WO2021010280A1 - Speaker system and vehicle - Google Patents

Speaker system and vehicle Download PDF

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Publication number
WO2021010280A1
WO2021010280A1 PCT/JP2020/026862 JP2020026862W WO2021010280A1 WO 2021010280 A1 WO2021010280 A1 WO 2021010280A1 JP 2020026862 W JP2020026862 W JP 2020026862W WO 2021010280 A1 WO2021010280 A1 WO 2021010280A1
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WO
WIPO (PCT)
Prior art keywords
sound absorbing
sound
absorbing structure
room
standing wave
Prior art date
Application number
PCT/JP2020/026862
Other languages
French (fr)
Japanese (ja)
Inventor
本地　由和
内田　勝也
三木　晃
Original Assignee
ヤマハ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ヤマハ株式会社 filed Critical ヤマハ株式会社
Priority to CN202080050392.6A priority Critical patent/CN114097252A/en
Publication of WO2021010280A1 publication Critical patent/WO2021010280A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
    • H04R1/2807—Enclosures comprising vibrating or resonating arrangements
    • H04R1/2811—Enclosures comprising vibrating or resonating arrangements for loudspeaker transducers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R11/00—Arrangements for holding or mounting articles, not otherwise provided for
    • B60R11/02—Arrangements for holding or mounting articles, not otherwise provided for for radio sets, television sets, telephones, or the like; Arrangement of controls thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R11/00—Arrangements for holding or mounting articles, not otherwise provided for
    • B60R11/02—Arrangements for holding or mounting articles, not otherwise provided for for radio sets, television sets, telephones, or the like; Arrangement of controls thereof
    • B60R11/0217—Arrangements for holding or mounting articles, not otherwise provided for for radio sets, television sets, telephones, or the like; Arrangement of controls thereof for loud-speakers
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R11/00—Arrangements for holding or mounting articles, not otherwise provided for
    • B60R2011/0001—Arrangements for holding or mounting articles, not otherwise provided for characterised by position
    • B60R2011/0003—Arrangements for holding or mounting articles, not otherwise provided for characterised by position inside the vehicle
    • B60R2011/0036—Luggage compartment
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2201/00—Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
    • H04R2201/02—Details casings, cabinets or mounting therein for transducers covered by H04R1/02 but not provided for in any of its subgroups

Definitions

  • the present invention relates to a speaker system and a vehicle equipped with the speaker system.
  • Patent Document 1 In a vehicle provided with a passenger compartment and a trunk compartment, a vehicle in which a sound absorbing structure is arranged in the trunk compartment as described in Patent Document 1 is known for the purpose of reducing noise in the passenger compartment. There is.
  • the sound absorbing structure of Patent Document 1 reduces road noise generated from tires and standing waves in a trunk room.
  • One of the problems to be solved in this disclosure is to provide a technology capable of improving the sound environment in a space partitioned into two rooms by a partition member in which a speaker is installed.
  • the speaker system is attached to a partition member that divides a closed space into a first chamber and a second chamber, and outputs sound toward the first chamber. It includes a speaker and a sound absorbing structure provided in the first chamber or the second chamber and absorbing sound caused by a standing wave generated in the closed space.
  • FIG. 7 is a cross-sectional view taken along the line EE of FIG. It is a figure which shows the sound pressure distribution of the primary standing wave in the vehicle interior before and after the sound absorption structure is provided.
  • It is a side view which shows another example of arrangement of the sound absorbing structure composed of a tube sound absorbing body. It is a side view which shows still another example of arrangement of the sound absorbing structure composed of a tube sound absorbing body.
  • FIG. 5 is a side view showing still another example of the arrangement of a sound absorbing structure composed of a Helmholtz resonator. It is sectional drawing which shows another example of a Helmholtz resonator. FIG. 5 is a cross-sectional view showing still another example of a Helmholtz resonator. It is a side view which shows an example of the room to which the speaker system of this disclosure is applied together with the waveform of the primary standing wave. It is a figure which shows the distribution of the sound pressure of the primary standing wave in the room before and after the sound absorption structure is provided in the room shown in FIG.
  • FIG. 1 is a side view showing a vehicle provided with a speaker system according to an embodiment of the present disclosure.
  • the vehicle 1 has a closed space 9.
  • the closed space 9 is simply referred to as "space 9".
  • the space 9 has a vehicle compartment 2 which is an example of the first room and a trunk room 3 which is an example of the second room.
  • the passenger compartment 2 is a space for accommodating people.
  • a front seat 5a and a rear seat 5b are installed in the passenger compartment 2.
  • the space 9 is divided into a passenger compartment 2 and a trunk compartment 3 by a rear seat 5b and a rear tray 6 on the back surface thereof. That is, the rear seat 5b and the rear tray 6 serve as partition members for partitioning the space 9 into the vehicle interior 2 and the trunk compartment 3.
  • the speaker 7 is attached to the rear tray 6 with the sound emitting surface of the speaker 7 facing the passenger compartment 2.
  • the speaker 7 outputs sound toward the vehicle interior 2.
  • the speaker 7 is a speaker for reproducing low-pitched sound, and is referred to as a woofer unit or a subwoofer unit.
  • the rear tray 6 may be equipped with either or both of a mid-range sound reproduction speaker and a high-frequency sound reproduction speaker. Armrests 5c are provided between the left and right seats of the rear seats 5b.
  • the space 9 is divided into a passenger compartment 2 and a trunk compartment 3 by a rear seat 5b and a rear tray 6. Therefore, the trunk room 3 acts as a cabinet that forms a space behind the speaker 7. Normally, the passenger compartment 2 and the trunk compartment 3 are independent spaces. Therefore, standing waves due to the size of the respective spaces are generated in each of the passenger compartment 2 and the trunk compartment 3. However, if the rear tray 6 is arranged with a speaker 7 for reproducing a low-frequency sound having a larger diameter than a speaker for reproducing a mid-range sound and a speaker for reproducing a high-frequency sound, the speaker 7 The passenger compartment 2 and the trunk compartment 3 are acoustically connected via the diaphragm.
  • the reproduction frequency band of the speaker 7 includes the frequency of the primary standing wave among the frequencies of the standing wave.
  • the reproduction frequency band means the effective frequency range specified in the Japan Electronics and Information Technology Industries Association standard JEITA RC-8124C "speaker system".
  • the standing wave shown in FIG. 3 is generated in the space 9 from the front end 2a of the passenger compartment 2 to the rear end 3a of the trunk room 3.
  • the front end 2a and the rear end 3a are examples of the two ends of the space 9.
  • the primary standing wave having the lowest frequency is the length in the front-rear direction of the space 9 (between the front end portion 2a and the rear end portion 3a) in the case of a general vehicle. It has a wavelength (1 wavelength) twice as long as (distance) L.
  • the frequency of this primary standing wave is about 60 Hz when the length L of the space 9 is 2.83 m.
  • the frequency of the primary standing wave is the fundamental frequency of the standing wave.
  • FIG. 4 is a diagram showing the relationship between the sound pressure at the rear end 3a of the trunk room 3 and the frequencies of the primary, secondary, and tertiary standing waves. Not only when the primary standing wave (60Hz) is generated, but also when the secondary standing wave (120Hz) is generated and when the tertiary standing wave (180Hz) is generated, at the rear end 3a of the trunk room 3. The sound pressure of is the highest. The sound pressure at the front end 2a of the passenger compartment 2 is also the highest when a standing wave is generated, similarly to the sound pressure at the rear end 3a of the trunk room 3.
  • FIG. 5 is a graph showing the relationship between the sound pressure at the point 5a1 (see FIGS. 1 and 3) of the front seat 5a and the frequency of the standing wave.
  • the sound pressure changes according to the frequency of the standing wave (60 Hz, 120 Hz, 180 Hz).
  • the sound pressure of the sound output from the speaker 7 becomes extremely high or low at a specific position in the vehicle interior 2.
  • the primary standing wave greatly affects the change in sound pressure.
  • the sound absorbing structure 10A is attached to the trunk room 3 in order to suppress the standing wave, as shown in FIG.
  • the sound absorbing structure 10A is an aggregate of tubular sound absorbing bodies 10a to 10i.
  • the number of tube sound absorbers 10a to 10i is not limited to "8".
  • the sound absorbing structure 10A may have one or more tube sound absorbing bodies.
  • Each of the tube sound absorbing bodies 10a to 10i is a closed tube having a closed end portion 10x and an open end portion 10y, as shown in the cross-sectional view of FIG.
  • the closed end 10x is an example of a closed end in a tubular tube sound absorber.
  • the open end portion 10y is an example of the other end of the tubular sound absorbing body that is open.
  • the sound absorbing structure 10A is attached with the open end 10y of the pipe sound absorbing bodies 10a to 10i facing the rear end 3a of the trunk room 3.
  • the sound pressure of the standing wave becomes the highest. Since the sound absorbing structure 10 is attached with the open end 10y facing the rear end 3a, the sound absorbing structure 10A can effectively suppress standing waves.
  • each of the tube sound absorbing bodies 10a to 10i is composed of a closed tube as in this example, the tube sound absorbing bodies 10a to 10i resonate at frequencies of odd-order standing waves. Therefore, the sound absorbing structure 10 can efficiently suppress odd-order standing waves.
  • the length A of the inner space shown in FIG. 8 has a primary standing wave in the space 9, specifically, a frequency f1 (60 Hz).
  • the length shown in Eq. (1) is set so that the standing wave having the wavelength ⁇ ( ⁇ 2 L) resonates with the sound absorbing structure 10A.
