JP2020043443A - Speaker cabinet and plate material - Google Patents

Abstract

To suppress generation of standing waves in a speaker cabinet while preventing a volume of an internal space of the speaker cabinet from decreasing.SOLUTION: The speaker cabinet includes a cabinet body 110, having a double wall structure in which a plurality of air chambers 140 are formed on at least a part of a wall that partitions an internal space for housing a speaker unit and an external space, provided with a hole 150 for communicating at least one of the plurality of air chambers with the internal space is on a wall surface 110 on the internal space side. At least on one of partitions 130 that partitions the air chambers 140 communicating with the internal space through the hole 150 and each of the plurality of air chambers 140 adjacent to the air chamber 140, a communication hole 152 for communicating the air chambers 140 is provided.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a speaker cabinet for housing a speaker unit and a plate material suitable for the speaker cabinet.

  The speaker cabinet preferably has high rigidity, and is more preferably lightweight. Patent Literature 1 discloses a technique that can reduce the weight while securing the rigidity of a speaker cabinet. In Patent Literature 1, a honeycomb core is interposed between wall surfaces of a double structure forming a housing of a speaker cabinet to secure rigidity of the speaker cabinet, and a through hole is provided in a wall surface of the honeycomb core. As a hermetic structure that blocks the space occupied by the honeycomb core from the outside air, a technology for reducing the weight by filling the space with a gas lighter than air (or making it vacuum) has been disclosed.

Japanese Utility Model Publication No. 01-175084

  In a speaker comprising a speaker unit and a speaker cabinet for accommodating the speaker unit, the sound wave radiated from the back of the speaker unit to the internal space of the speaker cabinet and the sound wave reflected by the inner surface of the speaker cabinet are superimposed. A standing wave may be generated in the interior space of the cabinet. When such a standing wave is generated, a peak or a dip occurs in the frequency characteristic of the sound reproduced by the loudspeaker according to the frequency of the standing wave, thereby causing a problem that the reproduced sound quality is deteriorated.

  As a measure for suppressing the generation of such a standing wave, it is conceivable to install a sound absorbing material formed of a nonwoven fabric, a porous material, or the like in the speaker cabinet. However, when the sound absorbing material is installed in the speaker cabinet, other problems such as a decrease in the volume of the internal space of the speaker cabinet and a decrease in reproduced sound in a low frequency range occur.

  The present invention has been made in view of the above circumstances, and has as its object to provide a technique for suppressing the generation of standing waves in a speaker cabinet while avoiding a decrease in the volume of the internal space of the speaker cabinet. And

  In order to solve the above problems, the present invention has a double wall structure in which a plurality of air chambers are formed inside at least a part of a wall that partitions an internal space and an external space that house a speaker unit, A cabinet body provided with a hole for communicating at least one of the plurality of air chambers with the internal space on a wall surface on the internal space side, wherein the air chamber communicates with the internal space via the hole; A speaker cabinet is provided, wherein at least one of walls partitioning each of the plurality of air chambers adjacent to the chamber is provided with a communication hole for communicating the air chambers.

  In a speaker cabinet of a more preferred aspect, an air chamber communicating with the internal space through the hole and an air chamber communicating with the air chamber through the communication hole have a Helmholtz sound absorber, a sound absorbing tube, and an acoustic maze structure. At least one of them is formed.

  In a speaker cabinet of a further preferred aspect, at least one of the Helmholtz sound absorber and the sound absorbing tube is formed, and the sound absorbing frequency of the Helmholtz sound absorber or the sound absorbing frequency of the sound absorbing tube is a frequency of a standing wave generated in the internal space. Is a value in the vicinity of.

  In a speaker cabinet according to a further preferred aspect, at least one of the Helmholtz sound absorber and the sound absorbing tube is formed on a wall facing in a direction intersecting a direction in which the standing wave is generated, and an antinode of the standing wave. It is formed near the position.

  In another preferred aspect of the speaker cabinet, at least a part of a wall that partitions the internal space and the external space is configured by stacking a plurality of the double wall structures.

