Horn for a coaxial speaker, and coaxial speaker

Abstract

To provide a coaxial speaker horn capable of easily adjusting characteristics of a coaxial speaker.SOLUTION: A coaxial speaker horn is the horn 4 constituting a coaxial speaker 1 together with a tweeter 3 and a woofer 2, and including a plurality of dot-like through-holes 41 arranged in a whole periphery of the horn 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a horn for a coaxial speaker and a coaxial speaker.

Background Art

[0002] Patent Document 1 discloses a coaxial speaker in which a tweeter that outputs high-frequency sound and a woofer that outputs low- and mid-frequency sound are arranged coaxially. In the coaxial speaker of Patent Document 1, the tweeter is arranged on the front side of the woofer (the side from which the woofer outputs sound) in the axial direction, and a horn (web guide) is attached to the tweeter. The horn is formed in a cylindrical shape (cone shape) whose diameter gradually increases as it goes from the tweeter toward the front side of the woofer in the axial direction. The horn serves to increase the sound pressure output from the tweeter and to control the directivity of the sound output from the tweeter.

[0003] In the coaxial speaker of Patent Document 1 having such a horn structure, a plurality of through holes are formed in the horn so that the sound of the woofer propagates to the front side of the horn. Each through hole is formed in a slit shape extending in the radial direction of the horn as viewed from the axial direction. The plurality of slit-shaped through holes are arranged at intervals in the circumferential direction of the horn. In the coaxial speaker of Patent Document 1 having such a horn structure, by setting the slit-shaped through hole to a predetermined opening area, the horn functions as a low-pass filter for the woofer. Further, the horn (particularly the area of the horn where no slit-shaped through hole is formed) also functions as a compression chamber for the woofer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in a speaker system including a tweeter and a woofer, such as a coaxial speaker, generally, in order to suppress the disturbance of characteristics caused by the combination of the tweeter and the woofer, the characteristics of the speaker system are adjusted by a passive crossover network. However, in the coaxial speaker of Patent Document 1 in which the horn functions as a low-pass filter or a compression chamber, the frequency characteristics of the woofer differ greatly between the state of the woofer alone and the state combined with the tweeter and the horn. For this reason, there is a problem that it becomes difficult to adjust the characteristics of the coaxial speaker by the passive crossover network.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a horn for a coaxial speaker that can easily adjust the characteristics of the coaxial speaker, and a coaxial speaker including the same.

Means for Solving the Problems

[0007] A first aspect of the present invention is a horn for a coaxial speaker that constitutes a coaxial speaker together with a tweeter and a woofer, and has a plurality of dot-like through holes arranged over the entire circumference of the horn Moreover, the plurality of through holes are arranged in the radial direction of the horn as viewed from the axial direction of the horn, and the opening area of the through hole located on the inner side in the radial direction is smaller than the opening area of the through hole located on the outer side in the radial direction. It is a horn for a coaxial speaker.

[0008] A second aspect of the present invention is a coaxial speaker including the horn for the coaxial speaker, a tweeter attached to a central portion of the horn as viewed from the axial direction of the horn, and a woofer arranged coaxially with the tweeter on the rear side of the tweeter.

Effects of the Invention

[0009] According to the present invention, the characteristics of the coaxial speaker can be easily adjusted.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0011] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 4. As shown in FIGS. 1 and 2, the coaxial speaker 1 includes a woofer 2, a tweeter 3, and a horn 4 (horn for coaxial speaker). The woofer 2 outputs mainly low and midrange sounds by vibrating. The tweeter 3 outputs mainly high-range sounds by vibrating. The woofer 2 and the tweeter 3 are coaxially arranged with a gap in their vibration directions. In FIGS. 1 to 3, the vibration directions of the woofer 2 and the tweeter 3 are indicated in the X-axis direction (the direction indicated by the arrow is the positive direction of the X-axis, and the opposite direction is the negative direction of the X-axis). Also, the fact that the woofer 2 and the tweeter 3 are coaxially arranged means that the woofer 2 and the tweeter 3 are arranged such that the central axes (the axis indicated by reference numeral O1 in FIGS. 1 to 3) of the woofer 2 and the tweeter 3 extending in the X-axis direction completely or substantially coincide.

