JP6883816B2 - Cylindrical speaker structure, speaker device, audio system, speaker device manufacturing method, and speaker device modification method - Google Patents

Description

The present invention relates to a tubular speaker structure, a speaker device, an audio system, a speaker device manufacturing method, and a speaker device modification method. In particular, a high-power high-end machine capable of satisfactorily reproducing a weak signal including subtle nuances is used. It is related to the speaker structure, etc., which can obtain Hi-Fi (High Fidelity) reproducibility of the original sound of an excellent CD sound source, etc., and can easily provide a highly realistic audio environment at low cost. is there.

<Technical concept of conventional speakers>
In the conventional speaker, the voice coil of the speaker unit receives an electric voice signal to vibrate the cone, and applies a sparse and dense pressure to the air particularly in front of the cone to generate sound. In this case, the compressional wave on the front surface of the cone and the compressional wave generated secondarily on the back surface of the cone interfere with each other, and a low-pitched sound with particularly low directivity wraps around to cancel the sound generated on the front surface. In order to eliminate this wraparound, the speaker unit is often set in an enclosure.

The most ideal form of speaker enclosure in such a scheme is theoretically a flat (single plate) "vibration-free" and "infinite plane" baffle. In an actual speaker, the cone, which is the vibrating body of the speaker unit, is supported by the frame, baffle plate, and enclosure of the speaker unit. The reaction force of the vibration of the cone is generated in the opposite direction as vibration, but these vibrations are regarded as "unnecessary vibrations" and are considered to be a factor of deterioration of sound quality.

Therefore, it is important to use a robust material with a heavy specific density as a component of the enclosure, and to seal the enclosure and put a sound deadening material in it to muffle the inner surface of the enclosure and prevent vibration of the enclosure itself. It has been. Exceptions to the closed type are the bass reflex type and the open rear type, but in any case, basically "eliminate unnecessary vibration" and "make the front sound unaffected by the sound generated on the back". There is no change in the idea.

In addition, it is known to some audiophiles that the sound quality changes depending on the material of the enclosure and baffle plate, and manufacturers have launched products in response to this. However, even in this case, the basic policy of eliminating unnecessary vibration remains unchanged.

<Prior art>
Conventionally, many technical proposals have been made for speaker devices. For example, in Patent Document 1 described later, for the purpose of improving the sound quality in the low and middle range of a bass reflex type speaker, a tubular housing having openings at both ends and a columnar shape having a size smaller than the inner size of the housing are provided. A speaker unit is attached to one opening of the housing, and a columnar member having no opening on the speaker unit side is provided in the other opening of the housing in a tubular shape between the member and the housing. A configuration is disclosed in which a tubular gap functions as a duct and the other opening functions as a port by being attached so as to form a gap.

Further, in Patent Document 2 described later, the outer housing and the inner housing are substantially concentric circles as a speaker device capable of reproducing a unique sound that can correspond to the range of the viewer's sensibility, not necessarily reproducing the original sound faithfully. It is arranged in a shape, and the configuration in which a sound absorbing material is put in the inner housing is disclosed. According to this, the sound absorbing material inside the inner housing makes the sound in the inner space non-resonant, and by making both housings made of metal, the sound between them is made to resonate, or is emitted from the inner space. It is said that it is possible to emit a unique sound by synthesizing a non-resonating sound and a resonating sound emitted from the outer space.

Further, in Patent Document 3 described later, a cylindrical shape is provided as a speaker device that has less time-related disturbance, can faithfully reproduce complex low-frequency waveforms such as musical sounds, and has a wide service area in the sound field space. On one end surface of the speaker housing, the speaker unit is fixed so as to substantially cover the front surface and the back surface of the diaphragm, and on the other bottom surface, the speaker unit has an opening, and a support rod is provided on the back surface of the magnet. The configuration in which the weight is fixed is disclosed. The weight holds the support rod substantially in the vertical direction and acoustically and virtually grounds the magnet, which attenuates and suppresses the vibration transmitted from the magnet to the support rod.

Further, in Patent Document 4 described later, one end side and the other end side of the pipe are completely opened as a speaker device capable of obtaining a sound image having a sense of spaciousness over the entire tubular member (pipe) which is a housing. The speaker unit driven based on the audio signal is coaxially arranged on one end side of the pipe, and the pipe is formed to be light and thin enough to be vibrated by the sound wave from the speaker unit. It is disclosed. As a result, when the sound wave from the speaker unit passes through the inside of the pipe and is radiated to the outside from the completely open other end side, the pipe wall of the pipe is vibrated and vibrated by this sound wave, and the pipe wall of this pipe is vibrated. Sound waves corresponding to audio signals are emitted from the entire outer surface.

Japanese Unexamined Patent Publication No. 2013-81061 "Bass reflex type omnidirectional speaker" Japanese Unexamined Patent Publication No. 2016-116093 "Speaker device" Japanese Unexamined Patent Publication No. 2001-224089 "Speaker device" JP-A-2007-208734 "Speaker device and audio output method"

<Problems with conventional speakers>
By the way, the conventional speaker has the following problems.
(1) Weak to weak signals With conventional speakers, the main sound is produced only from the front of the speaker cone. Therefore, the speaker unit is said to have excellent large diameter, high output, wide range, and flat characteristics, and dampers and edges have been strengthened to control the movement of powerful cones. As a result, there is a problem that a weak signal, which is important for reproducing "good sound" such as reality, presence, and ease of hearing, cannot be pronounced and cannot be reproduced well. Further, the audio signal is an alternating current wave having various spectrums, and by muting the sound on the back of the unit, the sound energy of one of the alternating currents is muted. Therefore, even if the sound of a strong signal can be reproduced, there is a problem that a weak signal including a subtle nuance is canceled by being transmitted to the sound absorbing material and the heavy unit.

(2) High-output high-end machine is required to obtain high-definition reproducibility. Therefore, Hi-Fi (High Fidelity, high fidelity) reproduction of the original sound (CD sound source, etc.) is high-output high-end. There is a problem that it has to be low except when listening at a certain volume or higher on the machine. In other words, it is difficult to enjoy highly realistic audio from high-end audio equipment such as high-output devices, multi-speakers, and multi-amplifiers, except for some audiophiles who can hear a certain volume or higher in an environment such as an audio room. The current situation.

(3) There is no small speaker that can obtain high-definition reproducibility even at low volume. High-definition such as SACD (Super Audio CD), DSD (Direct Stream Digital), sampling frequency, and high-resolution sound source download service with high quantization bit rate. Sound sources, DACs (Digital to Analog Converters), and amplifiers compatible with these high-definition sound sources have been developed. However, there is a lack of high-definition efforts for hepato-renal speakers. In particular, there is no speaker that can obtain the balance of reproduction frequency and high-definition reproducibility even at low volume.

(4) There is no device that can fully enjoy high-definition audio at low cost easily. Since it is difficult to enjoy highly realistic audio in the true open air, the headphone and headphone amplifier market is booming. However, listening with only the ears puts a heavy burden on the ears and cannot be enjoyed for a long time. That is, there is no device that can fully enjoy high-definition audio at low cost and easily without time limitation and without putting an excessive burden on the ears.

(5) Unnaturalness of reproduction only by speaker cones In the first place, it is unnatural to reproduce the multi-layered performance of musical instruments made of wood, metal, and combinations thereof, such as orchestras, only by speaker cones. , Attempts to eliminate the unnaturalness as much as possible are still insufficient.

Therefore, the problem to be solved by the present invention is to eliminate the problems of the prior art, in particular, to be able to reproduce weak signals including subtle nuances satisfactorily, and to provide an excellent CD sound source without using a high-output high-end machine. It is an object of the present invention to provide a speaker structure or the like that can obtain Hi-Fi reproducibility of the original sound of the above and can easily provide a highly realistic audio environment at low cost.

That is, an object of the present invention is to provide a speaker structure or the like capable of satisfactorily reproducing a weak signal and obtaining high-definition reproducibility without increasing the diameter, output, or size. High-definition audio can be obtained even at low volume, and a speaker structure that can be miniaturized can be provided. High-definition audio is inexpensive, easy, time-limited, and does not place an excessive burden on the ears. It is to provide a speaker structure and the like that can fully enjoy the above, and further, to provide a speaker structure and the like that can obtain a more natural reproduced sound by eliminating the unnaturalness of reproduction by only the speaker cone.

<Problem solving policy>
As a result of research on the above issues, the inventor of the present application has established the following solution policy.
(1) By reproducing the sound that was not reproduced as sound by the cone, we aim to reproduce the recording site (Hi-Fi + stereoscopic sound image) beyond the Hi-Fi reproduction of the CD sound source.
(2) The structure is such that the sound is emitted not only from the speaker unit but also from the entire enclosure.
(3) All "vibration energy" generated from the speaker unit is transmitted to the enclosure and converted into sound.
(4) The structure is such that even minute harmonic components can be pronounced.
(5) Not only the tone of the musical instrument, but also the rise (attack), attenuation (decay), sustain (sustain), and mute (release) of the sound can be realistically expressed.
(6) Spruce, bamboo, and other materials used in musical instruments are used in combination.
(7) In the case of wood, tune the sound in consideration of the combination and the direction of the grain.
(8) Use the pressure inside the enclosure (sound from the back of the cone) and internal reverberation.
(9) Consider the bass reflex method for bass control and tuning of the sound of the entire speaker device.
(10) A unique internal structure is used to control mid-high range, low range, and internal reverberation.
(11) Since the vibration from the speaker unit is vibrated by the speaker body, a strong bottom plate is used.