  • the resonance frequency f0 of the sound absorbing structure 10A composed of the tube sound absorbing bodies 10a to 10i is substantially equal to the frequency f1 of the primary standing wave. Therefore, when the open end portion 10y of the sound absorbing structure 10A is located near the rear end portion 3a of the trunk room 3, the sound caused by the standing wave is absorbed by the sound absorbing structure 10A. Therefore, as shown in FIG. 9, when the sound absorbing structure 10A is installed, the sound pressure decreases at both ends of the space 9 and increases at the central portion of the space 9. Specifically, the sound pressure at the central portion of the space 9 increases by about 2 dB. That is, since the standing wave is suppressed, the change in sound pressure caused by the standing wave becomes small in the front and rear range in the vehicle in the space 9. As a result, the sound environment is improved, and the sound quality of the sound in the passenger compartment 2, for example, the sound output from the speaker 7 to the passenger compartment 2 is improved.
  • the sound absorbing structure 10A Since the sound absorbing structure 10A is installed in the trunk room 3, standing waves are suppressed. Therefore, in the passenger compartment 2 where a person rides, the sound in the low frequency range such as audio output from the speaker 7 to the passenger compartment 2 is not easily affected by the standing wave. Therefore, the sound environment is improved, and the sound quality of the sound in the passenger compartment 2, for example, the sound output from the speaker 7 to the passenger compartment 2 is improved.
  • the fundamental frequency of the standing wave that is, the frequency f1 of the primary standing wave is close to the resonance frequency f0 of the sound absorbing structure 10A.
  • the frequency f1 of the primary standing wave ranges from the frequency obtained by multiplying the resonance frequency f0 of the sound absorbing structure 10 by 0.9 to the frequency obtained by multiplying the resonance frequency f0 by 1.1. If it is within the range, a relatively good effect of suppressing standing waves can be obtained.
  • the sound absorbing structure 10A is attached to the bottom surface in the trunk room 3. Therefore, the sound absorbing structure 10A having a flat shape as shown in the illustrated example is fixed to the trunk room 3. As a result, the user can easily attach the sound absorbing structure 10A.
  • FIG. 10 shows an example of mounting the sound absorbing structure 10B in the vehicle of the present embodiment.
  • the sound absorbing structure 10B is arranged at a portion corresponding to the rear end of the vehicle 1 in the trunk room 3.
  • the tube sound absorbing body constituting the sound absorbing structure 10B extends in the vertical direction.
  • the sound absorbing structure 10B is attached so that the open end 10y of the pipe sound absorbing body faces the bottom surface of the trunk room 3 at the rear end 3a of the trunk room 3.
  • the sound absorbing structure 10B When the sound absorbing structure 10B is attached to the position corresponding to the rear end of the vehicle 1 in the trunk room 3, the sound absorbing structure 10B is required to have higher rigidity than the configuration in which the sound absorbing structure 10B is provided on the bottom surface of the trunk room 3. There is an advantage that it is not done.
  • the sound absorbing structures 10A, 10B, and 10C are attached independently. However, two or more of the sound absorbing structures 10A, 10B, and 10C may be attached to the vehicle 1.
  • the Helmholtz resonator 14A is a rectangular parallelepiped flat plate-shaped sound absorbing structure composed of a combination of plate materials.
  • the Helmholtz resonator 14A has one or more (three in the illustrated example) resonant air chambers 14a and one or more (three in the illustrated example) neck 14b.
  • the resonance air chamber 14a is an internal space of the hollow member 14a1.
  • the hollow member 14a1 has an opening 14a2.
  • the resonant air chamber 14a has a rectangular parallelepiped shape.
  • the neck 14b is an open tube.
  • the neck 14b corresponds one-to-one with the resonant air chamber 14a.
  • the neck 14b communicates with the opening 14a2 of the corresponding resonant air chamber 14a. Therefore, the outside air can flow into the resonance air chamber 14a through the neck 14b.
  • the neck 14b is an example of a communication portion.
  • the resonance air chamber 14a side is the rear and the neck 14b side is the front.
  • the resonance air chamber 14a (hollow member 14a1) is formed by a bottom plate 15a, an upper plate 15b, a rear plate 15c, side plates 15d and 15e, and a partition plate 15f.
  • the top plate 15b is separated from the bottom plate 15a. There is a space between the bottom plate 15a and the top plate 15b.
  • the rear plate 15c is joined to the bottom plate 15a and the top plate 15b on the rear side of the Helmholtz resonator 14a.
  • the side plate 15d is joined to the bottom plate 15a and the top plate 15b on the left side of the Helmholtz resonator 14a.
  • the side plate 15e is joined to the bottom plate 15a and the top plate 15b on the right side of the Helmholtz resonator 14a.
  • the partition plate 15f extends in the left-right direction of the Helmholtz resonator 14a and is joined to the bottom plate 15a and the top plate 15b at a position between the front and the rear of the Helmholtz resonator 14a.
  • the two partition plates 15f are separated from each other, and the opening 14a2 is formed by the two partition plates 15f.
  • the neck 14b is formed by a bottom plate 15a, an upper plate 15b, and partition plates 15g and 15h.
  • the partition plates 15g and 15h extend from the front of the Helmholtz resonator 14a to the partition plate 15f, and are joined to the bottom plate 15a and the top plate 15b.
  • the resonance frequency f0 of the sound absorbing structure composed of the Helmholtz resonator 14A can be expressed by Eq. (2).
  • c is the speed of sound
  • s is the opening area of the neck 14b
  • V is the volume of the resonance air chamber 14a
  • l is the length of the neck 14b
  • ⁇ is the correction value of the opening end of the neck 14b.
  • the sound absorbing structure composed of the Helmholtz resonator 14A is provided on the bottom surface of the trunk chamber 3 with a ventilation gap between the neck 14b and the rear end portion 3a of the trunk chamber 3. It is attached.
  • the Helmholtz resonator 14A can be configured more compactly than the sound absorbing structures 10A to 10C composed of the tube sound absorbing body. Therefore, the arrangement of the sound absorbing structure becomes easy.
  • the Helmholtz resonator 14B may be attached to the rear end portion 3a in the trunk chamber 3.
  • a Helmholtz resonator 14B may be provided from the bottom surface of the trunk chamber 3 along the rear end 3a of the trunk chamber 3.
  • the neck 14b is located at the rear end 3a of the trunk chamber 3.
  • the Helmholtz resonator 14C may be mounted in front of the driver's seat, which is the front seat 5a.
  • the neck of the Helmholtz resonator 14C may be oriented sideways, and the open end of the neck may be located at the front end 2a of the passenger compartment 2.
  • the Helmholtz resonators 14A, 14B, and 14C are attached independently, but two or more of them may be attached to the vehicle 1.
  • FIG. 17 shows another example of the Helmholtz resonator.
  • the Helmholtz resonator 14D has a rectangular parallelepiped box-shaped resonant air chamber 14a and a neck 14b. The outside air can flow into the resonant air chamber 14a via the neck 14b.
  • the neck 14b has a through hole 14e provided in a thick front plate 14d.
  • FIG. 18 further shows another example of the Helmholtz resonator.
  • the Helmholtz resonator 14E has a rectangular parallelepiped box-shaped resonant chamber 14a and a neck 14b.
  • the neck 14b is composed of a tubular portion 14g provided on the front plate 14d.
  • the Helmholtz resonator 14E also includes one or more resonant air chambers 14ax and one or more necks 14bx on the sides of the Helmholtz resonator 14E.
  • the Helmholtz resonator 14E shown in FIG. 18 includes a plurality of resonant air chambers 14ax and a plurality of necks 14bx.
  • the hollow member 14ax1 having the resonance air chamber 14ax as an internal space has an opening 14ax2 on the side of the Helmholtz resonator 14E, that is, in a direction orthogonal to the direction in which the neck 14b extends.
  • the neck 14bx communicates with the opening 14ax2.
  • the resonance air chamber 14ax is provided for the purpose of suppressing a standing wave or the like having a frequency different from the frequency of the standing wave generated in the space 9 of the vehicle 1.
  • the resonance air chamber 14ax is provided in the trunk room 3 or the passenger compartment 2 in order to suppress a standing wave generated only in the trunk chamber 3 or only the passenger compartment 2, road noise generated in the tires, and the like.
  • the Helmholtz resonator 14E suppresses not only the standing wave of the space 9 composed of the passenger compartment 2 and the trunk compartment 3, but also other standing waves or noise, so that the passenger compartment is further suppressed.
  • the sound environment of 2 can be improved.
  • FIG. 19 is a side view showing an example of a room to which the speaker system of the present disclosure is applied, together with a waveform of a primary standing wave.
  • the room 20 is configured as a small space by a floor portion 21, a ceiling portion 22, front and rear wall portions 23 and 24, and side wall portions (not shown).
  • Room 20 is another example of a closed space.
  • the wall portions 23 and 24 include fittings such as a door between the floor portion 21 and the ceiling portion 22.
  • the partition member 25 is provided between the wall portions 23 and 24.
  • the partition member 25 divides the room 20 into a first room 26 and a second room 27.
  • a speaker 7 for reproducing low-pitched sound is attached to the partition member 25 with the sound emitting surface of the speaker 7 facing the first chamber 26.
  • the speaker 7 outputs sound toward the first chamber 26.
  • Room 20 is, for example, a karaoke room or a living room.
  • the speaker 7 acts to acoustically connect the first chamber 26 and the second chamber 27. Then, a standing wave having a waveform as shown by the alternate long and short dash line 28 is generated in one space formed by the first chamber 26 and the second chamber 27.
  • FIG. 20 shows changes in the sound pressure distribution before and after installing the sound absorbing structure that suppresses the primary standing wave in the second chamber 27 shown in FIG.
  • the sound absorbing structure when the sound absorbing structure is installed in one space formed by the first chamber 26 and the second chamber 27, the sound absorbing structure can suppress the standing wave and the sound in the bass range. Sound quality can be improved.
