JP4870242B1 - Bass reflex omnidirectional speaker - Google Patents

Abstract

There has been a demand for a bass reflex type omnidirectional speaker that improves the sound quality in the low and mid tones as compared with the conventional bass reflex type speaker and further exhibits omnidirectionality.
A bass-reflex omnidirectional speaker according to the present invention includes a speaker, a cylindrical casing having openings at both ends, and a columnar member having a size smaller than the inner dimension of the casing. A speaker is attached to one opening, and a columnar member is attached to the other opening of the casing so as to form a cylindrical gap between the casing and the cylindrical gap as a duct. The other opening is made to function as a port.
[Selection] Figure 1

Description

  The present invention relates to a bass-reflex type omnidirectional speaker, and more particularly to a bass-reflex type speaker that improves the sound quality of a low-mid range compared to a conventional bass-reflex type speaker and further exhibits omnidirectionality.

  Conventionally, based on Helmholtz's resonance theory, using a cylindrical duct and a hole-shaped port provided in a housing called an enclosure as shown in FIG. There are known bass reflex type speakers, and Patent Literatures 1 to 4 disclose bass reflex type speakers having various shapes and positions of ducts and ports.

JP-A-4-70198 Japanese National Patent Publication No. 4-235500 JP-A-8-140177 JP 2009-5180 A JP 2002-10383 A JP 2004-72140 A Japanese Patent No. 4262291

However, the conventional bass reflex type speakers as described in Patent Documents 1 to 4 have the disadvantage that directivity exists by all means because the duct and the port are provided only in one direction. there were.
In addition, sound emitted from the back of the speaker into the housing (sound waves and air flow caused by sound) generates turbulent flow around the duct. The emitted sound is not smoothly emitted from the port through the duct to the outside of the housing, and as a result, only the amplification effect far from the theoretical value derived from Helmholtz's resonance theory can be obtained, and the amplification performance is also insufficient There was a drawback of being.

  On the other hand, it is classified into a different type of speaker from the bass reflex type speaker. However, in a speaker called a back load horn type, as shown in Patent Document 5 and Patent Document 6, the sound emitted from the back of the speaker is a vertically long horn. A speaker emitting from the lower part of the housing is disclosed.

However, if the speaker uses a simple horn-shaped housing such as a back-loaded horn type, as shown in Patent Document 5 and Patent Document 6, sound emitted from the back of the speaker is emitted from the lower part of the horn housing. Although it is possible to realize omnidirectionality by the above, there is a disadvantage that the effect of amplifying the low-frequency sound cannot be realized because the duct and the port are not provided.
In addition, in a bass reflex type speaker that requires a duct and a port, the idea of using a simple cylindrical casing described in Patent Document 5 and Patent Document 6 cannot be used as it is. It has been difficult to produce a bass reflex type speaker that has a duct and a port at the lower part of the body and realizes omnidirectionality.

Here, Patent Document 7 discloses a speaker described as a “pipe type” that emits sound from the back of the speaker from the bottom of a cylindrical housing.
However, in this speaker as well, similarly to Patent Document 5 and Patent Document 6, it is possible to realize non-directionality by emitting sound from the back of the speaker from the lower part of the housing (see FIG. 1 of Patent Document 7). However, the sound-absorbing material installed in the housing is installed in a state close to the position near the back of the speaker (see FIG. 1 of Patent Document 7), or the sound-absorbing material is connected to the back of the speaker. (See FIG. 2 of Patent Document 7).
Therefore, since the speaker does not have a portion corresponding to the duct at the lower part of the casing, it does not exhibit a function as a bass reflex type speaker, and it is difficult to amplify a low-frequency sound.

  From the above, to date, no bass reflex type speaker has been developed that has omnidirectionality and has improved the sound quality in the low to mid range.

  The present invention has been made in view of the above-described conventional problems. The bass reflex type omnidirectional speaker is improved in sound quality in the low and mid range compared to the conventional bass reflex type speaker and further exhibits omnidirectionality. It is for the purpose of provision.

