit 3 includes a diaphragm 4 and a drive unit 5. The drive unit 5 is of an electrodynamic type, and includes a magnetic circuit 6 including a permanent magnet and a voice coil 7 inserted into the magnetic gap of the magnetic circuit 6. When the voice coil 7 is electrically driven by an acoustic signal, mechanical reciprocal vibration in the direction of the central axis 3 a of the speaker unit 3 is generated in the voice coil 7 by the magnetic gap and transmitted to the diaphragm 4. In other words, sound reproduction can be performed by reciprocating the diaphragm 4 back and forth by the drive unit 5 disposed behind the diaphragm 4. The front load 2 is disposed on the front side of the diaphragm 4 of the speaker unit 3 with a gap from the surface of the diaphragm 4 that does not contact at the maximum amplitude. The front load 2 can be supported by a spacer or the like not shown. The front load 2 has a surface that faces the surface of the diaphragm 4 along a three-dimensional shape of the diaphragm 4 and is added to the diaphragm 4 from the surrounding air as an acoustic impedance accompanying the vibration of the diaphragm 4. It has a large mass compared to the mass it has, for example a mass of several kg.
[0025]
As the front load 2, the surface on the side facing the surface of the diaphragm 4 of the speaker unit 3 is shaped so that the unevenness of the diaphragm 4 is reversed, and a uniform gap is maintained between the front load 2 and the diaphragm 4. Can do. Since the front load 2 and the diaphragm 4 maintain a uniform gap, even when the diaphragm 4 vibrates with a large amplitude during low volume reproduction, a uniform acoustic load is applied to the diaphragm 4 as a whole. Can do.
[0026]
FIG. 2 shows the effect of disposing the front load 2 in front of the diaphragm 4 of the speaker unit 3. The reproduction sound pressure when the drive power is constant and the frequency is changed has almost no effect in the low sound range, and the reproduction sound pressure decreases as shown by hatching in the middle and high sound range. That is, it can be seen that it operates as a kind of low-pass filter. In terms of audibility, it is possible to obtain a bass sound and a feeling of speed that are equal to or greater than the structure and diameter of the speaker unit 3.
[0027]
The front load 2 has a shape that conforms to the three-dimensional shape of the diaphragm 4 on the surface facing the surface of the diaphragm 4, and has a larger mass than the mass of air added to the diaphragm 4. It is considered that the vibration transmitted to the air from the front surface of the diaphragm 4 with the vibration of the plate 4 is reflected on the surface of the front load 2 and returned to the diaphragm 4. For the diaphragm 4, this corresponds to an increase in the resistance of the air serving as a sound radiation medium, and an equivalent large mass is added to cause vibration. Even if the mass of the diaphragm 4 itself is not increased, the mass as the vibration system is increased, so that it is possible to reproduce up to the low frequency range and there is no increase in the mass of the diaphragm 4 itself. Is estimated to be possible.
[0028]
Figure 3 shows a schematic configuration of a main part of the speaker device 11 according to one embodiment of the present invention. In this embodiment, parts corresponding to those in the embodiment of FIG. 1 are denoted by the same reference numerals, and redundant description is omitted. In the present embodiment, the speaker unit 3 is basically the same as the embodiment of FIG. 1, but the front load 12 is different. The front load 12 has such a shape that the surface on the side facing the diaphragm 4 of the speaker unit 3 expands the gap in the peripheral portion as compared with the central portion. That is, as compared with the shape of the front unit 2 in FIG. 1 as shown by a broken line, as shown by the solid line, the surface on the side where the front load 12 faces the surface of the diaphragm 4 of the speaker unit 3 is compared with the center part. It becomes a shape that the gap is enlarged at the peripheral portion. By forming the front load 12 in such a shape, the load applied to the central portion of the diaphragm 4 having relatively high strength can be increased, and the load applied to the periphery of the diaphragm 4 can be reduced. And the air layer between the front load 12 and the front load 12 can be facilitated.
