JP2010136248A - Horn for speaker and horn speaker employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a horn for a speaker which is compact but attains narrow directivity for performing playback at a high audio playback level in any arbitrary direction. <P>SOLUTION: The horn for the speaker includes: a throat part of which the one end is connected to the front side of a speaker diaphragm; a horn part connected to the other end of the throat part. The throat part includes a rectangular opening at the other end connected to the horn part. The horn part includes a throat connecting part wherein the rectangular opening of the throat part appears, a reflection curved surface having a parabolic cross section with the rectangular opening as a focal position, and a first plane part and a second plane part disposed to hold the throat connecting part and the reflection curved surface therebetween. A slit opening defined by the first plane part and the second plane part has a height h2 approximately equal to the height h1 of the rectangular opening of the throat part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a speaker horn that is attached to the front side of a speaker diaphragm and controls the directivity of radiated sound waves, and a horn speaker using the horn, and in particular, a high sound reproduction level in an arbitrary direction even if it is small. The present invention relates to a narrow directional speaker horn.

  Conventionally, in order to control the directivity of a reproduced sound wave radiated from a speaker, a horn or a reflector is sometimes attached to the front side of the speaker diaphragm. There are various types and methods for controlling the directivity of the speaker depending on the purpose of directivity control and the correspondence to the speaker type. In particular, various methods have been proposed for achieving narrow directivity to achieve a high sound reproduction level at a specific listening position.

  For example, as a narrow-directional speaker, a reflector that has at least a part of a spheroid whose inner surface has two focal points, and a reflector that is closer to the reflector on the line connecting the two focal points. There is a sound device including a sound source that irradiates the reflector with sound at or near the focal point, and the reflector has a reflective layer made of a hard material on the inner surface of a support layer made of a vibration absorbing material (patent) Reference 1).

  In the horn speaker, the driver unit includes a throat portion connected to one end and a bell portion continuously formed at the other end of the throat portion, and the first pair of throat portions formed substantially parallel to each other. A throat portion wall surface and a second pair of throat wall surfaces that expand at a predetermined angle are formed to form a rectangular cross section, and a bell portion is formed continuously with the first pair of throat wall surfaces. The first pair of bell wall surfaces and the second pair of throat wall surfaces that expand at a certain angle in correspondence with the horizontal direction are formed in a curved line so as to face each other in the vertical direction. There is a loudspeaker horn configured to form a rectangular cross section with a second pair of bell wall surfaces (Patent Document 2).

  In addition, for the purpose of enabling the speaker to be attached to a place having an opening narrower than the minimum opening of the speaker, the first opening having one end opened in a rectangular shape and the other end having a circular shape are provided. A second opening portion that is open in a shape, an inner wall that continuously connects the first opening portion and the second opening portion in a curved shape, an opening area of the first opening portion, and a second opening portion A holder is formed in which the opening area is substantially the same, the cross-sectional opening area in the direction perpendicular to the inner wall is substantially the same as the opening area of each opening, and a speaker is attached to the second opening to attach the speaker. There is a speaker mounting holder that emits sound waves from a first opening (Patent Document 3).

No. 8-7440 Japanese Utility Model Publication No. 64-6638 Japanese Utility Model Publication No. 4-121197

  However, when a substantially parabolic reflector as in Patent Document 1 is provided, there is a disadvantage that it tends to be large as a narrow directivity speaker. In addition, even if the speaker is attached to the front side of the speaker as in Patent Document 2 or Patent Document 3, it is not sufficient for a narrow directivity speaker that realizes a high sound reproduction level in an arbitrary direction. There is a problem that there is.

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a speaker horn and a horn speaker using the speaker horn, which is attached to the front side of the speaker diaphragm. An object of the present invention is to provide a speaker horn that realizes a narrow directivity for reproduction at a high sound reproduction level in an arbitrary direction even if it is small.