  In order to achieve the above object, a bass reflex omnidirectional speaker according to claim 1 of the present invention has a speaker, a cylindrical casing having openings at both ends, and a dimension smaller than the inner dimension of the casing. By providing a columnar member, a speaker is attached to one opening of the housing, and a columnar member is attached to the other opening of the housing so as to form a cylindrical gap with the housing. The cylindrical gap functions as a duct and the other opening functions as a port.

  The bass-reflex omnidirectional speaker according to claim 2 of the present invention has a plate-like member connected to the columnar member, and the sound generated from the back surface of the speaker radially between the plate-like member and the other opening. The cylindrical gap is made to function as a duct, and the gap is made to function as a port.

  In the bass reflex omnidirectional speaker according to claim 3 of the present invention, the columnar member further forms a cylindrical gap and a gap between the casing and the plate-like member, and prevents the casing from tilting. For this reason, it is provided with a plurality of L-shaped spacer portions in side view.

  The bass reflex omnidirectional speaker according to claim 4 of the present invention is characterized in that the central axis of the casing and the central axis of the columnar member are the same axis.

In the bass reflex omnidirectional speaker according to claim 5 of the present invention, the difference between the cross-sectional area inside the housing and the cross-sectional area of the columnar member is 1 cm ^{2 in} a cross section perpendicular to the central axis direction of the housing and the columnar member. It is ˜80 cm ² .

  The bass reflex omnidirectional speaker according to claim 6 of the present invention is characterized in that a gap formed between the end of the other opening of the housing and the plate-like member is 3 mm or more.

  In the bass reflex omnidirectional speaker according to claim 7 of the present invention, the columnar member has a columnar shape, an elliptical columnar shape, a prismatic shape, a substantially cylindrical shape, a substantially elliptical columnar shape, a substantially prismatic shape, a conical shape, a pyramidal shape, a hemisphere. Or a combination of these shapes.

  In the bass reflex omnidirectional speaker according to claim 8 of the present invention, the casing has a cylindrical shape, an elliptical cylindrical shape, a rectangular cylindrical shape, a substantially cylindrical shape, a substantially elliptical cylindrical shape, a substantially rectangular cylindrical shape, a conical shape, It is a pyramid shape or a combination of these shapes.

  The bass reflex omnidirectional speaker according to claim 9 of the present invention is characterized in that the casing is a bamboo tube.

  According to the bass reflex type omnidirectional speaker according to the present invention, it is possible to improve the sound quality in the low and mid range compared to the conventional bass reflex type speaker, and to realize omnidirectionality.

It is a schematic diagram which shows 1st Embodiment of the bass-reflex omnidirectional speaker which concerns on this invention. It is sectional drawing of FIG. It is a schematic diagram which shows the base used for the bass-reflex omnidirectional speaker of FIG. It is a figure which shows the cut surface of the A-A 'part of FIG. It is a schematic diagram which shows 2nd Embodiment of the bass-reflex omnidirectional speaker which concerns on this invention. It is sectional drawing of FIG. It is a figure which shows the cut surface of the BB 'part of FIG. It is a schematic diagram which shows 3rd Embodiment of the bass-reflex omnidirectional speaker which concerns on this invention. It is sectional drawing of FIG. It is a figure which shows the cut surface of the C-C 'part of FIG. It is a schematic diagram which shows the bass-reflex omnidirectional speaker of a reference example. It is sectional drawing of FIG. It is a figure which shows the cut surface of the D-D 'part of FIG. It is a schematic diagram which shows the frequency characteristic of the bass-reflex omnidirectional speaker of an Example and a reference example. It is sectional drawing of the conventional bass-reflex type speaker.

  Embodiments of the present invention will be described with reference to the drawings. Note that each embodiment described below is merely an example embodying the present invention, and does not limit the technical scope of the present invention.

