WO2009130778A1

WO2009130778A1 - Speaker system

Info

Publication number: WO2009130778A1
Application number: PCT/JP2008/057957
Authority: WO
Inventors: 天平勝田; 弘司貝和
Original assignee: 東北パイオニア株式会社
Priority date: 2008-04-24
Filing date: 2008-04-24
Publication date: 2009-10-29

Abstract

A high-quality sound speaker system which restrains standing sound waves arising at a cabinet to reduce unwanted vibration. On a first cabinet (2) of a speaker system (1), at least one of a pair of planar surfaces (201, 203) in opposition to the acoustic radiation side of a speaker unit is formed in the inclined shape, more particularly a cross-sectional surface is formed in the trapezoidal shape such that a pair of planar surfaces (201, 203) are not paralleled. Therefore, generation of unwanted standing sound waves can be restrained, and high-quality sound waves can be radiated from an acoustic radiation section (210) on an acoustic port (21).

Description

Speaker system

The present invention relates to a speaker system.

A kelton bass reproduction speaker system in which a second cabinet is arranged in a first cabinet and two speaker units are arranged in the second cabinet is known (for example, see Patent Document 1).

JP 05-328473 A

However, for example, in the speaker system described in Patent Document 1, the first cabinet is formed in a rectangular parallelepiped, and a pair of opposing surfaces are formed in parallel, so that the stationary system is fixed between the pair of surfaces. Waves may be generated, causing problems such as unnecessary vibration, abnormal noise, and poor sound quality in the cabinet.

The present invention is an example of a problem to deal with such a problem. That is, it is an object of the present invention to suppress occurrence of standing waves in the cabinet to reduce unnecessary vibrations, to provide a high-quality speaker system, and the like.

In order to achieve such an object, the present invention comprises a configuration according to the following claims.

The speaker system according to the present invention includes a first cabinet, a second cabinet disposed in the first cabinet, and the first cabinet, the opening end of which is disposed in the first cabinet. A substantially cylindrical acoustic port formed on the acoustic radiation side, and a pair of speaker units arranged in the second cabinet so that the non-sound radiation side faces each other. At least one of the pair of surfaces is inclined so that the pair of surfaces facing the sound radiation side of the speaker unit are non-parallel.

FIG. 1A is a front view of a speaker system 1 according to an embodiment of the present invention, and FIG. 1B is a top view of the speaker system 1 shown in FIG. It is sectional drawing of the speaker system 1 shown to FIG. 1 (B). It is a schematic diagram for demonstrating the speaker system 1 shown in FIG. It is sectional drawing in the other position of the speaker system 1 shown in FIG. 5A is a cross-sectional perspective view of the speaker system 1, and FIG. 5B is a cross-sectional perspective view from another viewing direction of the speaker system 1. FIG. 3 is a diagram for explaining a speaker unit 31 (31A, 31B) and an audio signal processing device 70 of the speaker system 1. FIG. It is a figure for demonstrating the vehicle-mounted audio system 500 which employ | adopted the speaker system 1 which concerns on one Embodiment of this invention. FIG. 8A is a diagram for explaining the frequency response of the speaker system 1 according to one embodiment of the present invention, and FIG. 8B is a diagram for explaining the frequency response of the speaker system according to the comparative example. It is.

A speaker system according to an embodiment of the present invention is disposed in a first cabinet, a second cabinet disposed in the first cabinet, and the first cabinet, and an opening end portion is the first cabinet. A substantially cylindrical acoustic port formed on the acoustic radiation side of the cabinet, and a pair of speaker units disposed in the second cabinet so that the non-sound radiation side faces each other. The speaker unit is characterized in that at least one of the pair of surfaces is inclined so that the pair of surfaces facing the sound radiation side of the speaker unit are non-parallel.

In the above speaker system, since at least one surface of the pair of surfaces is inclined so that the pair of surfaces of the first cabinet facing the sound radiation side of the speaker unit are non-parallel, Since at least one surface of the pair of surfaces is inclined with respect to the bottom surface of the first cabinet, the generation of standing waves between the pair of surfaces of the first cabinet is suppressed. Can do. In addition, the speaker system can emit a relatively high quality reproduced sound.