[0029]
The center axis 3a of the speaker unit 3 in the embodiment of FIGS. 1 and 3 is described in the vertical direction of the drawing, and indicates that the speaker unit 3 is used in the vertical direction. Of course, it may be used horizontally.
[0030]
FIG. 4 shows, as another embodiment of the present invention, an overall appearance configuration of a speaker device 21 using a vertically placed speaker box 20 with a front load 22 removed. The front load 22 is made of aluminum die cast, for example, and has a mass of several kg. The speaker unit 23 is supported on the top of the speaker box 20 from the inside so that the diaphragm 24 having a diameter of, for example, about 160 mm is on the upper side and the driving unit 25 described below is on the lower side. The front load 22 can be fixed to a boss 26 protruding from the top of the speaker box 20 with a bolt 27 or the like. The height of the boss 26 is a height at which the diaphragm 24 does not contact even when the speaker device 21 is driven at the rated maximum input. If the front load 25 is attached by adding a spacer or the like to the boss, the gap between the diaphragm 24 and the front load 22 can be adjusted.
[0031]
5, 6 and 7 show the speaker device 21 of FIG. 4 as viewed from the front side, the right side and the top side, respectively. The speaker device 21 incorporates a driving amplifier, the speaker box 20 can be divided into an upper portion 31 and a lower portion 32, and an inner portion 33 described later is housed inside. The upper portion 31, the lower portion 32, and the inner portion 33 can be manufactured by, for example, aluminum die casting or foamed polypropylene molding. A power supply unit 34 is mounted on the bottom of the speaker box 20, and an amplifier unit 35 described later is housed on the back side. The speaker unit 23 shown in FIG. 4 is mounted in a state where the central axis 23a is in the vertical direction and the upper portion 31 and the lower portion 32 are divided into the speaker box 20.
[0032]
FIG. 8 shows a configuration of the speaker device 21 of FIG. A weight 40 is attached to the back side of the drive unit 25 of the speaker unit 23. For example, four arms 41 are provided in the weight 40 so as to extend in the lateral direction, and are fixed by being sandwiched between bosses standing on the top and bottom surfaces of the upper portion 31 and the lower portion 32 of the speaker box 20. The The weight 40 is made of, for example, zinc die cast and has a larger mass than the front load 22. In the speaker unit 23, the drive unit 25 is supported by a bolt 42 inserted through the center of a weight 40 supported by the speaker box 20. The periphery of the diaphragm 24 of the speaker unit 23 is pressed around the opening 44 provided in the upper portion 31 of the speaker box 20 through a cushioning material 43 such as felt or rubber. In the speaker box 20, the inner portion 33 and the amplifier unit 35 are attached after the speaker unit 23 is mounted.
[0033]
FIG. 9 shows the structure viewed from the section line IX-IX in FIG. FIG. 10 shows a support structure for one arm 41 of the weight 40. A boss 46 erected from the bottom surface of the lower portion 32 of the speaker box 20 is disposed at the X-shaped apex position. A boss 47 erected from the top surface of the upper portion 31 of the speaker box 20 is also arranged at a corresponding position. An attachment portion 50 is provided at the tip of the arm 41, and a through hole 51 is formed in the attachment portion 50. A boss 46 erected from the bottom surface of the lower portion 32 of the speaker box 20 is hollow, and a bolt 52 can be inserted therein. The diameter of the threaded portion of the bolt 52 is made smaller than the inner diameter of the through hole 51 so that the bolt 52 and the mounting portion 51 are not in direct contact with each other, and the tip of the bolt 52 is raised from the top surface of the upper portion 31. The mounting portion 50 is fixed by being formed on the boss 47 provided or screwed into the female screw to be inserted. Between the end face of the boss 46 and the boss 47 and the surface of the mounting portion 50, a cushioning material 53 made of felt, rubber or the like is interposed.