[0012] The woofer 2 is configured such that the sound output from the woofer 2 mainly propagates to one side in the vibration direction of the woofer 2 (the side indicated by the positive direction of the X-axis in FIGS. 1 to 3). Note that the sound output from the woofer 2 also propagates to the other side in the vibration direction (the side indicated by the negative direction of the X-axis in FIGS. 1 to 3). In the following description, the side from which sound is mainly output from the woofer 2 (one side in the vibration direction) may be referred to as the front side. Also, the side opposite to the front side may be referred to as the rear side. In FIGS. 1 and 2, the upper side or the upper direction corresponds to the "front side" and is shown in the positive X-axis direction. Also, in FIGS. 1 and 2, the lower side or the lower direction corresponds to the "rear side" and is shown in the negative X-axis direction. As shown in FIG. 3, the woofer 2 is formed in a circular shape when viewed from the front side.

[0013] As shown in FIGS. 1 and 2, the tweeter 3 is arranged coaxially with the woofer 2 with a space therebetween on the front side of the woofer 2. As shown in FIG. 3, the tweeter 3 is formed in a circular shape similar to the woofer 2 when viewed from the front side. The size (diameter dimension) of the tweeter 3 when viewed from the front side is sufficiently smaller than the size (diameter dimension) of the woofer 2.

[0014] As shown in FIGS. 1 and 2, the horn 4 is attached to the tweeter 3. The horn 4 increases the sound pressure output from the tweeter 3 and controls the directivity of the sound output from the tweeter 3. Specifically, the horn 4 actively directs the sound output from the tweeter 3 toward the front side of the horn 4. The horn 4 is formed in a cylindrical shape whose diameter dimension increases as it goes toward one side in the axial direction (positive X-axis direction). The horn 4 is arranged such that its axial direction (X-axis direction) faces the vibration direction of the tweeter 3 (vertical direction in FIGS. 1 and 2), and the side where the diameter dimension increases in the axial direction faces the front side. The tweeter 3 is attached to the first end portion (rear end) of the horn 4 having a small diameter dimension, that is, to the central portion of the horn 4. As shown in FIG. 3, the horn 4 is formed in a circular shape similar to the woofer 2 and the tweeter 3 when viewed from the front side. The size (diameter dimension) of the horn 4 when viewed from the front side is larger than the size (diameter dimension) of the woofer 2. The circular-shaped woofer 2, tweeter 3, and horn 4 when viewed from the front side are arranged such that their central axes (the axis indicated by reference numeral O1) completely or substantially coincide.

[0015] As shown in FIGS. 1 and 2, the horn 4 has a plurality of through holes 41. Each through hole 41 penetrates in the axial direction of the horn 4. Note that the fact that each through hole 41 penetrates in the axial direction of the horn 4 does not necessarily mean that the penetration direction of the through hole 41 completely coincides with the axial direction of the horn 4, and for example, it may be slightly inclined with respect to the axial direction of the horn 4. The through holes 41 of the horn 4 have the role of allowing the sound output from the front side by the tweeter 3 and the woofer 2 disposed on the rear side of the horn 4 to pass through and propagating it to the front side of the horn 4. As shown in FIG. 3, each through hole 41 of the horn 4 is formed in a dot shape when viewed from the front side (axial direction). In the present embodiment, the shape of the dot-shaped through hole 41 when viewed from the front side is circular. Note that the shape of the dot-shaped through hole 41 may be a regular polygon such as a square, or may be an ellipse or a slightly flattened polygon (a shape with an aspect ratio close to 1) close to a circle or a regular polygon.

[0016] The plurality of through holes 41 are arranged over the entire circumference of the horn 4. The fact that the plurality of through holes 41 are arranged over the entire circumference of the horn 4 means that the dot-shaped through holes 41 are arranged in a ring shape at equal intervals over the entire range in the circumferential direction (the direction indicated by reference numeral C in FIGS. 2 and 3) of the horn 4. The shape of the ring unit 40 formed by arranging the dot-shaped through holes 41 in a ring shape only needs to correspond to the shape of the woofer 2 when viewed from the front side, and is circular in the present embodiment. The interval between the dot-shaped through holes 41 in the circumferential direction may be made small to such an extent that the horn 4 does not function as a low-pass filter or a compression chamber of the woofer 2, for example.