  According to another embodiment of the present invention, there is provided a plate material having a double wall structure in which a plurality of air chambers are formed, wherein a hole for communicating at least one of the plurality of air chambers with the outside is provided. The air chambers are communicated with at least one of the walls provided on one surface and partitioning each of the plurality of air chambers adjacent to the air chamber and the air chamber communicating with the outside through the hole. A plate member provided with a communication hole for causing the plate member to be provided.

It is a perspective view showing the appearance of speaker 1 of a 1st embodiment of the present invention. FIG. 2 is a cross-sectional view of the speaker 1. FIG. 3 is a cross-sectional view illustrating a detailed configuration of a wall 100 of a cabinet body of the speaker cabinet 10. FIG. 2 is a diagram illustrating a specific configuration example of a wall 100. FIG. 3 is a diagram illustrating a primary standing wave generated in a speaker cabinet 10 in a Y direction. It is sectional drawing which shows the structure of 500 A of Helmholtz sound absorbers. It is a figure showing the example of composition of wall 100 which constitutes speaker cabinet 10 of a 2nd embodiment of the present invention. It is a figure showing the example of composition of wall 100 which constitutes speaker cabinet 10 of a 2nd embodiment of the present invention. It is a figure showing the example of composition of wall 100 which constitutes speaker cabinet 10 of a 2nd embodiment of the present invention. It is a figure showing the example of composition of wall 100 which constitutes speaker cabinet 10 of a 2nd embodiment of the present invention. It is a figure showing the example of composition of wall 100 which constitutes speaker cabinet 10 of a 2nd embodiment of the present invention. It is a figure showing the example of composition of wall 100 which constitutes speaker cabinet 10 of a 3rd embodiment of the present invention. It is a perspective view showing the appearance of speaker 1A of modification (2). It is a figure for explaining a standing wave generated in speaker cabinet 10A of speaker 1A, and composition for controlling the standing wave concerned.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(A: First embodiment)
FIG. 1 is a perspective view illustrating an appearance of the speaker 1 according to the first embodiment of the present invention. The speaker 1 includes a speaker unit 20 driven by a sound signal supplied from a sound source (not shown), and a speaker cabinet 10 that houses the speaker unit 20. The speaker cabinet 10 has a hollow cubic cabinet body. The cabinet body of the speaker cabinet 10 has six walls that define a space for housing the speaker unit 20. These six walls define an internal space of the cabinet body (that is, an internal space of the speaker cabinet 10) and an external space. Hereinafter, two walls facing each other in the X direction of FIG. 1 are referred to as a right side wall 100R and a left side wall 100L, and two walls facing each other in a Y direction orthogonal to the X direction are referred to as a front wall 100F and a back wall 100B. The two walls facing each other in the Z direction orthogonal to both the direction and the Y direction are referred to as a top wall 100T and a bottom wall 100S. FIG. 1 shows only the right side wall 100R, the front wall 100F, and the top wall 100T among the six walls of the cabinet body. The front wall 100F is provided with a through hole into which the speaker unit 20 is fitted, and the speaker 1 is formed by fitting the speaker unit 20 into this through hole.

  FIG. 2 is a cross-sectional view of the speaker 1 taken along the line CC ′ in FIG. Each of the front wall 100F, the rear wall 100B, the top wall 100T, and the bottom wall 100S has a double wall structure having an inner wall 110 and an outer wall 120, which are walls on the inner space side for housing the speaker unit 20. . Although not shown in detail in FIG. 2, the right side wall 100R and the left side wall 100L also have the double wall structure. That is, all six walls of the cabinet body have a double wall structure. Hereinafter, when it is not necessary to distinguish each of the six walls of the cabinet body, it is described as “wall 100”.