(First embodiment)
First, the configuration of the bass reflex omnidirectional speaker 1a according to the first embodiment will be described. 1 is a schematic diagram showing a first embodiment of a bass reflex omnidirectional speaker according to the present invention, FIG. 2 is a cross-sectional view of FIG. 1, and FIG. 3 is a bass reflex omnidirectional speaker of FIG. 4 is a schematic view showing a pedestal used in FIG. 4, and FIG. 4 is a view showing a cut surface of AA ′ portion of FIG.
As shown in FIGS. 1 and 2, the bass-reflex omnidirectional speaker 1 a according to the present embodiment includes a speaker 2, a cylindrical housing 3, and a pedestal 4, and one opening 5 a of the housing 3. Has a structure in which a speaker 2 is attached and a base 4 is attached to the other opening 5b.
As shown in FIGS. 1 and 2, the pedestal 4 is mainly composed of a columnar member 6 and a plate-like member 8. The columnar member 6 forms a cylindrical gap 7 between the housing 5 and the other opening 5b, and the plate-like member 8 forms a housing from the back of the speaker 2 between the other opening 5b. It attaches so that the clearance gap 9 which discharge | releases the sound produced inside the body 3 radially may be formed.

  Note that the bass reflex omnidirectional speaker 1a according to the first embodiment is attached so that the casing 3 is fitted into the pedestal 4 because the columnar member 6 includes an L-shaped spacer portion 10 in side view. As a result, the spacer unit 10a is placed on the spacer unit 10b while being prevented from being tilted. The body 3 and the pedestal 4 may be fixed.

  Next, each component requirement will be described.

(speaker)
A known speaker 2 is used. The speaker wiring is arranged along the inner surface of the housing 3 and is taken out from a gap 9 described later and connected to an amplifier (not shown), a player (not shown), and the like.
Further, a cone, a diffuser, or the like for diffusing sound emitted from the front of the speaker 3 radially may be provided on the upper portion of the speaker 3.

(Casing)
The casing 3 in the present invention is a cylinder having openings 5 at both ends, and one having an inner dimension larger than the columnar member 6 described later is used.

  As for the shape of the housing 3, the bass reflex omnidirectional speaker 1 a of the present embodiment uses a cylindrical shape, but is not particularly limited as long as the inside is hollow, the cylindrical shape, Various shapes such as an elliptical cylindrical shape, a rectangular cylindrical shape, a substantially cylindrical shape, a substantially elliptical cylindrical shape, a substantially rectangular cylindrical shape, a conical shape, and a pyramidal shape can be used. In addition, about a rectangular tube shape, a substantially rectangular tube shape, and a pyramid shape, it is the meaning including the thing of various polygonal shapes.

The material of the housing 3 is not particularly limited, and various materials such as wooden, bamboo, metal, and plastic can be used. Among them, a bamboo cylinder is used from the following points. It is preferable.
The bamboo cylinder, which is a natural material, has a shape in which the inner surface and the outer surface are wavy, and there are nodes, and there are fine irregularities on the inner and outer surfaces. Therefore, since the discontinuous surface diffuses the sound generated from the back surface of the speaker 2, an effect of suppressing the occurrence of standing waves such as pipe ringing can be exhibited.
Also, not only bass-reflex type, it is ideal that only the speaker part vibrates, and the housing itself that supports it does not vibrate, but because bamboo is hard as a material, the housing itself is more than other materials Can be suppressed.
In addition, the use of a bamboo tube also improves the design.
Furthermore, the use of bamboo can contribute to the maintenance of bamboo forests that have been devastated in recent years.

  Note that a separate sound absorbing material or the like can be provided on the inner surface of the housing 3.

(Pedestal, columnar member, plate member)
The pedestal 4 in the present invention radiates the sound generated from the back surface of the speaker 2 between the columnar member 6 for forming the cylindrical gap 7 between the inside of the housing 3 and the other opening 5b. What has at least two parts of the plate-like member 8 for forming the gap 9 and causing the bass-reflex omnidirectional speaker 1a to stand vertically or upright on the floor or the ground is used.
In this embodiment, as shown in FIG. 3, a cylindrical gap 7 and a gap 9 are formed between the casing 3 and the columnar member 6 and the plate-like member 8, and the tilting of the casing is prevented. A plurality of L-shaped spacer portions 10 for side view are provided.
Further, the columnar member 6 can be made hollow inside, thereby not only forming a cylindrical gap 7 between the inside of the housing 3 but also storing a circuit for controlling the speaker and the like. There is an advantage that it can be used as a container.