  A speaker horn according to the present invention is a speaker horn comprising a throat portion connected at one end to the front side of a speaker diaphragm, and a horn portion connected to the other end of the throat portion, the throat portion being a horn portion. A throat portion having a rectangular opening at a throat portion, a reflective curved surface having a parabolic section with the rectangular opening as a focal point, a throat connecting portion, A first flat surface portion and a second flat surface portion arranged so as to sandwich the reflection curved surface, and the slit opening defined by the first flat surface portion and the second flat surface portion is the height of the rectangular opening of the throat portion It has a height h2 substantially equal to h1.

  Preferably, in the speaker horn according to the present invention, the throat connecting portion of the horn portion includes a first plane portion, a second plane portion, and a third plane portion defining a slit opening together with the reflection curved surface, and a third plane portion. And a fourth flat part provided with a rectangular opening of the throat part substantially orthogonal to the fourth flat part and the rectangular opening are blocked by the third flat part and are not directly seen from the slit opening on the back side thereof Is arranged.

  Preferably, in the speaker horn according to the present invention, the throat connecting portion of the horn portion further includes a fifth flat portion connecting the fourth flat portion and the reflection curved surface, and the fifth flat portion is the third flat portion. And is connected to the reflective curved surface at the top of the parabolic cross section.

  Further preferably, in the speaker horn of the present invention, the third flat surface portion, the fourth flat surface portion, and the fifth flat surface portion constituting the throat connecting portion of the horn portion are lower than the reflectance of the reflection curved surface. It further has a sound absorbing member with reflectivity.

  Preferably, in the speaker horn according to the present invention, one end of the throat portion is a circular opening corresponding to the speaker diaphragm.

  Preferably, the horn speaker of the present invention includes the speaker horn and a speaker having a speaker diaphragm.

  Hereinafter, the operation of the present invention will be described.

  The speaker horn according to the present invention includes a throat portion whose one end is connected to the front side of the speaker diaphragm, and a horn portion connected to the other end of the throat portion. The speaker horn further includes a speaker having a speaker diaphragm, and constitutes the horn speaker of the present invention. For example, the throat portion has a rectangular opening at the other end connected to the horn portion even if the one end is a circular opening corresponding to the circular speaker diaphragm, and the horn portion has a height of the rectangular opening. A slit opening having a height h2 substantially equal to h1 is provided. Therefore, this speaker horn is a narrow directional speaker horn that has a small size as a whole and that realizes a high sound reproduction level in an arbitrary direction.

  The horn part of the speaker horn has a throat coupling part where a rectangular opening of the throat part appears, a reflection curved surface having a parabolic section with the rectangular opening as a focal point, and a throat coupling part and a reflection curved surface so as to sandwich the throat part. A first plane part and a second plane part arranged in parallel. Therefore, the throat connecting portion and the reflection curved surface, and the first flat surface portion and the second flat surface portion define the sound path of the horn portion including the reflection curved surface. Since the slit opening which is the exit of the sound path has a height h2 which is substantially equal to the height h1 of the rectangular opening of the throat portion, the slit opening becomes an elongated opening sandwiched between the first plane portion and the second plane portion.

  In the horn portion of the speaker horn, the sound wave radiated from the slit opening travels in an arbitrary direction due to the reflection curved surface having a parabolic cross section. The reflection curved surface has a cross-sectional shape formed as a part of a parabola on a cross-sectional plane that is substantially parallel to the first flat surface portion and the second flat surface portion and defines the cross-sectional shape thereof. That is, since the reflection curved surface is provided with a rectangular opening of the throat portion from which the sound wave guided from the speaker diaphragm is radiated at the focal point of the parabola, the sound wave emitted from the slit opening easily proceeds in an arbitrary direction. In addition, you may replace the shape of the parabola which a reflective curved surface has with an ellipse.

