JP2013081061

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DESCRIPTION JP2013081061
Abstract: [Problems] There has been a demand for a bass reflex nondirectional speaker that
improves the sound quality in the low to mid range compared to a conventional bass reflex
speaker and further exhibits nondirectionality. A bass reflex nondirectional speaker according to
the present invention comprises 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 of the openings, and a columnar member is attached to the other opening of the
casing so as to form a tubular gap with the casing, thereby forming a tubular gap as a duct. It is
characterized in that it functions and the other opening functions as a port. [Selected figure]
Figure 1
Bass reflex type omnidirectional speaker
[0001]
The present invention relates to a bass reflex nondirectional speaker, and more particularly to a
bass reflex speaker that improves the sound quality in the low to mid range compared to a
conventional bass reflex speaker and further exhibits nondirectionality.
[0002]
Conventionally, based on Helmholtz's theory of resonance, using a tubular duct and a hole-like
port provided in an enclosure called an enclosure as shown in FIG. The bass reflex type speaker
which amplifies is known, and the bass reflex type speaker which made the duct and the port
various shapes and positions at patent documents 1-4 is indicated.
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[0003]
JP-A-4-70198 JP-A-4-235500 JP-A-8-140177 JP-A 2009-5180 JP-A 2002-10383 JP-A 200472140 JP Patent 4262291
[0004]
However, the conventional bass reflex type speaker as described in Patent Documents 1 to 4 has
a drawback that directivity is always present since the duct and the port are provided only in one
direction. there were.
In addition, since the sound (flow of air due to sound waves and sound) emitted from the back of
the speaker into the inside of the case generates turbulence around the duct, such turbulence
flows from the back of the speaker into the inside of the case. The emitted sound is not smoothly
emitted from the port through the duct to the outside of the housing, and as a result,
amplification effects far beyond the theoretical value derived from Helmholtz's resonance theory
can be obtained, and the amplification performance is insufficient. There was a drawback of
being.
[0005]
On the other hand, although it is classified into the speaker of a kind different from a bass reflex
type speaker, in the speaker called back load horn type, as shown to patent document 5 and
patent document 6, the horn coming out of the speaker back is a horn of longitudinally long
shape. A speaker emitting from the lower part of the housing is disclosed.
[0006]
However, in the case of a speaker using a simple horn-like housing such as a back load horn type,
sound emitted from the back of the speaker is emitted from the lower portion of the horn
housing as shown in Patent Documents 5 and 6 Although it is possible to realize nondirectionality by the above, there is a drawback that the amplification effect of the sound in the
low range can not be realized because the duct and the port are not provided.
Further, in the bass reflex type speaker requiring the duct and the port, the concept of using the
simple cylindrical casing described in Patent Document 5 and Patent Document 6 can not be
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used as it is, so It has been difficult to create a bass reflex type speaker that has a duct and a port
at the bottom of the body and also achieves nondirectionality.
[0007]
Here, Patent Document 7 discloses a speaker described as a pipe type that emits sound
emitted from the back of the speaker from the lower part of a cylindrical casing.
However, even with the speaker, it is possible to realize nondirectionality by emitting the sound
from the back of the speaker from the lower part of the housing as in Patent Document 5 and
Patent Document 6 (see FIG. 1 of Patent Document 7) However, the sound absorbing material
installed inside the case 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, in the said speaker, since the lower part of a housing ¦ casing does not have a part
corresponded to a duct, it did not express the function as a bass reflex type speaker, and it was
difficult to amplify the sound of a bass region.
[0008]
From the above, up to the present, no bass reflex type speaker has been developed which has
non-directionality and realizes improvement of the sound quality in the low to mid range.
[0009]
The present invention has been made in view of the above-described conventional problems, and
improves the sound quality in the low to mid range compared to a conventional bass reflex
speaker, and further shows a non-directional bass reflex non-directional speaker It is intended to
be provided.
[0010]
In order to achieve the above object, a bass reflex nondirectional speaker according to claim 1 of
the present invention comprises a speaker, a cylindrical casing having openings at both ends, and
a size smaller than the inner size of the casing. A columnar member is provided, a speaker is
attached to one opening of the housing, and a columnar member is attached to the other opening
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of the housing so as to form a cylindrical gap with the housing. A tubular gap functions as a duct,
and the other opening functions as a port.