<Problem solving means>
That is, based on the fact that the speaker structure is a structure that sounds from the entire enclosure and the material for that purpose is examined, and as a result of other multifaceted examinations, it is found that the above problems can be solved, and the present invention is based on this. It came to be completed. That is, the inventions claimed in the present application as means for solving the above problems, or at least the inventions disclosed, are as follows.

[1] A tubular enclosure with an open end and
A speaker unit that is driven on the basis of the audio signal is disposed in the enclosure coaxially with said open end,
The speaker unit is provided with a bass reflex provided at the opposite end.
A part of the opposite end is also opened by the bass reflex hole of the bass reflex.
The side surface of the enclosure is formed of a non-homogeneous thin plate.
The thin plate body is formed by using two sheet-like wood materials.
A reinforcing sheet is attached to the sheet-shaped wood material, and the thickness of the thin plate including the reinforcing sheet is 0.5 mm or more and 0.8 mm or less.
As a vibration propagation means (hereinafter, "sound bridge") for transmitting vibration from the speaker unit to the enclosure, a baffle plate surrounding the speaker unit and an additional sound bridge made of aluminum, copper, steel plate or stainless steel are provided. Or there are multiple
Inside the enclosure, a tower-shaped reflector that reflects sound waves from the speaker unit is provided at the bass reflex port of the bass reflex.
With this configuration, each of the actions described in <SE1> to <SE3> below is performed.
A cylinder characterized in that all vibration energy generated in this tubular speaker structure is transmitted to the enclosure, sound is produced from the entire enclosure, and sound waves are transmitted to the outside through the side surface portion of the enclosure. Shaped speaker structure.
<SE1> Sound inside the enclosure including reflection passes through the thin plate body.
<SE2> The thin plate body vibrates based on a change in internal pressure due to the diaphragm of the speaker unit, and sound is transmitted through the thin plate body.
<SE3> The sound bridge vibrates the thin plate body, and sound passes through the thin plate body.
[2] The tubular speaker structure according to [1], wherein spruce, bamboo, or both are used as the sheet-shaped wood material.
[3] The tubular speaker structure according to [1], wherein two spruce veneers are used as the thin plate body.
[4] The spruce veneer constituting the thin plate body has a thickness of 0.3 mm or less including the reinforcing material attached to the thin plate body, and therefore the thickness of the entire thin plate body is 0.6 mm or less. The tubular speaker structure according to [3].

[5] The tubular speaker structure according to any one of [3] and [4], wherein the spruce veneer used on the inside has a vertical grain and the spruce veneer used on the outside has a horizontal grain.
[6] The tubular speaker structure according to any one of [1], [2], [3], [4], and [5], wherein the reinforcing sheet is Japanese paper.
[7] The tubular speaker structure according to any one of [1], [2], [3], [4], [5], and [6] , wherein the enclosure has a cylindrical shape.

[ 8 ] A speaker device having the tubular speaker structure according to any one of [1], [2], [3], [4], [5], [6], and [7].
[ 9 ] The method for manufacturing a speaker device according to [8 ], wherein one or a plurality of stabilizers are attached to an enclosure.
[ 10 ] A method for modifying a speaker device according to [8 ], which comprises attaching one or more stabilizers to an enclosure.
[ 11 ] An audio system including the speaker device according to [8].

<Effect of the present invention>
Since the tubular speaker structure, the speaker device, the audio system, the speaker device manufacturing method, and the speaker device modification method of the present invention are configured as described above, according to these, weak signals including subtle nuances can be reproduced satisfactorily. It is possible to obtain Hi-Fi reproducibility of the original sound of an excellent CD sound source or the like without using a high-output high-end machine, and it is possible to provide a highly realistic audio environment inexpensively and easily.

In other words, it is possible to reproduce weak signals well and obtain high-definition reproducibility without increasing the diameter, output, and size, and it is also possible to obtain high-definition reproducibility even at low volume. Moreover, it can be miniaturized, and it is possible to provide a speaker structure or the like that can fully enjoy high-definition audio at low cost, easily, without time limitation, and without imposing an excessive burden on the ear. It is possible to eliminate the unnaturalness of reproduction by only the speaker cone and obtain a more natural reproduction sound.

According to the tubular speaker structure of the present invention, not only the speaker unit but also all the "vibration energy" generated is transmitted to the enclosure, and the sound is produced from the entire enclosure. Rise (attack), attenuation (decay), sustain (sustain), and mute (release) can be expressed with good reproducibility. Furthermore, since the thin plates that make up the enclosure are non-homogeneous (eg, sheet-like wood materials such as spruce and bamboo), vibrations that were not reproduced as sound by the cone can be reproduced with high definition. , It is possible to obtain a reproduced sound that exceeds the Hi-Fi reproduction of the CD sound source and is close to the reproduction (Hi-Fi + stereophonic sound image) at the recording site.

Further, according to the speaker device manufacturing method and the speaker device modification method of the present invention, the sound quality can be freely changed by simply attaching one or more tape-shaped stabilizers to the enclosure according to appropriate specifications. Therefore, as a manufacturing method, it is possible to manufacture a speaker device corresponding to the characteristics of the sound source to be reproduced (music genre, type of musical instrument / voice, characteristics of volume and sound quality, etc.), and the user can freely design the sound quality. It is possible to provide a speaker device having the possible specifications.

It is a side sectional view which shows the basic structure example of the tubular speaker structure of this invention. It is a side view of the configuration example shown in FIG. It is a top view (top view) of the configuration example shown in FIG. It is a bottom view of the configuration example shown in FIG. It is explanatory drawing which shows the example of the forming method of the thin plate body which concerns on this invention. It is a side sectional view which shows the structural example of the tubular speaker structure of this invention provided with the virtual ground part. It is a side sectional view which shows the structural example of the tubular speaker structure of this invention provided with a reflective part. It is explanatory drawing of the side sectional view which shows the operation in the configuration example shown in FIG. 7. It is a side sectional view which shows the design example of the reflection part in the tubular speaker structure of this invention. It is explanatory drawing of the side sectional view which shows the shape example of the reflector in the tubular speaker structure of this invention. It is explanatory drawing of the partial side sectional view which shows the structural example of the tubular speaker structure of this invention which made the reflective part a floating mount. It is explanatory drawing of the partial side sectional view which shows the example of the sound bridge structure in the tubular speaker structure of this invention. It is explanatory drawing which shows the structure of each sound bridge shown in the structure example of FIG. 12, and is the figure seen from the inner surface side of the baffle plate. It is explanatory drawing of the partial side sectional view which shows the structural example of the tubular speaker structure of this invention provided with a stabilizer.

<Basic configuration of the present invention>
Hereinafter, the present invention will be described in detail with reference to the drawings. It should be noted that each figure is an example, and the present invention is not strictly limited to the form, dimensions, arrangement and other specifications shown in each figure. For example, the locations of the terminals 5T and the like shown in FIG. 11 and the like are not the same, but all of them show the configuration examples according to the present invention.
FIG. 1 is a side sectional view showing a basic configuration example of the tubular speaker structure of the present invention. Also,
2, 3 and 4, respectively, are a side view, a plan view (top view), and a bottom view of the configuration example shown in FIG. As shown in these, the tubular speaker structure 10 is arranged on the open end 2 side coaxially with the enclosure 1 and the tubular enclosure 1 in which at least one end side 2 is open, and is driven based on an audio signal. The speaker unit 4 is provided, and the side surface portion of the enclosure 1 is formed of a non-homogeneous thin plate body 5, whereby sound waves are configured to pass through the side surface portion of the enclosure 1 and be radiated to the outside. The main configuration is that.

It should be noted that each figure is an example of the basic configuration of the tubular speaker structure of the present invention, and the present invention is not limited to the configuration shown in the figure. For example, it is desirable to provide one or more bass reflex structures 6 (bass reflex port 6P, bass reflex hole 6H), but even if the structure is not provided, it is within the scope of the present invention. The same applies to spike 7. Of course, as described above, the present invention is not limited by the illustrated shape, proportion, and the like. The present invention is not limited to the illustrated configuration, and the same applies to the description described later in FIGS. 5 and later.

With this configuration, in the tubular speaker structure 10 of the present invention, when the speaker unit 4 provided on the open end 2 side is driven based on the audio signal, the sound wave emitted from the cone propagates in the forward direction of the speaker unit 4. , The sound wave propagates to the inside of the enclosure 1 behind the speaker unit 4. The latter sound wave passes through the non-homogeneous thin plate body 5 constituting the side surface portion of the enclosure 1 and is radiated to the outside. In this way, the sound emitted from the speaker unit 4 is sounded forward, and is also sounded from the entire thin plate 5 forming the side surface of the enclosure 1.

The "cylindrical shape" of the enclosure 1 in the present invention is not limited to its cross-sectional shape. Therefore, the cross-sectional shape includes all circles, ellipses, equilateral triangles and other triangles, squares and other quadrangles, other polygons, semicircles and other figures. The cylindrical enclosure is one of the excellent examples in which the effects of the present invention can be sufficiently obtained, and an omnidirectional speaker can be configured. Therefore, the following description describes the cylindrical enclosure. The example of 1 is mainly performed. It also includes the case where the cross section is enlarged toward one of the ends 2 and 3. The enclosure 1 fulfills the three functions of the housing of the speaker structure 10, the vibrating body, and the resonance tube.

As described above, the speaker unit 4 is not only a sound source that emits sound from the front to the front, but also a vibration source and a rear sound source. That is, the vibration from the speaker unit 4 propagates as follows.
Vibration: Speaker unit vibration-> Baffle plate->Enclosure-> Converted to sound Back sound: Speaker unit back sound-> Enclosure internal sound pressure-> Enclosure (side)-> Converted to sound Enclosure (side) 1 or thin plate 5 Functions as a passive radiator (passive sound radiator). So to speak, it is a principle close to the mechanism in which the vibration of strings of guitars, violins, etc. vibrates the front plate through the bridge to generate sound.

