Sound output device

Abstract

The present invention includes: a housing including an arrangement case forming an internal space and a sound duct forming a sound conduction space; a feedback microphone to which external sound is input; a first speaker unit that outputs sound; and a second speaker unit that outputs sound in an output frequency band different from the output frequency band of the sound output from the first speaker unit, wherein a first space and a second space are formed inside the housing, the feedback microphone and the first speaker unit are arranged in the first space, the second speaker unit is arranged in the second space, and an equalizer that separates the first space and the second space is arranged between the first speaker unit and the second speaker unit.

Description

Technical Field

[0001] The present technology relates to the technical field of a sound output device, which includes a first speaker unit and a second speaker unit that are different in terms of a sound output band. Background Art

[0002] There is a sound output device that is worn on the head or ears to be used as a headphone or earphone and outputs sound from a speaker.

[0003] In a sound output device, it is preferably ensured the output state of wide-band sound, and the quality of the sound heard by the user is improved by outputting wide-band sound.

[0004] In order to output such wide-band sound, there is a sound output device that includes a plurality of speaker units provided in a housing (for example, see Patent Document 1). In such a sound output device, the plurality of speaker units have different sound output bands, which enables the output of wide-band sound. The sound output device disclosed in Patent Document 1 is provided with, for example, two dynamic speaker units.

[0005] In addition, a sound output device having a configuration including the plurality of speaker units as described above may be provided with a feedback microphone, and external sound is input as noise to the feedback microphone, and may have a so-called noise cancellation function for ensuring high-quality sound by canceling the noise input to the feedback microphone.

[0006] Citation List

[0007] Patent Document

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-26746 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] Meanwhile, in a sound output device such as a headphone or earphone having a plurality of speaker units as described above, the plurality of speaker units output sound in different frequency bands. Therefore, the sound quality can be improved by outputting wide-band sound.

[0011] In addition, in a sound output device having a noise cancellation function, it is also desired that the sound quality is improved by improving the quality of the sound output from the plurality of speaker units due to appropriately performing the noise cancellation function.

[0012] In view of this, an object of the sound output device according to the present technology is to improve the sound quality and enhance the performance of the noise cancellation function.

[0013] Solutions to the Problems

[0014] First, the sound output device according to the present technology includes: a housing including a layout housing forming an internal space and a sound duct forming a sound conduction space; a feedback microphone into which external sound is input; a first speaker unit that outputs sound; and a second speaker unit that outputs sound with an output frequency band different from the output frequency band of the sound output from the first speaker unit. Wherein, a first space and a second space are provided inside the housing, the feedback microphone and the first speaker unit are arranged in the first space, the second speaker unit is arranged in the second space, and an equalizer that separates the first space and the second space is disposed between the first speaker unit and the second speaker unit.

[0015] With this configuration, the first space in which the feedback microphone and the first speaker unit are arranged and the second space in which the second speaker unit is arranged are separated by an equalizer, whereby the sound output from the second speaker unit is less likely to be input to the feedback microphone.

[0016] Second, in the above-mentioned sound output device, it is desirable that the second speaker unit is arranged in the conduction space.

[0017] This configuration eliminates the need to form a dedicated space inside the housing for arranging the second speaker unit.

[0018] Third, in the above-mentioned sound output device, it is desirable that the feedback microphone and the first speaker unit are held by the sound duct.

[0019] This configuration eliminates the need to arrange separate components for holding the feedback microphone and the first speaker unit respectively.

[0020] Fourth, in the above-mentioned sound output device, it is desirable that the sound duct is provided with a partition wall between the feedback microphone and the first speaker unit. The partition wall is formed with a communication hole that allows communication between the feedback microphone and the first speaker unit, and the communication hole penetrates in a direction perpendicular to the axial direction of the sound duct.

[0021] With this configuration, the direction in which the communication hole penetrates and the direction in which the conduction space extends are perpendicular to each other, which prevents the sound duct from being too long in one direction.

[0022] Fifth, in the above-mentioned sound output device, it is desirable that the first speaker unit and the second speaker unit are arranged separately from each other in the axial direction of the sound duct.

[0023] With this configuration, the first speaker unit and the second speaker unit are positioned separately from each other in the axial direction of the sound duct inside the sound duct, thereby effectively utilizing the space inside the sound duct.

[0024] Sixth, in the above-described sound output device, it is desirable that the first speaker unit and the feedback microphone are arranged separately from each other in a direction perpendicular to the axial direction of the sound duct.