  FIG. 3 is an enlarged view of a cross section of the wall 100. As shown in FIG. 3, the space between the inner side wall 110 and the outer side wall 120 of the wall 100 is divided into a plurality of air chambers 140 by a plurality of partitions 130. In the present embodiment, in each of the six walls 100 of the cabinet body, the distance L between the inner wall 110 and the outer wall 120 (see FIG. 3) is all the same, and the volume of each of the plurality of air chambers 140 Are the same, but the interval L may be different for each wall 100, and the volume of the air chamber 140 may be different for each wall 100. Some of the partitions 130 are provided with communication holes 152 that allow the air chambers 140 to communicate with each other. In the present embodiment, a communication hole 152 is provided so that the two air chambers 140 communicate with each other. As shown in FIG. 3, holes 150 are provided in the inner wall 110 of the wall 100 to allow at least one of the plurality of air chambers 140 to communicate with the internal space of the cabinet body. More specifically, in the present embodiment, one hole 150 is provided in the inner wall 110 for two air chambers 140 that communicate with each other via the communication hole 152. The two air chambers 140 communicating with each other through the communication holes 152 communicate with the internal space of the cabinet body through the corresponding holes 150, and function as a resonance air chamber (body or cavity) of the Helmholtz sound absorber.

  As a specific configuration of the wall 100, as shown in FIG. 4, a configuration in which the honeycomb core 400 is sandwiched between two thin plate members 410A and 410B and holes 150 are provided in the plate member 410A corresponding to the inner side wall 110 is considered. As shown in FIG. 4, the opening area s of the hole 150 is smaller than the hexagonal area formed by the honeycomb core 400. It is generally known that a structure in which a honeycomb core is sandwiched between thin plate members can obtain light weight and high rigidity. Therefore, by using the structure shown in FIG. 4 for the wall 100, it is possible to increase the rigidity of the cabinet main body while avoiding an increase in the weight of the cabinet main body. From the viewpoint of avoiding an increase in the weight of the cabinet body, paper, resin, wood, or the like is preferable as the constituent material of the wall 100.

In the present embodiment, the generation of standing waves in the internal space of the cabinet body can be suppressed by the Helmholtz sound absorber formed by the two air chambers 140 communicating with each other via the communication hole 152. More specifically, first, attention is paid to a standing wave in a one-dimensional mode (axial wave) in the internal space of the cabinet body. If the distance between the walls 100 facing each other in the cabinet body is D, (1 or more natural number m) m of the one-dimensional mode generated between these walls 100 frequency f _m of the next standing wave below Equation (1). The order m of the standing wave in the one-dimensional mode represents the number of nodes in the standing wave whose amplitude is always zero. In the following equation (1), c is the speed of sound.

  Next, in each of the X direction, the Y direction, and the Z direction in FIG. 1, the two opposing walls 100 are adjusted so as to match the frequency of the standing wave of the one-dimensional mode generated between the opposing two walls 100. Adjust the sound absorption frequency of the formed Helmholtz sound absorber. Hereinafter, the case where the primary standing wave (standing wave indicated by a dotted line in FIG. 5) of the one-dimensional mode standing wave generated in the Y direction in FIG. 1 is suppressed will be described as an example. A method for adjusting the sound absorption frequency will be described. As shown in FIG. 5, the primary standing wave of the one-dimensional mode standing wave generated in the Y direction in FIG. 1 becomes an antinode where the amplitude becomes maximum near the wall 100F and the wall 100B, and the wall 100F And a node near the middle of the wall 100B.

As described above, in the present embodiment, a Helmholtz sound absorber is formed by the two air chambers 140 communicating with each other via the communication hole 152. The length of the neck of the Helmholtz sound absorber is the thickness 1 of the inner wall 110 (plate material 410A), and the opening area of the neck is the opening area s of the hole 150. When the volume of the air chamber 140 is V, the Helmholtz sound absorber 500A illustrated in FIG. 6 is formed by the two air chambers 140 that communicate with each other through the communication hole 152. Sound-absorption frequency _{f 0} of the Helmholtz sound absorber 500A is represented by the following formula (2). In the equation (2), δ is an opening end correction value, and when the diameter of the neck opening is d as shown in FIG. 6, δ ≒ 0.8 × d. The same manner, represented by n if (n is the natural number of 2 or more) Helmholtz sound absorber is formed by a number of air chambers 140, sound-absorption frequency f ₀ is the following equation (3) of the Helmholtz sound absorber to communicate with each other .