[0017] The plurality of through holes 41 are also arranged in the radial direction of the horn 4 (the direction from the position of the axis O1 indicating the center of the horn 4 to the outside of the horn 4 as indicated by the symbol R in FIG. 3) when the horn 4 is viewed from the front side (the axial direction of the horn 4). Specifically, a ring unit 40 formed by arranging dot-like through holes 41 in a ring shape is arranged in a plurality of concentric circles (radial direction of the horn 4) centered on the axis of the horn 4 (the axis indicated by the symbol O1 in FIGS. 1 to 3). The fact that the plurality of through holes 41 are arranged in the radial direction of the horn 4 does not necessarily mean that these plurality of through holes 41 are strictly arranged on a straight line extending in the radial direction of the horn 4 from the axis of the horn 4, and also includes the case where they are slightly displaced in the circumferential direction with respect to the straight line. That is, the through holes 41 adjacent to each other in the radial direction of the horn 4 may be displaced from each other in the circumferential direction of the horn 4. The interval between the through holes 41 in the radial direction (the interval between the ring units 40) may be made small, for example, to such an extent that the horn 4 does not function as a low-pass filter or a compression chamber of the woofer 2. In the present embodiment, the plurality of through holes 41 are arranged in a spiral shape imitating the Fibonacci sequence. Note that the plurality of through holes 41 may be arranged, for example, radially around the axis of the horn 4.

[0018] In the present embodiment, the opening area of the through hole 41 located inside the horn 4 in the radial direction is smaller than the opening area of the through hole 41 located outside the horn 4 in the radial direction. That is, the opening area of the through hole 41 increases from the inside to the outside of the horn 4 in the radial direction. The opening area of the through hole 41 is the area in the state of being viewed from the front side (the axial direction of the horn 4) as shown in FIG. 3.

[0019] The upper limit value of the opening area of each through hole 41 is set so as to maintain the function of increasing the sound pressure of a sound (a high-frequency sound) of a predetermined frequency output from the tweeter 3 by the horn 4. This is because if the opening area of each through hole 41 is excessively large, the function of the horn 4 (the function of increasing the sound pressure of a sound of a predetermined frequency output from the tweeter 3) will be impaired.

[0020] The lower limit value of the opening area of each through hole 41 is set so that sound of a predetermined frequency (sound in the low to mid - frequency range) output from the woofer 2 is transmitted through the through hole 41 to the front side of the horn 4. The range of the opening area of each through hole 41 may be set so that, for example, the diameter dimension of the circular through hole 41 formed when viewed from the front side is 2.5 mm or more and 7.5 mm or less.

[0021] The total opening area of the plurality of through holes 41 formed in the horn 4 may be 35% or more of the entire area of the horn 4 (the total area of the horn 4) when viewed from the front side. Also, the total opening area of the through holes 41 may be 60% or less of the total area of the horn 4.

[0022] The plurality of through holes 41 are formed only in the region of the horn 4 that overlaps the woofer 2 when viewed from the front side as shown in FIG. 3. That is, the through holes 41 of the horn 4 are not formed in the region of the horn 4 that is located outside the woofer 2 in the radial direction. In the present embodiment, the plurality of through holes 41 are formed in the entire region of the horn 4 that overlaps the woofer 2 (the region indicated by reference numeral R1 in FIGS. 1 and 3). Therefore, the shape of the entire plurality of through holes 41 when viewed from the front side is formed in a shape corresponding to the woofer 2 (circular in the present embodiment).

[0023] As shown in FIGS. 1 and 2, the coaxial speaker 1 of the present embodiment further includes a woofer cover 5 that partitions the space between the woofer 2 and the horn 4 arranged in the axial direction of the horn 4 from the external space. The woofer cover 5 is formed in a cylindrical shape extending forward from the woofer 2 to the horn 4. Although not shown, the shape of the woofer cover 5 as viewed from the front side (axial direction of the horn 4) is formed in a shape corresponding to the woofer 2. The shape of the woofer cover 5 corresponding to the woofer 2 as viewed from the front side is a shape corresponding to the outer periphery of the woofer 2 (a shape substantially coinciding with the outer periphery of the woofer 2), and in the present embodiment, it is a circular shape corresponding to the outer peripheral circle of the woofer 2. In the present embodiment, the woofer cover 5 is integrally formed with the horn 4. The plurality of through holes 41 formed in the horn 4 are located inside the woofer cover 5 in the radial direction of the horn 4. Since the space between the woofer 2 and the horn 4 is surrounded by the woofer cover 5, the sound output from the woofer 2 to the front side can be efficiently propagated to the front side of the horn 4 through the through holes 41 of the horn 4.