The first cabinet is formed such that the distance between the pair of surfaces of the first cabinet is shorter on the acoustic port formation position side than on the bottom surface side.
Further, the first cabinet is characterized in that the distance between the surfaces of the pair of surfaces is shortened from the bottom surface portion toward the mounting position of the acoustic port. That is, the first cabinet is characterized in that the cross-sectional shape along the height direction passing through the central axis of the speaker unit is formed in a trapezoidal shape.

Hereinafter, a speaker system 1 according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a front view of a speaker system 1 according to an embodiment of the present invention. FIG. 1B is a top view of the speaker system 1 shown in FIG. FIG. 2 is a cross-sectional view of the speaker system 1 shown in FIG. Specifically, FIG. 2 is a cross-sectional view along the height direction passing through the central axis of the speaker unit.

FIG. 3 is a schematic diagram for explaining the speaker system 1 shown in FIG. 4 is a cross-sectional view at another position of the speaker system 1 shown in FIG. 5A is a cross-sectional perspective view of the speaker system 1, and FIG. 5B is a cross-sectional perspective view from another viewing direction of the speaker system 1. FIG. FIG. 6 is a diagram for explaining the speaker unit 31 (31 A, 31 B) and the audio signal processing device 70 of the speaker system 1.

The speaker system 1 according to the present embodiment can be employed in, for example, a bass reproduction speaker system, a so-called subwoofer.

The speaker system 1 according to the present embodiment includes a first cabinet 2 and a second cabinet 3 as shown in the drawings. The first cabinet 2 is also called an external cabinet, and the second cabinet 3 is also called an internal cabinet.
The first cabinet 2 accommodates a second cabinet 3 therein, and the second cabinet 3 is provided with a speaker unit 31. Specifically, the second cabinet 3 includes a pair (one set) of

speaker units

31A and 31B. The speaker units 31 A and 31 B are arranged so that the sound radiation directions are opposite to each other, and the phases of vibrations to the second cabinet 3 are opposite to each other, and unnecessary vibrations are compared in the second cabinet 3. Small.
The speaker system 1 according to the present embodiment includes an acoustic port 21 as a sound emitting unit 210 in the first cabinet 2. The speaker system 1 radiates reproduced sound from the sound emitting unit 210 when the speaker unit 31 is driven.

Specifically, the speaker system 1 is formed so that the rear part of the diaphragm of the speaker unit 31 of the second cabinet 3 is a sealed space. When the speaker system 1 is driven, a so-called Helmholtz resonance occurs due to the stiffness of the air in the first cabinet 2 and the equivalent mass of the air in the acoustic port 21, thereby performing low-frequency reproduction. The acoustic characteristic of the speaker system 1 has a band-pass characteristic that provides a relatively high sound pressure in a predetermined frequency range FL to FH due to the resonance.

Hereinafter, each component of the speaker system 1 will be described in detail with reference to the drawings.

[First cabinet 2]
The first cabinet 2 includes a housing 20, an acoustic port (also referred to as a port) 21, and a port cover 22. The acoustic port 21 corresponds to an embodiment of a sound emitting part and a cylindrical part. The port cover 22 corresponds to an embodiment of a lid (reflecting member).

For example, when viewed from the front side, the housing 20 of the first cabinet 2 is formed in a vertically long substantially box shape as shown in FIG. 1A, and when viewed from the upper surface side (top surface side), FIG. B) is formed in a rectangular shape, and the acoustic port 21 is formed such that the axis of the acoustic port 21 is disposed along the longitudinal direction. As shown in FIG. A cross-sectional shape along the vertical direction is formed in a trapezoidal shape.
As a material of the housing 20, for example, a known material such as a resin such as plastic, wood, metal, or alloy can be used. In addition, as the housing 20, it is preferable to employ a material having relatively high vibration resistance, rigidity, and the like, for example.

Specifically, the housing 20 includes a front surface portion 201, a rear surface portion 202, a bottom surface portion 203, an upper surface portion (top surface portion) 204, side surface portions 205 (205A, 205B), and corner portions 206 to 209.

The front part 201 is formed to be inclined with respect to the bottom part 203 by a specified angle (R1). The rear surface portion 202 is formed to be inclined with respect to the bottom surface portion 203 by a specified angle (R2). The top surface portion 204 is formed substantially parallel to the bottom surface portion 203. The side surface portions 205 (205A, 205B) are formed along a direction (vertical direction) orthogonal to the bottom surface portion 203, and are formed substantially parallel to each other at equal intervals.

