JP2018107540A - Tubular speaker structure, speaker device, audio system, speaker device manufacturing method, and speaker device remodeling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker structure capable of providing an audio environment with low cost and easily realizing high reality, capable of satisfactorily regenerating a weak signal including subtle nuances without using a high-output type high-end machine, and obtaining Hi-Fi reproducibility of an original sound such as an excellent CD sound source.SOLUTION: A tubular speaker structure 10 includes: a tubular enclosure 1 having at least one end side 2 open; and a speaker unit 4 disposed coaxially with the enclosure 1 on the open end 2 side and driven on the basis of an audio signal. A side surface portion of the enclosure 1 is formed by a non-uniform thin plate member 5. The sound waves are transmitted through the side surface portion of the enclosure 1 and radiated to the outside.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cylindrical speaker structure, a speaker device, an audio system, a speaker device manufacturing method, and a speaker device remodeling method, and in particular, a weak signal including a subtle nuance can be satisfactorily reproduced and a high-output type high-end machine is used. In particular, the present invention relates to a loudspeaker structure that can obtain high-fidelity (High Fidelity) reproducibility of an original sound such as an excellent CD sound source, and can provide an audio environment with high reality at low cost. is there.

<Technical thought of conventional speakers>
In a conventional speaker, a voice coil of a speaker unit receives an electric sound signal, vibrates the cone, and generates a sound by applying a dense pressure to the air on the front of the cone, particularly in front of the cone. In this case, the sparse wave generated on the front surface of the cone and the sparse wave generated on the back surface of the cone interfere with each other, and a low-directed low frequency sneak occurs 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 ideal form of speaker enclosure in such a system is theoretically a flat (single plate) “no vibration” and “infinite plane” baffle. In an actual speaker, the cone that 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 cone vibration is generated in the opposite direction as the vibration, but these vibrations are regarded as “unnecessary vibrations”, which are the causes of the deterioration of sound quality.

  For this reason, it is important to prevent the inner surface of the enclosure from silencing and the vibration of the enclosure itself by using a solid material with high specific gravity and a robust material, and by sealing the enclosure and inserting a sound deadening material. It has been broken. Exceptions to the sealed type include bass reflex type and rear open type, but in any case, basically "Suppress unwanted vibration", "Prevent the front sound from being affected by the sound generated on the back. There is no change in the way of thinking.

  In addition, some audio enthusiasts know that the sound quality changes depending on the material of the enclosure and baffle plate, and manufacturers have launched products that respond to this. However, even in this case, the basic policy of eliminating unnecessary vibration remains the same.

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

  Further, in Patent Document 2 described later, an outer casing and an inner casing are substantially concentric circles as a speaker device that can reproduce a unique sound that can correspond to the width of the viewer's sensibility, not necessarily faithful to the original sound. The structure which has arrange | positioned in the shape and put the sound absorption material in the inner side housing | casing is disclosed. And according to this, the sound of the inner space is made not to resonate by the sound absorbing material in the inner housing, or the sound between them is made to resonate by making both the housings made of metal, or emitted from the inner space. It is possible to release a unique sound by synthesizing a non-resonant sound and a resonating sound emitted from the outer space.

  Further, Patent Document 3 listed below has a cylindrical shape as a speaker device that can reproduce a low-frequency complex waveform such as a musical sound faithfully with little disturbance in time relation and has a wide service area in the sound field space. One end face of the speaker housing is fixed so as to substantially cover the speaker unit except for the front and rear faces of the diaphragm, and the other bottom face has a structure having an opening, and a support bar is provided on the back face of the magnet via a support bar. A configuration in which a weight is fixed is disclosed. This weight holds the support bar in a substantially vertical direction and grounds the magnet acoustically and virtually, thereby suppressing the vibration transmitted from the magnet to the support bar.