  • the sound absorbing structure may be installed in the first chamber 26.
  • the sound absorbing structure for example, the above-mentioned tube sound absorbing body or Helmholtz resonator is used.
  • the room 20 having this sound absorbing structure is, for example, a relatively narrow room of about 8 tatami mats or less in which a standing wave belonging to a low frequency range of 150 Hz or less becomes a problem, and suppresses the standing wave more preferably.
  • This sound absorbing structure may be adopted in a room of a larger size.
  • the first room 26 may be a living room and the second room 27 may be, for example, a walk-in closet.
  • a speaker that is attached to a partition member that divides a closed space into a first chamber and a second chamber and outputs sound toward the first chamber, and the first chamber or the first chamber. It is provided in two chambers, and includes a sound absorbing structure that absorbs sound caused by a standing wave generated in the closed space. Since the sound absorbing structure is provided in the first room or the second room, standing waves can be suppressed and the sound environment in a small space such as a vehicle interior can be improved.
  • the reproducible band of the speaker includes the frequency of the primary standing wave among the standing waves generated in the closed space.
  • the primary standing wave which has a particularly large effect on the reproduced sound, is suppressed. Therefore, the sound environment in a small space such as a vehicle interior can be satisfactorily improved.
  • the fundamental frequency of the standing wave is obtained by multiplying the resonance frequency by 1.1 from the frequency obtained by multiplying the resonance frequency of the sound absorbing structure by 0.9. It is in the range up to the frequency.
  • the fundamental frequency of the standing wave is within the range from the frequency obtained by multiplying the resonance frequency of the sound absorbing structure by 0.9 to the frequency obtained by multiplying the resonance frequency by 1.1. Standing waves are well suppressed.
  • the closed space has two ends, the partition member is provided between the two ends, and the wavelength of the standing wave having the fundamental frequency. Is twice as long as the distance between the two ends. In this case, since the standing wave having the resonance frequency is suppressed, the sound quality of the sound in the low frequency range is improved.
  • the first room is the passenger compartment of the vehicle
  • the second chamber is the trunk room of the vehicle.
  • the standing wave is suppressed in the vehicle. Therefore, the variation in the sound pressure distribution in the low frequency range such as audio in the vehicle interior is reduced, and the sound quality is improved.
  • the sound absorbing structure is located at the rear end of the vehicle in the trunk room. In this case, since the sound absorbing structure is attached to the trunk room, it is easier to secure the mounting space as compared with the configuration in which the sound absorbing structure is attached to the passenger compartment.
  • the sound absorbing structure is located on the bottom surface of the trunk room.
  • the sound absorbing structure can be easily attached as compared with the configuration in which the sound absorbing structure is located on the side surface of the trunk room.
  • At least a part of the sound absorbing structure is located in front of the driver's seat in the passenger compartment. In this case as well, since the standing wave is suppressed, the variation in the sound pressure distribution in the low frequency range such as audio in the vehicle interior is reduced, and the sound quality is improved.
  • the sound absorbing structure communicates with a tubular tube sound absorbing body having a closed end and an opened other end, or a hollow member having an opening, and the opening. It is provided with a communication unit and a Helmholtz resonator having. In this case, since the tube sound absorber or the Helmholtz resonator is provided as the sound absorbing structure, the standing wave is well suppressed.
  • the above-mentioned vehicle is equipped with the above-mentioned speaker system. Since the vehicle includes the speaker system having the sound absorbing structure described above, the standing wave in the internal space of the vehicle can be reduced, and the sound quality of the sound output from the speaker to the vehicle interior can be improved.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Multimedia (AREA)
  • Mechanical Engineering (AREA)
  • Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Details Of Audible-Bandwidth Transducers (AREA)

Abstract

A speaker system is provided with: a speaker 7 which is attached to a dividing member 6 that divides a space 9 into a first room 2 and a second room 3, and which outputs sound towards the first room 2; and a sound absorption structure 10A which is provided to the first room or the second room and absorbs sound caused by standing waves produced inside the space 9.

Description

スピーカーシステム及び車両Speaker system and vehicle
　本発明は、スピーカーシステムと、そのスピーカーシステムを備えた車両に関する。 The present invention relates to a speaker system and a vehicle equipped with the speaker system.
　人が乗車する車室とトランクルームとを備えた車両において、車室内の騒音を低減することを目的として、特許文献１に記載のような、トランクルームに吸音構造体が配置された車載が知られている。特許文献１の吸音構造体は、タイヤから発生したロードノイズおよびトランクルーム内の定在波を低減させる。 In a vehicle provided with a passenger compartment and a trunk compartment, a vehicle in which a sound absorbing structure is arranged in the trunk compartment as described in Patent Document 1 is known for the purpose of reducing noise in the passenger compartment. There is. The sound absorbing structure of Patent Document 1 reduces road noise generated from tires and standing waves in a trunk room.
特許第５３５９１６７号公報Japanese Patent No. 5359167
　本開示は、スピーカーが設置される仕切部材によって２つの室に仕切られる空間における音環境を改善できる技術を提供することを解決課題の一つとする。 One of the problems to be solved in this disclosure is to provide a technology capable of improving the sound environment in a space partitioned into two rooms by a partition member in which a speaker is installed.
　上述課題を解決するために、本開示の一態様に係わるスピーカーシステムは、閉じた空間を第１室と第２室とに仕切る仕切部材に取り付けられ、前記第１室に向けて音を出力するスピーカーと、前記第１室又は前記第２室に設けられ、前記閉じた空間に発生する定在波に起因する音を吸音する吸音構造体とを備える。 In order to solve the above-mentioned problems, the speaker system according to one aspect of the present disclosure is attached to a partition member that divides a closed space into a first chamber and a second chamber, and outputs sound toward the first chamber. It includes a speaker and a sound absorbing structure provided in the first chamber or the second chamber and absorbing sound caused by a standing wave generated in the closed space.
本開示の一実施形態に係るスピーカーシステムを備えた車両を示す側面図である。It is a side view which shows the vehicle which provided the speaker system which concerns on one Embodiment of this disclosure. スピーカーシステムにおけるスピーカーの配置を示す平面図である。It is a top view which shows the arrangement of the speaker in a speaker system. 吸音構造体を有しない車両における一次定在波の波形を示す側面図である。It is a side view which shows the waveform of the primary standing wave in the vehicle which does not have a sound absorbing structure. 車両のトランクルームの後端部における音圧と、定在波の周波数と、の関係を示す図である。It is a figure which shows the relationship between the sound pressure at the rear end part of the trunk room of a vehicle, and the frequency of a standing wave. 車両のフロントシートにおける音圧と、定在波の周波数と、の関係を示す図である。It is a figure which shows the relationship between the sound pressure in the front seat of a vehicle, and the frequency of a standing wave. 管吸音体によって構成される吸音構造体の配置例を示す平面図である。It is a top view which shows the arrangement example of the sound absorption structure which is composed of a tube sound absorption body. 管吸音体によって構成される吸音構造体の一例を示す斜視図である。It is a perspective view which shows an example of the sound absorption structure which is composed of a tube sound absorption body. 図７のＥ－Ｅ断面図である。FIG. 7 is a cross-sectional view taken along the line EE of FIG. 吸音構造体を設ける前と設けた後での車両室内の一次定在波の音圧分布を示す図である。It is a figure which shows the sound pressure distribution of the primary standing wave in the vehicle interior before and after the sound absorption structure is provided. 管吸音体によって構成される吸音構造体の配置の他の例を示す側面図である。It is a side view which shows another example of arrangement of the sound absorbing structure composed of a tube sound absorbing body. 管吸音体によって構成される吸音構造体の配置のさらに他の例を示す側面図である。It is a side view which shows still another example of arrangement of the sound absorbing structure composed of a tube sound absorbing body. ヘルムホルツ共鳴器によって構成される吸音構造体を示す斜視図である。It is a perspective view which shows the sound absorption structure which consists of a Helmholtz resonator. 図１２に示す吸音構造体の取付例を示す側面図である。It is a side view which shows the mounting example of the sound absorption structure shown in FIG. 図１２に示す吸音構造体の取付例を示す平面図である。It is a top view which shows the mounting example of the sound absorption structure shown in FIG. ヘルムホルツ共鳴器によって構成される吸音構造体の配置の他の例を示す側面図である。It is a side view which shows another example of the arrangement of the sound absorbing structure composed of a Helmholtz resonator. ヘルムホルツ共鳴器によって構成される吸音構造体の配置のさらに他の例を示す側面図である。FIG. 5 is a side view showing still another example of the arrangement of a sound absorbing structure composed of a Helmholtz resonator. ヘルムホルツ共鳴器の他の例を示す断面図である。It is sectional drawing which shows another example of a Helmholtz resonator. ヘルムホルツ共鳴器のさらに他の例を示す断面図である。FIG. 5 is a cross-sectional view showing still another example of a Helmholtz resonator. 本開示のスピーカーシステムを適用する部屋の一例を、一次定在波の波形と共に示す側面図である。It is a side view which shows an example of the room to which the speaker system of this disclosure is applied together with the waveform of the primary standing wave. 図１９に示した部屋において、吸音構造体を設ける前と設けた後での室内の一次定在波の音圧の分布を示す図である。It is a figure which shows the distribution of the sound pressure of the primary standing wave in the room before and after the sound absorption structure is provided in the room shown in FIG.
　以下、図面を参照しながら本開示に係る実施の形態を説明する。図面において、各部の寸法及び縮尺は実際のものと適宜異なる。以下に記載する実施の形態は、本開示の好適な具体例である。このため、本実施形態には、技術的に好ましい種々の限定が付されている。しかしながら、本開示の範囲は、以下の説明において特に本開示を限定する旨の記載がない限り、これらの形態に限られるものではない。 Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. In the drawings, the dimensions and scale of each part are appropriately different from the actual ones. The embodiments described below are preferred specific examples of the present disclosure. For this reason, the present embodiment is provided with various technically preferable limitations. However, the scope of the present disclosure is not limited to these forms unless otherwise stated in the following description to limit the present disclosure.