Specifically, for example, as shown in FIG. 3, the first cabinet 2 includes a pair of surfaces (201, 202) of the first cabinet 2 facing the sound emission direction of the pair of speaker units 31 A, 31 B. Are formed in such a shape that they intersect each other at an intersection (or line of intersection) P2012 located outside the first cabinet 2.

That is, the first cabinet 2 has the pair of surfaces (201, 201) such that the pair of surfaces (201, 202) facing the acoustic emission side of the speaker unit 31 arranged in the second cabinet 3 are non-parallel. , 202) at least one surface is inclined.
The shape of the 1st cabinet 2 is not restricted to the said form. In the first cabinet 2, for example, one of the front surface portion 201 and the rear surface portion 202 is formed along a direction (vertical direction) orthogonal to the bottom surface portion 203, and the other surface is formed on the bottom surface portion 203. It may be formed in an inclined shape.

The first cabinet 2 has a pair of surfaces (201, 202) facing the acoustic radiation side of the speaker unit 31 arranged in the second cabinet 3 from the bottom surface 203 side to the acoustic port 21 formation position side. The surface distance is gradually reduced.
That is, the first cabinet 2 is formed such that the distance between the pair of surfaces (201, 202) of the first cabinet 2 is shorter on the acoustic port formation position side than on the bottom surface portion 203 side.

For example, in a general speaker system in which the first cabinet is formed in a rectangular parallelepiped, the distance between the front portion and the rear portion of the cabinet is parallel at a constant distance. In some cases, a standing wave having a wavelength of about 2 / n (n = 1, 2, 3,...) Of the distance L between the front surface portion and the rear surface portion is relatively large in the first cabinet 2. The characteristics may deteriorate.
On the other hand, in the speaker system 1 according to the present invention, as shown in FIGS. 2 and 3, the first cabinet 2 is formed in a trapezoidal cross section, so that the front surface portion 201 and the rear surface portion 202 are non-parallel. The front surface portion 201 and the rear surface portion 202 are formed so that the distance between the surfaces on the upper acoustic port forming position side is shorter than the bottom surface portion 203 side. Since it is formed to be inclined, the generation of the standing wave described above can be suppressed, and unnecessary vibration is relatively small. For this reason, the speaker system 1 can obtain relatively high-quality reproduced sound.

Further, the angle R1 between the bottom surface portion 203 and the front surface portion 201 may be the same as or different from the angle R2 between the bottom surface portion 203 and the rear surface portion 202. In the present embodiment, as shown in FIG. 3, the angles R1 and R2 are formed as acute angles, and the angle R1 is formed smaller than the angle R2, so that a standing wave or the like in the first cabinet 2 is unnecessary. Vibration can be further reduced.

Moreover, as shown in FIG. 2, you may provide an inclined surface part in the corner | angular part of each surface of the 1st cabinet 2. As shown in FIG. Specifically, as shown in FIG. 2, the corner 206 between the front surface 201 and the bottom surface 203, the corner 207 between the bottom 203 and the rear surface 202, and the rear surface 202 and the top surface 204. An inclined surface may be provided on at least one or all of the corner 208 between the corners 209 between the top surface portion 204 and the front surface portion 201. Since the 1st cabinet 2 has the said inclined surface part, the unnecessary vibration by the standing wave etc. which arise in the 1st cabinet 2 can be reduced more.

Further, the first cabinet 2 according to the present embodiment has a pair of surfaces (201, 202) of the first cabinet 2, as shown in FIGS. 1 (A), 1 (B), 2 and 3. A pair of surfaces (203, 204) formed in a direction perpendicular to the acoustic radiation direction of the pair of speaker units arranged in the second cabinet (minimum distance), or a pair of surfaces ( 205A, 205B) longer than the distance. That is, in the first cabinet 2 according to the present embodiment, the distance between the pair of surfaces (201, 202) along the acoustic direction SD of the

speaker units

31A, 31B of the second cabinet 3 is in a direction orthogonal thereto. The distance between the pair of surfaces (203, 204) along the distance or the distance between the pair of surfaces (205A, 205B) is long. In short, the first cabinet 2 is formed so that the longitudinal direction of the first cabinet 2 is substantially parallel to the acoustic radiation direction of the speaker unit.