[0034]
In this way, the speaker device 21 that houses the front load 22, the speaker unit 23, and the weight 40 in the speaker box 20 is configured. The speaker unit 23 includes a diaphragm 24 and a drive unit 25. The drive unit 25 disposed behind the diaphragm 24 reciprocally vibrates the diaphragm 24 back and forth to perform sound reproduction. It is installed so that the direction is vertical. The front load 22 is arranged on the front side of the diaphragm 24 of the speaker unit 23 with a gap that does not come in contact with the surface of the diaphragm 24 at the maximum amplitude, and the surface on the side facing the surface of the diaphragm 24 is The diaphragm 24 has a shape along the three-dimensional shape, and has a mass larger than the mass of air added to the diaphragm 24. The weight 40 is disposed behind the driving unit 25 of the speaker unit 23, has a mass that becomes a virtual ground with respect to the speaker unit 23, and supports the speaker unit 23 via the driving unit 25.
[0035]
Since the front load 22 has a shape along the three-dimensional shape of the diaphragm 24 on the surface facing the surface of the diaphragm 24, the front load 22 has a larger mass than the mass of air added to the diaphragm 24. The vibration transmitted from the front surface of the diaphragm 24 to the air accompanying the vibration of the diaphragm 24 is reflected by the surface of the front load 22 and returned to the diaphragm 24. For the diaphragm 24, this corresponds to an increase in the resistance of the air serving as a sound radiation medium, and vibration is performed with an equivalently large mass added. Even if the mass of the diaphragm 24 itself is not increased, since the mass as the vibration system is increased, it is possible to reproduce up to the low frequency range. Since there is no increase in the mass of the diaphragm 24 itself, it is presumed that bass reproduction with a sense of speed is possible in terms of hearing. Behind the drive unit 25 of the speaker unit 23 is a weight 40 that has a mass that is virtually grounded to the speaker unit 23 and supports the speaker unit 23 via the drive unit 25. Even if the diaphragm 24 receives a reaction force from the air, it is absorbed by the weight 40, and transmission of vibration to the surroundings can be reduced, so that sound quality can be prevented from being deteriorated by the surrounding vibrations.
[0036]
As shown in FIG. 8, the speaker box 20 houses a tube 55 therein, communicates with a side portion 56 of the speaker unit 23, and forms a bass reflex duct in which an opening 57 is provided at the bottom. Works as. A sound absorbing material 58 or the like may be inserted into the speaker box.
[0037]
The front load 22 and the speaker unit 23 are arranged such that the speaker unit 23 faces upward and the front load 22 is disposed above the speaker unit 23, but the speaker unit 23 is attached downward and the front load 22 is connected to the speaker. It can also be arranged below the unit 23. Thus, the speaker unit 23 and the front load 22 may be supported by the speaker box so that the common axis is in the vertical direction. Since the front load 22 and the speaker unit 23 are supported by the speaker box so that the common axis is in the vertical direction, even if the mass of the front load 22 and the speaker unit 23 is increased, the front load 22 and the speaker unit 23 are easily supported in a balanced manner. Can do. Even when the weight 40 is added to the back of the speaker unit 23, it can be arranged along the vertical axis and can be easily supported in a balanced manner.
[0038]
【The invention's effect】
As described above, according to the present invention, the front load having a mass larger than the mass of air added to the diaphragm is disposed on the front side of the diaphragm of the speaker unit. In the front load, the surface facing the diaphragm surface covers the entire surface of the diaphragm and has a shape that conforms to the three-dimensional shape of the diaphragm. Therefore, vibration transmitted from the front surface of the diaphragm to the air accompanying the vibration of the diaphragm Is reflected by the surface of the front load and returned to the diaphragm. Even with a small speaker device, bass reproduction with a sense of speed can be achieved.