  Here, since the throat portion has a rectangular opening having a height h1 substantially equal to the height h2 of the slit opening at the other end connected to the horn portion, the sound path of the horn portion is slit-like. Further, it is possible to suppress an increase in the sound pressure level in a direction other than the arbitrary direction, and it is possible to realize a more preferable directional characteristic. That is, since the size in the height direction matches between the rectangular opening of the throat portion and the throat connecting portion that is the entrance portion of the horn portion, the change in acoustic impedance is reduced, and as a result, the reflection of sound waves is reduced. As a result, less turbulent sound waves easily travel inside the horn's sound path. Therefore, a horn speaker using the speaker horn of the present invention exhibits a narrow directivity that realizes a high sound reproduction level in an arbitrary direction even if it is small.

  The reflection curved surface may be formed by cutting an extruded material having a parabolic cross section so that the height h3 is substantially equal to the height h1 of the rectangular opening of the throat portion. Note that the first plane portion and the second plane portion may be opposed to each other so as to open to the slit opening side instead of parallel so as to suppress the occurrence of standing waves inside the sound path of the horn portion. Therefore, the height h3 of the reflection curved surface may be equal to or less than the height h1 of the rectangular opening of the throat portion, and may be equal to or less than the height h2 of the slit opening.

  Specifically, the horn part has a throat connecting part, and the throat connecting part includes a third flat part defining a slit opening together with the first flat part, the second flat part, and the reflection curved surface, and a third flat part. And a fourth flat surface portion provided with a rectangular opening of the throat portion. The fourth flat surface portion and the rectangular opening are shielded by the third flat surface portion, so that the back side of the third flat surface portion, that is, the sound. It is preferable that it is disposed at a position not directly viewed from the slit opening on the inner side of the road. By using such a speaker horn, the direct sound radiated from the rectangular opening of the throat part will not be radiated from the slit opening in the frequency band where narrow directivity should be obtained. Thus, a strong narrow directivity in any direction can be realized.

  The throat coupling portion further includes a fifth plane portion that couples the fourth plane portion and the reflection curved surface, and the fifth plane portion is provided substantially parallel to the third plane portion, and at the top of the parabolic cross section. You may connect with a reflective curved surface. Moreover, these 3rd plane part, 4th plane part, and 5th plane part may further have the sound-absorbing member of a reflectance lower than the reflectance of a reflective curved surface. If the throat coupling part that defines the sound path of the horn part causes strong reflection, the peak dip due to reflection tends to appear on the reproduction frequency characteristics, so the throat coupling part has excellent sound absorption with low reflectivity. By doing so, the peak dip can be suppressed.

  The speaker horn of the present invention can be provided on the front side of the speaker diaphragm to provide a speaker horn that realizes narrow directivity for reproduction at a high sound reproduction level in any direction even if it is small. it can.

  The speaker horn of the present invention is attached to the front surface side of the speaker diaphragm, so that even if it is small, the purpose of realizing narrow directivity for reproduction at a high sound reproduction level in an arbitrary direction is that of the speaker diaphragm. A horn for a speaker having a throat portion connected to one end on the front side and a horn portion connected to the other end of the throat portion, the throat portion having a rectangular opening at the other end connected to the horn portion The horn portion is disposed so as to sandwich the throat coupling portion where the rectangular opening of the throat portion appears, the reflection curved surface having a parabolic cross section with the rectangular opening as a focal point, and the throat coupling portion and the reflection curved surface. A slit plane defined by the first plane part and the second plane part, and a height h2 substantially equal to a height h1 of the rectangular opening of the throat part. By having a was achieved.

  Hereinafter, a speaker horn and a horn speaker using the same according to preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

  FIG. 1 is a diagram illustrating a horn speaker 1 using a speaker horn 3 according to a preferred embodiment of the present invention. FIG. 1A is a top view illustrating the horn speaker 1, and FIG. 1B is a front view thereof. FIG. 2 is a cross-sectional view of the horn speaker 1. 3 is a partially enlarged view for explaining the speaker 2 and the throat portion 4 constituting the horn speaker 1, FIG. 3 (a) is a front view, and FIG. 3 (b) is a side sectional view thereof. FIG. 3C is a rear view. Other internal structures that are not necessary for the description are omitted.