As for the shape of the columnar member 6, the bass-reflex omnidirectional speaker 1 a of the present embodiment uses a cylindrical one, but a cylindrical gap 7 is formed between the housing and the columnar member. If it is, the shape is not particularly limited, and various shapes such as a columnar shape, an elliptical columnar shape, a prismatic shape, a substantially cylindrical shape, a substantially elliptical columnar shape, a substantially rectangular columnar shape, a conical shape, a pyramid shape, and a hemispherical shape are used. be able to. Here, the square tube shape, the substantially square tube shape, and the pyramid shape include various polygonal shapes.
In addition, since the cylindrical gap 7 needs to be formed between the housing 3 and the columnar member 6, the size of the columnar member 6 needs to be smaller than the inner dimension of the housing.

  The shape of the plate member 8 is not particularly limited as long as a cylindrical gap 7 is formed between the housing 3 and the columnar member 6. A foot (not shown) or the like can be provided, but if it is plate-shaped as shown in FIG. 5, the bass-reflex omnidirectional speaker 1a can be stably or vertically erected on the floor or the ground. In addition, it is not preferable from the appearance that sound generated from the back surface of the speaker 2 is emitted radially from the inside of the housing 3, and it is preferable because the design is excellent.

  Further, the shape of the spacer portion 10 that can be provided as necessary is not particularly limited as long as the cylindrical gap 7 is formed between the housing 3 and the columnar member 6. 1 and FIG. 2, when the side view is L-shaped, the sound generated from the back surface of the speaker 2 can be emitted radially from the inside of the housing 3 as described above, and the housing 3 This is preferable because it is possible to prevent the tilting.

  The material of the columnar member 6, the plate-like member 8, and the spacer portion 10 is not particularly limited as in the case 3, and various materials such as wooden, bamboo, metal, and plastic are used. be able to.

  Furthermore, the columnar member 6, the plate-like member 8, and the spacer portion 10 can be provided with a separate sound absorbing material as in the case 3.

(Cylindrical gap)
The bass-reflex omnidirectional speaker of the present invention is characterized in that the cylindrical gap 7 is formed between the inside of the housing 3 and the columnar member 6 as described above.
Since this cylindrical gap 7 serves as a duct of a bass-reflex omnidirectional speaker, if the gap in a vertical sectional view with respect to the central axis direction of the housing 3 and the columnar member 6 is cylindrical, Even if there is a difference in the size or width of the gap, there is no particular problem. However, it is preferable that the gap has a certain degree of uniformity so that there is no extreme difference in the size and width of the gap. Therefore, it is preferable that the central axis of the housing 3 and the central axis of the columnar member 6 are the same axis.

The size (area) of the cylindrical gap 7 is appropriately determined depending on the size of the bass reflex omnidirectional speaker, the sound range to be amplified, and the like.
Here, the bass reflex speaker is a speaker that amplifies the sound in the low range using Helmholtz's resonance theory, and its resonance frequency is determined by the cross-sectional area of the duct, the length of the duct, the volume of the housing, and the characteristics of the speaker. However, as long as the same housing and speaker are used, the volume of the housing and the characteristics of the speaker are the same as those of the conventional bass reflex speaker in the bass reflex omnidirectional speaker of the present invention.
Therefore, in the bass reflex omnidirectional speaker of the present invention, the cylindrical gap 7 serves as a duct, and therefore the resonance frequency is the cross-sectional area inside the housing 3 corresponding to the area of the duct and the columnar member 6. It is determined by the difference in cross-sectional area and the height of the columnar member 6. That is, as shown in FIG. 4, when the inner diameter of the housing 3 is r1, the radius of the columnar member 6 is r2, and the length of the columnar member 6 is h1, the resonance frequency is π (r1) ² −π (r2) ^2. And h1. In this embodiment, since the columnar member 6 includes the spacer portion 10, the area corresponding to the duct is precisely the cross-sectional area of the spacer portion from π (r1) ² −π (r2) ^2. In the case where π (r1) ² −π (r2) ² is sufficiently larger than the cross-sectional area of the spacer portion 10 as in the present embodiment, the cross-sectional area of the spacer portion 10 is taken into consideration. A bass-reflex omnidirectional speaker can be produced without any problems.
Then, it is preferable that the difference between the cross-sectional area of the housing 3 inside of the cross-sectional area and the columnar member 6 in the vertical cross section with respect to the central axis of the housing 3 and the columnar member 6 among these is 1cm ² ~80cm ^2, more preferably ^{7cm 2 ~40cm} 2, more preferably from 10 cm ² to 20 cm ^2.
Moreover, it is preferable that the height of the columnar member 6 is 1 cm-50 cm, More preferably, it is 5 cm-20 cm.