<Effect of making a tubular enclosure with a thin plate>
The effects of forming the side surface of the enclosure 1 with the thin plate body 5 and making it tubular (particularly cylindrical) are listed.
(1) When the enclosure has a cylindrical shape, tension is generated by bending the thin plate into a cylindrical shape, and the strength of the housing can be ensured.
(2) It is a sounding body with optimum vibration characteristics and transmission characteristics, which is thin and light.
(3) High sound resolution (sounds of each instrument can be heard individually).
(4) A moderate internal reverberation creates a high sense of presence.
(5) Since the direct sound of the speaker unit spreads upward and is sounded horizontally 360 degrees from the surface of the cylindrical enclosure, a three-dimensional sound image is formed.
(6) Since all the thin cylinders serve as sounding bodies, the sounding area is wide and the sounding efficiency of vibration sound and transmitted sound is high.
(7) Since the sound from the unit does not reach directly, it is easy on the ears and enables long-time listening in the near field (short distance).

(8) When a wooden board is used as the thin plate body, it has compression and extension strength in the direction of the annual ring and is flexible in the direction perpendicular to the annual ring.
(9) By laminating the plates together with the thickness of the plates and combining the vertical and horizontal directions of the annual rings, it is possible to obtain a thin and strong structure and a vibrating body whose sound quality can be controlled.
(10) The conventional passive radiator (a passive cone having no drive function is driven by the internal pressure of the enclosure to enhance the bass) is aimed at enhancing the bass portion, but in the present invention, it is intended. , It is possible to output from treble to bass.
(11) When the enclosure is cylindrical, the sound from the side of the cylinder is diffused as a cylindrical wave, so that the listener receives a high-pressure sound, and due to the characteristics of the cylindrical wave, a clear sound reaches a long distance even at a low volume. To do.
(12) In the case of a configuration in which a bass reflex is provided, rich bass exceeding the size can be reproduced.
(13) It is possible to experience the vibration of sound more clearly than when a lightweight cone such as paper vibrates due to the vibration of a wooden board. In other words, the pronunciation is more like an instrument.
(14) The sound in the enclosure is transmitted and pronounced with high efficiency. Since this transmission is attenuated, standing waves are less likely to be generated and the sound is less turbid.

By the way, in the present invention, the end portion 3 on the opposite side of the speaker unit 4 of the enclosure 1 is opened only in the case of the bass reflex hole 6H when the bass reflex 6 is provided at the end portion. That is, in the tubular speaker structure 10 of the present invention, the end 2 provided with the speaker unit 4 is naturally an open end, but the opposite end 3 is not, in principle, an open end, and the bass reflex 6 The bass reflex hole 6H forms an open portion at the end 3 only in the configuration provided with. Bass reflexes can also be installed on cylinders and baffles.

This point is different from the above-mentioned patent document 4 disclosure technique in which not only the end portion where the speaker unit is provided but also the end portion on the opposite side facing the speaker unit is completely opened. In other words, in the prior art, the open end on the opposite side of the speaker unit is configured as the end where sound is radiated as necessary, and a thin enclosure made of polycarbonate or the like is used to obtain a spacious sound image. However, in the present invention, the side surface portion of the enclosure 1 made of the thin plate body 5 is the medium from which sound is radiated, and it is necessary that the speaker unit 4 facing end portion 3 is the open end portion. is not it. Only when the bass reflex 6 is provided at the end 3 on the opposite side of the speaker unit 4, there is only an open end as the bass reflex hole 6H, which is completely different in technical features from the open end of the prior art. is there. The general definition of bass reflex is as follows.
Bus reflex port: Hole opened to the outside Bus reflex duct: Pipe Bus reflex duct length: Pipe length Bus reflex duct diameter: Inner diameter: Pipe inner diameter, Outer diameter: Duct outer diameter

<Structure of thin plate>
In the tubular speaker structure 10 of the present invention, the non-homogeneous thin plate body 5 can be formed by using one or more sheet-shaped wood materials. It is possible to use one or two sheet-shaped wood materials, but even three or more sheets are within the scope of the present invention. When a plurality of sheet-shaped wood materials are used, they can be preferably used by being bonded together. As the plant material, veneers of various tree species such as spruce and bamboo can be preferably used, but the plant material is not limited thereto. Not only the veneer but also a machined sheet-like material or other sheet-like material may be used.

In any case, first of all, it is important to use a non-homogeneous material, not a homogeneous material such as polycarbonate as in the prior art, regardless of whether it is a wood material or not. In that respect, among the vegetable materials, wood materials, particularly wood veneers and sliced materials are suitable. Due to the non-homogeneity, that is, the wide range of characteristics related to resonance, the range of locations where each sound wave having a unique frequency is likely to vibrate is widened. Therefore, in the tubular speaker structure 10 of the present invention, various sound qualities can be obtained. It becomes possible to reproduce each sound more naturally.

It is important that the thin plate body 5 is made non-homogeneous as a whole by using a sheet-like wood material or the like which is inhomogeneous, but in the most basic idea of the present invention, it is said to be inhomogeneous. As long as it can be done, its components do not necessarily have to be made of wood. The interpretation of "non-homogeneity" is that, for example, even if a homogeneous material such as synthetic resin or metal is used for the purpose of adjusting the volume and sound quality by changing the transmittance (F ratio) of the thin plate body 5, the whole It can also be said that the non-homogeneity is sufficient. However, the sheet-shaped wood material is still a suitable component of the thin plate body 5.

Further, it can be assumed that a reinforcing sheet is attached to the sheet-shaped wood material. For example, in the case of a veneer, its thickness is about 0.1 mm to several mm, and it is effective to use a reinforcing sheet in order to improve strength, stability and workability. As the reinforcing sheet, Japanese paper or other paper or a resin sheet can be preferably used.

When a sheet-shaped wood material is used as the thin plate body 5, spruce, bamboo, or both can be preferably used. Spruce will be described in more detail. Spruce is a suitable material for pianos, guitars, and violins, although the unique properties such as density and specific gravity differ depending on the type of wood, and even if the wood is of the same type, it varies depending on the weather conditions of the habitat. It is a wood used as. Spruce has a sound (vibration) propagation speed of 5,500 m / s, which is faster than iron. Moreover, the specific gravity is 0.45, which is lighter than 7.9 of iron. The characteristics of wood required for musical instruments include high vibration propagation speed, low specific density, flexibility, elasticity, and good timbre, and spruce is highly evaluated in all of these. Also in the present invention, it can be most preferably used as a sheet-like wood material.

As the sheet-like wood material used for the thin plate body 5 of the tubular speaker structure 10 of the present invention, spruce or bamboo can be preferably used as described above, but most preferably, the thin plate body using two spruce veneers. 5 can be configured. In that case, the spruce veneer used on the inside may have a vertical grain, and the spruce veneer used on the outside may have a horizontal grain. Including this, the thin plate body will be described in more detail.

As a veneer which is a suitable material for forming the thin plate body 5, there are veneers of most tree species distributed as wood. The thickness of the veneer is usually about 0.1 mm to several mm, and the thin one is used with a reinforcing sheet such as Japanese paper or resin sheet attached to increase the strength and facilitate the construction. There is also. In the present invention, special attention has been paid to spruce and bamboo. In particular, spruce is a wood used for violins, guitars, and piano soundboards, and is a material having excellent sound transmission, speed, and sound output.

On the other hand, bamboo has high strength, so it is effective for increasing the strength of the enclosure. Hard maple is often used for the back plate of the violin, and it is considered that the purpose is to support the front plate and reflect sound from the front plate. Therefore, it is desirable to use a hard maple veneer for the reflective part described later.

<Experiment_Examination of veneer for thin plate formation>
Among the experiments conducted in the process leading to the completion of the present invention, the results of examining spruce and bamboo in particular are described. It is an experimental result using the following two types of veneers.
Japanese paper with a thickness of 0.05 mm was pasted on a spruce grain veneer with a thickness of 0.25 mm to obtain a sheet-like wood material with a thickness of 0.3 mm. Hereinafter, it is simply referred to as "spruce".
Further, Japanese paper having a thickness of 0.05 mm was pasted on a bamboo veneer having a thickness of 0.25 mm to obtain a sheet-like wood material having a thickness of 0.3 mm. Hereinafter, it is simply referred to as "bamboo".

Using these sheets, two sheets were bonded together to form a thin plate body. Depending on the type of sheet used on the inside and outside of the enclosure, four patterns of thin plates were produced: inner and outer "spruce", inner and outer "bamboo", inner "spruce" outer "bamboo", inner "bamboo" and outer "spruce". Furthermore, we made a combination of vertical and horizontal wood grain, and made a prototype of a tubular speaker structure with such a thin plate as an enclosure, and evaluated its sounding characteristics.

As a result, the following trends were found.
(1) Bamboo When bamboo is used as the inside of a thin plate, the internal reverberation becomes stronger. Moreover, even if the volume is large, the sound is unlikely to break down. On the other hand, when bamboo is used as the outside, the impact of the emitted sound becomes stronger. In addition, although the sound has a clear outline at a low volume, the reverberation inside the enclosure may become large at a high volume.