  In the horn speaker 1 of the present embodiment, a speaker 2 that converts an audio signal into sound is attached to a speaker horn 3. As will be described later, the speaker horn 3 has a slit opening 5s with a reduced overall height and a parabolic reflection curved surface 7. Even if the horn speaker 1 is a small speaker having a horn including a parabolic reflecting wall, it can be reproduced at a high sound reproduction level at the listening point P0 in the front direction, while the directivity angle θ is It is possible to realize a narrow directivity with a low sound reproduction level at the listening point Px in the increasing direction.

  The speaker 2 is an electrodynamic speaker having a diameter of about 3 cm and having an inverted dome-shaped circular diaphragm 2s. When a voice signal current is supplied to a voice coil arranged in a magnetic gap of a magnetic circuit, the speaker 2 Generates a driving force. As a result, the speaker diaphragm 2s connected to the bobbin around which the voice coil is wound vibrates and radiates sound waves. One end having a circular opening 4 c of the throat portion 4 of the speaker horn 3 is connected to the front side of the speaker 2.

  The speaker horn 3 includes a throat portion 4 to which the speaker 2 is attached, and a horn portion 5 to be attached so as to accommodate the throat portion 4 inside the sound path. As shown, the throat portion 4 has a rectangular opening 4s at the other end connected to the horn portion 5. The rectangular opening 4s is a rectangular opening having an opening area substantially equal to or larger than the circular opening 4c, and the cross-sectional shape of the throat portion 4 continuously changes from the circular opening 4c to the rectangular opening 4s. To do. In this embodiment, the rectangular opening 4 has a width of about 5.0 mm, and its height h1 is about 46.6 mm. The throat portion 4 of the present embodiment is configured such that the center point of the circular opening 4c coincides with the center point that defines the rectangular opening 4s.

  The horn part 5 holds the throat connecting part 6 to which the rectangular opening 4s of the throat part 4 is attached, the reflection curved surface 7 having a parabolic cross section having the rectangular opening 4s as a focal point, and the throat connecting part 6 and the reflecting curved surface 7. The first plane part 8 and the second plane part 9 are arranged so as to be substantially parallel to each other. As a result, the throat connecting portion 6 and the reflection curved surface 7, and the first flat surface portion 8 and the second flat surface portion 9 define the sound path of the horn portion 5 including the reflection curved surface 7. The slit opening 5s is an exit for a sound path defined by the throat connecting portion 6 and the reflection curved surface 7, the first flat surface portion 8 and the second flat surface portion 9, and the first flat surface portion 8 and the second flat surface. It becomes a long and narrow opening sandwiched between the portions 9. In this embodiment, the width of the slit opening 5s is about 415.0 mm, and its height h2 is about 50.0 mm. Therefore, the height h2 of the slit opening 5s has a height substantially equal to the height h1 of the rectangular opening 4s of the throat portion 4. Note that the throat portion and the speaker 2 connected to the throat connecting portion 6 are exposed at the center portion of the slit opening 5s when viewed from the front.

  Since the reflection curved surface 7 constituting the horn part 5 has a parabolic cross section with the rectangular opening 4s of the throat part 4 attached through the throat connecting part 6 as a focal point, as shown in FIG. The sound wave radiated from the opening 5s travels in the direction of the listening point P0. As a result, the horn speaker 1 of the present embodiment can realize narrow directivity. The reflection curved surface 7 is formed by cutting an extruded material having a parabolic cross section of a thermoplastic resin such as ABS or a metal such as an aluminum alloy so that the height h3 is substantially equal to the height h1 of the rectangular opening 4s of the throat portion 4. Can be formed. In addition, the depth of the horn part 5 is about 110.0 mm.