In the speaker 1 of the present embodiment, the volume V of the air chamber 140 is fixed. Therefore, the manufacturer adjusts the opening area s of the holes 150, either one of the number n of air chamber 140 communicating with each other through the communication hole 152, or by adjusting both the sound-absorption frequency f ₀ be able to. For example, either the back wall 100B and a front wall 100F, or both to form a plurality of Helmholtz sound absorber in the above manner, the sound absorption frequency f ₀ thereof Helmholtz sound absorber is to m = 1 in formula (1) _One of the opening area s of the hole 150 provided in the rear wall 100B and the front wall 100F and the number n of the air chambers 140 communicating with each other via the communication hole 152 so that the value becomes a value in the vicinity of the frequency f1 calculated as described above. By adjusting one or both of them, the generation of the primary standing wave in the Y direction can be suppressed.

Similarly, a plurality of Helmholtz sound absorber formed in one or both of the above manner of the right side wall 100R and the left side wall 100L, the sound-absorption frequency f ₀ thereof Helmholtz sound absorber, the said frequency f ₁ near the value Thus, by adjusting one or both of the opening area s of the hole 150 and the number n of the air chambers 140 communicating with each other via the communication hole 152, generation of a primary standing wave in the X direction is suppressed. be able to. Further, by forming a plurality of Helmholtz sound absorber in the above manner to one or both of the top panel wall 100T and bottom walls 100S, the sound-absorption frequency f ₀ thereof Helmholtz sound absorber, the said frequency f ₁ near the value as By adjusting one or both of the opening area s of the hole 150 and the number n of the air chambers 140 communicating with each other via the communication hole 152, the generation of the primary standing wave in the Z direction is suppressed. Can be.

  As described above, according to the present embodiment, it is possible to independently and independently suppress the primary standing wave in each of the X, Y, and Z directions. In addition, in the present embodiment, there is no need to install a sound absorbing material or another structure in the internal space of the cabinet main body, and the volume of the internal space of the cabinet main body is not compressed. That is, according to the present embodiment, it is possible to prevent the standing space of a specific frequency from being generated in the speaker cabinet 10 while avoiding a decrease in the volume of the internal space of the speaker cabinet 10 that houses the speaker unit 20. Thus, the reproduction sound quality can be improved. Further, according to the present embodiment, a part of or all of the six walls 100 of the cabinet main body has a double wall structure using a honeycomb core, thereby preventing the cabinet main body from increasing in weight. The rigidity of the main body can be increased.

(B: Second embodiment)
FIG. 7 is a diagram illustrating a configuration example of the wall 100 in the speaker 1 according to the second embodiment of the present invention, and FIG. 8 is a diagram in which a part of the plate member 410A is removed from FIG. As shown in FIG. 7, in the present embodiment, a hole 150 having substantially the same size as a hexagon formed by the honeycomb core 400 is provided in the plate 410A corresponding to the inner wall 110. In FIG. 7, the holes 150 are hatched. In the present embodiment, as shown in FIG. 8, the air chamber 140 communicating with the internal space of the cabinet body through the hole 150 has one end, and the three air chambers 140 arranged in a straight line without branching communicate with each other. In addition, a communication hole is provided over the entire surface of the partition 130 that partitions the three air chambers 140. As a result, in the present embodiment, as shown by a dotted rectangle in FIGS. 7 and 8, the air chamber 140 communicates with the internal space of the cabinet main body through the hole 150 and communicates with the air chamber 140 through the communication hole. The other air chamber 140 forms a one-side closed sound absorbing tube. By adjusting the length of the sound absorbing tube such that the sound absorbing frequency of the sound absorbing tube becomes a value near the frequency of the standing wave to be suppressed, the generation of the standing wave can be suppressed.