(Gap)
Next, a gap 9 formed between the other opening 5b and the plate-like member 8 serves as a port of a bass-reflex omnidirectional speaker, and is a slit as shown in FIGS. If the shape is adopted, sound can be emitted radially, so that omnidirectionality can be realized, which is preferable. Note that the gap 9 can be opened only in one direction when omnidirectionality is not particularly required.

  The size (width) of the gap 9 is appropriately determined according to the size of the bass reflex omnidirectional speaker and the sound range to be amplified, as with the size of the cylindrical gap 7, The gap formed between the end of the opening and the plate member is preferably 3 mm or more, more preferably 5 mm to 500 cm, and even more preferably 10 mm to 200 mm.

  The size (width) of the gap 9 is preferably longer than the width of the cylindrical gap 7.

(Second Embodiment)
Next, the configuration of the bass reflex omnidirectional speaker 1b according to the second embodiment will be described. FIG. 5 is a schematic view showing a second embodiment of a bass reflex omnidirectional speaker according to the present invention, FIG. 6 is a cross-sectional view of FIG. 5, and FIG. It is a figure which shows a cut surface.

  The bass-reflex omnidirectional speaker 1b according to the present embodiment does not include the spacer portion 10 as shown in FIGS. 5 and 6, and separately uses the jig 11 such as a stay or a metal fitting, and the cylindrical gap 7 and the gap. Except that 9 is formed, it has the same configuration as the bass-reflex omnidirectional speaker 1a of the first embodiment. Also by adopting such a form, the cylindrical gap 7 and the gap 9 corresponding to the duct and the port can be formed, so that the bass reflex omnidirectional speaker of the present invention can be manufactured.

In this embodiment as well, as in the case of the bass reflex omnidirectional speaker 1a of the first embodiment, the resonance frequency is π (r1) ² −π (r2) ^{2 as} shown in FIG. If π (r1) ² −π (r2) ² is sufficiently larger than the cross-sectional area of the jig 11, the bass reflex can be considered without considering the cross-sectional area of the jig 11. A type omnidirectional speaker can be produced.

(Third embodiment)
Next, the structure of the bass reflex omnidirectional speaker 1c according to the third embodiment will be described. FIG. 8 is a schematic diagram showing a third embodiment of a bass reflex omnidirectional speaker according to the present invention, FIG. 9 is a cross-sectional view of FIG. 8, and FIG. It is a figure which shows a cut surface.

The bass-reflex omnidirectional speaker 1c of this embodiment has a structure in which speakers are attached to both openings of the housing 3.
Specifically, as shown in FIGS. 8 and 9, a columnar member 6 connected to a high-frequency speaker 2 a is attached to the upper opening, and a low-frequency sound is attached to the lower opening of the housing 3. The speaker 2b is attached. A columnar member 6 having a built-in loudspeaker 2 a is attached so as to form a cylindrical gap 7 and a gap 9 between the columnar member 6 and the housing 3.
Further, a diffuser 12a that radiates sound generated from the speaker 2a is attached above the high-frequency speaker 2a, and a diffuser 12b that radiates sound generated from the speaker 2b below the low-frequency speaker 2b. Is attached.