(2) Spruce When spruce is used as the inside of a thin plate, the internal reverberation is moderate. In addition, in the stage before fixing the baffle, the bass may collapse at the time of high volume, but this is complemented by pasting a tape-shaped veneer in the horizontal direction inside the enclosure, and the bass is increased. It can be planned and there is no problem. On the other hand, when spruce is used as an outside, a soft and natural sound is emitted. Although the clear feeling tends to be slightly reduced compared to bamboo, it does not get tired of listening even at medium volume, and is suitable for long-time listening and BGM playback.

(3) Vertical and horizontal grain of wood For both bamboo and spruce, if the grain of wood is vertical (in the axial direction of the enclosure), the sound will have a sense of speed and impact. In the vertical direction of bamboo, the characteristics are particularly strong.

(4) Product-level specification example As a result of the above experiments, an enclosure specification example when the parameters are H260 mm, W120 mm, speaker: ~ 20 W, and diameter 6 cm to 8 cm can be as follows, for example.
Two sheets of wood material with a thickness of 0.3 mm (veneer 0.25 mm + Japanese paper for reinforcement 0.05 mm) are laminated to make a thickness of 0.6 mm. The sheet-shaped wood material has a vertical grain on one side and a horizontal grain on the other side. This specification is one of the best balances of vibration transmission by thinness, delicacy of transmitted sound, strength maintenance required for products, and aesthetics. In addition, the combination of vertical spruce on the inside and horizontal spruce on the outside provides excellent acoustic characteristics. By arranging the spruce side on the outside, "shining" is generated on the surface, which improves the aesthetic appearance.
However, the present invention is not limited to such specifications.

<Example of thin plate forming method>
FIG. 5 is an explanatory view showing an example of a method for forming a thin plate body according to the present invention. The spruce veneers 15a and 15b shown above are pasted together to form a thin plate 15 shown below as a developed view. Both the vertical wood grain spruce veneer 15a (upper left) and the horizontal wood grain spruce veneer 15b (upper right) are reinforced with Japanese paper as described above. An appropriate adhesive such as a woodworking bond can be used, and the adhesive is formed by the following procedure.
(1) Both the veneers 15a and 15b are cut to the size of the circumference of the finally formed cylinder + 1 cm.
(2) The two veneers 15a and 15b are bonded by shifting them by 1 cm in the rounding direction.
(3) The sheet (thin plate body) 15 formed by laminating is rolled, and the two sides of 1 cm width that are shifted become the margins Wa and Wb.
(4) Glue margins Wa and Wb are bonded together to form a cylinder.
The inner and outer 1 cm margins Wa and Wb are stacked on top of each other with the seam as a boundary, and the inner and outer sides of the seam are covered by the margins Wa and Wb, respectively. As a result, the strength of the joint portion is maintained, and the cylinder is maintained as it is.

<About the inhomogeneity of the thin plates that make up the enclosure>
As described above, the tubular speaker structure of the present invention is characterized in that the thin plate body constituting the enclosure is non-homogeneous. This will be supplementarily explained, although there is some overlap.
In the tubular speaker structure of the present invention, sound is produced by transmitting vibration from the speaker unit to the thin plate enclosure, and by transmitting the internal sound of the thin plate enclosure generated from the back surface of the speaker unit through the enclosure. In other words, the enclosure becomes the sounding body. A non-homogeneous material is used as the thin plate, and a wood material such as wood or bamboo is particularly suitable, and an optimum result can be obtained particularly with a thin plate made of spruce.

Wood materials such as wood and bamboo are non-homogeneous materials with structures such as annual rings, grain, and conduits. Therefore, the acoustic characteristics such as the vibration propagation speed, the transmission characteristic, and the resonance characteristic differ depending on not only the type of wood but also the annual ring, the appearance of the grain, the thickness, and the like. Therefore, the combination thereof becomes an acoustic characteristic variable, and in the enclosure which is the sounding body according to the present invention, the acoustic characteristics differ depending on the portion. That is, in the speaker device of the thin plate enclosure made of the non-homogeneous material, the physical properties of each part of the thin plate are slightly different.

Due to the distribution of different physical properties in such a thin plate body, in the present invention, it is possible to obtain excellent characteristics as a sounding body and an enclosure that standing waves and resonance points at a specific frequency are unlikely to be generated. Further, since the structure in which different physical properties are distributed in this thin plate body is also a structure that receives various sounds and vibrations from the speaker unit and is easily divided and vibrated, the non-homogeneous thin plate body according to the present invention has various pronunciations. It is also a material and structure suitable for.

Spruce is the most suitable thin plate, but spruce is light in wood, has a high speed of sound (vibration propagation speed), has a low internal loss rate (vibration absorption rate), reacts quickly to the vibration of the speaker unit, and is efficient. It has the property of emitting sound. On the other hand, metals such as iron have a high elastic modulus but a low internal loss, and reverberation measures are required, so they are not materials that utilize the sound of the enclosure. In addition, since synthetic resins such as rubber and plastic have high internal loss and low elastic modulus, they vibrate the entire member and are difficult to react to minute vibrations, and in particular, it is difficult to propagate vibrations in the high frequency band with high sensitivity. It becomes.

In this way, since homogeneous materials such as metals, rubbers, and plastics have a literally homogeneous molecular structure, the acoustic characteristics such as the natural frequency and resonance frequency of the material are likely to be sharply exhibited, and the characteristics are such. It will be regarded as a "habit" of the sound of the speaker. From the above, in the present invention, a non-homogeneous material is selected as a speaker material for producing all kinds of musical instruments and sounds faithfully to the original sound and more naturally.

However, in the present invention, it cannot be denied that a homogeneous material and a non-homogeneous material are used in combination. Even when a homogeneous material such as resin or metal is bonded to a thin plate which is a non-homogeneous material because of the required acoustic characteristics, the thin plate body as a whole is a non-uniform material. It is within the scope of the present invention. When a non-homogeneous material is used as a thin plate, problems of strength, durability, sophistication of quality, and homogenization may occur in commercialization, but all of these are orthogonal to the grain of wood already mentioned. It can be solved without any problem by letting them stick together or installing a stabilizer, which will be described later.

<About the thickness of the thin plate>
Regarding the thickness of the thin plate body, the specification example and the like have been described above, but will be further described.
The thickness of the thin plate is the main parameter depending on the tree species and the direction of the annual rings when a sheet-shaped wood material is used as the thin plate, and the bonding method when two or more veneers are used. In addition, the thickness of the thin plate is a major parameter in terms of desired sound quality and acoustic characteristics. In consideration of these, it can be said that the thickness of the thin plate body according to the present invention is preferably 0.1 mm or more and 5 mm or less. More preferably, it is 0.3 mm or more and 1 mm or less, and more preferably 0.5 mm or more and 0.8 mm or less.

The reason why it is desirable to set it to 0.1 mm or more and 5 mm or less is that when this range is from the thinnest level of the veneer to a material other than the veneer such as paper (void tube) and wood, the thin plate body aimed at by the present invention. This is because the effect can be obtained in a desirable range. For example, when a medium-sized unit and a void tube are used, the effect of the present invention can be obtained even with a considerable thickness of 5 mm. Of course, the thickness may be 3 mm.
In addition, the reason why it is more desirable to make it 0.3 mm or more and 1 mm or less is that when a veneer is used for the thin plate body, the specification using a small unit is composed of one veneer, and the larger specification is a veneer 3 This is because it is desirable to have a veneer structure.
Further, it is more desirable to set the thickness to 0.5 mm or more and 0.8 mm or less in consideration of the possibility of a more desirable range depending on the tree species, etc., based on the 0.6 mm thickness in the examples of the present invention. is there.

<Virtual ground>
FIG. 6 is a side sectional view showing a configuration example of the tubular speaker structure of the present invention provided with a virtual ground portion. As shown in the figure, in this configuration example, in addition to the configuration shown in FIG. 1 and the like, a virtual ground portion 2VG for increasing the vibration efficiency of the thin plate body 25 is provided as a characteristic configuration. The virtual ground portion 2VG can be formed by providing the virtual grounding means 29 as shown in the figure. As the virtual grounding means 29, a material made of a material capable of obtaining a larger inertia by mass and a larger deformation preventing effect by hardness can be preferably used. For example, it is a plate material using a metal such as iron, and the weight of the bass reflex structure 26 is also an element constituting the virtual ground portion 2VG. In the figure, an example using a donut-shaped body installed around the bass reflex hole 6H is shown, but of course, the present invention is not limited to this. However, when the bass reflex structure 26 is provided, it is desirable to provide the virtual grounding means 29 in the bass reflex structure 26 as shown in the figure. In the figure below, there is an example showing an example of using an iron weight as a virtual grounding means.

With such a configuration, the virtual ground 2VG can be formed from the upper surface of the virtual grounding means 29 to the ground plane GND of the main tubular speaker structure 210. That is, by immobilizing as a virtual ground 2VG, vibration on inertia due to mass and deformation prevention due to hardness are realized in this range, so that the enclosure 21 by the thin plate body 25 receives the vibration received by itself from the virtual ground 2VG. It cannot propagate to, and it has no choice but to vibrate itself. As a result, the vibration efficiency and timbre of the seat (enclosure) 21 are enhanced. The virtual ground 2VG forms, so to speak, a "semi-insulating" structure for further increasing the vibration efficiency of the seat (enclosure) 21.

<Reflector>
FIG. 7 is a side sectional view showing a configuration example of the tubular speaker structure of the present invention provided with a reflecting portion. Further, FIG. 8 is an explanatory view of a side sectional view showing the operation in the configuration example shown in FIG. 7. As shown in these, the tubular speaker structure 310 of the present invention is characterized in that a reflecting unit 3R for reflecting sound waves from the speaker unit 34 is provided in the enclosure 31. In the figure, an example of a reflector 3R composed of a tower-shaped reflector (hereinafter, also referred to as “reflector”) 3R1 and an umbrella-shaped nose portion (hereinafter, also referred to as “reflector 2”) 3R2 is shown. The invention is not limited to this. The nose portion 3R2 may not be provided, or the reflector 3R1 and the nose portion 3R2 may have different shapes.