[0011]
In the bass reflex nondirectional speaker according to claim 2 of the present invention, the platelike member is connected to the columnar member, and the plate-like member radiates the sound
generated from the back of the speaker between the other opening and the other. It is
characterized in that the cylindrical clearance is made to function as a duct and the clearance is
made to function as a port by being attached so as to form a clearance to be released.
[0012]
In the bass reflex type nondirectional 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 platelike member, and prevents the casing from being tilted. And a plurality of L-shaped spacer
portions in a side view.
[0013]
The bass reflex nondirectional speaker according to claim 4 of the present invention is
characterized in that the central axis of the housing and the central axis of the columnar member
are the same axis.
[0014]
In the bass reflex nondirectional speaker according to claim 5 of the present invention, in the
cross section perpendicular to the central axis direction of the housing and the columnar
member, the difference between the sectional area inside the housing and the sectional area of
the columnar member is 1 cm < 2> -80 cm <2>.
[0015]
The bass reflex nondirectional 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 casing and the
plate member is 3 mm or more.
[0016]
In the bass reflex type nondirectional speaker according to claim 7 of the present invention, the
shape of the columnar member is cylindrical, elliptic cylindrical, prismatic, substantially
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cylindrical, substantially elliptic cylindrical, substantially prismatic, conical, pyramidal,
hemispherical Or a combination of these shapes.
[0017]
In the bass reflex type nondirectional speaker according to claim 8 of the present invention, the
shape of the casing is cylindrical, elliptical cylindrical, square cylindrical, substantially cylindrical,
substantially elliptical cylindrical, substantially rectangular cylindrical, conical It has a pyramidal
shape or a combination of these shapes.
[0018]
The bass reflex nondirectional speaker according to claim 9 of the present invention is
characterized in that the casing is a bamboo tube.
[0019]
According to the bass reflex nondirectional speaker according to the present invention, it is
possible to improve the sound quality in the low to mid range compared to the conventional bass
reflex speaker and to realize omnidirectionality.
[0020]
It is a schematic diagram which shows 1st Embodiment of the bass reflex type nondirectional
speaker based on this invention.
It is sectional drawing of FIG.
It is a schematic diagram which shows the base used for the bass reflex type nondirectional
speaker of FIG.
It is a figure which shows the cut surface of the A-A ridge part of FIG.
It is a schematic diagram which shows 2nd Embodiment of the bass reflex type nondirectional
speaker based on this invention.
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It is sectional drawing of FIG.
It is a figure which shows the cut surface of the BB ridge part of FIG.
It is a schematic diagram which shows 3rd Embodiment of the bass reflex type nondirectional
speaker based on this invention.
It is sectional drawing of FIG.
It is a figure which shows the cut surface of the CC ridge part of FIG.
It is a schematic diagram which shows the bass reflex nondirectional speaker of a reference
example.
It is sectional drawing of FIG.
It is a figure which shows the cut surface of the DD ridge part of FIG. It is a schematic diagram
which shows the frequency characteristic of the bass reflex nondirectional speaker of an Example
and a reference example. It is sectional drawing of the conventional bass reflex type speaker.
[0021]
Embodiments of the present invention will be described based on the drawings. The
embodiments described below are merely examples embodying the present invention, and do not
limit the technical scope of the present invention.
[0022]
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First Embodiment First, the configuration of a bass reflex nondirectional speaker 1a according to
a first embodiment will be described. FIG. 1 is a schematic view showing a first embodiment of a
bass reflex nondirectional speaker according to the present invention, FIG. 2 is a sectional view of
FIG. 1, and FIG. 3 is a bass reflex nondirectional speaker of FIG. FIG. 4 is a schematic view
showing a pedestal used in FIG. 4, and FIG. 4 is a view showing a cut surface of the AA ′ portion
of FIG. 2. As shown in FIGS. 1 and 2, the bass reflex nondirectional speaker 1 a according to the
present embodiment includes the speaker 2, a cylindrical housing 3, and a pedestal 4, and one
opening 5 a of the housing 3. The speaker 2 is attached to the speaker 4 and the pedestal 4 is
attached to the other opening 5b. The pedestal 4 is mainly configured by a columnar member 6
and a plate-like member 8 as shown in FIGS. 1 and 2. Then, the columnar member 6 forms a
cylindrical gap 7 with the housing 3 with respect to the other opening 5b, and the plate-like
member 8 is housed from the rear surface of the speaker 2 with the other opening 5b. It is
attached so as to form a gap 9 that radiates the sound generated inside the body 3 radially.