[0025] With this configuration, the first speaker unit and the second speaker unit are positioned separately from each other in the axial direction of the sound duct, and the first speaker unit and the feedback microphone are positioned separately from each other in a direction perpendicular to the axial direction of the sound duct. Therefore, the first speaker unit, the second speaker unit, and the feedback microphone are not aligned in one direction.

[0026] Seventh, in the above-described sound output device, it is desirable that the diaphragm of the first speaker unit and the equalizer are positioned to face each other.

[0027] This configuration prevents an increase in the size of the sound duct in the direction in which the diaphragm and the first equalizer are arranged. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Together with Figures 2 to 5 shows an embodiment of a sound output device according to the present technology, which is a perspective view of the sound output device with the ear pads removed.

[0029] Figure 2 is a cross-sectional view of the sound output device.

[0030] Figure 3 is a conceptual diagram showing a first configuration example of the arrangement positions of the first speaker unit, the second speaker unit, and the feedback microphone.

[0031] Figure 4 is a conceptual diagram showing a second configuration example of the arrangement positions of the first speaker unit, the second speaker unit, and the feedback microphone.

[0032] Figure 5 is a conceptual diagram showing a third configuration example of the arrangement positions of the first speaker unit, the second speaker unit, and the feedback microphone. DETAILED DESCRIPTION

[0033] Hereinafter, modes for embodying a sound output device according to the present technology will be described with reference to the drawings.

[0034] In the embodiments described below, the sound output device according to the present technology is applied to a headphone. However, the present technology is not limited to being applied to a headphone, and can be widely applied to various other sound output devices such as earphones.

[0035] Note that the sound output device described below is provided with a speaker unit as a sound output unit and a sound duct as a path (conduction space) for the sound output from the speaker unit, and in the following description, the front-back direction, the up-down direction, and the left-right direction are defined, and the axial direction of the sound duct is defined as the left-right direction.

[0036] However, the front-back direction, the up-down direction, and the left-right direction described below are defined only for convenience, and when implementing the present technology, they are not limited to the definitions described below.

[0037] <Configuration of the sound output device>

[0038] The configuration of the sound output device 1 will be described below (see Figure 1 and Figure 2 ).

[0039] The sound output device 1 is used in pairs, for example, one for the left ear and the other for the right ear. However, only one sound output device 1 can be used to capture sound.

[0040] The sound output device 1 includes the required units provided inside the housing 2, and the housing 2 is obtained by connecting and arranging the housing body 3 and the sound duct 4.

[0041] The internal space of the housing body 3 is formed as an arrangement space 3a. The housing body 3 is obtained by connecting the inner housing part 5 and the outer housing part 6 in the left-right direction. The inner housing part 5 has a concave shape that opens to the outer housing part 6 side, and except for the lower end part, the outer housing part 6 has a concave shape that opens to the inner housing part 5 side.

[0042] The inner housing part 5 is formed with an insertion hole 5a that penetrates in the left-right direction. The inner housing part 5 has a through hole 5b formed above the insertion hole 5a and penetrating in the left-right direction. The inner housing part 5 has a first input hole 5c formed between the insertion hole 5a and the through hole 5b and penetrating in the front-back direction.

[0043] The outer housing part 6 is formed with a second input hole 6a that penetrates in the left-right direction.

[0044] Filters (not shown) are respectively disposed in the through hole 5b, the first input hole 5c, and the second input hole 6a, and the filters prevent dust from entering the housing body 3 through the through hole 5b, the first input hole 5c, and the second input hole 6a.

[0045] The lower end part of the outer housing part 6 serves as a tubular cord insertion part 7. A connection cord (not shown) is inserted into the cord insertion part 7, and input / output, power supply, etc. of signals to each unit arranged inside the housing 2 are performed through the connection cord.

[0046] The sound conduit 4 is formed into a substantially cylindrical shape and has a central axis 4a that extends substantially in the left-right direction, such that the axial direction is substantially aligned with the left-right direction. The opening at the front end of the sound conduit 4 is formed as a sound output port 4b. The opening of the sound conduit 4 at the end opposite to the sound output port 4b is formed as an insertion opening 4c. The end of the sound conduit 4 that is axially opposite to the sound output port 4b is provided as a holding portion 8, and the portion other than the holding portion 8 is provided as a sound guiding portion 9. The diameter of the sound guiding portion 9 is smaller than the diameter of the holding portion 8.