[0024] The coaxial speaker 1 of the present embodiment further has a case component 6 that constitutes a part of the case covering the space behind the woofer 2, the tweeter 3, and the horn 4. The case component 6 surrounds the second end portion of the horn 4 having a large diameter dimension (the front end of the horn 4 in FIGS. 1 and 2), and is formed in a cylindrical shape extending from the second end portion of the horn 4 to the rear side of the horn 4. The case component 6 has a bass reflex port 61. The bass reflex port 61 is a hole for propagating the sound output from the woofer 2 to the rear side to the outside of the case.

[0025] In the coaxial speaker 1 of this embodiment, the sound output from the woofer 2 to the front side (especially the sound in the lower midrange) efficiently propagates to the front side of the horn 4 through the through holes 41 of the horn 4. Further, the horn 4 increases the sound pressure of the sound output from the tweeter 3 (especially the sound in the high range) and controls the directivity of the sound. Thereby, the sound (the sound in the lower midrange and the high range) output from the coaxial speaker 1 can reach farther. Such a coaxial speaker 1 can be effectively used, for example, as a ceiling-suspended speaker that is suspended from a high ceiling and radiates sound from the ceiling toward the floor surface.

[0026] As described above, in the horn 4 (horn for coaxial speaker) and the coaxial speaker 1 of this embodiment, the horn 4 has a plurality of dot-shaped through holes 41 arranged over its entire circumference. In this shape, it is difficult for the horn 4 to function as a low-pass filter or a compression chamber of the woofer 2. And it is possible to suppress or prevent the frequency characteristics of the woofer 2 in the state incorporated in the coaxial speaker 1 from changing from the frequency characteristics of the woofer 2 alone. Thereby, it is possible to easily adjust the characteristics of the coaxial speaker 1 by the passive crossover network.

[0027] Further, since a plurality of dot-shaped through holes 41 are arranged over the entire circumference of the horn 4, the horn 4 can function as a horn that increases the sound pressure of the sound of a predetermined frequency output from the tweeter 3. In other words, it is possible to suppress the function of such a horn 4 from being impaired by the formation of the through holes 41. That is, even in the region of the horn 4 where the through holes 41 are formed, the sound pressure of the tweeter 3 can be increased.

[0028] In addition, in the horn 4 and the coaxial speaker 1 of the present embodiment, the total opening area of the plurality of through holes 41 as viewed from the axial direction of the horn 4 is 35% or more of the entire area of the horn 4. Therefore, it is possible to further suppress or prevent the frequency characteristics of the woofer 2 in the state of being incorporated in the coaxial speaker 1 from changing from the frequency characteristics of the woofer 2 alone. As a result, it is possible to more easily adjust the characteristics of the coaxial speaker 1 by the passive crossover network.

[0029] In addition, in the horn 4 and the coaxial speaker 1 of the present embodiment, the total opening area of the plurality of through holes 41 as viewed from the axial direction of the horn 4 is 60% or less of the entire area of the horn 4. Therefore, it is possible to more effectively suppress the function of the horn 4 (the function of increasing the sound pressure of the sound of a predetermined frequency output from the tweeter 3) from being impaired. In other words, even in the region of the horn 4 where the through holes 41 are formed, the sound pressure of the tweeter 3 can be effectively increased.

[0030] In addition, in the horn 4 and the coaxial speaker 1 of the present embodiment, the upper limit value of the opening area of each through hole 41 is set so as to maintain the function of the horn 4 to increase the sound pressure of the sound of a predetermined frequency output from the tweeter 3. By setting the upper limit value of the opening area of each through hole 41 in this way, it is possible to more effectively suppress the above-described "function of the horn 4" from being impaired.

[0031] From the above, in the horn 4 and the coaxial speaker 1 of the present embodiment, it is possible to easily adjust the characteristics of the coaxial speaker 1 and suppress the "function of the horn 4" from being impaired.

[0032] Also, in the horn 4 and the coaxial speaker 1 of the present embodiment, the opening area of the through-hole 41 located inside the horn 4 in the radial direction is smaller than the opening area of the through-hole 41 located outside the horn 4 in the radial direction. Therefore, even if the number of through-holes 41 arranged in the circumferential direction of the horn 4 is made equal between the first annular region located inside the horn 4 in the radial direction and the second annular region located outside the horn 4 in the radial direction, it is possible to suppress or prevent the ratio of the opening area of the through-hole 41 to the area of the horn 4 from being different between the first annular region and the second annular region. That is, it is possible to make the ratio of the opening area of the through-hole 41 to the area of the horn 4 uniform.