[0023]
In the bass reflex type nondirectional speaker 1a according to the first embodiment, since the
columnar member 6 includes the spacer portion 10 in an L shape in a side view, the housing 3 is
mounted so as to be fitted to the pedestal 4 In this state, tilting is prevented by the spacer
portion 10a, and it is in a state of being placed on the spacer portion 10b, but in addition to
being attached in a simply fitted state, The body 3 and the pedestal 4 may be fixed.
[0024]
Next, each configuration requirement will be described.
[0025]
(Speaker) The speaker 2 uses a known one.
Further, the wiring of the speaker is disposed along the inner surface of the housing 3 and is
taken out from a gap 9 described later to be connected to an amplifier (not shown), a player (not
shown) or the like.
In addition, a cone or a diffuser may be provided on the top of the speaker 3 to radially diffuse
the sound emitted from the front of the speaker 3.
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[0026]
(Case) The case 3 in the present invention is a cylinder having the opening 5 at both ends, and
the case whose inner size is larger than the columnar member 6 described later is used.
[0027]
With regard to the shape of the housing 3, although the bass reflex nondirectional speaker 1a of
the present embodiment uses a cylindrical one, the shape is not particularly limited as long as the
inside is hollow, and a cylindrical shape is used. Various shapes such as an elliptical cylinder, a
square cylinder, a substantially cylindrical shape, a substantially elliptic cylinder, a substantially
square cylinder, a cone, and a pyramid can be used.
The term square cylinder shape, substantially square cylinder shape, and pyramid shape
intended to include various polygonal shapes.
is
[0028]
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 in view of the
following points, etc. Is preferred. The natural material bamboo tube has a corrugated inner
surface and an outer surface, and there are knots and fine irregularities on the inner surface and
the outer surface. Therefore, since such a discontinuous surface diffusely reflects the sound
generated from the rear surface of the speaker 2, the effect of suppressing the generation of a
standing wave such as pipe noise can be exhibited. In addition to the bass reflex type, it is ideal
that the speaker unit vibrates only the speaker portion and the case itself supporting it does not
vibrate, but because bamboo is harder as a material, the case itself than other materials Vibration
can be suppressed. In addition, the use of a bamboo tube makes it excellent in design.
Furthermore, the use of bamboo can also contribute to the maintenance of bamboo forests,
which have recently been severely degraded.
[0029]
A sound absorbing material or the like may be separately provided on the inner surface of the
housing 3.
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[0030]
(Pedestal, Columnar Member, Plate-like Member) The pedestal 4 in the present invention is a
speaker between the columnar member 6 for forming the cylindrical gap 7 with the inside of the
housing 3 and the other opening 5b. (2) A gap 9 is formed which radiates the sound generated
from the rear side radially and which has at least two portions of a plate member 8 for erecting
or erecting the bass reflex nondirectional speaker 1a on the floor or the ground Ru.
In the present embodiment, as shown in FIG. 3, a cylindrical gap 7 and a gap 9 are formed
between the housing 3 and the columnar member 6 and the plate-like member 8, and the
housing is prevented from being tilted. A plurality of side-view L-shaped spacer portions 10 are
provided for this purpose. In addition, the columnar member 6 may be hollow inside, and not
only to form the cylindrical gap 7 between itself and the inside of the housing 3 but also to store
circuits for controlling the speaker etc. Has the advantage of being able to be used as a container.
[0031]
With regard to the shape of the columnar member 6, although the bass reflex nondirectional
speaker 1a of this embodiment uses a cylindrical one, a cylindrical gap 7 is formed between the
housing and the columnar member. The shape is not particularly limited as long as it is a shape,
and various shapes such as cylindrical, elliptic cylindrical, prismatic, substantially cylindrical,
substantially elliptic cylindrical, substantially prismatic, conical, pyramidal, and hemispherical are
used. be able to. Here, the term rectangular cylindrical shape, substantially rectangular
cylindrical shape, and pyramidal shape is intended to include various polygonal shapes.