  In the present embodiment, the air chamber 140 communicating with the internal space of the cabinet main body through the hole 150 and the other air chamber 140 communicating with the air chamber 140 through the communication hole 152 form a one-side closed sound absorbing tube. The case where it does is explained. However, as shown in FIGS. 9 and 10, the air chambers 140 located at both ends of the plurality of air chambers 140 communicating with each other through the communication holes 152 without branching are formed into a hexagon formed by the honeycomb core 400. A two-sided closed sound absorbing tube is formed by communicating with the internal space of the cabinet main body through a hole 150 having substantially the same size, and the sound absorbing frequency of the sound absorbing tube is set to a value near the frequency of the standing wave to be suppressed. By adjusting the length of the sound absorbing tube, the generation of the standing wave can be suppressed.

  When the air chambers 140 at both ends of the plurality of air chambers 140 communicating with each other through the communication holes 152 without branching are communicated with the internal space of the cabinet main body through the holes 150, as shown in FIG. By making the hole 150 smaller than the hexagon formed by the honeycomb core 400, it is also possible to form a sound absorbing tube having a property intermediate between a one-side closed tube and a two-side open tube. Depending on the relationship with the frequency of the standing wave to be suppressed, it may be determined which one of a one-side closed tube, a two-side open tube, and a sound absorbing tube having a property intermediate between the two is formed.

  As described above, also in the present embodiment, a standing wave having a specific frequency is generated in the speaker cabinet 10 while preventing the volume of the internal space of the speaker cabinet 10 that houses the speaker unit 20 from being reduced. This can be suppressed, and the reproduction sound quality can be improved. Further, according to the present embodiment, similarly to the first embodiment, it is possible to increase the rigidity of the cabinet main body while avoiding an increase in the weight of the cabinet main body.

(C: Third embodiment)
FIG. 12 is a diagram illustrating a configuration example of the wall 100 in the speaker according to the third embodiment of the present invention. In FIG. 12, a part of the plate 410A of the inner wall 110 has been removed. As shown in FIG. 12, the opening area s of the hole 150 in the present embodiment is smaller than the hexagonal area formed by the honeycomb core 400 as in the first embodiment. As shown in FIG. 12, communication holes 152 are provided in a plurality of the six partitions 130 that define the air chamber 140 that communicates with the internal space of the cabinet body through the holes 150. As a result, in the speaker of the present embodiment, an acoustic maze structure is formed by the air chambers 140 communicating with the internal space of the cabinet body through the holes 150 and the plurality of air chambers 140 communicating with the air chambers 140 while branching. With this acoustic maze structure, the generation of standing waves over a wide frequency band is suppressed.

  As described above, according to the present embodiment, a standing wave is generated in the speaker cabinet 10 over a wide frequency band while avoiding a decrease in the volume of the internal space of the speaker cabinet 10 that houses the speaker unit 20. And the quality of reproduced sound can be improved. Further, according to the present embodiment, similarly to the first embodiment, it is possible to increase the rigidity of the cabinet main body while avoiding an increase in the weight of the cabinet main body.

(D: Modification)
As described above, the first to third embodiments of the present invention have been described. However, it is a matter of course that the following modifications are added to the above embodiments.
(1) In the first embodiment described above, the case where the standing wave having the lowest order among the standing waves in the one-dimensional mode, that is, the standing wave with m = 1 is suppressed. For the standing wave, that is, for the higher-order standing wave, the opening of the hole 150 is cut so that the sound absorption frequency f ₀ calculated according to the equation (3) becomes a value near the frequency fm of the _m-th standing wave. It can be suppressed by adjusting at least one of the area s and the number n of the air chambers 140 communicating with each other via the communication holes 152. Similarly, in the second embodiment, the sound absorption frequency f ₀ of the sound absorbing tube formed by the air chambers 140 communicating with each other via the communication holes is set to a value near the frequency fm of the _m-th standing wave. It can be suppressed by adjusting the length of the sound absorbing tube.

(2) In the cabinet body of each of the above embodiments, part or all of the six walls 100 is a hollow cube having a double-wall structure, but part or all of the six walls 100 is hollow having a double-wall structure. The present invention may be applied to a speaker 1A (see FIG. 13) in which a speaker unit 20 is housed in a speaker cabinet 10A having a rectangular parallelepiped cabinet body. FIG. 13 is a perspective view illustrating an appearance of a speaker 1A according to the present modification. The cabinet body of the speaker cabinet 10A has a hollow space having a length in the X direction in the internal space of Dx, a length in the Y direction of Dy (Dy ≠ Dx), and a length in the Z direction of Dz (Dz ≠ Dx or Dz ≠ Dy). It is a rectangular parallelepiped.