Also, the surface of the vibration plate side facing the surface of the front load speaker unit, shaped to expand the gap at the periphery compared to the center with its strength as compared with the peripheral portion in the diaphragm Therefore, it is possible to increase the load applied to the center of the diaphragm with relatively high strength, to reduce the load applied to the periphery of the diaphragm, and to easily enter and exit the air layer between the diaphragm and the front load. can do.
[0039]
In addition , a front load is disposed on the front side of the diaphragm of the speaker unit, and a weight serving as a virtual ground is disposed on the rear side of the driving unit of the speaker unit. In the front load, the surface facing the diaphragm surface covers the entire surface of the diaphragm, and has a shape along the three-dimensional shape of the diaphragm, and has a mass larger than the mass of air added to the diaphragm. Therefore, even with a small speaker device, low sound reproduction with a sense of speed can be achieved. Since a weight that supports the speaker unit via the drive unit is disposed behind the drive unit of the speaker unit, even if the diaphragm receives a reaction force from the air, it is absorbed by the weight and is moved to the surroundings. It is possible to reduce the transmission of vibrations and prevent the sound quality from being deteriorated by ambient vibrations .
[0042]
Also, by arranging the front loading and speaker units vertically, in a low frequency range, even if the mass of the front loading and the speaker unit is increased, it can be easily supported. Even when a weight is added to the back of the speaker unit, it is possible to easily support a weight that is disposed along the vertical axis and has a large mass for the low frequency range.
[0043]
In addition, since the directivity of the reproduced sound is lost in the low sound range, the reproduced sound can be heard with sufficient sound quality even when the direction of the speaker unit is vertical.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a schematic configuration of a main part of a speaker device 1 according to an embodiment of the present invention.
2 is a graph showing a schematic output sound pressure frequency characteristic of the speaker device 1 of FIG. 1; FIG.
FIG. 3 is a side sectional view showing a schematic configuration of a main part of a speaker device 11 according to another embodiment of the present invention.
FIG. 4 is a perspective view showing an external appearance of a speaker device 21 according to still another embodiment of the present invention in a state where a front load 22 is removed.
5 is a front view of the speaker device 21 of FIG. 4. FIG.
6 is a right side view of the speaker device 21 of FIG. 4. FIG.
7 is a plan view of the speaker device 21 of FIG. 4. FIG.
8 is a right side cross-sectional view of the speaker device 21 of FIG.
9 is a cross-sectional view taken along section line IX-IX in FIG. 8;
10 is a cross-sectional view showing a structure of a mounting portion of the weight 40 in FIG.
[Explanation of symbols]
1, 11, 21 Speaker device 2, 12, 22 Front load 3, 23 Speaker unit 3 a, 23 a Center axis 4, 24 Diaphragm 5, 25 Drive unit 20 Speaker box 26, 46, 47 Boss 27, 42, 52 Bolt 31 Upper part 32 Lower part 40 Weights 43, 53 Buffer material 50 Mounting part

Claims (1)

Diaphragm and a driving unit, the have line sound reproduction by reciprocally oscillating back and forth the diaphragm by the driving unit which is arranged behind the diaphragm, direction after the front is installed such that the vertical direction and the speaker unit that,
On the front side of the front Symbol diaphragm, the disposed with a gap so as not to contact at the maximum amplitude from the diaphragm surface, the surface on the side facing the diaphragm surface of the diaphragm covers the entire surface of the diaphragm has a shape along the three-dimensional shape, the surface of the side facing the front Kifu rotation plate surface, the gap at the periphery compared to the gap definitive in the center of the diaphragm is stronger than the peripheral portion is expanded A front load having a shape larger than the mass of air added to the diaphragm ,
A weight disposed behind the drive unit, having a mass that becomes a virtual ground with respect to the speaker unit, and a weight that supports the speaker unit via the drive unit;
A speaker box that houses the speaker unit and the weight and supports the weight via a cushioning material, the front load so that a common axis of the front load and the speaker unit is in a vertical direction. And a speaker box for supporting the speaker .

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