１．実施形態
　図１は、本開示の一実施形態に係るスピーカーシステムを備えた車両を示す側面図である。車両１は、閉じた空間９を有する。以下、閉じた空間９を、単に「空間９」と称する。空間９は、第１室の一例である車室２と、第２室の一例であるトランクルーム３とを有する。車室２は人を収容する空間である。車室２には、フロントシート５ａとリアシート５ｂとが設置される。空間９は、車室２とトランクルーム３とに、リアシート５ｂとその背面のリアトレイ６とにより仕切られる。すなわち、リアシート５ｂとリアトレイ６は、空間９を車室２とトランクルーム３とに仕切る仕切部材としての役目を果たす。 1. 1. Embodiment FIG. 1 is a side view showing a vehicle provided with a speaker system according to an embodiment of the present disclosure. The vehicle 1 has a closed space 9. Hereinafter, the closed space 9 is simply referred to as "space 9". The space 9 has a vehicle compartment 2 which is an example of the first room and a trunk room 3 which is an example of the second room. The passenger compartment 2 is a space for accommodating people. A front seat 5a and a rear seat 5b are installed in the passenger compartment 2. The space 9 is divided into a passenger compartment 2 and a trunk compartment 3 by a rear seat 5b and a rear tray 6 on the back surface thereof. That is, the rear seat 5b and the rear tray 6 serve as partition members for partitioning the space 9 into the vehicle interior 2 and the trunk compartment 3.
　図１と、図２の平面図に示すように、リアトレイ６にスピーカー７が、スピーカー７の放音面を車室２に向けた状態で取り付けられる。スピーカー７は、車室２に向けて音を出力する。スピーカー７は低音域の音の再生用のスピーカーであり、ウーハーユニット又はサブウーハーユニットと称される。リアトレイ６には、低音域の音の再生用のスピーカー７以外に、中音域の音の再生用のスピーカーあるいは高音域の音の再生用のスピーカーのいずれか又は双方が取り付けられてもよい。リアシート５ｂの左右の座席の間にアームレスト５ｃが設けられる。 As shown in the plan views of FIGS. 1 and 2, the speaker 7 is attached to the rear tray 6 with the sound emitting surface of the speaker 7 facing the passenger compartment 2. The speaker 7 outputs sound toward the vehicle interior 2. The speaker 7 is a speaker for reproducing low-pitched sound, and is referred to as a woofer unit or a subwoofer unit. In addition to the low-frequency sound reproduction speaker 7, the rear tray 6 may be equipped with either or both of a mid-range sound reproduction speaker and a high-frequency sound reproduction speaker. Armrests 5c are provided between the left and right seats of the rear seats 5b.
　図１に示すように、空間９が、車室２とトランクルーム３とに、リアシート５ｂとリアトレイ６とによって仕切られる。このため、トランクルーム３はスピーカー７の背後空間を形成するキャビネットとして作用する。通常は、車室２とトランクルーム３とは、独立した空間である。このため、車室２とトランクルーム３の各々に、それぞれの空間の大きさに起因する定在波が発生する。しかし、リアトレイ６に、中音域の音の再生用のスピーカーおよび高音域の音の再生用のスピーカーよりも、口径の大きい低音域の音の再生用のスピーカー７が配置された場合、スピーカー７の振動板を介して、車室２とトランクルーム３とが音響的に接続される。この結果、車室２とトランクルーム３とによって形成される空間９は、音響的には１つの空間として機能する。このため、図３に二点鎖線１１で示す波形を有する定在波が発生する。スピーカー７の再生周波数帯域は、この定在波の周波数のうち一次定在波の周波数を含む。再生周波数帯域とは、電子情報技術産業協会規格JEITA RC-8124C「スピーカシステム」に規定する実効周波数範囲を意味する。 As shown in FIG. 1, the space 9 is divided into a passenger compartment 2 and a trunk compartment 3 by a rear seat 5b and a rear tray 6. Therefore, the trunk room 3 acts as a cabinet that forms a space behind the speaker 7. Normally, the passenger compartment 2 and the trunk compartment 3 are independent spaces. Therefore, standing waves due to the size of the respective spaces are generated in each of the passenger compartment 2 and the trunk compartment 3. However, if the rear tray 6 is arranged with a speaker 7 for reproducing a low-frequency sound having a larger diameter than a speaker for reproducing a mid-range sound and a speaker for reproducing a high-frequency sound, the speaker 7 The passenger compartment 2 and the trunk compartment 3 are acoustically connected via the diaphragm. As a result, the space 9 formed by the vehicle interior 2 and the trunk compartment 3 acoustically functions as one space. Therefore, a standing wave having the waveform shown by the alternate long and short dash line 11 in FIG. 3 is generated. The reproduction frequency band of the speaker 7 includes the frequency of the primary standing wave among the frequencies of the standing wave. The reproduction frequency band means the effective frequency range specified in the Japan Electronics and Information Technology Industries Association standard JEITA RC-8124C "speaker system".
　図３に示す定在波は、車室２の前端部２ａからトランクルーム３の後端部３ａまでの空間９で発生する。前端部２ａと後端部３ａは、空間９の２つの端部の一例である。空間９で発生する定在波のうち、最も低い周波数を有する一次定在波は、一般的な車両の場合、空間９の前後方向の長さ（前端部２ａと後端部３ａとの間の距離）Ｌの２倍の長さの波長（１波長）を有する。この一次定在波の周波数は、空間９の長さＬが２．８３ｍである場合、約６０Ｈｚとなる。一次定在波の周波数は、定在波の基本周波数である。 The standing wave shown in FIG. 3 is generated in the space 9 from the front end 2a of the passenger compartment 2 to the rear end 3a of the trunk room 3. The front end 2a and the rear end 3a are examples of the two ends of the space 9. Among the standing waves generated in the space 9, the primary standing wave having the lowest frequency is the length in the front-rear direction of the space 9 (between the front end portion 2a and the rear end portion 3a) in the case of a general vehicle. It has a wavelength (1 wavelength) twice as long as (distance) L. The frequency of this primary standing wave is about 60 Hz when the length L of the space 9 is 2.83 m. The frequency of the primary standing wave is the fundamental frequency of the standing wave.
　車両内部には、一次定在波だけでなく、それ以上の次数、すなわち一次周波数（基本周波数である６０Ｈｚ）の整数倍の周波数を有する定在波も発生する。図４はトランクルーム３の後端部３ａにおける音圧と、一次、二次、及び三次定在波の周波数と、の関係を示す図である。一次定在波（６０Ｈｚ）が発生した場合のみならず、二次定在波（１２０Ｈｚ）が発生した場合および三次定在波（１８０Ｈｚ）が発生した場合においても、トランクルーム３の後端部３ａでの音圧が最高になる。車室２の前端部２ａにおける音圧も、トランクルーム３の後端部３ａにおける音圧と同様に、定在波が発生した場合に最高になる。 Inside the vehicle, not only a primary standing wave but also a standing wave having a higher order, that is, an integral multiple of the primary frequency (basic frequency of 60 Hz) is generated. FIG. 4 is a diagram showing the relationship between the sound pressure at the rear end 3a of the trunk room 3 and the frequencies of the primary, secondary, and tertiary standing waves. Not only when the primary standing wave (60Hz) is generated, but also when the secondary standing wave (120Hz) is generated and when the tertiary standing wave (180Hz) is generated, at the rear end 3a of the trunk room 3. The sound pressure of is the highest. The sound pressure at the front end 2a of the passenger compartment 2 is also the highest when a standing wave is generated, similarly to the sound pressure at the rear end 3a of the trunk room 3.
　図５はフロントシート５ａの点５ａ１（図１、図３参照）における音圧と、定在波の周波数と、の関係を示すグラフである。点５ａ１においては、定在波の周波数（６０Ｈｚ、１２０Ｈｚ、１８０Ｈｚ）に応じて音圧が変化する。このような定在波に起因する音圧の変化が、スピーカー７から車室２へ出力された音において品質の劣化を招く。すなわち、定在波の発生により、車室２内の特定位置において、スピーカー７から出力された音の音圧が、極端に高く又は低くなる。例えば車室２内の点５ａ１において、意図せずに音圧が変わり、音質の低下を招く。特に一次定在波は音圧の変化に大きく影響する。 FIG. 5 is a graph showing the relationship between the sound pressure at the point 5a1 (see FIGS. 1 and 3) of the front seat 5a and the frequency of the standing wave. At point 5a1, the sound pressure changes according to the frequency of the standing wave (60 Hz, 120 Hz, 180 Hz). Such a change in sound pressure caused by a standing wave causes deterioration in the quality of the sound output from the speaker 7 to the passenger compartment 2. That is, due to the generation of the standing wave, the sound pressure of the sound output from the speaker 7 becomes extremely high or low at a specific position in the vehicle interior 2. For example, at the point 5a1 in the passenger compartment 2, the sound pressure changes unintentionally, resulting in deterioration of sound quality. In particular, the primary standing wave greatly affects the change in sound pressure.