  FIG. 14 illustrates the waveform of a standing wave in a one-dimensional mode generated in the X, Y, and Z directions in the internal space of the cabinet body of the speaker cabinet 10A. In FIG. 14, the waveforms of the primary standing waves in the X, Y, and Z directions are drawn by dotted lines, and the waveforms of the secondary standing waves are drawn by dashed lines. In the case where the generation of one of the primary standing wave GX1 and the secondary standing wave GX2 in FIG. 14 is suppressed, at least one of the right side wall 100R and the left side wall 100L of the cabinet main body has the double wall structure described above. The sound absorbing frequency of a sound absorber (Helmholtz sound absorber or sound absorbing tube) formed by the plurality of air chambers 140 that form the air chamber 140 and communicate with each other through the communication hole 152 is close to the frequency of the standing wave to be suppressed. What is necessary is just to adjust the parameter of the said sound absorber so that it may become a value. The parameters of the sound absorber are the opening cross-sectional area s of the hole 150 and the number n of the air chambers 140 communicating with each other in the case of a Helmholtz sound absorber, and the length of the sound absorber in the case of a sound absorber. .

  Further, in the case of suppressing the generation of one of the primary standing wave GY1 and the secondary standing wave GY2 in FIG. 14, a plurality of air chambers are provided on at least one of the front wall 100F and the rear wall 100B of the cabinet body. 140 is formed, and the parameters of the sound absorber are adjusted such that the sound absorption frequency of the sound absorber formed by the plurality of air chambers communicating with each other through the communication hole 152 is a value near the frequency of the standing wave to be suppressed. You should do it. Similarly, when suppressing the generation of either the primary standing wave GZ1 or the secondary standing wave GZ2 in FIG. 14, a plurality of airflows are provided on at least one of the top wall 100T and the bottom wall 100S of the cabinet body. The chamber 140 is formed, and the parameters of the sound absorber are set so that the sound absorption frequency of the sound absorber formed by the plurality of air chambers communicating with each other through the communication hole 152 becomes a value near the frequency of the standing wave to be suppressed. It should be adjusted.

In the case where both the standing wave GX1 and the standing wave GX2 in FIG. 14 are to be suppressed, the sound absorber formed on at least one of the right side wall 100R and the left side wall 100L is one of the following two groups. The parameters of the sound absorber may be determined so as to belong to. The first group is a group of sound absorbers in which the sound absorption frequency f ₀ has a value near the frequency f ₁ of the primary standing wave. The second group is a group of sound absorbers in which the sound absorption frequency f ₀ has a value near the frequency f ₂ of the secondary standing wave. In this case, the number of sound absorbers belonging to the first group is a number corresponding to the magnitude of the primary standing wave, specifically, a magnitude corresponding to the magnitude of the amplitude at the antinode of the standing wave (the greater the magnitude, the larger the number). ), And the number of sound absorbers belonging to the second group is preferably a number corresponding to the magnitude of the secondary standing wave. According to this aspect, it is possible to suppress the standing waves of each order separately according to their magnitudes.

(3) In the first embodiment, the generation of the standing wave is suppressed by the Helmholtz resonator provided on the inner wall 110 of the two walls 100 facing each other in the direction in which the standing wave is generated. However, it is also possible to suppress the generation of the standing wave by a Helmholtz resonator provided on the inner wall 110 of the two walls 100 facing each other in a direction intersecting the direction in which the standing wave is generated. For example, the sound absorption frequency of the Helmholtz resonator provided on each of the inner walls 110 of the wall 100T and the wall 100S facing each other in the Z direction is close to the frequency of the one-dimensional mode standing wave GY2 generated in the Y direction. By adjusting the parameters of the Helmholtz resonator, it is possible to suppress the generation of the standing wave GY2. As described above, when the generation of the standing wave is suppressed by the Helmholtz resonator provided on the inner side wall 110 of the two walls 100 facing each other in the direction intersecting the direction in which the standing wave is generated, the antinode of the standing wave It is preferable to provide a Helmholtz resonator (more specifically, a neck of the Helmholtz resonator) near the position. This is because the generation of standing waves can be efficiently suppressed.