  Also by adopting such a configuration, the casing 3 and the columnar member 6 corresponding to the cylindrical gap 7 corresponding to the duct and the port are formed in the opening on the high sound speaker 2a side of the casing 3. A ring-shaped gap can be formed, and a high-frequency sound that is not often required for amplification can be built into the columnar member. Therefore, the bass-reflex omnidirectional speaker of the present invention can have two speakers attached to the housing.

Here, in this embodiment, unlike the case of the first embodiment and the second embodiment, since there is no spacer portion 10 and jig 11, the resonance frequency is as shown in FIG. 10. Π (r1) ² −π (r2) ² and h1.

(Reference example)
Next, a reference example related to the bass reflex omnidirectional speaker according to the present invention will be described. 11 is a schematic view showing a bass-reflex omnidirectional speaker of a reference example, FIG. 12 is a cross-sectional view of FIG. 11, and FIG. 13 is a view showing a cut surface of a DD ′ portion of FIG.

As shown in FIGS. 11 and 12, a bass-reflex omnidirectional speaker 101 of a reference example has a speaker 102 attached to one opening 105a of a cylindrical casing 103 having openings at both ends, and the other opening. The pedestal 104 is attached to the portion 105b.
The pedestal 104 includes a plate-like member 108 having an opening serving as a port portion 109 at the center, a cylindrical duct portion 107 connected to the port portion 109 and extending toward the inside of the housing 103, and a plate-like shape. A plurality of foot portions 106 that support the member 108 are configured.

  Thus, even by adopting the structure as in the reference example, the sound emitted from the port part is diffused radially, so that omnidirectionality can be realized. The amplification effect can also be expressed.

Here, also in the bass-reflex omnidirectional speaker 101 of the reference example, the amplification performance in the low and mid-range is determined by the cross-sectional area of the duct and the length of the duct. Specifically, as shown in FIGS. 11 and 13, assuming that the inner diameter of the duct is r3 and the length of the duct portion is h2, the amplification performance is determined by π (r3) ² and h2.
Therefore, if the value of π (r1) ² −π (r2) ² of the bass reflex omnidirectional speaker of the present invention described above and the value of π (r3) ² of the bass reflex omnidirectional speaker of the reference example are the same. The same resonance frequency can be realized.

  Next, the present invention will be described in more detail with reference to examples and reference examples.

(Example)
A bamboo tube with a length of 100 cm, an outer diameter of approximately 13 cm, and an inner diameter of approximately 11 cm is used as the casing, with a speaker (manufactured by FOSTEX, part number FE103En) attached to one opening, and the other opening is removed. Produced a bass-reflex omnidirectional speaker of the example by attaching a pedestal. Here, the pedestal is provided with a columnar member having a height of 10 cm and a diameter of 10 cm on a plate-shaped member having a thickness of 30 mm, and L1: 10 cm, L2: 1 cm, L3: 1.5 cm in FIG. 4 on the side wall of the columnar member. A spacer having four L-shaped spacer portions having a size of 2 in side view was prepared.
By attaching such a pedestal, the area of the duct of the bass-reflex omnidirectional speaker (a cylindrical gap formed between the inside of the casing and the columnar member = perpendicular to the central axis direction of the casing and the columnar member) The difference between the cross-sectional area inside the casing and the cross-sectional area of the columnar member in a cross-sectional view is about 16.5 cm ^2, and the size of the port (between the end of the other opening and the plate-like member) Is 1 cm.

(Reference example)
A bass reflex omnidirectional speaker of a reference example was manufactured by attaching the same bamboo cylinder and speaker as in the example and attaching a pedestal to the other opening. Here, the pedestal is provided with a cylindrical duct portion having a height of 10 cm extending toward the inside of the housing and an inner diameter of 4.6 cm on a plate-like member having an opening with a radius of 2.3 cm at the center, and a height of 6 cm. A plate having four legs for supporting a 5 cm plate member was produced.
By attaching this pedestal, the area of the duct of the bass reflex type omnidirectional speaker is about 16.6 cm ² which is substantially the same as the embodiment, and the size of the port is about 16.6 cm ² . .