[0047] The sound conduit 4 is connected to the arrangement housing 3 such that the holding portion 8 is placed in the arrangement space 3a of the arrangement housing 3, and a part of the sound guiding portion 9 (excluding the part on the holding portion 8 side) protrudes from the insertion hole 5a to the outside of the arrangement housing 3. In the sound conduit 4, an annular stepped surface that faces the insertion opening 4c is formed at the boundary between the holding portion 8 and the sound guiding portion 9, and this stepped surface is formed as an attachment surface 4d.

[0048] The holding portion 8 has a speaker holding portion 10 and a microphone holding portion 11. The speaker holding portion 10 has a concave shape with an opening on the side, and the microphone holding portion 11 has a concave shape with an opening on the top. The upper end portion of the speaker holding portion 10 and the lower end portion of the microphone holding portion 11 are shared. The portion shared by the speaker holding portion 10 and the microphone holding portion 11 is provided as a partition wall 12. The partition wall 12 is formed with a communication hole 12a that vertically penetrates the partition wall 12, and this communication hole 12a allows communication between the space inside the speaker holding portion 10 and the space inside the microphone holding portion 11.

[0049] The ear pad 13 is externally mounted to the front end of the sound guiding portion 9 in the sound conduit 4. The ear pad 13 includes a flexible material, such as a rubber material.

[0050] The first speaker unit 14 is arranged in the speaker holding portion 10 of the sound conduit 4. The first speaker unit 14 is a dynamic type speaker unit and includes a cabinet 14a and a diaphragm 14b. In the cabinet 14a, a coil bobbin and a magnetic circuit unit (not shown) are arranged. The cabinet 14a is formed into a substantially cylindrical shape. In the speaker holding portion 10, relative to the cabinet 14a, the diaphragm 14b is located closer to the sound guiding portion 9, and its outer periphery is axially fixed to one end of the cabinet 14a.

[0051] The cabinet 14a of the first speaker unit 14 is held by the first speaker holder 15, and the first speaker holder 15 is attached to the speaker holding portion 10. The first speaker holder 15 has a sound emission hole 15a penetrating in the left - right direction. In a state where the first speaker holder 15 is attached to the speaker holding portion 10, the insertion opening 4c of the speaker holding portion 10 is closed by the first speaker holder 15.

[0052] When sound is output from the first speaker unit 14, the sound output from the rear side of the first speaker unit 14 (i.e., the side opposite to the diaphragm 14b) is emitted to the outside through the through - hole 5b via the sound emission hole 15a. In addition, the air present near the diaphragm 14b is also discharged from the through - hole 5b.

[0053] The feedback microphone 16 is disposed in the microphone holding portion 11. External sound (noise) is input to the feedback microphone 16 through the first input hole 5c.

[0054] The second speaker unit 17 is disposed in the sound guiding portion 9 of the sound conduit 4. The second speaker unit 17 is a balanced armature speaker unit and includes a housing 17a, a cover 17b, and a sound output unit (not shown). Note that the second speaker unit 17 can be a dynamic speaker unit.

[0055] The housing 17a is formed in a box shape that is open in at least one direction. The cover 17b is attached to the upper end portion of the housing 17a and closes the space inside the housing 17a. The cover 17b is formed with a sound output hole (not shown) penetrating vertically through the cover 17b. The sound output unit is accommodated in the housing 17a and includes a coil, a magnet, a diaphragm, etc.

[0056] One end of the second speaker unit 17 in the left - right direction is held by the second speaker holder 18, and the second speaker holder 18 is attached to the sound guiding portion 9.

[0057] In the outer housing 2, the space where the first speaker unit 14 and the feedback microphone 16 are arranged is defined as the first space 19, and the space where the second speaker unit 17 is arranged is defined as the second space 20. The second space 20 also serves as a conduction space 20A, where the sound output from the first speaker unit 14 and the sound output from the second speaker unit 17 are guided toward the sound output port 4b.

[0058] In the sound output device 1, the first speaker unit 14 and the second speaker unit 17 are arranged separately from each other in the axial direction of the sound conduit 4, and the first speaker unit 14 and the feedback microphone 16 are arranged separately from each other in a direction perpendicular to the axial direction of the sound conduit 4.