  For example, when the generation of the standing wave GY2 is suppressed by the Helmholtz resonator provided on the inner wall 110 of each of the wall 100T and the wall 100S, the antinode of the standing wave GY2 is in the vicinity of each of the wall 100B and the wall 100F, and Since it is located near the midpoint of the line segment drawn from the wall 100B to the wall 100F along the Y direction, a Helmholtz resonator is provided near each of the walls 100B and 100F in the wall 100T or 100S and near the midpoint. Preferably, it is provided. Similarly, it is also possible to suppress the generation of the standing wave by a sound absorbing tube provided on the inner side wall 110 of the two walls 100 facing each other in a direction intersecting the direction in which the standing wave is generated. It is preferable to provide an open end of the sound absorbing tube in the vicinity of the antinode of the standing wave.

(4) The sound absorption frequency f ₀ of the sound absorber formed on part or all of the wall 100 of the cabinet body in the speaker 1A of FIG. 13 is a value near the frequency f calculated according to the following equation (5). As described above, by adjusting the parameters of the sound absorber, it is also possible to suppress the generation of the standing wave of the high-dimensional mode of the two-dimensional mode or higher. Incidentally, m _x in the formula _(5), m _y and m _z is any integer of 0 or more both, represents the number of standing waves in the X direction, the section Y and Z directions of the high-dimensional mode . The standing wave of the one-dimensional mode described above, m _x, in any two of 0 of the m _y and m _z, remaining one is a standing wave of non-zero value, the high-dimensional mode constant the standing waves _m x, any one of _{m y} and _{m z} refers to a standing wave or _m x, standing waves do not both be 0 _{m y} and _{m z,} it is 0.

When both the standing wave in the one-dimensional mode and the standing wave in the high-dimensional mode are to be suppressed, each of the sound absorbers formed on a part or all of the wall of the cabinet body has the following two types. What is necessary is just to determine the parameters of the sound absorber so as to belong to any of the groups. The first group is a group of sound absorbers in which the sound absorption frequency f ₀ has a value near the frequency of the primary standing wave, and the second group is the sound absorption frequency f ₀ near the frequency of the standing wave in the high-dimensional mode. Is a group of sound absorbers having a value of. Also in this case, the number of sound absorbers belonging to the first group is a number corresponding to the size of the standing wave in the one-dimensional mode, and the number of sound absorbers belonging to the second group is the number of standing waves in the high-dimensional mode. Is preferably a number corresponding to the size of. According to this aspect, the standing wave in the one-dimensional mode and the standing wave in the high-dimensional mode can be suppressed separately according to their magnitudes.

(5) In each of the above embodiments, the Helmholtz sound absorber and the sound absorbing tube are formed by the air chamber 140 communicating with the internal space of the cabinet main body through the hole 150 and the air chamber 140 communicating with the air chamber 140 through the communication hole 152. And any one of the acoustic maze structures is formed, but all or any two of them may be formed. In short, the air chamber 140 communicating with the internal space through the hole 150 and the air chamber 140 communicating with the air chamber 140 through the communication hole 152 form at least one of the Helmholtz sound absorber, the sound absorbing tube, and the acoustic maze structure. Any form in which one is formed may be used. For example, in a mode in which a Helmholtz sound absorber or a sound absorbing tube is formed on the right side wall 100R of the cabinet body and an acoustic maze structure is formed on the left side wall 100L, a standing wave having a specific frequency in the X direction in the cabinet body. Can be suppressed by the Helmholtz sound absorber, and the generation of the standing wave in the X direction over a wide band can be suppressed by the acoustic maze structure. The right side wall 100R of the cabinet body has at least one of a Helmholtz sound absorber and a sound absorbing tube and an acoustic maze structure, and the left side wall 100L has at least one of a Helmholtz sound absorber and a sound absorbing tube and an acoustic maze structure. The same effect can be obtained in the embodiment.