(Measurement of frequency characteristics)
Next, the frequency characteristics of the bass-reflex omnidirectional speaker produced as described above were measured. The results are shown in FIG.
As a result, both the example and the reference example were able to exhibit a higher amplification effect than the conventional bass reflex type speaker shown in FIG. Specifically, a high amplification effect can be produced not only for low-frequency sound (50-200 Hz) but also for mid-low-frequency sound (200-500 Hz), which is originally said to be difficult for bass reflex type speakers. did it.
Among them, particularly in the example relating to the bass-reflex type omnidirectional speaker of the present invention, it was possible to express the amplification effect of the sound in the lower midrange higher than that in the reference example. The reason for this is that in the reference example, the sound emitted from the back of the speaker to the inside of the housing causes a slight turbulent flow in the vicinity of the connecting portion between the plate-like member and the duct portion. This is because it is considered that the sound released from the back of the speaker into the housing is smoothly released from the cylindrical gap and the gap.
From the above, it has been found that the bass reflex omnidirectional speaker according to the present invention can further improve the amplification effect of the sound in the low midrange while exhibiting omnidirectionality.

DESCRIPTION OF SYMBOLS 1a Bass-reflex type omnidirectional speaker 1b Bass-reflex type omnidirectional speaker 1c Bass-reflex type omnidirectional speaker 2 Speaker 3 Case 4 Base 5a Opening part 5b Opening part 6 Columnar member 7 Cylindrical gap 8 Plate-like member 9 Gap 10 Spacer Part 10a Spacer part 10b Spacer part 11 Jig 12a Diffuser 12b Diffuser 101 Bass reflex omnidirectional speaker 102 Speaker 103 Case 104 Base 105a Opening part 105b Opening part 106 Foot part 107 Duct part 108 Plate member 109 Port part

Claims (9)

Speakers,
A cylindrical housing having openings at both ends;
A columnar member having a size smaller than the inner size of the housing,
The speaker is attached to one opening of the housing,
By attaching the columnar member to the other opening of the housing so as to form a cylindrical gap with the housing,
A bass-reflex omnidirectional speaker characterized in that the cylindrical gap functions as a duct and the other opening functions as a port. In the columnar member,
A plate-like member is connected, and the plate-like member is attached so as to form a gap that emits a sound generated from the back surface of the speaker radially between the other opening portion,
The bass-reflex omnidirectional speaker according to claim 1, wherein the cylindrical gap functions as a duct and the gap functions as a port. The columnar member is
Furthermore, a plurality of L-shaped spacer portions are provided between the casing and the plate-like member so as to form the cylindrical gap and the gap and prevent the casing from tilting. The bass-reflex omnidirectional speaker according to claim 2, wherein the bass-reflex omnidirectional speaker is used. The central axis of the housing and the central axis of the columnar member are
The bass-reflex omnidirectional speaker according to any one of claims 1 to 3, wherein the same is the same axis. In a cross section perpendicular to the central axis direction of the casing and the columnar member,
The difference between the cross-sectional area inside the housing and the cross-sectional area of the columnar member is
Bass-reflex type omnidirectional loudspeaker as claimed in any one of claims 4, characterized in that a 1cm ² ~80cm ^2. A gap formed between the end of the other opening of the housing and the plate-like member,
The bass-reflex omnidirectional speaker according to any one of claims 2 to 5, wherein the bass-reflex omnidirectional speaker is 3 mm or more. The shape of the columnar member is
The cylindrical shape, elliptical columnar shape, prismatic shape, substantially cylindrical shape, substantially elliptical columnar shape, substantially rectangular columnar shape, conical shape, pyramid shape, hemispherical shape, or a combination of these shapes. The bass-reflex omnidirectional speaker according to any one of the above. The shape of the housing is
8. A cylindrical shape, an elliptical cylindrical shape, a rectangular cylindrical shape, a substantially cylindrical shape, a substantially elliptical cylindrical shape, a substantially rectangular cylindrical shape, a conical shape, a pyramid shape, or a combination of these shapes. The bass-reflex omnidirectional speaker according to any one of the above. The housing is
The bass-reflex omnidirectional speaker according to any one of claims 1 to 8, wherein the bass-reflex omnidirectional speaker is a bamboo tube.