[0033] Also, in the horn 4 and the coaxial speaker 1 of the present embodiment, when viewed from the axial direction of the horn 4, a plurality of through-holes 41 are formed only in the region of the horn 4 that overlaps with the woofer 2. As a result, the sound output from the front side of the woofer 2 can be efficiently transmitted through the through-holes 41 of the horn 4 to the front side of the horn 4.

[0034] Hereinafter, in the coaxial speaker 1 of the present embodiment, with reference to FIG. 4, the point that the frequency characteristics of the woofer 2 incorporated in the coaxial speaker 1 can be made closer to the frequency characteristics of the woofer 2 alone will be described. FIG. 4 is a graph showing the results of comparing the frequency characteristics of the woofer 2 in a state incorporated in the coaxial speaker 1 of the present embodiment as an example and the frequency characteristics of the woofer 2 alone (in a state where the tweeter 3 and the horn 4 are removed from the coaxial speaker 1 of the present embodiment).

[0035] The woofer 2 handled in "Example" and "Woofer alone" is the same. In the "Example", the total opening area of the plurality of through-holes 41 viewed from the axial direction of the horn 4 is 37% of the total area of the horn 4. Each through-hole 41 is formed in a circular shape when viewed from the axial direction of the horn 4. The opening area of the through-hole 41 located inside in the radial direction is smaller than the opening area of the through-hole 41 located outside in the radial direction. And the diameter dimension of each through-hole 41 is set in steps of 0.5 mm in the range of 2.5 mm to 7.5 mm.

[0036] As shown in the graph of FIG. 4, it was confirmed that the frequency characteristics of the "Example" are close to the frequency characteristics of the "woofer alone". That is, in the horn 4 (horn for coaxial speaker) and the coaxial speaker 1 of the present embodiment, it was confirmed that the change in the frequency characteristics of the woofer 2 incorporated in the coaxial speaker 1 from the frequency characteristics of the woofer 2 alone can be effectively suppressed.

[0037] As described above, the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0038] In the present invention, the upper limit value of the opening area of each through hole 41 is, for example, (λ / 4), where λ is the wavelength of the sound corresponding to the upper limit frequency among the sounds output from the tweeter 3 and whose sound pressure is increased by the horn 4. 2 The following may be the case. The upper limit frequency may be, for example, the upper limit of the frequency of the sound set according to the specifications required for the coaxial speaker 1. By setting the upper limit value of the opening area of each through hole 41 in this way, it is possible to effectively suppress the impairment of the "function of the horn 4" described above.

[0039] In the present invention, the individual opening areas of all the through holes 41 formed in the horn 4 may be equal to each other, for example.

[0040] In the present invention, the shapes of the woofer 2, the tweeter 3, and the horn 4 as viewed from the front side (axial direction) are not limited to circular shapes, and may be, for example, elliptical shapes.

Description of Reference Numerals

[0041] 1... Coaxial speaker, 2... Woofer, 3... Tweeter, 4... Horn

Claims

1. A horn for a coaxial speaker that constitutes a coaxial speaker together with a tweeter and a woofer, having a plurality of dot-shaped through holes arranged over the entire circumference of the horn, the plurality of through holes being arranged in the radial direction of the horn as viewed from the axial direction of the horn, a horn for a coaxial speaker, wherein the opening area of the through hole located on the inner side in the radial direction is smaller than the opening area of the through hole located on the outer side in the radial direction.

2. The horn for a coaxial speaker according to claim 1, wherein the total opening area of the plurality of through holes as viewed from the axial direction of the horn is 35% or more and 60% or less of the area of the entire horn as viewed from the axial direction.

3. The horn for a coaxial speaker according to claim 1 or claim 2, wherein the upper limit value of the opening area of each of the through holes is set so as to maintain the function of increasing the sound pressure of sound at a predetermined frequency output from the tweeter.

4. The horn for a coaxial speaker according to any one of claims 1 to 3, wherein a plurality of the through holes are formed only in a region overlapping the woofer as viewed from the axial direction of the horn.

5. A coaxial speaker comprising: a horn for a coaxial speaker according to any one of claims 1 to 4; a tweeter attached to the central portion of the horn as viewed from the axial direction of the horn; and a woofer arranged coaxially with the tweeter behind the tweeter.

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