(6) At least one of the six walls 100 or at least a part of the wall 100 that divides the inner space and the outer space of the cabinet body is laminated with a plurality of double wall structures in which a plurality of air chambers 140 are formed. May be configured. The speaker cabinet 10 may be configured by engraving a block configured by laminating a plurality of double wall structures in which a plurality of air chambers 140 are formed.

(7) In the above embodiment, the application example of the present invention to the speaker including the speaker unit and the speaker cabinet accommodating the speaker unit has been described. However, the speaker cabinet 10 of each of the above embodiments or the speaker in the modification (2). The cabinet 10A may be manufactured and sold alone. In short, at least a part of a wall that partitions an internal space for housing a speaker unit and an external space has a double wall structure in which a plurality of air chambers are formed, and at least one of the plurality of air chambers is provided. And a plurality of air chambers adjacent to the air chamber, wherein the air chamber communicates with the internal space via the hole, and a plurality of air chambers are provided. A speaker cabinet may be provided in which at least one of the walls partitioning each of the speaker cabinets is provided with a communication hole for communicating the air chambers.

  Further, a plate material constituting the wall 100 of the speaker cabinet 10, that is, a plate material having a double wall structure in which a plurality of air chambers are formed, and at least one of the plurality of air chambers communicates with the outside. A hole is provided on one surface, and at least one of the walls defining an air chamber communicating with the outside via the hole and each of a plurality of air chambers adjacent to the air chamber includes air chambers. May be manufactured and sold as a single body, provided with a communication hole for communicating with the plate. By configuring a speaker cabinet using such a plate material, the same effects as those of the above embodiments can be obtained. Further, by using the plate material as a building material for the interior of a building such as a house, it is possible to suppress the generation of standing waves in a room such as a house.

  1, 1A speaker, 10, 10A speaker cabinet, 20 speaker unit, 100 wall, 100F front wall, 100B rear wall, 100R right wall, 100L left wall, 100T top wall, 100S bottom Wall: 110: inner wall, 120: outer wall, 130: partition, 140: air chamber, 150: hole, 152: communication hole.

Claims (6)

At least a part of a wall that separates an internal space and an external space accommodating the speaker unit has a double wall structure in which a plurality of air chambers are formed, and at least one of the plurality of air chambers is A cabinet body provided with a hole communicating with the internal space provided on a wall surface on the internal space side,
At least one of the walls defining an air chamber communicating with the internal space through the hole and each of a plurality of air chambers adjacent to the air chamber is provided with a communication hole for communicating the air chambers. A speaker cabinet characterized by the following.   At least one of a Helmholtz sound absorber, a sound absorbing pipe, and an acoustic maze structure is formed by an air chamber communicating with the internal space through the hole and an air chamber communicating with the air chamber through the communication hole. The speaker cabinet according to claim 1, wherein:   At least one of the Helmholtz sound absorber and the sound absorbing tube is formed, and a sound absorbing frequency of the Helmholtz sound absorber or a sound absorbing frequency of the sound absorbing tube is a value near a frequency of a standing wave generated in the internal space. The speaker cabinet according to claim 2, wherein   At least one of the Helmholtz sound absorber and the sound absorbing tube is formed on a wall facing in a direction intersecting a direction in which the standing wave is generated, and is formed near an antinode of the standing wave. The speaker cabinet according to claim 3, wherein   The speaker according to any one of claims 1 to 4, wherein at least a part of a wall that partitions the internal space and the external space is configured by stacking a plurality of the double wall structures. cabinet. A plate material having a double wall structure in which a plurality of air chambers are formed, wherein a hole is provided on one surface for communicating at least one of the plurality of air chambers with the outside. A plate member, characterized in that at least one of walls defining an air chamber communicating with the air chamber and each of a plurality of air chambers adjacent to the air chamber is provided with a communication hole for communicating the air chambers.

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