Further, 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 size of the
housing.
[0032]
The shape of the plate-like member 8 is not particularly limited as long as the cylindrical gap 7 is
formed between the housing 3 and the columnar member 6 and the shape is not particularly
limited. Although a foot (not shown) or the like can be provided, if it is plate-shaped as shown in
FIG. 5, the bass reflex nondirectional speaker 1a can be stably erected or erected on the floor or
the ground. At the same time, emitting the sound generated from the back surface of the speaker
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2 radially from the inside of the housing 3 can be difficult to understand from the appearance,
and is also preferable because it becomes excellent in design.
[0033]
Further, the shape of the spacer portion 10 which can be provided as needed is not particularly
limited as long as the cylindrical gap 7 is formed between the housing 3 and the columnar
member 6 However, when L-shaped in a side view as shown in FIG. 1 and FIG. 2, the sound
generated from the back of the speaker 2 can be radially emitted from the inside of the housing
3 as described above, and Is preferable because it can prevent the
[0034]
The materials of the columnar member 6, the plate member 8 and the spacer portion 10 are not
particularly limited as in the case 3 but various materials such as wooden, bamboo, metal and
plastic are used. be able to.
[0035]
Furthermore, a sound absorbing material or the like can be separately provided to the columnar
member 6, the plate-like member 8, and the spacer portion 10 as in the case 3.
[0036]
(Cylindrical Clearance) As described above, the bass reflex nondirectional speaker of the present
invention is characterized in that the cylindrical clear clearance 7 is formed between the inside of
the housing 3 and the columnar member 6.
Since this cylindrical gap 7 serves as a duct for a bass reflex nondirectional speaker, if the gap in
a cross-sectional view perpendicular to the central axis direction of the housing 3 and the
columnar member 6 is cylindrical, There is no particular problem even if there is a difference in
the size and width of the gap, but it is preferable to have some degree of uniformity, if possible,
without an 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 be the same axis.
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[0037]
The size (area) of the cylindrical gap 7 is appropriately determined depending on the size of the
bass reflex nondirectional speaker, the sound range to be amplified, and the like.
Here, the bass reflex type speaker is a speaker that amplifies sound in the low frequency range
using Helmholtz's resonance theory, and the resonance frequency is determined by the cross
section of the duct, the length of the duct, the volume of the housing, and the characteristics of
the speaker However, as far 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 nondirectional speaker of the present invention.
Therefore, in the bass reflex type nondirectional speaker of the present invention, since the
cylindrical gap 7 serves as a duct, the resonance frequency corresponds to the cross-sectional
area of the inside of 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, assuming that 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 as shown in FIG.
4, the resonance frequency is π (r1) <2> -π (r2). It will be determined by <2> and h1. In the
present embodiment, since the columnar member 6 is provided with the spacer portion 10, the
area corresponding to the duct is exactly the same as the spacer portion from π (r1) <2> -π (r2)
<2>. However, if π (r1) <2> -π (r2) <2> is sufficiently large relative to the cross-sectional area of
the spacer section 10 as in this embodiment, the spacer The bass reflex nondirectional speaker
can be manufactured without considering the cross sectional area of the part 10. And among
these, the difference between the cross-sectional area inside the housing 3 and the crosssectional area of the columnar member 6 in a cross-sectional view perpendicular to the central
axis direction of the housing 3 and the columnar member 6 is 1 cm <2> -80 cm <2> It is
preferably 7 cm <2> to 40 cm <2>, more preferably 10 cm <2> to 20 cm <2>. The height of the
columnar member 6 is preferably 1 cm to 50 cm, and more preferably 5 cm to 20 cm.
[0038]
Next, the gap 9 formed between the other opening 5b and the plate member 8 serves as a port of
the bass reflex nondirectional speaker, as shown in FIGS. 1 to 4. If such a slit-like form is adopted,
it is possible to emit sound radially, which is preferable because nondirectionality can be realized.
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In addition, the gap 9 can be opened only in one direction, particularly when nondirectionality is
not required.