  Moreover, the 1st plane part 8 and the 2nd plane part 9 which comprise the horn part 5 of a present Example cross rather than parallel so that generation | occurrence | production of the standing wave inside the sound path of the horn part 5 may be suppressed. The angle is about 5 °, and they face each other so as to open from the back side of the sound path to the slit opening 5s side. Therefore, the height h3 of the reflective curved surface 7 changes with the height h2 of the slit opening 5s as the upper limit. However, since the throat connecting portion 6 where the rectangular opening 4s of the throat portion 4 appears is provided near the slit opening 5s, the height h3 of the reflective curved surface 7 is the height h1 of the rectangular opening 4s of the throat portion 4. It becomes the following. The first plane portion 8 and the second plane portion 9 may be parallel, but if the crossing angle is in the range of about 3 ° to about 10 ° as in this embodiment, the horn speaker 1 Can achieve both good acoustic characteristics and downsizing.

  Since the throat portion 4 has a rectangular opening 4s having a height h1 substantially equal to the height h2 of the slit opening 5s at the other end connected to the horn portion 5, a circular shape corresponding to the circular opening 4c of the throat portion 4 is provided. Compared with the case where the opening is provided, the change in the acoustic impedance is further reduced by matching the dimensions in the height direction. As a result, the reflection of the sound wave is reduced, and the sound wave with less wavefront disturbance easily travels inside the sound path of the horn unit 5. Therefore, the horn speaker 1 using the speaker horn 3 of the present invention exhibits a narrow directivity that realizes a high sound reproduction level in an arbitrary direction even if it is small. In the case of the present embodiment, narrow directivity is realized at 0.8 kHz or higher where the wavelength of the sound wave is relatively shorter than the dimension of the horn portion 5.

  The throat portion 4 and the horn portion 5 constituting the speaker horn 3 may be integrally formed of a molded product such as resin, and the sound path of the speaker horn 3 is separated vertically. In addition, the upper member including the first flat portion 8 and the lower member including the second flat portion 9 may be divided and combined.

  FIG. 4 is a diagram for explaining a horn speaker 11 using a speaker horn 13 according to another preferred embodiment of the present invention. 4A is a top view for explaining the horn speaker 11, and FIG. 4B is a front view thereof. FIG. 5 is a sectional view of the horn speaker 11. 6 is a partially enlarged view for explaining the speaker 12 and the throat portion 14 constituting the horn speaker 11, FIG. 6 (a) is a front view, and FIG. 6 (b) is a side sectional view thereof. FIG. 6C is a rear view. Other internal structures that are not necessary for the description are omitted.

  In the horn speaker 11 of this embodiment, a speaker 12 that converts a sound signal into sound is attached to a speaker horn 13 as in the case of the previous embodiment. As will be described later, the speaker horn 13 has a slit opening 15 s with a reduced overall height and a parabolic reflection curved surface 17, which is about half the size of the previous embodiment. Even if the horn speaker 11 is a smaller speaker, it can be reproduced at a high sound reproduction level at the listening point P0 in the front direction, while it is low at the listening point Px in the direction in which the absolute value of the directivity angle θ increases. It is possible to realize a narrow directivity that is an audio reproduction level.

  Note that the speaker 12 of the present embodiment is the same speaker as the speaker 2 of the previous embodiment, and a description thereof will be omitted. One end having a circular opening 14 c of the throat portion 14 of the speaker horn 13 is connected to the front side of the speaker 12. The circular opening 14c of the throat portion 14 is a portion inside the throat portion 14 illustrated by a dotted line in FIG.