The reflector 3R1 reflects a standing wave (standing wave) in the enclosure 31 through the sheet by reflection to increase the transmission efficiency of the internal sound. On the other hand, the nose portion 3R2 acts to prevent mid- and high-pitched sounds from entering the bass reflex port when the bass reflex 36 is provided. As the material of the reflecting portion 3R, any material having a high sound reflectance can be appropriately used. For example, hard maple can be preferably used in the case of wood, and aluminum can be preferably used in the case of metal. Further, these materials may be attached to HDF (High Density Fiberboard) to form the HDF (High Density Fiberboard). In addition, when lowering the reflectance of the reflector 3R or reducing the reverberation of the internal sound of the enclosure 31, MDF (Medium Density Fiberboard) can be used to reduce the reflectance and internal sound. Can be controlled.

The sounding principle of the tubular speaker structure of the present invention is the following three.
(1) Reflection / transmission of sound inside the enclosure → Sound transmission (drawing below)
(2) Change in internal pressure due to speaker diaphragm → Seat vibration → Sound transmission (3) Seat vibration due to sound bridge mechanism → Sound transmission Of these, (1) will be explained with reference to FIG.

Speaker vibration → Internal air compressional wave → Sound generated by the sound is transmitted to the outside via the enclosure 31 (seat) as shown in the figure.
<1> Direct transmission (3Rs1 in the figure): Internal sound → Seat vibration → Sound transmission (external air compressional wave)
<2> Reflection transmission (3Rs2 in the figure): Internal sound → Reflector → Seat vibration → Sound transmission (external air compressional wave)
<3> Reflection transmission 2 (prevention of internal diffuse reflection, 3Rs3 in the figure): Internal reflection sound → reflector → sheet vibration → sound transmission (external air compressional wave)
Without a reflector, even a sheet will have diffuse reflections. Diffuse reflection causes excessive echo and impairs the purity of successive sounds. Therefore, it is desirable to provide the reflecting portion 3R in order to obtain higher definition reproducibility.

As described above, FIGS. 7 and 8 show a configuration example assuming the installation of a bass reflex port, but this may not be provided. Regardless of whether or not the bass reflex port is installed, the reflection and transmission functions of the reflection unit 3R do not change. Further, by virtual grounding by the virtual grounding means 39, the members and the seat of the reflector 3R1 or less form and maintain the same structure as the speaker device, and the vibration of the seat is maximized by the "seat structure". It has a "semi-insulating" structure for pronunciation.

Further, the baffle plate 38 can be said to be one of the "sound bridges" as an element for transmitting vibration. The term sound bridge is commonly used primarily for soundproofing buildings and, rarely for musical instruments. However, there is no precedent for using this concept in speakers. The sound bridge will be explained in detail later.

FIG. 9 is an explanatory view of a partial side sectional view showing a design example of the reflecting portion in the tubular speaker structure of the present invention. The basic function of the reflecting unit is as described with reference to FIG. 7 and the like, but the reflecting unit 4R can be designed to determine its properties, thereby controlling the timbre. Specifically, treble-mid-bass balance, sustain, bass reflex effect, bass reflex phase (front of speaker, control of the phase of the sound emitted from the thin plate and the phase of the bass reflex (whether or not to delay, the degree of delay)), etc. , Can be controlled by the design of the reflector 4R.

Each parameter shown in the figure will be described.
P1: Material of structural base material of reflector 4R1 MDF (medium density fiberboard), HDF, wood (type), metal, resin, etc. The tone can be controlled by the material.
P2: Material of surface material of reflector 4R1 MDF, HDF, wood (type), metal, resin, etc. The tone can be controlled by the material. However, P2 may not be provided.
P3: Shape of reflector This will be described later with reference to FIG.

G1: Gap between the reflector body and the nose The degree of function of the bass reflex 46 (bass reflex generates bass) and the degree of vibration energy transmission to the thin plate body can be adjusted. The escape of sound pressure to the outside can be adjusted by G1.
G2: Along with the diameter G1 of the nose portion, it is possible to prevent the sound from being diffracted from the speaker unit. If G2 is large, the sound from the unit is less likely to be diffracted, and the sound that escapes to the bass reflex port 46P is reduced accordingly, and the sound can be more transmitted through the thin plate body.

G3: The smaller the diameter of the minimum diameter portion of the reflector, the smaller the escape of sound to the bass reflex port 46P, and the lower the fluidity of the air inside the enclosure 41. That is, more sound can be transmitted and pronounced from the thin plate body.
G4: Angle of the apex angle of the nose portion Since the sound from the back surface of the speaker unit is distributed in the left-right direction and the lower direction, the degree can be controlled by the size of the G4 and the nose portion.

The installation of the nose portion 4R2 is not essential. It is better not to install the nose portion 4R2 when a liberating sound is desired or when the purpose is to positively output mid-range and high-range sounds from the bass reflex port 46P. Further, although the configuration of the floating mount is also shown in the drawing (fixing portion 4S, cushioning material 4F, etc.), the floating mount will be described later with reference to FIG.

<Example of reflector formation>
FIG. 10 is an explanatory view of a side sectional view showing an example of the shape of the reflector in the tubular speaker structure of the present invention, and is an example of a variation in which reflection is controlled according to an incident angle of sound. From left to right, they are (a) strong reflection type, (b) weak reflection type, and (c) balanced type.
(A) Strong reflection type By providing one or more parts (convex parts) where the distance between the reflector and the thin plate is short and forming a two-stage type or a multi-stage type, the separability of the mid-high range and the low range can be improved. While increasing, the transparency of each can be increased. Can produce sharp and energetic sounds.

(B) Weak reflection type The sound pressure inside the enclosure of the sound on the back of the speaker unit is relaxed by making the reflector slim (slim) so that the space inside the enclosure can be widened. It also weakens the reflection of internal sound by the reflector. As a result, it is possible to produce a delicate sound that reproduces the room tone at the time of recording and a comfortable sound with less stimulation.
(C) Balanced type This is an intermediate form between the strong reflection type and the weak reflection type, and high fidelity without habit can be obtained. This is effective when reproducing sound that is faithful to the signal.

<Floating mount method>
FIG. 11 is an explanatory view of a partial side sectional view showing a configuration example of the tubular speaker structure of the present invention in which the reflecting portion is a floating mount. As shown in the figure, the tubular speaker structure 510 is characterized in that the reflecting portion 5R is fixed by a floating mount method and is independent of other components. In the example of the figure, when fixing the reflector 5R1 to the bottom plate 50 by using the fixing means 5S, a cushioning means 5F such as a soft cushioning material (layer) is interposed between the reflector bottom plate 5R10 and the bottom plate 50 and fixed. By interposing a cushioning means 5E such as a cushioning material between the means 5S and each fixing destination, the reflective portion 5R is made into a floating mount. Further, the gap between the fixing means 5S and the buffering means 5F or the like is filled with a silicon resin or the like.

In the example of the figure, a virtual grounding means 59 such as an iron weight is adhesively fixed on the reflector bottom plate 5R10, and the fixing means 5S is fixed through the virtual grounding means 59. Bolts and the like can be preferably used as the fixing means 5S, and synthetic rubber and the like can be preferably used as the buffering means 5E and 5F, but the present invention is not limited thereto. Moreover, what is illustrated is an example of a floating mount system, and the present invention is not limited to such a configuration.

The reflector 5R1 has a function of preventing diffused reflection of the sound emitted from the back surface of the speaker unit 54 inside the enclosure 51, reflecting the sound inside the enclosure 51, and transmitting the thin plate body. The reflector 5R1 has a bottom plate. When the vibration of 50 is received, the internal sound of the enclosure 51 and the vibration of the reflector 5R1 itself affect each other, which has an adverse effect that the sound transmitted to the inside of the enclosure 51 and the thin plate body becomes muddy. However, by fixing the reflector 5R1 more than the floating mount method, the reflector 5R1 is less susceptible to the vibration of the speaker unit 54 and other housing components. That is, by making it a floating mount, it is possible to enhance each function of the reflecting unit 5R such as reflection, transmission, sound generation and reduction of internal reverberation of internal sound.

<Sound bridge>
The tubular speaker structure 510 may be configured to be provided with a vibration propagation means (sound bridge) that transmits vibration from the speaker unit 54 to the enclosure 51. The baffle plate 58 surrounding the speaker unit 54 can also function as a sound bridge. Since the baffle plate 58 integrated with the speaker unit 54 is also integrated with the enclosure 51 by adhesion or the like, the enclosure 51 is eventually integrated with the speaker unit 54 via a sound bridge called the baffle plate 58. Become. Therefore, the enclosure 51, which is a thin plate body, is positively vibrated, and the sound is satisfactorily radiated to the outside of the enclosure 51. In particular, mid-range and high-range sounds can be satisfactorily transmitted to the enclosure 51, and vibration can be dynamically transmitted by the gravity of the baffle plate 58 itself and the speaker unit.

Further, the vibration from the speaker unit 54 transmitted to the enclosure 51 integrated through the sound bridge (baffle plate 58) reflects the reaction force of the vibration of the enclosure 51 from the bottom plate 50 and the spike 57. This is because the enclosure 51 using the thin plate body causes the bottom plate 50 or less to be in a semi-insulating state as vibration. As a result, the vibration of the enclosure 51 is increased, and the sounding to the outside of the enclosure 51 is clarified. In this figure, the semi-insulating structure is more solid due to the fact that the virtual ground portion 5VG is formed by the virtual grounding means 59 (iron weight), and the vibration of the enclosure 51 is maximized. is there.