[0039]
The size (width) of the gap 9 is appropriately determined depending on the size of the bass reflex
nondirectional speaker, the sound range to be amplified, etc., as with the size of the tubular gap
7, but the other side of the case 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 still more preferably
10 mm to 200 mm.
[0040]
The size (width) of the gap 9 is preferably longer than the width of the cylindrical gap 7.
[0041]
Second Embodiment Next, the configuration of a bass reflex nondirectional speaker 1b according
to a second embodiment will be described.
FIG. 5 is a schematic view showing a second embodiment of the bass reflex omnidirectional
speaker according to the present invention, FIG. 6 is a sectional view of FIG. 5, and FIG. 7 is a BB
'portion of FIG. It is a figure which shows a cut surface.
[0042]
The bass reflex nondirectional speaker 1b according to this embodiment does not have the
spacer portion 10 as shown in FIGS. 5 and 6, and separately uses the jig 11 such as a stay or a
fitting to form the cylindrical gap 7 and the gap The configuration is the same as that of the bass
reflex nondirectional speaker 1a according to the first embodiment except that 9 is formed.
Also by adopting such a form, since the cylindrical gap 7 and the gap 9 corresponding to the
duct and the port can be formed, the bass reflex nondirectional speaker of the present invention
can be manufactured.
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[0043]
Also in the present embodiment, as in the case of the bass reflex nondirectional speaker 1a of the
first embodiment, the resonance frequency is π (r1) <2> -π (r2) as shown in FIG. Is determined
by <2> and h1, and if π (r1) <2> −π (r2) <2> is sufficiently large relative to the cross-sectional
area of the jig 11, A bass reflex nondirectional speaker can be manufactured without considering
the cross section.
[0044]
Third Embodiment Next, a configuration of a bass reflex nondirectional speaker 1c according to a
third embodiment will be described.
FIG. 8 is a schematic view showing a third embodiment of the bass reflex omnidirectional speaker
according to the present invention, FIG. 9 is a cross-sectional view of FIG. 8, and FIG. 10 is a
section CC 'of FIG. It is a figure which shows a cut surface.
[0045]
The bass reflex nondirectional speaker 1 c of this embodiment has a structure in which the
speakers are attached to both openings of the housing 3. Specifically, as shown in FIG. 8 and FIG.
9, the columnar member 6 to which the high-tone speaker 2a is connected is attached to the
upper opening, and for the low-pitched opening of the housing 3 The speaker 2b is attached.
Then, a columnar member 6 in which the high-sound speaker 2 a is built in is attached so as to
form a cylindrical gap 7 and a gap 9 between the column member 6 and the housing 3. Further,
a diffuser 12a for radially emitting the sound generated from the speaker 2a is attached above
the high sound speaker 2a, and a diffuser 12b for radially emitted the sound generated from the
speaker 2b below the bass speaker 2b Is attached.
[0046]
Even by adopting such a configuration, the housing 3 and the columnar member 6 are formed in
the opening on the high sound speaker 2 a side of the housing 3 by the housing 3 and the
columnar member 6 corresponding to the cylindrical gap 7 and port corresponding to a duct. It
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is possible to form a ring-shaped gap, and further, high-pitched sound, for which there is not
much demand for amplification, can be incorporated in the columnar member. Therefore, the
bass reflex nondirectional speaker of the present invention can attach two speakers to the
housing.
[0047]
Here, in the present embodiment, unlike the case of the first embodiment and the second
embodiment, since the spacer portion 10 and the jig 11 are not provided, the resonance
frequency thereof is as shown in FIG. It is determined by π (r1) <2> -π (r2) <2> and h1.
[0048]
Reference Example Next, a reference example related to the bass reflex nondirectional speaker
according to the present invention will be described.
11 is a schematic view showing a bass reflex nondirectional speaker according to a reference
example, FIG. 12 is a cross-sectional view of FIG. 11, and FIG. 13 is a cross-sectional view of a DD ridge portion of FIG.
[0049]
As shown in FIGS. 11 and 12, in the bass reflex nondirectional speaker 101 of the reference
example, the speaker 102 is attached to one opening 105 a 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 has a plate-like member 108 provided with 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 supporting the member 108 are provided.
[0050]
As described above, even by adopting the structure as in the reference example, the sound
emitted from the port portion diffuses radially, so that nondirectionality can be realized, and the
low-mid range by the duct portion and the port portion can be realized. Can also be expressed.