　定在波を抑制するため、本実施形態においては、図１に示すように、トランクルーム３に吸音構造体１０Ａが取り付けられる。図６の平面図および図７の斜視図に示すように、吸音構造体１０Ａは、管状の管吸音体１０ａ～１０ｉの集合体である。管吸音体１０ａ～１０ｉの数は「８」に限らない。吸音構造体１０Ａは、１以上の管吸音体を有すればよい。管吸音体１０ａ～１０ｉの各々は、図８の断面図に示すように、閉塞端部１０ｘと開口端部１０ｙとを有する閉管である。閉塞端部１０ｘは、管状の管吸音体における閉塞された一端の一例である。開口端部１０ｙは、管状の管吸音体における開口された他端の一例である。図６に示すように、吸音構造体１０Ａは、管吸音体１０ａ～１０ｉの開口端部１０ｙがトランクルーム３の後端部３ａに向いた状態で取り付けられる。トランクルーム３の後端部３ａでは、定在波の音圧が最高になる。開口端部１０ｙが後端部３ａに向けられた状態で吸音構造体１０が取り付けられるため、吸音構造体１０Ａは定在波を効果的に抑制できる。この例のように管吸音体１０ａ～１０ｉの各々が閉管で構成される場合、奇数次の定在波の周波数で管吸音体１０ａ～１０ｉは共鳴する。このため、吸音構造体１０は、奇数次の定在波を効率良く抑制できる。 In this embodiment, the sound absorbing structure 10A is attached to the trunk room 3 in order to suppress the standing wave, as shown in FIG. As shown in the plan view of FIG. 6 and the perspective view of FIG. 7, the sound absorbing structure 10A is an aggregate of tubular sound absorbing bodies 10a to 10i. The number of tube sound absorbers 10a to 10i is not limited to "8". The sound absorbing structure 10A may have one or more tube sound absorbing bodies. Each of the tube sound absorbing bodies 10a to 10i is a closed tube having a closed end portion 10x and an open end portion 10y, as shown in the cross-sectional view of FIG. The closed end 10x is an example of a closed end in a tubular tube sound absorber. The open end portion 10y is an example of the other end of the tubular sound absorbing body that is open. As shown in FIG. 6, the sound absorbing structure 10A is attached with the open end 10y of the pipe sound absorbing bodies 10a to 10i facing the rear end 3a of the trunk room 3. At the rear end 3a of the trunk room 3, the sound pressure of the standing wave becomes the highest. Since the sound absorbing structure 10 is attached with the open end 10y facing the rear end 3a, the sound absorbing structure 10A can effectively suppress standing waves. When each of the tube sound absorbing bodies 10a to 10i is composed of a closed tube as in this example, the tube sound absorbing bodies 10a to 10i resonate at frequencies of odd-order standing waves. Therefore, the sound absorbing structure 10 can efficiently suppress odd-order standing waves.
　管吸音体１０ａ～１０ｉで構成される吸音構造体１０Ａにおいて、図８に示す内空部の長さＡは、空間９における一次定在波、具体的には、周波数ｆ１（６０Ｈｚ）を有し波長λ（≒２Ｌ）を有する定在波と吸音構造体１０Ａが共鳴するように、（１）式で示す長さに設定される。
Figure JPOXMLDOC01-appb-M000001
 In the sound absorbing structure 10A composed of the tube sound absorbing bodies 10a to 10i, the length A of the inner space shown in FIG. 8 has a primary standing wave in the space 9, specifically, a frequency f1 (60 Hz). The length shown in Eq. (1) is set so that the standing wave having the wavelength λ (≈2 L) resonates with the sound absorbing structure 10A.
Figure JPOXMLDOC01-appb-M000001
　管吸音体１０ａ～１０ｉで構成される吸音構造体１０Ａの共鳴周波数ｆ０は、一次定在波の周波数ｆ１にほぼ等しい。このため、吸音構造体１０Ａの開口端部１０ｙが、トランクルーム３の後端部３ａ付近に位置する場合、定在波に起因する音が吸音構造体１０Ａに吸音される。このため、図９に示すように、吸音構造体１０Ａが設置される場合、空間９の両端部で音圧が下がり、且つ、空間９の中央部では音圧が上がる。具体的には空間９の中央部での音圧が２ｄB程度上がる。つまり、定在波が抑制されるため、空間９における車内の前後の範囲において、定在波に起因する音圧の変化が小さくなる。この結果、音環境が改善され、車室２内の音、例えば、スピーカー７から車室２へ出力された音、における音質が向上する。 The resonance frequency f0 of the sound absorbing structure 10A composed of the tube sound absorbing bodies 10a to 10i is substantially equal to the frequency f1 of the primary standing wave. Therefore, when the open end portion 10y of the sound absorbing structure 10A is located near the rear end portion 3a of the trunk room 3, the sound caused by the standing wave is absorbed by the sound absorbing structure 10A. Therefore, as shown in FIG. 9, when the sound absorbing structure 10A is installed, the sound pressure decreases at both ends of the space 9 and increases at the central portion of the space 9. Specifically, the sound pressure at the central portion of the space 9 increases by about 2 dB. That is, since the standing wave is suppressed, the change in sound pressure caused by the standing wave becomes small in the front and rear range in the vehicle in the space 9. As a result, the sound environment is improved, and the sound quality of the sound in the passenger compartment 2, for example, the sound output from the speaker 7 to the passenger compartment 2 is improved.
　吸音構造体１０Ａがトランクルーム３に設置されるため、定在波が抑制される。このため、人が乗車する車室２において、スピーカー７から車室２に出力されるオーデイオ等の低音域における音が、定在波の影響を受け難い。よって、音環境が改善され、車室２内の音、例えば、スピーカー７から車室２へ出力された音、において音質が向上する。 Since the sound absorbing structure 10A is installed in the trunk room 3, standing waves are suppressed. Therefore, in the passenger compartment 2 where a person rides, the sound in the low frequency range such as audio output from the speaker 7 to the passenger compartment 2 is not easily affected by the standing wave. Therefore, the sound environment is improved, and the sound quality of the sound in the passenger compartment 2, for example, the sound output from the speaker 7 to the passenger compartment 2 is improved.
　定在波の基本周波数、すなわち一次定在波の周波数ｆ１は、吸音構造体１０Ａの共鳴周波数ｆ０と、近いことが好ましい。具体的には、一次定在波の周波数ｆ１が、吸音構造体１０の共鳴周波数ｆ０に０．９を乗じることによって得られる周波数から共鳴周波数ｆ０に１．１を乗じることによって得られる周波数までの範囲内にあれば、比較的良好な定在波の抑制効果が得られる。 It is preferable that the fundamental frequency of the standing wave, that is, the frequency f1 of the primary standing wave is close to the resonance frequency f0 of the sound absorbing structure 10A. Specifically, the frequency f1 of the primary standing wave ranges from the frequency obtained by multiplying the resonance frequency f0 of the sound absorbing structure 10 by 0.9 to the frequency obtained by multiplying the resonance frequency f0 by 1.1. If it is within the range, a relatively good effect of suppressing standing waves can be obtained.
　図１、図６に示すように、吸音構造体１０Ａは、トランクルーム３において底面に取り付けられる。このため、図示例で示したような平坦な形状を有する吸音構造体１０Ａが、トランクルーム３に固定される。この結果、ユーザは、吸音構造体１０Ａを容易に取り付けることができる。 As shown in FIGS. 1 and 6, the sound absorbing structure 10A is attached to the bottom surface in the trunk room 3. Therefore, the sound absorbing structure 10A having a flat shape as shown in the illustrated example is fixed to the trunk room 3. As a result, the user can easily attach the sound absorbing structure 10A.
　図１０は本実施形態の車両における吸音構造体１０Ｂの取付例を示す。この取付例では、トランクルーム３において、車両１の後端に相当する部分に、吸音構造体１０Ｂが配置される。吸音構造体１０Ｂを構成する管吸音体は、上下方向に延在する。管吸音体の開口端部１０ｙが、トランクルーム３の後端部３ａにおいて、トランクルーム３の底面と対向するように、吸音構造体１０Ｂが取り付けられる。 FIG. 10 shows an example of mounting the sound absorbing structure 10B in the vehicle of the present embodiment. In this mounting example, the sound absorbing structure 10B is arranged at a portion corresponding to the rear end of the vehicle 1 in the trunk room 3. The tube sound absorbing body constituting the sound absorbing structure 10B extends in the vertical direction. The sound absorbing structure 10B is attached so that the open end 10y of the pipe sound absorbing body faces the bottom surface of the trunk room 3 at the rear end 3a of the trunk room 3.
　吸音構造体１０Ｂが、トランクルーム３における、車両１の後端部に相当する位置に取り付けられる場合、吸音構造体１０Ｂがトランクルーム３の底面に設ける構成に比較し、吸音構造体１０Ｂに高い剛性が要求されないという利点がある。 When the sound absorbing structure 10B is attached to the position corresponding to the rear end of the vehicle 1 in the trunk room 3, the sound absorbing structure 10B is required to have higher rigidity than the configuration in which the sound absorbing structure 10B is provided on the bottom surface of the trunk room 3. There is an advantage that it is not done.
　図１１は本実施形態の車両における吸音構造体１０Ｃの取付例をさらに示す。この例では、管吸音体によって構成される吸音構造体１０Ｃの少なくとも一部が、運転席であるフロントシート５ａより前に位置するように、吸音構造体１０Ｃが、車室２に取り付けられる。吸音構造体１０Ｃの開口端部１０ｙは、車室２の前端部２ａに位置する。より具体的には、車室２において助手席の底面と対向する部分から車室２の前面にわたって、吸音構造体１０Ｃが設けられる。吸音構造体１０Ｃは、車室２の前端部２ａに設けられるダッシュボードに取り付けられてもよい。管吸音体によって構成される吸音構造体１０Ａ～１０Ｃは、必要な管路長を確保するために、管路が曲がっていてもよい。 FIG. 11 further shows an example of mounting the sound absorbing structure 10C in the vehicle of the present embodiment. In this example, the sound absorbing structure 10C is attached to the passenger compartment 2 so that at least a part of the sound absorbing structure 10C composed of the pipe sound absorbing body is located in front of the front seat 5a which is the driver's seat. The open end portion 10y of the sound absorbing structure 10C is located at the front end portion 2a of the vehicle interior 2. More specifically, the sound absorbing structure 10C is provided from the portion of the passenger compartment 2 facing the bottom surface of the passenger seat to the front surface of the passenger compartment 2. The sound absorbing structure 10C may be attached to a dashboard provided at the front end portion 2a of the vehicle interior 2. The sound absorbing structures 10A to 10C composed of the pipe sound absorbing bodies may have curved pipes in order to secure the required pipe length.