FIG. 12 is an explanatory view of a partial side sectional view showing an example of a sound bridge configuration in the tubular speaker structure of the present invention. Further, FIG. 13 is an explanatory view showing the configuration of each sound bridge shown in the configuration example of FIG. 12, and is a view viewed from the inner surface side of the baffle plate. As shown in these, the tubular speaker structure 610 may be provided with one or more additional sound bridges in addition to the baffle plate 68 surrounding the speaker unit as a sound bridge. The additional sound bridge receives the vibration of the speaker unit and transmits it to the enclosure 61 by directly contacting the sound bridge with the speaker unit or indirectly via a bolt for fixing the speaker unit or the like. The figure shows an example of the umbrella-shaped body 6B2 and the rod-shaped body 6B3 as the additional sound bridge. These examples will be described.

(1) Umbrella-shaped body The umbrella-shaped body 6B2 is provided so as to be in contact with the entire circumference of the enclosure 61 from above the speaker unit 64. The umbrella-shaped body 6B2 can be made of, for example, aluminum, copper, or steel plate, but the present invention is not limited to this. Further, the shape and other specifications are not limited to this example. The umbrella-shaped body 6B2 assists the sound bridge function of the baffle plate 68 and acts to transmit the middle and treble to the enclosure 61, and in particular, can transmit the delicate middle and treble. Further, according to this configuration, since it is in contact with the entire inner circumference of the enclosure 61, vibration can be transmitted evenly.

(2) Rod-shaped body Instead of the umbrella-shaped body, the rod-shaped body 6B3 can be provided as an auxiliary sound bridge function. In this example, the speaker unit 64 has a configuration consisting of eight rod-shaped bodies 6B3 extending radially from the center on the back surface of the speaker magnet 64M. Each rod-shaped body 6B3 is provided so as to be in contact with the enclosure 61. The rod-shaped body 6B3 can be made of, for example, stainless steel, but this is not the case. Further, the shape and other specifications are not limited to this example. The rod-shaped body 6B3 assists the sound bridge function of the baffle plate 68, and since it is close to the speaker unit vibration source, particularly high vibration energy can be obtained, so that the action of transmitting the bass, middle, and treble to the enclosure 61 is enhanced. Can be done.

By the way, in the figure, 6BV: a portion for transmitting vibration from each sound bridge to the cylinder, 6BVl: a region extending from 6BV to the lower end of the cylinder. The vibration caused by the sound bridge is attenuated by the distance propagating through the thin plate body which is the medium. At 6BV, the cylinder vibrates due to vibration close to that of the speaker unit, but it attenuates from the treble part as it advances to the lower end of 6BVl. There are two types of this attenuation, one is attenuation due to diffusion (pronunciation) and the other is attenuation due to absorption of the thin plate (heat conversion). , It can be inferred that a sound with little attenuation is produced.

As illustrated in FIGS. 12 and 14 below, a plurality of types of additional sound bridges may be provided in combination. FIG. 12 and the like show an example in which the umbrella-shaped body 6B2 and the rod-shaped body 6B3 are used in combination. Further, the virtual grounding means 69 in the configuration example shown in FIG. 12 has a different installation position from that shown in FIG. The virtual grounding means can also be appropriately designed in consideration of the virtual ground function, the sound bridge function, the manufacturing method, and the like.

<Stabilizer>
FIG. 14 is an explanatory view of a partial side sectional view showing a configuration example of the tubular speaker structure of the present invention provided with a stabilizer. As shown in the figure, the tubular speaker structure 710 is characterized in that one or a plurality of stabilizers 7Z1 and the like are provided to separately vibrate the thin plate body (enclosure 71). The figure shows an example in which two tape-shaped stabilizers 7Z1 and 7Z2 are attached to a thin plate body, but the shape, specifications, and number of stabilizers installed are not limited. However, the tape-shaped form that can be installed by a simple method of sticking to a thin plate body is a suitable example as a stabilizer for the present invention.

The stabilizer controls vibration and adjusts the sound quality. Specifically, it has the following actions.
(1) Divided vibration By installing a stabilizer 7Z1 or the like, the enclosure 71 has a structure that facilitates split vibration, so that it becomes easier to produce high-pitched sounds on the speaker unit 74 side of the enclosure 71 (thin plate) and low-pitched sounds on the opposite side. .. When the enclosure 71 is divided into three regions by the two stabilizers 7Z1 and 7Z2 as shown in the figure, the middle tone can be easily pronounced from the central portion. The structure that easily divides and vibrates can improve the resolution of vibration by an audio signal. That is, since the bass that tends to remain as vibration does not affect the middle and treble, it is possible to produce a clean middle and treble.

(2) Vibration suppression It is possible to prevent the enclosure 71 from vibrating excessively, continuing to vibrate, and resonating at a specific frequency. As a result, it is possible to linearly follow the change in vibration from the speaker unit 74.
(3) Complementing stress with respect to internal pressure The enclosure 71 expands due to sound pressure (internal pressure) from the back of the speaker, and stress (strain) is generated. This stress (strain) becomes sound, but excessive stress with respect to the input signal hinders the faithful reproduction of the original sound. By installing the stabilizer 7Z1 or the like, it is possible to obtain a vibrating body having an appropriately high stress while ensuring sensitivity to a weak signal.

The sound areas in the high, middle, and low frequencies will be further described.
The treble becomes a sound when the enclosure 71 vibrates due to the sound of each sound bridge and the back of the speaker. Since treble and treble vibrations have a higher attenuation rate and higher straightness than bass vibrations, it is desirable to radiate them as sound at the upper part of the enclosure 71. On the other hand, since the bass is mainly the pressure wave of air from the speaker cone, it reaches the bottom mainly through the air on the inner surface of the enclosure, but the pressure wave loses its place due to the reflector 7R1 and vibrates to the bottom of the enclosure 71. It attenuates by that.

A stabilizer 7Z1 is installed in order to completely attenuate the vibration caused by this pressure wave at the bottom and prevent the bass from being transmitted to the upper part of the enclosure 71. Further, since the bass pressure wave has high dynamic energy, the stabilizers 7Z1 and 7Z2 function so as to reproduce as a tight bass even at a high volume or when reproducing a sound source rich in bass.

The effects and advantages of providing the stabilizer are as follows.
(1) Bass with a clear outline can be pronounced.
(2) Clearness of mid-high range is improved.
(3) The sound generation power of the speaker system as a whole is improved. That is, as the stress on the internal pressure of the enclosure increases, the strain in the portion other than the stabilizer installation location increases, the pressure on the bass reflex port increases, and the function of the bass reflex mechanism increases.
(4) High input resistance is improved. In other words, even if the volume of the amplifier is raised, the sound is less likely to collapse.
(5) The strength and durability of the enclosure are improved.

The specific form of the stabilizer is not limited, and for example, an inflexible annular member may be used. However, the tape-shaped form that can be installed by a simple method of sticking to a thin plate body is a suitable example as a stabilizer for the present invention. Further, as the material of the stabilizer, an appropriate material can be used as long as it is lightweight and has a large tensile strength. Since the stabilizer itself vibrates, it is required to be lightweight so as not to excessively prevent the thin plate body from vibrating by the stabilizer. Further, a large tensile strength is desirable in order to obtain a strength capable of complementing the radial stress and the circumferential stress.

Specifically, for example, a thin plate of bamboo or wood, a thin plate of other wood material, an aluminum thin plate, carbon fiber, or the like can be preferably used as a material. In the case of a thin plate of wood, the grain can be used more preferably, and if it is used so as to have a vertical grain in the longitudinal direction of the stabilizer, sufficient strength can be obtained. Specific examples are described below.

Specifications and installation method of tape-shaped stabilizer ・ Thickness: About 0.3 mm for wood (depending on the material, it may be thinner)
・ Width: about 10 mm (depending on the material, it may be thinner)
Installation method-Attach the stabilizer to the inner circumference of the enclosure using a woodwork bond (1 lap + margin).
The stabilizer can be installed vertically instead of horizontally, and the sound quality can be freely changed by parameters such as the number of stabilizers, the installation interval, and the material.

A speaker device having any of the above-described tubular speaker structures is also within the scope of the present invention. In addition, an audio system including such a speaker device, a speaker device manufacturing method in which one or more stabilizers are attached to an enclosure when manufacturing such a speaker device, and a speaker device in which one or more stabilizers are attached to an enclosure. The modification method is also within the scope of the present invention.

<Speaker orientation>
As shown in each figure, in the present invention, since the speaker unit is installed facing upward, it is difficult for the initial vibration (first amplitude) to move upward due to inertia and gravity, but after the second amplitude, the speaker unit It is not easily affected by the structure (damping force due to dampers and edges). Then, after the signal ends, the inertia can be easily canceled by the braking force and gravity. As a result, the following effects can be obtained.
(1) Attack becomes stronger (2) Sustain becomes stable.
(3) Fine expression of sound is possible even at low volume.
(4) Mute can be done instantly.