The acoustic port 21 is disposed in the first cabinet 2 and has a substantially cylindrical shape. The acoustic port 21 has an opening end formed on the acoustic radiation side surface (front surface portion 201) of the first cabinet 2. The sound emitting unit 210 according to the present embodiment has an opening of the acoustic port 21 formed in the front surface part 201 of the first cabinet 2.

Specifically, the acoustic port 21 includes a trumpet-shaped portion 211, a tubular portion 212, and a rear end 213. Since the acoustic port 21 is formed in the shape described above, it is possible to suppress the generation of so-called wind noise during driving.
The cylindrical portion 212 is disposed in the first cabinet 2 and its axis (CL21) is substantially parallel to the center axis (CL3) of the speaker unit 31 (31A, 31B) by a specified distance (LZ2). It is formed as follows. Moreover, the cylindrical part 212 is formed so that the axis | shaft may become substantially parallel to the longitudinal direction of the 1st cabinet 2, as shown to FIG. 1 (B) and FIG.

Further, the acoustic port 21 extends so that the axial direction thereof is substantially parallel at a specified interval along the central axis of the speaker unit 31.
Therefore, when the pair of speaker units 31 (31A, 31B) is driven, even if vibration is generated in the acoustic port 21 due to the propagation of vibration from the speaker unit 31, the axial direction and the first cabinet 2 Since the longitudinal directions of the first cabinet 2 coincide with each other, the first cabinet 2 has a relatively high stability.

The acoustic port 21 is formed so that the central axis (CL21) of the cylindrical portion 212 is oblique with respect to a direction orthogonal to the front surface portion 201, specifically, an angle R1 (acute angle). That is, the front surface portion 201 of the first cabinet 2 is formed to have an acute angle with respect to the tubular portion 212 of the acoustic port 21.
Further, the cylindrical portion 212 of the acoustic port 21 includes a distance (LZ21A) between the central axis (CL21) of the cylindrical portion 212 and the top surface portion 204 of the first cabinet 2, and a central axis ( Specifically, the distance (LZ21B) is formed to be larger than the distance (LZ21A) so that the distance (LZ21B) between the CL21) and the bottom surface portion 203 of the first cabinet 2 is different. That is, the acoustic port 21 (sound emission part 210) is formed in the vicinity of the top surface part 204 of the first cabinet 2.

The trumpet-shaped portion 211 is formed on the acoustic radiation side of the tubular portion 212, and the opening end is formed on the front surface portion 201 of the first cabinet 2. Further, the trumpet-shaped portion 211 is formed in a shape in which the opening end portion on the acoustic radiation side is expanded in a trumpet shape, specifically, a shape in which the inner diameter increases from the inside to the opening side.
As described above, the acoustic port 21 has an axis formed obliquely with respect to a direction orthogonal to the front surface portion 201, and has a trumpet-shaped portion 211 at the opening end portion. Unnecessary sound can be reduced.
Further, the trumpet-shaped portion 211 is formed in a shape in which the end portion on the sound radiation side protrudes in the sound radiation direction longer than the upper end portion side 211A of the first cabinet 2 and smoothly expands on the bottom surface side 211B. .
That is, the acoustic port 21 is formed in a shape in which the end portion on the sound radiation side is expanded, and the end portion on the sound radiation side is longer than the upper end portion side of the cabinet and extends to the bottom surface portion side.
As described above, since the trumpet-shaped portion 211 of the acoustic port 21 is formed in a smoothly expanded shape, for example, a problem that a relatively high flow velocity distribution is locally generated at the port end portion is suppressed. Can do.

The rear end 213 is formed on the opposite end to the acoustic radiation side end of the cylindrical portion 212. In this embodiment, the rear end 213 is formed in a trumpet-shaped shape, so-called wind cut. Generation of unnecessary sounds such as sounds can be suppressed.

Also, the acoustic port 21 has an inner diameter of the port, an axial length, a shape, and the like so that the equivalent mass due to the air inside the port becomes a specified amount and the speaker system 1 generates a predetermined Helmholtz resonance.

The acoustic port 21 is not limited to the shape described above. For example, in the acoustic port 21, only the cylindrical portion 212 may be formed on the front surface portion 201.