  The speaker horn 13 includes a throat portion 14 to which the speaker 12 is attached, and a horn portion 15 to be attached so that the throat portion 14 is accommodated inside the sound path. As illustrated, the throat portion 14 has a rectangular opening 14 s at the other end connected to the horn portion 15. The rectangular opening 14s has a width of about 5.0 mm and a height h1 of about 46.6 mm. The cross-sectional shape of the throat portion 14 continuously changes from the circular opening 14c to the rectangular opening 14s. The central point of the circular opening 14c does not coincide with the central point that defines the rectangular opening 14s, and the rectangular opening 14s is identical. It is offset to approach the direction. In the present embodiment, the rectangular opening 14 of the throat portion 14 appears in the throat connection portion 16 of the horn portion 15 so that the magnetic circuit portion of the speaker 12 and the throat connection portion 16 of the horn portion 15 do not interfere with each other.

  The horn portion 15 holds the throat connecting portion 16 to which the rectangular opening 14 s of the throat portion 14 is attached, the reflection curved surface 17 having a parabolic section with the rectangular opening 14 s as a focal point, the throat connecting portion 16 and the reflection curved surface 17. The first plane portion 18 and the second plane portion 19 are arranged so as to be substantially parallel to each other. As a result, the throat connecting portion 16 and the reflection curved surface 17, and the first flat surface portion 18 and the second flat surface portion 19 define the sound path of the horn portion 15 including the reflection curved surface 17. The slit opening 15s is an exit for the sound path defined by the throat connecting portion 16, the reflection curved surface 17, the first flat surface portion 18 and the second flat surface portion 19, and the first flat surface portion 18 and the second flat surface. It becomes a long and narrow opening sandwiched between the portions 19. In this embodiment, the width of the slit opening 15s is about 200.0 mm, and its height h2 is about 50.0 mm. Accordingly, the height h2 of the slit opening 15s has a height substantially equal to the height h1 of the rectangular opening 14s of the throat portion 14. When viewed from the front, the throat portion 14 and the speaker 12 to be connected are exposed outside the throat connection portion 16.

  Since the reflection curved surface 17 constituting the horn portion 15 has a parabolic cross section having a rectangular opening 14s of the throat portion 14 attached through the throat connecting portion 16 as a focal point, as shown in FIG. The sound wave radiated from the opening 15s travels in the direction of the listening point P0. As a result, the horn speaker 1 of the present embodiment can realize narrow directivity. In addition, the depth of the horn part 15 is about 102.0 mm. The horn portion 15 of the present embodiment has a reflective curved surface 17 inclined by about 20 °, although the area of the slit opening 15s is smaller than that of the horn portion 5 of the previous embodiment, so that the depth of the horn portion 15 is increased. A wide reflection curved surface 17 can be formed without increasing the height of the sound, and a narrow directivity with a high sound reproduction level can be realized in the direction of the listening point P0.

  Since the throat portion 14 has a rectangular opening 14s having a height h1 substantially equal to the height h2 of the slit opening 15s at the other end connected to the horn portion 15, a circular shape corresponding to the circular opening 4c of the throat portion 14 is provided. Compared with the case where the opening is provided, the change in the acoustic impedance is further reduced by matching the dimensions in the height direction. As a result, the reflection of the sound wave is reduced, and the sound wave with less wavefront disturbance easily travels inside the sound path of the horn unit 15. Therefore, the horn speaker 11 using the speaker horn 13 of the present invention exhibits a narrow directivity that realizes a high sound reproduction level in an arbitrary direction even if it is small. In the case of the present embodiment, narrow directivity is realized at 1.7 kHz or higher where the wavelength of the sound wave is relatively shorter than the dimension of the horn portion 15.

  Further, similarly to the previous embodiment, the first flat surface portion 18 and the second flat surface portion 19 constituting the horn portion 15 are configured so as to suppress the occurrence of standing waves inside the sound path of the horn 1 portion 5. The crossing angle is not parallel but is about 5 °, and they face each other so as to open from the back side of the sound path to the slit opening 5s side. Therefore, the height h3 of the reflective curved surface 17 changes with the height h2 of the slit opening 15s as the upper limit.