<Supplement_Cylindrical speaker structure, etc. Road to completion of invention>
Hereinafter, the process leading to the completion of the invention will be supplementarily described based on the confirmation of the fundamental idea of the present invention.
(1) Fundamental Idea of Cylindrical Speaker Structure of the Present Invention In the conventional speaker, in order to suppress unnecessary vibration as much as possible, a strong material is used for the enclosure and the baffle plate to prevent the vibration of the enclosure itself. In addition, since it is necessary to prevent the turbidity and resonance of the sound inside the enclosure due to the sound emitted from the back surface of the speaker unit from affecting the vibration of the cone due to the signal, measures have been taken with a sound deadening material. On the other hand, in the present invention, not only the speaker unit but also the enclosure is used as the sounding body. All the vibrations, waves, and other energy generated from the speaker unit are not regarded as unnecessary vibrations, but are converted into sound as much as possible. This is incompatible with the conventional way of thinking, and yet it has realized the acoustic characteristics that cannot be output by the conventional speaker.

(2) Construction of the principle of the present invention based on the laws of physics (2) -1 Law of inertia A speaker that is easy to move and stop is the most suitable as a vibrating body of a speaker. The ease of movement is the lightness of the specific gravity of the vibrating body and the vibration transmission speed, and the ease of stopping is the flexibility (loss characteristic) and the conversion rate from vibration energy to sound. Wood, especially spruce, is excellent as a material having these contradictory properties. In addition, it is considered that the output sound quality can be controlled by the difference in the type, size, thickness, and joining method of wood.

In addition, when the speaker unit is installed, the initial vibration (initial amplitude) becomes difficult to move upward due to the influence of inertia and gravity. However, after the second amplitude, it becomes less affected by the speaker structure (braking force due to dampers and edges), and after the signal ends, the inertia is easily canceled by the braking force and gravity. As a result, even when the volume is low, it is possible to obtain an effect on the fine expression of the sound, such as the rise (attack), attenuation (decay), sustain (sustain), and mute (release) of the sound. Conceivable.

(2) -2 Equation of motion When an external force F is applied to an object, an acceleration a is generated that is proportional to the force applied in the direction of the force and inversely proportional to the mass m of the object. That is, it is as shown in the following equation.
External force F = mass m x acceleration a
Here, the external force F: the electromagnetic force generated by the current to the voice coil, the mass m = the mass of the speaker swinging portion (voice coil, cone paper), and the acceleration a = the acceleration of the movement of the cone. Therefore, the cone moves faster when it is light and slow when it is heavy. Further, if the external force F, that is, the impact or current of the signal is large, the acceleration a of the cone is proportionally increased, and the vibration of the speaker unit is also proportionally increased. This equation of motion was applied to constructing the vibrating body of the present invention with a thin plate, devising the form of an umbrella-shaped sound bridge, and the like.

(2) -3 Action and reaction The generated vibration is transmitted to the speaker cylinder and becomes a reaction force on the bottom plate to push it back. If the bottom is solid as a base, the cylinder will have to vibrate. Therefore, the sound quality will change depending on the material and weight below the bottom. If the material is soft, the force escapes in both action and reaction, so the force is absorbed in the softest part. In addition, since gravity is also applied to the downward acceleration, it is considered that the downward action on the cylinder becomes stronger.

(2) -4 Law of Conservation of Energy Within an independent system, the energy as a whole is invariant regardless of any physical or chemical change. In the speaker device, the electricity input to the speaker unit becomes magnetic energy, and the magnetic energy becomes vibration energy that vibrates the cone by the voice coil.
This vibration energy is
<1> Cone vibration (front and back) → Air vibration (front and back)
<2> Air vibration on the back → Vibration of the cylinder → Sound of the cylinder (some are from the bass reflex port to the air vibration)
<3> The reaction force of the vibration of the cone → the vibration of the baffle plate → the vibration of the cylinder → the sound of the cylinder.

(2) -5 Conservation of mass, transmission loss When the sound inside the enclosure passes through the thin plate and is pronounced to the outside, transmission loss occurs. This is called the law of mass, and the transmission loss is ^{proportional to the product of the mass (area density) (kg / m 2} ) of the material and the frequency. That is, the larger the mass, the larger the transmission loss. It is this rule that conventional speakers use heavy wood to block the sound inside the enclosure. The present invention has considered how to construct an enclosure using a material having a low transmission loss and transmit the sound inside the enclosure. In addition, we devised and designed a thin plate body to satisfy these two elements in terms of sound quality, that is, a material with excellent characteristics in the propagation of vibration from the sound bridge and the sound.
In this way, these physical laws were applied to the concept stage, hypothesis construction, prototyping, evaluation, problem solving, and other principle construction and demonstration of the present invention.

(3) Excellent speaker conditions The sound of musical instruments varies from type to type and from individual to individual. Therefore, in order to faithfully reproduce the sound of one musical instrument, it is ideal to design a speaker dedicated to that musical instrument. However, even with a single instrument, the conditions are even different when it comes to reproducing the environment such as the atmosphere, reverberation, and audience voice of a performance situation, such as when reproducing a live performance in a large venue. The sound quality of the sound source also changes depending on the position, type, manufacturer, engineering, and recording equipment of the microphone. Even for vocals, there are conditions such as shouting voice, whispering voice, reverberating voice, voice with odd harmonics, and difference between male and female voices.

In view of these, what are the conditions for an excellent speaker and an ideal speaker?
<1> As the final stage of audio playback, all kinds of sound sources can be optimally played back.
<2> Excellent in the presence of players and musical instruments, the formation of the sound field to be played, and the reproduction of the player's emotions.
<3> Comfortable for long hours of listening
<4> The balance is not lost even when playing from high volume to extremely low volume.
<5> Compact and cost effective,
<6> You can own it with attachment,
<7> Made by someone who knows all about sound and music,
<8> It can be said that it is a speaker that allows each user to maximize the enjoyment and excitement of music.

(4) Utilization of unnecessary vibration As described above, unnecessary vibration has been conventionally considered to be negative in order to reproduce sound faithfully to a signal. There are the following two types of unnecessary vibration. The sound generated inside the speaker and the vibration of the speaker unit propagate to the enclosure. The internal loss is the ease with which the sound disappears inside the speaker enclosure, and a high value means that there is little reverberation inside the enclosure. Conventionally, a method has been adopted in which thick and heavy wood is used, unnecessary vibration is not leaked to the outside, and the reverberant sound that becomes unnecessary vibration inside the enclosure is lost by the sound absorbing material.

As a result, in principle, a sound faithful to the signal should be produced from the front of the speaker. However, there was a phenomenon that if too much sound absorbing material was added, the "sound" of the sound was lost and the sound became dull. Therefore, both manufacturers and users have tried tuning by changing the quantity, quality, and installation location of the sound absorbing material (in the bass reflex's own work, in order to make the most of the "sound", the policy is to not use the sound absorbing material. There are even users). Also, as mentioned above, it is known that the quality of the wood used for the enclosure also affects the sound quality of the speaker.

Taken together, it was speculated that the vibration of the enclosure itself also affects the sound quality of the speaker. If this is the case, it was thought that an infinitely lossless speaker could be constructed by positively converting the sound inside the enclosure, which has been regarded as unnecessary vibration, and the vibration of the speaker unit into sound. In other words, instead of converting the internal loss of the speaker into heat energy with a sound absorbing material and muting it, we thought that it would be better to perform energy conversion by actively transmitting the internal vibration to the cylinder and converting it into sound.

In addition, the solution to unnecessary vibration has conventionally been to make the baffle plate and the enclosure plate thicker and heavier. However, the vibration energy of the speaker unit is considerably strong, and it is not easy to suppress it physically and materially, and it vibrates not a little. If so, I came up with the idea that the vibration of the unit should be transmitted to all or part of the enclosure to vibrate it and make it sound positively. That is, it is a principle feature of this speaker that these two vibrating elements, which have been regarded as negative ones, are used and released as sound.

(5) Components of this speaker and its functions Based on the above considerations, we decided to configure the speaker. Its components and functions are as follows.
<1> Speaker unit: Main sounding body (vibration source)
<2> Baffle plate: Speaker mounting plate (vibration transmission)
<3> Cylinder: Enclosure main component (sub-sounding body) A cylinder made of thin plate is used.
<4> Bottom plate: Enclosure main component (reaction base (as ground for vibration source))
<5> Spike: Speaker support (reaction base support)
<6> Bass reflex port: Bass reflex port (bass reflex and internal echo control)

(6) Sound characteristics of this speaker The following characteristics were observed in the prototype speaker.
(6) -1 By transmitting the vibration from the unit to the cylinder, a strong attack of a musical instrument or the like is reproduced.
(6) -2 Various vibrations that cannot be reproduced by the speaker unit alone are generated in the body (cylinder) and reproduced. That is, in response to each vibration from the unit, the easily vibrating part of the cylinder vibrates (free vibration) and becomes a sound.

(6) -3 Various features due to the cylindrical structure of the enclosure
<1> The internal reverberation sound appropriately controlled by the reflector reverberates like an actual performance sound field (sustain effect).
<2> Although it is a thin plate body that has a high acoustic effect such as reacting to weak vibration, it is also required to function as an enclosure at the same time, and due to the strength improvement effect by molding it into a cylinder, these speaker units make sound. Weak vibrations that cannot be converted can be converted into sound (sensitivity).
<3> Since the sound is radiated as a cylindrical wave to the outside, a three-dimensional sound image (depth, height) can be reproduced together with the upper speaker and the lower bass reflex, and the localization becomes clear. That is, the main instrument or vocal with relatively high output vibrates the cylinder strongly, and the back sound is gently output. It is considered that this is due to the nature of the cylindrical wave.