The port cover 22 is formed in a shape that covers a part of the opening of the acoustic port 21 as shown in FIGS. 1 (A), 1 (B), 2, 4, and 5. Specifically, the port cover 22 is formed at a predetermined interval on the acoustic radiation side of the opening end of the acoustic port 21. Further, the port cover 22 has an upper portion joined to the top surface portion 204 of the first cabinet 2, a lower portion joined to the lower side of the first cabinet 2, or substantially in the vicinity of the central portion, and a lateral end portion of the first cover 2. The cabinet 2 is not joined. That is, an opening is formed in the horizontal direction between the port cover 22 and the first cabinet 2.

Specifically, an air passage 2201 that guides sound waves from the acoustic port 21 to the outside is formed between the port cover 22 and the front portion of the first cabinet 2. The ventilation path 2201 corresponds to an embodiment of the duct 220.
Sound waves from the acoustic port 21 are radiated through the ventilation path 2201 in a direction (horizontal direction) substantially orthogonal to the axial direction of the acoustic port 21 or in an oblique direction.

As described above, in this embodiment, the port cover 22 is provided in front of the acoustic radiation side of the acoustic port 21, the upper and lower portions of the port cover 22 are joined to the first cabinet 2, and the lateral end portion is the first end. Since it is formed in a structure that is not joined to the cabinet 2, for example, foreign matter can be prevented from entering the acoustic port 21 from the front, top, bottom, etc., and high-quality reproduced sound can be emitted in a substantially horizontal direction. it can.

Further, for example, as shown in FIGS. 1A and 1B, the width (F22) of the port cover 22 is shorter than the width (F210) of the opening end portion of the trumpet-shaped portion 211 of the acoustic port 21. Therefore, the reproduced sound can be efficiently radiated also to the front side of the acoustic port 21 in the axial direction.

Further, the port cover 22 is formed with a protruding portion 2222 that protrudes toward the sound emitting portion 210 of the acoustic port 21. Specifically, the protruding portion 2222 of the port cover 22 is formed in a smoothly raised shape centering on the position intersecting the axis of the acoustic port 21, and the sound wave emitted from the acoustic port 21 is transmitted to the port cover 22. The air can be efficiently radiated to the outside through the ventilation path 2201 formed by the protrusion 2222 and the acoustic port 21.

As shown in FIG. 2, the port cover 22 includes a first member 221 and a second member 222. Specifically, the port cover 22 is configured such that the first member 221 is disposed on the outside, the second member 222 is disposed on the inside (acoustic port side), and the second member 222 is joined to the first member 221. Yes. A protrusion 2222 is formed on the second member 222.

Further, the first cabinet 2 has a convex portion 23 having a sealed space (airtight space) formed therein in the vicinity of the lower front portion of the front portion 201 and below the port cover 22. The convex portion 23 is formed of, for example, a semi-translucent material, and transmits light generated by light emission of the light emitting element 231 provided on the front surface portion 201, for example, when driving or turning on the power. The light emitting element 231 may be controlled by a control circuit so as to emit light with a light emission intensity corresponding to the amplitude of an audio signal input to the speaker unit 31, for example.

[Second cabinet 3]
The second cabinet 3 is disposed in the first cabinet 2, and the housing 30 is formed in a substantially rectangular parallelepiped. The second cabinet 3 is provided with a plurality of speaker units 31, in this embodiment, a pair of

speaker units

31A and 31B.

Specifically, the second cabinet 3 according to the present embodiment includes a housing 30, a speaker unit 31 (31 A, 31 B), an amplifier 32, a substrate 33, a heat radiation fin 34, and a magnetic shielding member (plate-shaped member) 35. Have.

The housing 30 according to the present embodiment is formed in a rectangular parallelepiped shape so that the inside becomes a sealed space. As a forming material of the housing 30, for example, a known forming material such as a resin such as plastic, wood, metal, or alloy can be used. Moreover, the housing | casing 30 is being fixed to the bottom face part 203 of the 1st cabinet 2, the gravity center of the speaker system 1 becomes comparatively low, and can acquire comparatively high stability.