　上述の例では吸音構造体１０Ａ、１０Ｂ、及び１０Ｃがそれぞれ単独に取り付けられる。しかしながら、吸音構造体１０Ａ、１０Ｂ、及び１０Ｃのうちの２つ以上が車両１に取り付けられてもよい。 In the above example, the sound absorbing structures 10A, 10B, and 10C are attached independently. However, two or more of the sound absorbing structures 10A, 10B, and 10C may be attached to the vehicle 1.
　車室２に吸音構造体１０Ｃが設けられる場合にも、定在波の抑制することが可能であり、低音域における音の音質が向上する。 Even when the sound absorbing structure 10C is provided in the passenger compartment 2, standing waves can be suppressed and the sound quality of the sound in the low frequency range is improved.
　本開示において、吸音構造体としては、管吸音体のみならず、図１２に示すようなヘルムホルツ共鳴器１４Ａが用いられてもよい。ヘルムホルツ共鳴器１４Ａは、板材の組み合わせにより構成された直方体形の平板状の吸音構造体である。 In the present disclosure, as the sound absorbing structure, not only a tube sound absorbing body but also a Helmholtz resonator 14A as shown in FIG. 12 may be used. The Helmholtz resonator 14A is a rectangular parallelepiped flat plate-shaped sound absorbing structure composed of a combination of plate materials.
　ヘルムホルツ共鳴器１４Ａは、1つ以上（図示例は３つ）の共鳴気室１４ａと、1つ以上（図示例は３つ）のネック１４ｂと、を有する。共鳴気室１４ａは、中空の部材１４ａ１の内部空間である。中空の部材１４ａ１は、開口部１４ａ２を有する。共鳴気室１４ａは、直方体の形状を有する。ネック１４ｂは、開管である。ネック１４ｂは、共鳴気室１４ａと１対１に対応する。ネック１４ｂは、対応する共鳴気室１４ａの開口部１４ａ２と連通する。このため、外気は、ネック１４ｂを介して共鳴気室１４ａに流入できる。ネック１４ｂは、連通部の一例である。説明の便宜のため、共鳴気室１４ａ側を後、ネック１４ｂ側を前とする。
　共鳴気室１４ａ（中空の部材１４ａ１）は、底板１５ａと、上板１５ｂと、後板１５ｃと、側板１５ｄ及び１５ｅと、仕切板１５ｆと、によって形成される。上板１５ｂは、底板１５ａから離れている。底板１５ａと上板１５ｂとの間に空間が存在する。後板１５ｃは、ヘルムホルツ共鳴器１４ａの後側において、底板１５ａと上板１５ｂに接合される。側板１５ｄは、ヘルムホルツ共鳴器１４ａの左側において、底板１５ａと上板１５ｂに接合される。側板１５ｅは、ヘルムホルツ共鳴器１４ａの右側において、底板１５ａと上板１５ｂに接合される。仕切板１５ｆは、ヘルムホルツ共鳴器１４ａの左右方向に延在し、ヘルムホルツ共鳴器１４ａの前と後の間の位置において、底板１５ａと上板１５ｂとに接合される。２つの仕切板１５ｆは、相互に離れており、２つの仕切板１５ｆによって開口部１４ａ２が形成される。
　ネック１４ｂは、底板１５ａと、上板１５ｂと、仕切板１５ｇ及び１５ｈにより形成される。仕切板１５ｇ及び１５ｈは、ヘルムホルツ共鳴器１４ａの前から仕切板１５ｆまで延在し、底板１５ａと上板１５ｂとに接合される。 The Helmholtz resonator 14A has one or more (three in the illustrated example) resonant air chambers 14a and one or more (three in the illustrated example) neck 14b. The resonance air chamber 14a is an internal space of the hollow member 14a1. The hollow member 14a1 has an opening 14a2. The resonant air chamber 14a has a rectangular parallelepiped shape. The neck 14b is an open tube. The neck 14b corresponds one-to-one with the resonant air chamber 14a. The neck 14b communicates with the opening 14a2 of the corresponding resonant air chamber 14a. Therefore, the outside air can flow into the resonance air chamber 14a through the neck 14b. The neck 14b is an example of a communication portion. For convenience of explanation, the resonance air chamber 14a side is the rear and the neck 14b side is the front.
The resonance air chamber 14a (hollow member 14a1) is formed by a bottom plate 15a, an upper plate 15b, a rear plate 15c, side plates 15d and 15e, and a partition plate 15f. The top plate 15b is separated from the bottom plate 15a. There is a space between the bottom plate 15a and the top plate 15b. The rear plate 15c is joined to the bottom plate 15a and the top plate 15b on the rear side of the Helmholtz resonator 14a. The side plate 15d is joined to the bottom plate 15a and the top plate 15b on the left side of the Helmholtz resonator 14a. The side plate 15e is joined to the bottom plate 15a and the top plate 15b on the right side of the Helmholtz resonator 14a. The partition plate 15f extends in the left-right direction of the Helmholtz resonator 14a and is joined to the bottom plate 15a and the top plate 15b at a position between the front and the rear of the Helmholtz resonator 14a. The two partition plates 15f are separated from each other, and the opening 14a2 is formed by the two partition plates 15f.
The neck 14b is formed by a bottom plate 15a, an upper plate 15b, and partition plates 15g and 15h. The partition plates 15g and 15h extend from the front of the Helmholtz resonator 14a to the partition plate 15f, and are joined to the bottom plate 15a and the top plate 15b.
　ヘルムホルツ共鳴器１４Ａによって構成される吸音構造体の共鳴周波数ｆ０は（２）式により表現できる。（２）式において、ｃは音速、ｓはネック１４ｂの開口面積、Ｖは共鳴気室１４ａの容積、lはネック１４ｂの長さ、δはネック１４ｂの開口端の補正値である。
Figure JPOXMLDOC01-appb-M000002
 The resonance frequency f0 of the sound absorbing structure composed of the Helmholtz resonator 14A can be expressed by Eq. (2). In equation (2), c is the speed of sound, s is the opening area of the neck 14b, V is the volume of the resonance air chamber 14a, l is the length of the neck 14b, and δ is the correction value of the opening end of the neck 14b.
Figure JPOXMLDOC01-appb-M000002
　ヘルムホルツ共鳴器１４Ａによって構成される吸音構造体は、図１３及び図１４に示すように、ネック１４ｂとトランクルーム３の後端部３ａとの間に通気用間隔が生じる状態で、トランクルーム３の底面に取り付けられる。ヘルムホルツ共鳴器１４Ａは、管吸音体によって構成される吸音構造体１０Ａ～１０Ｃと比較してコンパクトに構成できる。よって、吸音構造体の配置が容易となる。 As shown in FIGS. 13 and 14, the sound absorbing structure composed of the Helmholtz resonator 14A is provided on the bottom surface of the trunk chamber 3 with a ventilation gap between the neck 14b and the rear end portion 3a of the trunk chamber 3. It is attached. The Helmholtz resonator 14A can be configured more compactly than the sound absorbing structures 10A to 10C composed of the tube sound absorbing body. Therefore, the arrangement of the sound absorbing structure becomes easy.
　図１５に示すように、ヘルムホルツ共鳴器１４Ｂは、トランクルーム３内の後端部３ａに取り付けられてもよい。ヘルムホルツ共鳴器１４Ｂが、トランクルーム３の底面からトランクルーム３の後端部３ａに沿って設けられてもよい。この場合、少なくともネック１４ｂがトランクルーム３の後端部３ａに位置される。図１６に示すように、ヘルムホルツ共鳴器１４Ｃは、フロントシート５ａである運転席の前方に取り付けられてもよい。この場合は、ヘルムホルツ共鳴器１４Ｃのネックが横向でもよく、ネックの開口端が車室２の前端部２ａに位置してもよい。 As shown in FIG. 15, the Helmholtz resonator 14B may be attached to the rear end portion 3a in the trunk chamber 3. A Helmholtz resonator 14B may be provided from the bottom surface of the trunk chamber 3 along the rear end 3a of the trunk chamber 3. In this case, at least the neck 14b is located at the rear end 3a of the trunk chamber 3. As shown in FIG. 16, the Helmholtz resonator 14C may be mounted in front of the driver's seat, which is the front seat 5a. In this case, the neck of the Helmholtz resonator 14C may be oriented sideways, and the open end of the neck may be located at the front end 2a of the passenger compartment 2.
　上述の例では、ヘルムホルツ共鳴器１４Ａ、１４Ｂ、及び１４Ｃがそれぞれ単独に取り付けられたが、これらのうちの２つ以上が車両１に取り付けられてもよい。 In the above example, the Helmholtz resonators 14A, 14B, and 14C are attached independently, but two or more of them may be attached to the vehicle 1.
　図１７はヘルムホルツ共鳴器の他の例を示す。ヘルムホルツ共鳴器１４Ｄは、直方体の箱状に構成された共鳴気室１４ａと、ネック１４ｂと、を有する。外気は、ネック１４ｂを介して共鳴気室１４ａに流入可能である。ネック１４ｂは、厚みを持つ前板１４ｄに設けられた貫通孔１４ｅを有する。 FIG. 17 shows another example of the Helmholtz resonator. The Helmholtz resonator 14D has a rectangular parallelepiped box-shaped resonant air chamber 14a and a neck 14b. The outside air can flow into the resonant air chamber 14a via the neck 14b. The neck 14b has a through hole 14e provided in a thick front plate 14d.