<4> Cylindrical waves are diffused in a plane compared to the sound wave vibration from the unit, and since the vibrating body is a sheet made of wood etc., the vibration pressure is high, and the hearing and experience close to the actual sound field can be obtained. Be done. It is considered that the characteristics of these cylindrical waves depend on the characteristic of the "plane sound source" that "the sound field is constant regardless of the distance on the surface of the sound source, and distance attenuation does not occur". At the same time, it is considered that the fact that listening in the near field is not jarring is due to the characteristics of this surface sound source.
<5> The radiated sound generated by the cylinder spreads over the entire reproduction field, and has an excellent sound field forming ability as compared with a general speaker which is a surface or point sound source. The directivity is determined by the relationship between the vibrating surface area of the sound source and the wavelength, and the larger the area of the vibrating surface with respect to the wavelength and the shorter the wavelength, the sharper the directivity can be obtained. In particular, highly directional treble is propagated to the vibrating surface enlarged by the cylinder by the sound bridge, and vibration and sound can be generated, which makes it possible to form a natural sound field unlike general surface and point sound source speakers.
<6> The sound passes well through the cylindrical wave (radiation of sound from the surface) by the sheet. Especially strongly recognized in pianos, violins, guitars, drums, etc.
<7> A pleasant sound field can be felt even in the near field (a place near the speakers).
<8> The sound field is maintained because the sound field is less likely to collapse or collapse due to volume.

(7) Members and Structure of Body Part The enclosure cylinder (body), which can be said to be the most important point of the speaker of the present invention, has been studied as follows, and the basis of the present invention has been completed.
<1> Bamboo laminated veneer was used.
<2> Bamboo veneer is used to ensure strength, and guitar / violin manufacturing materials such as spruce and Douglas-fir are attached to the surface, and tests are conducted to adjust the sound characteristics by changing the thickness and size (length, width, capacity). , Good results were obtained.
<3> Similar or similar effects were observed with other thin wood plates, but the one with the best sound was an enclosure made by laminating two pieces of spruce vertically and horizontally.

<4> It was confirmed that sound quality control is possible by combining the same or different types of veneers (rise, sustain, internal resonance, frequency characteristics, input resistance).
<5> This speaker basically has no front (front in all directions), but by attaching a veneer vertically to a part of the body or attaching a reflector, the direction in which it is provided. It was also possible to clarify the orientation of the front and back sides with the back side.
<6> It was also confirmed that the sound quality can be corrected by installing a thin tape-shaped plate inside the cylinder, as in the bracing used for guitars and violins.

(8) Guessing_Possibility of shock wave generation Why can the speaker of the present invention produce a sound with a reality that has never been seen before?
At the start of the prototype of this speaker, it was assumed that the sound of the conventional level could be obtained. However, when the sound was actually produced after the prototype was completed, the sound was beyond imagination, the sound was rising like a live musical instrument, and the reproduction of minute signals was felt. Considering the cause of this difference in sound from the conventional speaker, the generation of a shock wave can be considered as one of the causes.

The standard speed of sound is 340 m / s. However, the vibration propagation speed of spruce is 5,500 m / s, which is about 16 times the speed of sound. When a sound source (object) exceeds the speed of sound, a shock wave is generated from around the sound source. By using the principle of generation of this sonic boom (loud sound by shock waves), it is considered that "a shock wave is generated from an object that transmits vibrations exceeding the speed of sound". For example, even in a concert hall full of heavy-duty audience in winter, the sound of a single soloist's violin echoes throughout the venue. This is hard to imagine with the general concept of "sound." If the sound has a shock wave property, it may be close to a shock wave that does not easily attenuate and does not fall within the radiant energy law of "attenuating with the square of the distance".

In this speaker, the vibration from the speaker unit is transmitted downward by the vibration propagation speed of spruce at 5,500 m / s (simply downward, but because it is thin but thick, it also has a horizontal vibration vector. ). The condition for generating a shock wave is "the sound source (substance) exceeds the speed of sound", but the sound wave of vibration from the unit is synonymous with "the sound source (substance) exceeds the speed of sound" if it is vibration in the horizontal direction. There is a possibility of becoming. (Even the vibration transmitted downward produces horizontal vibration as long as it is vibration).

In fact, it can be felt that this speaker has less sound energy loss due to distance than the conventional speaker. In addition, it can be felt that the vibration of furniture and the like during performance is much higher than that of the conventional method. Therefore, it is highly probable that shock wave-like air vibration is generated from the cylinder portion. In any case, since the vibration propagation method of this speaker is close to that of an instrument that has the same structure as a violin, drum, or many other shock wave generating conditions, it reproduces attack, sustain, attenuation, and even overtones with high reality. I think it can be done.

<Conclusion>
According to the tubular speaker structure, the speaker device, the audio system, the speaker device manufacturing method, and the speaker device modification method of the present invention, a weak signal including a subtle nuance can be reproduced satisfactorily, and a high-output high-end machine can be obtained. It is possible to obtain Hi-Fi reproducibility of the original sound of an excellent CD sound source or the like without using it, and it is possible to provide an inexpensive and easily highly realistic audio environment. Therefore, it is an invention with high industrial applicability in the field of audio equipment and all related fields.

0, 20, 40, 50, 60, 70 ... Bottom plate 1, 21, 31, 41, 51, 61, 71 ... Enclosure 2, 22 ... Enclosure end (open end)
3, 23 ... The end of the enclosure (the other)
4, 24, 34, 54, 64, 74 ... Speaker units 5, 15, 25 ... Thin plate bodies 6, 26, 36, 46, 56, 66, 76 ... Bass reflex (bass reflex structure)
6H, 26H, 36H, 46H ... Bass reflex hole 6P ... Bass reflex port 7, 27, 37, 47, 57, 67, 77 ... Spike 8, 28, 38, 58, 68, 78 ... Bass reflex plate 10, 210, 310, 510 , 610, 710 ... Cylindrical speaker structure 15a, 15b ... Veneer 29, 39, 49, 59, 69, 79 ... Virtual grounding means 2VG, 3VG, 5VG, 6VG, 7VG ... Virtual ground portion 3R, 4R, 5R, 6R , 7R ... Reflectors 3R1, 4R1, 5R1, 6R1, 7R1 ... Reflectors 3R2, 4R2, 5R2, 6R2, 7R2 ... Nose (reflector 2)
3Rm, 4Rm, 5Rm, 6Rm, 7Rm ... Support 3Rs1 ... Direct transmission of internal sound 3Rs2 ... Reflection transmission of internal sound 3Rs3 ... Reflection transmission of internal sound 2
4F, 5E, 5F, 6E, 6F, 7F ... Buffer means 4S, 5S, 6S, 7S ... Fixing means 5R10 ... Reflector bottom plate 5T, 6T, 7T ... Terminal 6B2, 7B2 ... Umbrella-shaped body 6B3 ... Rod-shaped body 6BV ... Each The part that transmits vibration from the sound bridge to the cylinder 6BVl ... The area extending from 6BV to the bottom of the cylinder 64F ... Speaker frame 64M ... Speaker magnet 64N ... Speaker mounting nuts 7Z1, 7Z2 ... Stabilizer GND ... Ground Wa, Wb ... Glue margin

Claims (11)

A tubular enclosure with an open end and
A speaker unit that is driven on the basis of the audio signal is disposed in the enclosure coaxially with said open end,
The speaker unit is provided with a bass reflex provided at the opposite end.
A part of the opposite end is also opened by the bass reflex hole of the bass reflex.
The side surface of the enclosure is formed of a non-homogeneous thin plate.
The thin plate body is formed by using two sheet-like wood materials.
A reinforcing sheet is attached to the sheet-shaped wood material, and the thickness of the thin plate including the reinforcing sheet is 0.5 mm or more and 0.8 mm or less.
As a vibration propagation means (hereinafter, "sound bridge") for transmitting vibration from the speaker unit to the enclosure, a baffle plate surrounding the speaker unit and an additional sound bridge made of aluminum, copper, steel plate or stainless steel are included. Or there are multiple
Inside the enclosure, a tower-shaped reflector that reflects sound waves from the speaker unit is provided at the bass reflex port of the bass reflex.
With this configuration, each of the actions described in <SE1> to <SE3> below is performed.
A cylinder characterized in that all vibration energy generated in this tubular speaker structure is transmitted to the enclosure, sound is produced from the entire enclosure, and sound waves are transmitted to the outside through the side surface portion of the enclosure. Shaped speaker structure.
<SE1> Sound inside the enclosure including reflection passes through the thin plate body.
<SE2> The thin plate body vibrates based on a change in internal pressure due to the diaphragm of the speaker unit, and sound is transmitted through the thin plate body.
<SE3> The sound bridge vibrates the thin plate body, and sound passes through the thin plate body. The tubular speaker structure according to claim 1 , wherein spruce, bamboo, or both are used as the sheet-shaped wood material. The tubular speaker structure according to claim 1 , wherein two spruce veneers are used as the thin plate body. The spruce veneer constituting the thin plate body is characterized in that the thickness including the reinforcing material attached to the thin plate body is 0.3 mm or less, and therefore the thickness of the entire thin plate body is 0.6 mm or less. The tubular speaker structure according to claim 3. The tubular speaker structure according to any one of claims 3 and 4, wherein the spruce veneer used on the inside has a vertical grain and the spruce veneer used on the outside has a horizontal grain. The tubular speaker structure according to any one of claims 1, 2, 3, 4, and 5, wherein the reinforcing sheet is Japanese paper. The tubular speaker structure according to any one of claims 1, 2 , 3, 4, 5, and 6, wherein the enclosure has a cylindrical shape. A speaker device having the tubular speaker structure according to any one of claims 1, 2, 3, 4, 5, 6, and 7. The method for manufacturing a speaker device according to claim 8 , wherein one or a plurality of stabilizers are attached to the enclosure. The method for modifying a speaker device according to claim 8 , wherein one or a plurality of stabilizers are attached to the enclosure. An audio system including the speaker device according to claim 8.

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