[0059] The first equalizer 21 is attached to the attachment surface 4d of the sound duct 4, and the first equalizer 21 is positioned to face the diaphragm 14b of the first speaker unit 14. The first equalizer 21 has a function of applying a predetermined acoustic load resistance to each of the first speaker unit 14 and the feedback microphone 16, and is formed as a mesh film oriented, for example, in the left-right direction.

[0060] Since the first equalizer 21 is attached to the attachment surface 4d of the sound duct 4, the first equalizer 21 is located between the first speaker unit 14 and the second speaker unit 17, and the first space 19 and the second space 20 are separated by the first equalizer 21. In a state where the first equalizer 21 is disposed in the sound duct 4, a space 10a is formed between the first equalizer 21 and the diaphragm 14b of the first speaker unit 14, and the space 10a and the communication hole 12a communicate with each other.

[0061] In a state where the second speaker unit 17 is disposed in the second space 20, a space is formed at least above the second speaker unit 17 in the second space 20, and this space serves as a sound output path 20a for sound. The sound output from the first speaker unit 14 and the sound output from the second speaker unit 17 pass through the sound output path 20a and are output to the ear via the ear pad 13.

[0062] The second equalizer 22 is attached to the upper surface of the cover 17b of the second speaker unit 17 to cover the sound output hole. The second equalizer 22 has a function of applying a predetermined acoustic load resistance to the second speaker unit 17, and is formed as a mesh film oriented, for example, in the left-right direction.

[0063] The feedforward microphone 24 is disposed in the arrangement space 3a of the arrangement housing 3 while being held by the microphone holder 23. The feedforward microphone 24 is placed in the upper part of the arrangement space 3a and is positioned corresponding to the second input hole 6a.

[0064] In the sound output device 1, the sound output frequency band of the first speaker unit 14 is, for example, 5 Hz to 8 KHz, and the sound output frequency band of the second speaker unit 17 is, for example, 8 KHz or higher. The first speaker unit 14 has a low-frequency sound output function, and the second speaker unit 17 has a high-frequency sound output function. In addition, the sound output device 1 performs a noise cancellation function. Specifically, a signal having a phase opposite to that of the noise input to the feedback microphone 16 is generated, and the second speaker unit 17 is connected to the signal having the opposite phase.

[0065] As described above, the sound output device 1 includes the feedback microphone 16 disposed at a position close to the ear, and performs a feedback noise cancellation function to reduce noise by generating a signal having a phase opposite to that of the noise input to the feedback microphone 16.

[0066] In addition, the sound output device 1 is also configured to be able to perform a feedforward noise cancellation function to reduce noise by providing a feedforward microphone 24 on the outer periphery of the housing 2 and performing appropriate filtering processing on the noise input to the feedforward microphone 24.

[0067] <Operation of the sound output device>

[0068] As described above, in the sound output device 1, the first speaker unit 14 and the feedback microphone 16 are arranged in the first space 19, the second speaker unit 17 is arranged in the second space 20, the first equalizer 21 is arranged between the first speaker unit 14 and the second speaker unit 17, and the first space 19 and the second space 20 are separated by the first equalizer 21.

[0069] Therefore, when the noise cancellation function is performed in the sound output device 1, the first equalizer 21 prevents sound from being input from the second speaker unit 17 connected to the signal, which has a phase opposite to that of the noise input to the feedback microphone 16, to the feedback microphone 16. As a result, sound unnecessary for performing noise cancellation is not input from the second speaker unit 17 to the feedback microphone 16, and thus the noise cancellation function is appropriately performed.

[0070] <Summary>

[0071] As described above, in the sound output device 1, the first space 19 and the second space 20 are formed inside the housing 2, the feedback microphone 16 and the first speaker unit 14 are arranged in the first space 19, the second speaker unit 17 is arranged in the second space 20, and the first equalizer 21 that separates the first space 19 and the second space 20 is arranged between the first speaker unit 14 and the second speaker unit 17.

[0072] Therefore, when the noise cancellation function is performed in the sound output device 1, the first equalizer 21 prevents sound from being input from the second speaker unit 17 to the feedback microphone 16. Therefore, the noise cancellation function is appropriately performed, and the performance of the noise cancellation function can be improved.

[0073] In addition, since the first speaker unit 14 and the feedback microphone 16 are spatially separated from the second speaker unit 17 by the first equalizer 21, an acoustic load resistance can be set for each of the first speaker unit 14, the feedback microphone 16, and the second speaker unit 17, respectively. Thus, the sound quality in the sound output device 1 can be improved.