  However, in this embodiment, the throat connecting portion 16 of the horn portion 15 includes the first flat surface portion 18, the second flat surface portion 19, and the reflective curved surface 17, the third flat surface portion 20 that defines the slit opening 15s, and the third flat surface portion 20. And a fourth flat surface portion 21 provided with a rectangular opening 14s of the throat portion 14 substantially orthogonal to the flat surface portion 20. The fifth plane portion 22 is provided substantially parallel to the third plane portion 20 and is connected to the reflection curved surface 17 at the top of the parabolic cross section. As a result, the fourth flat surface portion 21 and the rectangular opening 14s are blocked by the third flat surface portion 20, and are disposed at positions that are not directly viewed from the slit opening 15s on the back side.

  On the surfaces of the third flat surface portion 20, the fourth flat surface portion 21, and the fifth flat surface portion 22 constituting these throat connecting portions 16, a sound absorbing member 23 having a reflectance lower than that of the reflective curved surface 17 is provided. It has been. Specifically, the sound absorbing member 23 of the present embodiment is a felt having a thickness of about 1.0 mm that increases the sound absorption rate at about 1.7 kHz or more, or a sound absorbing material having excellent sound absorbing properties such as foamed urethane or glass wool. Any material can be used. Further, in place of the sound absorbing member 23, a sound absorbing material may be packed in the sound guide portion in the vicinity of the throat connecting portion 16.

  By using such a speaker horn 13, the horn speaker 11 of the present embodiment allows direct sound radiated from the rectangular opening 14 s of the throat portion 14 to be transmitted from the slit opening 15 s in a frequency band where narrow directivity should be obtained. It is not emitted and strong narrow directivity can be realized. That is, in the case of the present embodiment, the throat connecting portion 16 is constituted by the third flat surface portion 20, the fourth flat surface portion 21, and the fifth flat surface portion 22, so that the rectangular shape of the throat portion 14 is obtained. The opening 14 s faces the top of the parabolic cross section of the reflection curved surface 17. As a result, the direct sound radiated from the rectangular opening 14s is less likely to be radiated from the slit opening 15s. In addition, since the throat coupling portion 16 that defines the sound path of the horn portion 15 includes the sound absorbing member 23 and does not generate a strong reflected wave, a peak dip that tends to appear on the reproduction frequency characteristics can be suppressed.

  FIG. 7 shows a horn speaker 11 including the speaker horn 13 according to the present embodiment at the listening point Px in the direction of each directivity angle θ with reference to the front (0 ° direction) sound pressure level that is the direction of the listening point P0. It is a frequency characteristic showing the level difference of the sound pressure level. That is, FIG. 7A is a graph showing the case where the directivity angle θ in FIG. 5 is −30 ° and the case where it is −50 °, and FIG. 7B is the graph in which the directivity angle θ in FIG. It is a graph showing the case of +30 degrees, the case of +60 degrees, and the case of +90 degrees.

  The horn speaker 11 can realize a narrow directivity capable of reproduction at a high sound reproduction level at the listening point P0 in the front direction. That is, as shown in the graph of FIG. 7, at the listening point Px in the direction in which the absolute value of the directivity angle θ increases, the sound reproduction level in the mid-high frequency band is the front (0 °) in the direction of the listening point P0. Direction) Decreases gradually with reference to the sound pressure level. Specifically, the average level of about 2.8 kHz to 20 kHz is about −9.4 dB and the directivity angle θ is about −9.4 dB when the directivity angle θ is −30 ° with reference to the front (0 ° direction) sound pressure level. When -50 ° is approximately -14.4 dB, when the directivity angle θ is + 30 °, approximately -10.7 dB, when the directivity angle θ is + 60 °, approximately -18.9 dB, and when the directivity angle θ is + 90 ° To about −22.4 dB. That is, even if the horn speaker 11 is small, it is possible to realize narrow directivity for reproduction at a high sound reproduction level in an arbitrary direction.