The speaker units 31 (31A, 31B) are arranged in the second cabinet 3 so that the non-sound radiation side (rear side) 31BK (opposite to the sound radiation side) faces each other, and the respective central axes It arrange | positions so that (CL3) may be located on the same axis | shaft. That is, the speaker units 31 (31A, 31B) are arranged so that the sound radiation directions (SD) are outward. In addition, the speaker unit 31 is arranged so as to be substantially parallel to the bottom surface portion 203 at a specified interval so that the central axis thereof is substantially parallel to the longitudinal direction of the first cabinet 2.

The speaker unit 31 according to the present embodiment includes a pair (one set) of

speaker units

31A and 31B. The

speaker units

31A and 31B have substantially the same configuration, and one speaker unit 31 will be described.

The speaker unit 31 includes, for example, a magnetic circuit 310, a frame 3101 joined to the magnetic circuit 310, and a vibrating body 314 that is arranged to vibrate on the frame 3101.
As the magnetic circuit 310, for example, an inner magnet type magnetic circuit, an outer magnet type magnetic circuit, or the like can be adopted. The outer magnet type magnetic circuit 310 according to the present embodiment includes a magnet 312 bonded to the yoke 311 and a plate 313 bonded to the magnet 312. In the magnetic circuit 310, a magnetic gap is formed between the plate 313 and the yoke 311.

The vibrating body 314 includes a voice coil bobbin 315, a voice coil 316, a diaphragm 317, a cap 317 A, an edge 318, and a damper 319.
A voice coil 316 wound around a voice coil bobbin 315 is loosely fitted in the magnetic gap of the magnetic circuit 310 and is arranged so as to freely vibrate. The voice coil bobbin 315 is supported by the frame 3101 through a damper 319 so as to be able to vibrate. Further, the outer end of the frame 3101 is fixed to the second cabinet 3.

As shown in FIGS. 2 and 6, the voice coil 316 of the speaker unit 31 is electrically connected to the amplifier 32, the external audio signal processing device 70, and the like via the

conductive wires

71 and 72, so that the audio A signal is input.
The diaphragm 317 is formed in a prescribed shape such as a cone shape, for example, an inner peripheral portion is fixed to the voice coil bobbin 315 with an adhesive or the like, and an outer peripheral portion is supported by the frame 3101 via an edge 318 so as to be able to vibrate. The diaphragm 317 has a cap 317A disposed at the center.

The pair of

speaker units

31A and 31B arranged in the second cabinet 3 are arranged with their respective magnets magnetized in the opposite directions along the sound radiation direction, and the respective voice coils. Are wound in the same winding direction, and when the same acoustic signal is input to the voice coil, each diaphragm vibrates so as to move in the opposite direction along the speaker central axis.

Further, as shown in FIG. 2, the housing 30 of the second cabinet 3 is provided with an audio signal processing circuit such as an amplifier 32 therein. Specifically, a substrate 33 is provided from the upper center portion of the housing 30 to the vicinity of the inner center portion, and an amplifier 32 is provided on the substrate 33. Further, as shown in FIGS. 2, 4, 5 (B), a heat radiation fin 34 for heat radiation of the amplifier 32 is provided on the housing 30. The heat radiating fins 34 according to the present embodiment are made of a relatively high heat conductive plate-like member, and are arranged in the vicinity of the acoustic port 21.
Further, the case 30 is provided with a magnetic-shielding member (plate-like member) 35 on its side surface portion in order to reduce leakage magnetic flux due to the speaker unit 31.
The casing 30 is provided with a reinforcing member 304 in the vicinity of the upper portion of the side surface on which the speaker unit 31 is provided.

The housing 30 of the second cabinet 3 is formed to be detachable from the first cabinet 2. Specifically, the second cabinet 3 is fixed to the fixing portion 301 of the bottom surface portion 203, and the bottom surface portion 203 is detachably fixed to the first cabinet 2 by an attachment fixing member 303. The housing 30 has a leg portion 302 formed at the lower portion thereof, and the leg portion 302 is fixed to a member to be attached such as a vehicle body.
In addition, a concave storage portion 301 C is formed on the bottom surface portion 203 of the housing 30, and wiring and the like are stored therein.

The shapes of the first cabinet 2 and the second cabinet 3 of the speaker system 1 according to the present embodiment will be described in detail.