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[0051]
Here, also in the bass reflex nondirectional speaker 101 of the reference example, the
amplification performance in the low to mid range is determined by the cross sectional area of
the duct and the length of the duct.
Specifically, assuming that the inner diameter of the duct is r3 and the length of the duct portion
is h2 as shown in FIGS. 11 and 13, the amplification performance is determined by π (r3) <2>
and h2. . Therefore, the value of π (r1) <2> -π (r2) <2> of the bass reflex nondirectional speaker
according to the present invention and the π (r3) <2> of the bass reflex omnidirectional speaker
of the reference example If the values are the same, the same resonant frequency can be realized.
[0052]
Next, the present invention will be described in more detail by way of examples and reference
examples.
[0053]
(Example) A bamboo tube with a length of 100 cm, an outer diameter of about 13 cm, and an
inner diameter of about 11 cm from which internal nodes have been removed is used for a
housing, and a speaker (FOSTEX, product number FE103En) is attached to one opening, A bass
reflex type nondirectional speaker of the example was manufactured by attaching a pedestal to
the opening of the.
Here, the pedestal is a plate-like member having a thickness of 30 mm and a columnar pillarshaped member having a height of 10 cm and a diameter of 10 cm, and L1: 10 cm, L2: 1 cm, and
L3: 1.5 cm in FIG. What provided four spacer parts of side view L-shape of the dimension of was
produced. Note that by attaching such a pedestal, the area of the duct of the bass reflex
nondirectional speaker (a cylindrical gap formed between the inside of the case and the columnar
member = perpendicular to the central axis direction of the casing and the columnar member
Between the cross-sectional area of the inside of the housing 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 (the
end of the other opening and the plate-like member The gap formed between is 1 cm.
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[0054]
(Reference Example) A bass reflex type nondirectional speaker of a reference example was
manufactured by attaching the same bamboo tube and speaker as in the example and attaching a
pedestal to the other opening. Here, the pedestal is a plate-like member provided with an opening
with a radius of 2.3 cm at the central portion, and a cylindrical duct portion having a height of 10
cm and an inner diameter of 4.6 cm extending toward the inside of the housing. One provided
with four feet supporting a 5 cm plate member was manufactured. By attaching such a pedestal,
the area of the duct of the bass reflex nondirectional speaker is about 16.6 cm <2> which is
substantially the same as that of the embodiment, and the size of the port is about 16.6 cm <2>.
It has become.
[0055]
(Measurement of Frequency Characteristic) Next, the frequency characteristic of the bass reflex
nondirectional speaker manufactured as described above was measured. The results are shown
in FIG. As a result, in both the example and the reference example, a high amplification effect was
able to be expressed as compared with the conventional bass reflex type speaker shown in FIG.
Specifically, high amplification effects can be expressed not only for sounds in the bass region
(50 to 200 Hz), but also for sounds in the mid-bass region (200 to 500 Hz) that are originally
said to be difficult in bass reflex speakers. did it. Further, among the examples, particularly in the
example according to the bass reflex nondirectional speaker of the present invention, it was
possible to make the amplification effect of the sound in the low to mid range higher than that of
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 generates a slight turbulence in the
vicinity of the connection portion between the plate member and the duct portion, whereas in the
embodiment, this noise is generated. This is because it is considered that the sound emitted from
the back of the speaker into the inside of the housing is smoothly emitted from the cylindrical
gap and the gap. From the above, it has been found that the bass reflex nondirectional speaker
according to the present invention can further improve the amplification effect of the sound in
the low to mid range while showing nondirectionality.
[0056]
1a bass reflex type omnidirectional speaker 1b bass reflex type omnidirectional speaker 1c bass
reflex type omnidirectional speaker 2 speaker 3 housing 4 base 5a opening 5b opening 6
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columnar member 7 cylindrical gap 8 plate member 9 gap 10 spacer Part 10a Spacer part 10b
Spacer part 11 Jig 12a Diffuser 12b Diffuser 101 Bass reflex type nondirectional speaker 102
Speaker 103 Casing 104 pedestal 105a Opening 105b Opening 106 Foot 107 Duct 108 Plate
member 109 Port
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