In the speaker horn 13 of the present embodiment, the inner surfaces of the first plane portion 18 and the second plane portion 19 that form the sound path are reflected on the inner surfaces of the speaker horn 13 of the previous embodiment. Although it is a high surface, it is not limited to such a case. Except for the reflection curved surface 17, any one of the above sound absorbing members 23 may be further provided on the inner side surfaces of the first plane portion 18 and the second plane portion 19 that form the sound path of the speaker horn 13. Suppresses peak dip and achieves smoother sound pressure frequency characteristics.
Peak dip can be suppressed while realizing a higher audio playback level.

  The speaker horn of the present invention can be applied not only to a horn speaker but also to a microphone that converts a sound wave into an audio signal.

It is a figure explaining the horn speaker 1 using the horn 3 for speakers by preferable embodiment of this invention. (Example 1) It is sectional drawing of the horn speaker 1 by preferable embodiment of this invention. (Example 1) It is the elements on larger scale explaining the speaker 2 and the throat part 4 which comprise the horn speaker 1 by preferable embodiment of this invention. (Example 1) It is a figure explaining the horn speaker 11 using the horn 13 for speakers by other preferable embodiment of this invention. (Example 2) It is sectional drawing of the horn speaker 11 by other preferable embodiment of this invention. (Example 2) It is the elements on larger scale explaining the speaker 12 and the throat part 14 which comprise the horn speaker 11 by other preferable embodiment of this invention. (Example 2) In the horn speaker 11 including the speaker horn 13 according to another preferred embodiment of the present invention, it is a frequency characteristic representing the level difference of the sound pressure level in the direction of each directivity angle θ with reference to the front sound pressure level. (Example 2)

Explanation of symbols

1, 11 Horn speaker 2, 12 Speaker 3, 13 Horn 4, 14 Throat part 5, 15 Horn part 6, 16 Throat connection part 7, 17 Reflective curved surface 8, 18 First plane part 9, 19 Second plane part 20 First 3 plane part 21 4th plane part 22 5th plane part 23 Sound absorbing member

Claims (6)

A speaker horn comprising: a throat portion connected at one end to the front side of the speaker diaphragm; and a horn portion connected to the other end of the throat portion,
The throat portion has a rectangular opening at the other end connected to the horn portion;
The horn portion sandwiches the throat connecting portion where the rectangular opening of the throat portion appears, a reflection curved surface having a parabolic section with the rectangular opening as a focal point, and the throat connecting portion and the reflection curved surface. A slit opening defined by the first plane part and the second plane part is substantially equal to a height h1 of the rectangular opening of the throat part. Have equal height h2,
Speaker horn. The throat connecting portion of the horn portion is substantially orthogonal to the third plane portion, the first plane portion, the second plane portion, and a third plane portion that defines the slit opening together with the reflection curved surface, A fourth plane part provided with the rectangular opening of the throat part,
The fourth flat surface portion and the rectangular opening are blocked by the third flat surface portion, and disposed at a position where the fourth flat surface portion and the rectangular opening are not directly viewed from the slit opening on the back side.
The speaker horn according to claim 1. The throat connecting portion of the horn portion further includes a fifth plane portion that connects the fourth plane portion and the reflection curved surface, and the fifth plane portion is provided substantially parallel to the third plane portion. Connected to the reflective curved surface at the top of the parabolic cross section,
The speaker horn according to claim 2. The third flat surface portion, the fourth flat surface portion, and the fifth flat surface portion constituting the throat connecting portion of the horn portion further provide a sound absorbing member having a reflectance lower than the reflectance of the reflective curved surface. Have
The speaker horn according to claim 2 or 3. The one end of the throat portion is a circular opening corresponding to the speaker diaphragm;
The speaker horn according to any one of claims 1 to 4. A horn speaker comprising: the speaker horn according to any one of claims 1 to 5; and a speaker having the speaker diaphragm.

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