As shown in FIG. 1B, the second cabinet 3 is formed in a rectangular parallelepiped, and the distance between the side portions (LY3) is the length between the side portions 205 (205A, 205B) of the second cabinet 2. (LY2) is formed in a shorter shape.
The central axis (CL3) of the second cabinet 3 is formed to be substantially parallel to the central axis (CL2) of the first cabinet 2 and the central axis (CL2) of the acoustic port 21.

As shown in FIG. 3, the length LX204 along the longitudinal direction of the top surface portion 204 of the first cabinet 2 is formed shorter than the length (LX2) of the bottom surface portion 203.
Further, the first cabinet 2 is formed such that the length (LX21C) along the longitudinal direction in the vicinity of the port mounting portion is shorter than the length (LX2) of the bottom surface portion 203 of the first cabinet 2.
The length (LX21) in the axial direction of the acoustic port 21 is shorter than the length (LX204) along the longitudinal direction of the top surface portion 204 of the first cabinet 2.
The length (LX3) along the longitudinal direction of the second cabinet 3 is shorter than the length (LX2) along the longitudinal direction of the first cabinet 2.

As shown in FIG. 3, the distance (LZ21A) from the central axis (CL21) of the acoustic port 21 to the top surface portion 204 along the height direction (direction perpendicular to the bottom surface portion 203) is from the central axis (CL21) to the bottom surface. It is shorter than the distance (LZ21B) to the part 203.
The distance (LZ4) from the top surface of the second cabinet 3 to the top surface of the first cabinet 2 is the distance (LZ5) from the top surface of the second cabinet 3 to the bottom surface 203 of the first cabinet 2. ) Shorter.
The distance (LZ1) from the center line (CL3) of the speaker unit 31 to the bottom surface portion 203 of the first cabinet 2 is shorter than the distance (LZ3) from the center line (CL3) to the top surface portion 204 of the first cabinet 2. .

FIG. 7 is a diagram for explaining an in-vehicle audio system 500 that employs the speaker system 1 according to an embodiment of the present invention.
The speaker system 1 can be employed in an in-vehicle audio system 500 of a vehicle, for example, as shown in FIG. Specifically, for example, the speaker system 1 is disposed in the rear portion of the seat of the vehicle, in the trunk, and the like, and the bottom surface portion 203 of the first cabinet 2 is fixed to the vehicle. At this time, if the front surface portion 201 of the first cabinet 2 is formed at substantially the same angle as the inclination angle on the back surface side of the seat, for example, it can be disposed close to the seat, so that it can be efficiently arranged. Arrangement space can be secured. Even when the speaker system 1 is arranged as described above, high-quality sound waves can be efficiently emitted from the acoustic port 21.

In the speaker system 1 configured as described above, when the same audio signal is input to the

speaker units

31A and 31B, the vibration bodies of the

speaker units

31A and 31B vibrate and radiate sound waves in the acoustic radiation direction (SD). In addition, Helmholtz resonance occurs in the first cabinet 2 and the acoustic port 21, and a bass reproduction sound is radiated from the sound emitting unit 210 of the acoustic port 21.
At that time, vibrations are transmitted to the housing 30 from each of the

speaker units

31A and 31B. However, since the respective vibrations cancel each other in the housing 30 itself and inside the housing 30, generation of unnecessary vibrations should be suppressed. Can do.

Further, as shown in FIG. 2, the first cabinet 2 has at least one of the pair of surfaces such that the pair of surfaces (201, 203) facing the sound radiation side of the speaker unit are non-parallel. Since the surfaces (201, 203) are inclined, more specifically, the cross-sectional shape is formed in a trapezoidal shape, it is possible to suppress the occurrence of unnecessary standing waves in the first cabinet 2, and the high Sound quality sound waves can be emitted from the sound emitting unit 210 of the acoustic port 21.

In addition, as described above, the speaker unit 31 is disposed so that the central axis thereof is substantially parallel to the longitudinal direction of the first cabinet 2, so that unnecessary vibration of the first cabinet 2 itself is suppressed. Can do.

Moreover, since the 2nd cabinet 3 is formed in a rectangular parallelepiped and the 1st cabinet 2 is formed in cross-sectional trapezoid shape, a standing wave generate | occur | produces between the 1st cabinet 2 and the 2nd cabinet 3. Can be deterred.