[0074] In addition, since the second speaker unit 17 is arranged in the internal space of the sound duct 4 and serves as the conduction space 20A of the sound conduction path, there is no need to form a dedicated space for arranging the second speaker unit 17 inside the housing 2, and thus the size of the sound output device 1 can be reduced.

[0075] In addition, since the feedback microphone 16 and the first speaker unit 14 are held by the sound duct 4, there is no need to provide separate members for holding the feedback microphone 16 and the first speaker unit 14 respectively. Thus, the number of components of the sound output device 1 can be reduced, and the size of the sound output device 1 can be reduced.

[0076] In addition, the sound duct 4 is provided with a partition wall 12 between the feedback microphone 16 and the first speaker unit 14. The partition wall 12 is formed with a communication hole 12a that allows communication between the feedback microphone 16 and the first speaker unit 14, and the communication hole 12a penetrates in a direction perpendicular to the axial direction of the sound duct 4.

[0077] Therefore, the direction in which the communication hole 12a penetrates and the direction in which the conduction space 12a extends are perpendicular to each other, which prevents the sound duct 4 from being too long in one direction. Therefore, the size of the sound output device 1 can be further reduced.

[0078] In addition, since the first speaker unit 14 and the second speaker unit 17 are arranged separately from each other in the axial direction of the sound duct 4, the first speaker unit 14 and the second speaker unit 17 are separately positioned from each other in the axial direction of the sound duct 4 inside the sound duct 4. Therefore, the space inside the sound duct 4 is effectively utilized, and thus the size of the sound output device 1 can be further reduced.

[0079] In addition, the first speaker unit 14 and the feedback microphone 16 are arranged separately from each other in a direction perpendicular to the axial direction of the sound duct 4.

[0080] Therefore, due to the configuration in which the first speaker unit 14 and the second speaker unit 17 are separately positioned from each other in the axial direction of the sound duct 4, and the first speaker unit 14 and the feedback microphone 16 are separately positioned from each other in a direction perpendicular to the axial direction of the sound duct 4, the first speaker unit 14, the second speaker unit 17, and the feedback microphone 16 are not aligned in one direction, which prevents the sound duct 4 from being too long in one direction. Therefore, the size of the sound output device 1 can be further reduced.

[0081] In addition, since the diaphragm 14b of the first speaker unit 14 and the first equalizer 21 are positioned to face each other, an increase in the size of the sound duct 4 in the arrangement direction of the diaphragm 14b and the first equalizer 21 can be prevented, and thus the size of the sound output device 1 can be further reduced.

[0082] Note that, although an example has been described above in which the first equalizer 21 is attached to the attachment surface 4d of the sound duct 4 and the first speaker unit 14 and the second speaker unit 17 are spatially separated, the first equalizer 21 may be arranged, for example, in the sound output path 20a, and the first speaker unit 14 and the second speaker unit 17 may be spatially separated by the first equalizer 21.

[0083] <Other>

[0084] Hereinafter, a configuration example of the arrangement positions of the first speaker unit 14, the feedback microphone 16, and the second speaker unit 17 will be described (see Figures 3 to 5 ).

[0085] In a first configuration example of the arrangement positions, as Figure 3 shown, the first speaker unit 14 and the second speaker unit 17 are arranged separately from each other in a direction perpendicular to the axial direction of the sound duct 4, the first speaker unit 14 and the feedback microphone 16 are arranged separately from each other in the axial direction of the sound duct 4, and the feedback microphone 16 is arranged closer to the sound output port 4b of the sound duct 4 than the first speaker unit 14. The first speaker unit 14 and the feedback microphone 16 are arranged in the first space 19, the second speaker unit 17 is arranged in the second space 20, and the first equalizer 21 separates the first space 19 and the second space 20.

[0086] In a second configuration example of the arrangement positions, as Figure 4 shown, the second speaker unit 17 and the feedback microphone 16 are arranged separately from each other in the axial direction of the sound duct 4, the first speaker unit 14 and the feedback microphone 16 are arranged separately from each other in a direction perpendicular to the axial direction of the sound duct 4, and the second speaker unit 17 is arranged closer to the sound output port 4b of the sound duct 4 than the first speaker unit 14 and the feedback microphone 16 (see Figure 4 ). The first speaker unit 14 and the feedback microphone 16 are arranged in the first space 19, the second speaker unit 17 is arranged in the second space 20, and the first equalizer 21 separates the first space 19 and the second space 20.