　図１８はヘルムホルツ共鳴器の他の例をさらに示す。ヘルムホルツ共鳴器１４Ｅは、直方体の箱状に構成された共鳴気室１４ａと、ネック１４ｂと、を有する。ネック１４ｂは、前板１４ｄに設けられた筒状部１４ｇにより構成される。 FIG. 18 further shows another example of the Helmholtz resonator. The Helmholtz resonator 14E has a rectangular parallelepiped box-shaped resonant chamber 14a and a neck 14b. The neck 14b is composed of a tubular portion 14g provided on the front plate 14d.
　ヘルムホルツ共鳴器１４Ｅは、ヘルムホルツ共鳴器１４Ｅの側面にも、１つ以上の共鳴気室１４ａｘと、１つ以上のネック１４ｂｘと、を備える。図１８に示すヘルムホルツ共鳴器１４Ｅは、複数の共鳴気室１４ａｘと、複数のネック１４ｂｘと、を備える。
　共鳴気室１４ａｘを内部空間として有する中空の部材１４ａｘ１は、ヘルムホルツ共鳴器１４Ｅの側方、すなわちネック１４ｂが延在する方向に対して直交する方向に、開口部１４ａｘ２を有する。ネック１４ｂｘは、開口部１４ａｘ２と連通する。
　共鳴気室１４ａｘは、車両１の空間９で発生する定在波が有する周波数とは異なる周波数を有する定在波等を抑制する目的で設けられている。例えば共鳴気室１４ａｘは、トランクルーム３だけ、あるいは車室２だけに発生する定在波、又は、タイヤで発生するロードノイズ等を抑制するために、トランクルーム３あるいは車室２に設けられる。 The Helmholtz resonator 14E also includes one or more resonant air chambers 14ax and one or more necks 14bx on the sides of the Helmholtz resonator 14E. The Helmholtz resonator 14E shown in FIG. 18 includes a plurality of resonant air chambers 14ax and a plurality of necks 14bx.
The hollow member 14ax1 having the resonance air chamber 14ax as an internal space has an opening 14ax2 on the side of the Helmholtz resonator 14E, that is, in a direction orthogonal to the direction in which the neck 14b extends. The neck 14bx communicates with the opening 14ax2.
The resonance air chamber 14ax is provided for the purpose of suppressing a standing wave or the like having a frequency different from the frequency of the standing wave generated in the space 9 of the vehicle 1. For example, the resonance air chamber 14ax is provided in the trunk room 3 or the passenger compartment 2 in order to suppress a standing wave generated only in the trunk chamber 3 or only the passenger compartment 2, road noise generated in the tires, and the like.
　図１８に示すように、ヘルムホルツ共鳴器１４Ｅは、車室２とトランクルーム３とによって構成される空間９の定在波のみではなく、他の定在波又は雑音等を抑制するため、さらに車室２の音環境を改善できる。 As shown in FIG. 18, the Helmholtz resonator 14E suppresses not only the standing wave of the space 9 composed of the passenger compartment 2 and the trunk compartment 3, but also other standing waves or noise, so that the passenger compartment is further suppressed. The sound environment of 2 can be improved.
２．変形例
　図１９は本開示のスピーカーシステムを適用する部屋の一例を、一次定在波の波形と共に示す側面図である。
　部屋２０は、床部２１と、天井部２２と、前後の壁部２３及び２４と、不図示の側面の壁部と、によって、小空間として構成される。部屋２０は、閉じた空間の他の例である。壁部２３及び２４は、便宜上、床部２１と天井部２２との間のドア等の建具を含むとする。仕切部材２５は、壁部２３と２４との間に設けられる。仕切部材２５は、部屋２０を第１室２６と第２室２７とに仕切る。仕切部材２５には、低音域の音の再生用のスピーカー７が、スピーカー７の放音面が第１室２６に向けられた状態で取り付けられる。スピーカー７は、第１室２６に向けて音を出力する。 2. 2. Modified Example FIG. 19 is a side view showing an example of a room to which the speaker system of the present disclosure is applied, together with a waveform of a primary standing wave.
The room 20 is configured as a small space by a floor portion 21, a ceiling portion 22, front and rear wall portions 23 and 24, and side wall portions (not shown). Room 20 is another example of a closed space. For convenience, the wall portions 23 and 24 include fittings such as a door between the floor portion 21 and the ceiling portion 22. The partition member 25 is provided between the wall portions 23 and 24. The partition member 25 divides the room 20 into a first room 26 and a second room 27. A speaker 7 for reproducing low-pitched sound is attached to the partition member 25 with the sound emitting surface of the speaker 7 facing the first chamber 26. The speaker 7 outputs sound toward the first chamber 26.
　部屋２０は例えばカラオケ室または居室等である。この場合も車両１の場合と同様に、スピーカー７が第１室２６と第２室２７を音響的に接続するように作用する。そして第１室２６と第２室２７とによって形成される１つの空間に、二点鎖線２８で示すような波形を有する定在波が発生する。 Room 20 is, for example, a karaoke room or a living room. In this case as well, as in the case of the vehicle 1, the speaker 7 acts to acoustically connect the first chamber 26 and the second chamber 27. Then, a standing wave having a waveform as shown by the alternate long and short dash line 28 is generated in one space formed by the first chamber 26 and the second chamber 27.
　図２０は、図１９に示した第２室２７に、一次定在波を抑制する吸音構造体を設置する前と、設置した後の音圧分布の変化を示す。図２０に示すように、第１室２６と第２室２７とによって形成される１つの空間に吸音構造体が設置される場合、吸音構造体は、定在波を抑制でき、低音域における音の音質を改善できる。吸音構造体は、第１室２６に設置されてもよい。吸音構造体としては、例えば、上述した管吸音体又はヘルムホルツ共鳴器等が用いられる。この吸音構造体を有する部屋２０は、例えば１５０Hz以下の低音域に属する定在波が問題となる８畳程度以下の比較的狭い部屋であり、より好適に定在波を抑制する。この吸音構造体は、これ以上の広さの部屋に採用されてもよい。第１室２６が居室であって第２室２７が例えばウォークインクローゼットであってもよい。 FIG. 20 shows changes in the sound pressure distribution before and after installing the sound absorbing structure that suppresses the primary standing wave in the second chamber 27 shown in FIG. As shown in FIG. 20, when the sound absorbing structure is installed in one space formed by the first chamber 26 and the second chamber 27, the sound absorbing structure can suppress the standing wave and the sound in the bass range. Sound quality can be improved. The sound absorbing structure may be installed in the first chamber 26. As the sound absorbing structure, for example, the above-mentioned tube sound absorbing body or Helmholtz resonator is used. The room 20 having this sound absorbing structure is, for example, a relatively narrow room of about 8 tatami mats or less in which a standing wave belonging to a low frequency range of 150 Hz or less becomes a problem, and suppresses the standing wave more preferably. This sound absorbing structure may be adopted in a room of a larger size. The first room 26 may be a living room and the second room 27 may be, for example, a walk-in closet.
　前述した実施形態は、本開示の代表的な形態である。本開示は、前述した実施形態に限定されず、本開示の要旨を逸脱しない範囲において、種々の変更、付加が可能である。 The above-described embodiment is a typical embodiment of the present disclosure. The present disclosure is not limited to the above-described embodiment, and various modifications and additions can be made without departing from the gist of the present disclosure.
３．実施形態及び各変形例の少なくとも１つから把握される態様
　上述した実施形態及び各変形例の少なくとも１つから以下の態様が把握される。 3. 3. Aspects grasped from at least one of the embodiments and each modification The following aspects are grasped from at least one of the above-described embodiment and each modification.
　上述したスピーカーシステムの一態様は、閉じた空間を第１室と第２室とに仕切る仕切部材に取り付けられ、前記第１室に向けて音を出力するスピーカーと、前記第１室又は前記第２室に設けられ、前記閉じた空間に発生する定在波に起因する音を吸音する吸音構造体と、を備える。第１室又は第２室に吸音構造体が備えられるため、定在波が抑制され、車室等の小空間における音環境を改善することができる。 One aspect of the speaker system described above is a speaker that is attached to a partition member that divides a closed space into a first chamber and a second chamber and outputs sound toward the first chamber, and the first chamber or the first chamber. It is provided in two chambers, and includes a sound absorbing structure that absorbs sound caused by a standing wave generated in the closed space. Since the sound absorbing structure is provided in the first room or the second room, standing waves can be suppressed and the sound environment in a small space such as a vehicle interior can be improved.
　上述したスピーカーシステムの一態様は、前記スピーカーの再生可能帯域が、前記閉じた空間で発生する前記定在波のうち一次定在波の周波数を含む。この場合、特に再生音に対する影響が大きい一次定在波が抑制される。このため、車室等の小空間における音環境を良好に改善することができる。 In one aspect of the speaker system described above, the reproducible band of the speaker includes the frequency of the primary standing wave among the standing waves generated in the closed space. In this case, the primary standing wave, which has a particularly large effect on the reproduced sound, is suppressed. Therefore, the sound environment in a small space such as a vehicle interior can be satisfactorily improved.