FIG. 8A is a diagram for explaining the frequency response of the speaker system 1 according to an embodiment of the present invention. FIG. 8B is a diagram for explaining the frequency response of the speaker system (1COM) according to the comparative example. 8A and 8B, the vertical axis represents the sound pressure level FR (unit dB), and the horizontal axis represents the frequency F (unit Hz).

In the speaker system (1COM) according to the comparative example, the first cabinet is formed in a rectangular parallelepiped, and the second cabinet 3 is formed in a rectangular parallelepiped.

As shown in FIG. 8A, in the speaker system 1 according to the present invention, the sound pressure level increases from about 20 Hz to about 50 Hz, and the sound pressure level becomes maximum at a frequency range of about 50 to about 100 Hz. When the frequency is about 100 Hz or higher, the sound pressure level rapidly decreases (band pass characteristic). Further, the sound pressure level shows a maximum value in the vicinity of about 60 Hz.

On the other hand, as shown in FIG. 8B, in the speaker system (1COM) according to the comparative example, the peak value of the sound pressure level is relatively small, and an unnecessary peak occurs at a frequency of about 300 Hz or more.

As described above, in the speaker system 1 according to the present invention, the first cabinet 2 includes the pair of surfaces (201, 203) facing the sound radiation side of the speaker unit so that they are not parallel to each other. Since at least one of the surfaces (201, 203) is inclined, more specifically, the cross-sectional shape is formed in a trapezoidal shape, it is possible to prevent unnecessary standing waves from being generated, Sound quality sound waves can be emitted from the sound emitting unit 210 of the acoustic port 21.

The present invention is not limited to the above embodiment. For example, the port cover 22 of the first cabinet 2 may not be provided.
Further, the length, inner diameter, shape, and the like of the acoustic port 21 of the second cabinet 3 are not limited to the above embodiment.
The speaker unit 31 is not limited to the above embodiment.

Claims

A first cabinet;
A second cabinet disposed within the first cabinet;
A substantially cylindrical acoustic port disposed in the first cabinet and having an open end formed on an acoustic radiation side surface of the first cabinet;
A pair of speaker units disposed in the second cabinet so that the non-sound radiation side faces each other;
The speaker system according to claim 1, wherein at least one of the pair of surfaces is inclined such that the pair of surfaces facing the sound radiation side of the speaker unit are non-parallel. .
The first cabinet has at least one surface of the pair of surfaces with respect to the bottom surface of the first cabinet so that the pair of surfaces facing the sound radiation side of the speaker unit are non-parallel. The speaker system according to claim 1, wherein the speaker system is inclined.
The first cabinet is formed such that a distance between the pair of surfaces of the first cabinet is shorter on the acoustic port formation position side than on the bottom surface side. The speaker system described in 1.
The speaker system according to claim 1 or 2, wherein the second cabinet is formed so that the inside is a sealed space.
3. The speaker system according to claim 1 or 2, wherein the second cabinet is formed in a rectangular parallelepiped shape.
The speaker system according to claim 1 or 2, wherein the second cabinet is fixed to a bottom surface portion of the first cabinet.
The first cabinet is formed such that the distance between the pair of surfaces of the first cabinet is orthogonal to the acoustic radiation direction of the pair of speaker units arranged in the second cabinet. The speaker system according to claim 1, wherein the speaker system is longer than a distance between the pair of surfaces.
The speaker unit has a central axis substantially parallel to the bottom surface of the first cabinet and is disposed in the second cabinet at a certain distance. The speaker system according to claim 1 or 2.
The speaker according to claim 1 or 2, wherein the acoustic port is arranged in the first cabinet so that an axis of the acoustic port is parallel to a central axis of the speaker unit. system.
In the first cabinet, an opening end portion of the acoustic port is formed on one surface side of a pair of surfaces facing the pair of speaker units arranged in the second cabinet. The speaker system according to claim 1 or claim 2, wherein
The speaker system according to claim 1 or 2, wherein the acoustic port is formed in a shape in which an opening end portion is expanded in a trumpet shape.
The speaker system according to claim 1 or 2, wherein the first cabinet has a port cover that covers a part of the opening of the acoustic port.
3. The speaker system according to claim 1, wherein the pair of speaker units are driven in the same phase or in opposite phase by the same audio signal.