[0087] In a third configuration example of the arrangement positions, as Figure 5As shown, the first speaker unit 14 and the feedback microphone 16 are arranged separately from each other in the axial direction of the sound duct 4, the first speaker unit 14 and the second speaker unit 17 are arranged separately from each other in a direction perpendicular to the axial direction of the sound duct 4, and the first speaker unit 14 and the feedback microphone 16 are arranged closer to the sound output port 4b of the sound duct 4 than the second speaker unit 17. The first speaker unit 14 and the feedback microphone 16 are arranged in the first space 19, the second speaker unit 17 is arranged in the second space 20, and the first equalizer 21 separates the first space 19 and the second space 20.

[0088] <This technology>

[0089] This technology may also have the following configurations.

[0090] (1) A sound output device, comprising:

[0091] A housing, including an arrangement housing forming an internal space and a sound duct forming a sound conduction space;

[0092] A feedback microphone, into which external sound is input;

[0093] A first speaker unit that outputs sound; and

[0094] A second speaker unit that outputs sound in an output frequency band different from the output frequency band of the sound output from the first speaker unit,

[0095] wherein, the housing has a first space and a second space inside,

[0096] The feedback microphone and the first speaker unit are arranged in the first space,

[0097] The second speaker unit is arranged in the second space, and

[0098] An equalizer that separates the first space and the second space is arranged between the first speaker unit and the second speaker unit.

[0099] (2) The sound output device according to (1) above,

[0100] wherein, the second speaker unit is arranged in the conduction space.

[0101] (3) The sound output device according to (1) or (2) above,

[0102] wherein, the feedback microphone and the first speaker unit are held by the sound duct.

[0103] (4) The sound output device according to (3) above,

[0104] Among them, the sound conduit is provided with a partition wall between the feedback microphone and the first speaker unit.

[0105] The partition wall is formed with a communication hole that allows communication between the feedback microphone and the first speaker unit, and

[0106] The communication hole penetrates in a direction perpendicular to the axial direction of the sound conduit.

[0107] (5) The sound output device according to (4) above,

[0108] Among them, the first speaker unit and the second speaker unit are arranged separately from each other in the axial direction of the sound conduit.

[0109] (6) The sound output device according to (5) above,

[0110] Among them, the first speaker unit and the feedback microphone are arranged separately from each other in a direction perpendicular to the axial direction of the sound conduit.

[0111] (7) The sound output device according to any one of (1) to (6) above,

[0112] Among them, the diaphragm of the first speaker unit and the equalizer are positioned to face each other.

[0113] List of reference signs

[0114] 1 Sound output device

[0115] 2 Housing

[0116] 3 Arrangement housing

[0117] 4 Sound conduit

[0118] 12 Partition wall

[0119] 12a Communication hole

[0120] 14 First speaker unit

[0121] 14b Diaphragm

[0122] 16 Feedback microphone

[0123] 17 Second speaker unit

[0124] 19 First space

[0125] 20 Second space

[0126] 20A Conduction space

[0127] 21 First equalizer

Claims

1. A sound output device, comprising: a housing including an arranged housing forming an internal space and a sound duct forming a sound conduction space; a feedback microphone to which external sound is input; a first speaker unit that outputs sound; and a second speaker unit that outputs sound having an output frequency band different from the output frequency band of the sound output from the first speaker unit, wherein the housing has a first space and a second space inside, the feedback microphone and the first speaker unit are arranged in the first space, the second speaker unit is arranged in the second space, and an equalizer that separates the first space and the second space is disposed between the first speaker unit and the second speaker unit.

2. The sound output device according to claim 1, wherein the second speaker unit is arranged in the conduction space.

3. The sound output device according to claim 1, wherein the feedback microphone and the first speaker unit are held by the sound duct.

4. The sound output device according to claim 3, wherein the sound duct is provided with a partition wall between the feedback microphone and the first speaker unit, the partition wall is formed with a communication hole allowing communication between the feedback microphone and the first speaker unit, and the communication hole penetrates in a direction perpendicular to the axial direction of the sound duct.

5. The sound output device according to claim 4, wherein the first speaker unit and the second speaker unit are arranged separately from each other in the axial direction of the sound duct.

6. The sound output device according to claim 5, wherein the first speaker unit and the feedback microphone are arranged separately from each other in a direction perpendicular to the axial direction of the sound duct.

7. The sound output device according to claim 1, wherein the diaphragm of the first speaker unit and the equalizer are positioned to face each other.

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