　上述したスピーカーシステムの一態様において、前記定在波の基本周波数は、前記吸音構造体の共鳴周波数に０．９を乗じることによって得られる周波数から前記共鳴周波数に１．１を乗じることによって得られる周波数までの範囲内にある。この場合、定在波の基本周波数が、吸音構造体の共鳴周波数に０．９を乗じることによって得られる周波数から共鳴周波数に１．１を乗じることによって得られる周波数までの範囲内にあるため、定在波の抑制が良好に行なわれる。 In one aspect of the speaker system described above, the fundamental frequency of the standing wave is obtained by multiplying the resonance frequency by 1.1 from the frequency obtained by multiplying the resonance frequency of the sound absorbing structure by 0.9. It is in the range up to the frequency. In this case, since the fundamental frequency of the standing wave is within the range from the frequency obtained by multiplying the resonance frequency of the sound absorbing structure by 0.9 to the frequency obtained by multiplying the resonance frequency by 1.1. Standing waves are well suppressed.
　上述したスピーカーシステムの一態様において、前記閉じた空間は、２つの端部を有し、前記仕切部材は、前記２つの端部の間に設けられ、前記基本周波数を有する前記定在波の波長は、前記２つの端部の間の距離の２倍の長さである。この場合、共振周波数を有する定在波が抑制されるため、低音域における音の音質が向上する。 In one aspect of the speaker system described above, the closed space has two ends, the partition member is provided between the two ends, and the wavelength of the standing wave having the fundamental frequency. Is twice as long as the distance between the two ends. In this case, since the standing wave having the resonance frequency is suppressed, the sound quality of the sound in the low frequency range is improved.
　上述したスピーカーシステムの一態様において、前記第１室は車両の車室であり、前記第２室は前記車両のトランクルームである。この場合、車両において定在波が抑制される。このため、車室におけるオーデイオ等の低音域における音圧分布のばらつきが小さくなり、音質が向上する。 In one aspect of the speaker system described above, the first room is the passenger compartment of the vehicle, and the second chamber is the trunk room of the vehicle. In this case, the standing wave is suppressed in the vehicle. Therefore, the variation in the sound pressure distribution in the low frequency range such as audio in the vehicle interior is reduced, and the sound quality is improved.
　上述したスピーカーシステムの一態様において、前記吸音構造体は、前記トランクルームのうち前記車両の後端に位置する。この場合、トランクルームに吸音構造体が取り付けられるため、吸音構造体が車室に取り付ける構成に比較し、取付スペースが確保しやすい。 In one aspect of the speaker system described above, the sound absorbing structure is located at the rear end of the vehicle in the trunk room. In this case, since the sound absorbing structure is attached to the trunk room, it is easier to secure the mounting space as compared with the configuration in which the sound absorbing structure is attached to the passenger compartment.
　上述したスピーカーシステムの一態様において、前記吸音構造体は、前記トランクルームの底面に位置する。この場合、吸音構造体がトランクルームの底面に位置するため、吸音構造体がトランクルームの側面に位置する構成に比較して、吸音構造体を容易に取り付けることができる。 In one aspect of the speaker system described above, the sound absorbing structure is located on the bottom surface of the trunk room. In this case, since the sound absorbing structure is located on the bottom surface of the trunk room, the sound absorbing structure can be easily attached as compared with the configuration in which the sound absorbing structure is located on the side surface of the trunk room.
　上述したスピーカーシステムの一態様において、前記吸音構造体の少なくとも一部が、前記車室において運転席よりも前方に位置する。この場合も、定在波が抑制されるため、車室におけるオーデイオ等の低音域における音圧分布のばらつきが小さくなり、音質が向上する。 In one aspect of the speaker system described above, at least a part of the sound absorbing structure is located in front of the driver's seat in the passenger compartment. In this case as well, since the standing wave is suppressed, the variation in the sound pressure distribution in the low frequency range such as audio in the vehicle interior is reduced, and the sound quality is improved.
　上述したスピーカーシステムの一態様において、前記吸音構造体は、閉塞された一端と開口された他端とを有する管状の管吸音体、又は、開口部を有する中空の部材と、前記開口部と連通する連通部と、を有するヘルムホルツ共鳴器を備える。この場合、管吸音体又はヘルムホルツ共鳴器が吸音構造体として備えられるため、定在波の抑制が良好に行なわれる。 In one aspect of the speaker system described above, the sound absorbing structure communicates with a tubular tube sound absorbing body having a closed end and an opened other end, or a hollow member having an opening, and the opening. It is provided with a communication unit and a Helmholtz resonator having. In this case, since the tube sound absorber or the Helmholtz resonator is provided as the sound absorbing structure, the standing wave is well suppressed.
　上述課題を解決するために、上述した車両は、上述したスピーカーシステムを備える。車両が上述した吸音構造体を有するスピーカーシステムを備えるため、車両の内部空間での定在波が低減され、スピーカーから車室に出力された音の音質を向上することができる。 In order to solve the above-mentioned problems, the above-mentioned vehicle is equipped with the above-mentioned speaker system. Since the vehicle includes the speaker system having the sound absorbing structure described above, the standing wave in the internal space of the vehicle can be reduced, and the sound quality of the sound output from the speaker to the vehicle interior can be improved.
　１…車両、２…車室、３…トランクルーム、５ａ…フロントシート、５ｂ…リアシート、６…リアトレイ、７…スピーカー、９…空間、１０Ａ～１０Ｃ…吸音構造体（管吸音体）、１１、１２…一次定在波の波形、１４Ａ～１４Ｅ…吸音構造体（ヘルムホルツ共鳴器）、２０…部屋、２１…床部、２２…天井部、２３、２４…壁部、２５…仕切部材、２６…第１室、２７…第２室、２８、２９…定在波の波形、３０…吸音構造体。 1 ... Vehicle, 2 ... Car room, 3 ... Trunk room, 5a ... Front seat, 5b ... Rear seat, 6 ... Rear tray, 7 ... Speaker, 9 ... Space, 10A-10C ... Sound absorbing structure (tube sound absorbing body), 11, 12 ... Primary standing wave waveform, 14A-14E ... Sound absorbing structure (Helmholtz resonator), 20 ... Room, 21 ... Floor, 22 ... Ceiling, 23, 24 ... Wall, 25 ... Partition member, 26 ... No. 1st room, 27 ... 2nd room, 28, 29 ... Standing wave waveform, 30 ... Sound absorbing structure.

Claims (10)

  1. 　閉じた空間を第１室と第２室とに仕切る仕切部材に取り付けられ、前記第１室に向けて音を出力するスピーカーと、
    　前記第１室又は前記第２室に設けられ、前記閉じた空間に発生する定在波に起因する音を吸音する吸音構造体と、
    　を備えるスピーカーシステム。     A speaker that is attached to a partition member that divides a closed space into a first room and a second room and outputs sound toward the first room.
    A sound absorbing structure provided in the first chamber or the second chamber and absorbing sound caused by a standing wave generated in the closed space, and a sound absorbing structure.
    Speaker system with.
  2. 　前記スピーカーの再生周波数帯域は、前記閉じた空間で発生する前記定在波のうち一次定在波の周波数を含む請求項１に記載のスピーカーシステム。 The speaker system according to claim 1, wherein the reproduction frequency band of the speaker includes the frequency of the primary standing wave among the standing waves generated in the closed space.
  3. 　前記定在波の基本周波数は、前記吸音構造体の共鳴周波数に０．９を乗じることによって得られる周波数から前記共鳴周波数に１．１を乗じることによって得られる周波数までの範囲内にある請求項１又は２に記載のスピーカーシステム。 Claim that the fundamental frequency of the standing wave is in the range from the frequency obtained by multiplying the resonance frequency of the sound absorbing structure by 0.9 to the frequency obtained by multiplying the resonance frequency by 1.1. The speaker system according to 1 or 2.
  4. 　前記閉じた空間は、２つの端部を有し、
    　前記仕切部材は、前記２つの端部の間に設けられ、
    　前記基本周波数を有する前記定在波の波長は、前記２つの端部の間の距離の２倍の長さである、請求項１から３までのいずれか１項に記載のスピーカーシステム。     The closed space has two ends and
    The partition member is provided between the two ends.
    The speaker system according to any one of claims 1 to 3, wherein the wavelength of the standing wave having the fundamental frequency is twice as long as the distance between the two ends.
  5. 　前記第１室は車両の車室であり、前記第２室は前記車両のトランクルームである、請求項１から４までのいずれか１項に記載のスピーカーシステム。 The speaker system according to any one of claims 1 to 4, wherein the first room is a vehicle compartment and the second room is a trunk room of the vehicle.
  6. 　前記吸音構造体は、前記トランクルームのうち前記車両の後端に位置する、請求項５に記載のスピーカーシステム。 The speaker system according to claim 5, wherein the sound absorbing structure is located at the rear end of the vehicle in the trunk room.
  7. 　前記吸音構造体は、前記トランクルームの底面に位置する、請求項５に記載のスピーカーシステム。 The speaker system according to claim 5, wherein the sound absorbing structure is located on the bottom surface of the trunk room.
  8. 　前記吸音構造体の少なくとも一部が、前記車室において運転席よりも前方に位置する、請求項５に記載のスピーカーシステム。 The speaker system according to claim 5, wherein at least a part of the sound absorbing structure is located in front of the driver's seat in the passenger compartment.
  9. 　前記吸音構造体は、
    　閉塞された一端と、開口された他端と、を有する管状の管吸音体、又は、
    　開口部を有する中空の部材と、前記開口部と連通する連通部と、を有するヘルムホルツ共鳴器
    　を備える請求項１から４までのいずれか１項に記載のスピーカーシステム。     The sound absorbing structure is
    A tubular tube sound absorber with a closed end and an open end, or
    The speaker system according to any one of claims 1 to 4, further comprising a Helmholtz resonator having a hollow member having an opening and a communicating portion communicating with the opening.
  10. 　請求項５から８までのいずれか１項に記載のスピーカーシステムを備えた車両。 A vehicle equipped with the speaker system according to any one of claims 5 to 8.
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