  Further, in Patent Document 4 described later, as a speaker device capable of obtaining a sound image having a feeling of spreading over the entire tubular member (pipe) that is a casing, one end side and the other end side of the pipe are completely opened. 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 sound waves 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 opened other end, the pipe wall is vibrated by this sound wave and vibrates. The sound wave corresponding to the audio signal is emitted from the entire outer surface.

Japanese Unexamined Patent Publication No. 2013-81061 “Bass-Reflex Non-Directional Speaker” Japanese Patent Laid-Open No. 2016-116093 “Speaker Device” Japanese Patent Laid-Open No. 2001-224089 “Speaker Device” JP 2007-208734 A "Speaker Device and Audio Output Method"

<Problems with conventional speakers>
The conventional speaker has the following problems.
(1) Weak to weak signals In conventional speakers, the main sound is produced only from the front of the speaker cone. Therefore, the speaker unit is considered to have excellent large diameter, high output, wide range, and flat characteristics, and dampers and edges have been reinforced to control powerful cone movement. As a result, there is a problem that a weak signal that is important for reproduction of “good sound” such as reality, realism, and ease of hearing cannot be pronounced or reproduced well. Further, the audio signal is an AC wave having various spectrums, but by canceling the sound on the back of the unit, one sound energy of AC is erased. Therefore, even if a strong signal sound 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) A high-output type high-end machine is required to obtain high-definition reproducibility. As a result, Hi-Fi (High Fidelity) reproduction of the original sound (CD sound source, etc.) is high-output type high-end. There is a problem that it must be low except when listening at a volume above a certain level. In other words, high-end audio equipment such as high-power devices, multi-speakers, and multi-amplifiers are difficult to enjoy with high-reality audio, except for some audiophiles who can hear a certain level of sound in an environment such as an audio room. Currently.

(3) There is no small speaker that can achieve high-definition reproducibility even at low volumes. High-definition sound source download services such as SACD (Super Audio CD), DSD (Direct Stream Digital), sampling frequency, and high quantization bit rate. Sound sources, DACs (Digital to Analog Converters), and amplifiers corresponding to these high-definition sound sources have been developed. However, there is a lack of high-definition efforts in liver and kidney speakers. In particular, there is no speaker that can achieve a balanced reproduction frequency and high reproducibility even at low volume.

(4) There is no device that can easily enjoy high-definition audio inexpensively and easily. In this way, it is difficult to enjoy highly realistic audio in true open air, so the headphone and headphone amplifier market is booming. However, listening with the ear alone is a burden on the ear and cannot be enjoyed for a long time. That is, there is no device that can sufficiently enjoy low-cost, easily high-definition audio without being limited in time and without overloading the ear.

(5) Unnatural reproduction only with speaker cones In the first place, it is unnatural to reproduce a multi-layered performance of musical instruments made of wood, metal, or a combination of them, such as orchestras, using only speaker cones. Attempts to eliminate the unnaturalness are still insufficient.

  Therefore, the problem to be solved by the present invention is to eliminate such problems of the prior art, and in particular, to reproduce a weak signal including subtle nuances satisfactorily, without using a high-output type high-quality machine, etc. It is possible to provide a speaker structure or the like that can obtain the Hi-Fi reproducibility of the original sound and can provide an audio environment with high reality at low cost.

  That is, an object of the present invention is to provide a speaker structure or the like that can reproduce a weak signal well and obtain high-definition reproducibility without increasing the diameter, increasing the output, and increasing the size. Providing high-definition reproducibility even at low volume, providing a speaker structure that can be miniaturized, low-cost and easy, high-definition audio without time restrictions and without overloading the ear Providing a speaker structure that can fully enjoy the sound, and further providing a speaker structure that eliminates the unnatural reproduction of the speaker cone alone and obtains a more natural reproduced sound.

<Problem solving policy>
The inventor of the present application has made the following solution policy as a result of research on the above problems.
(1) By reproducing the sound that was not reproduced as a sound with a cone, the reproduction of the recording site (Hi-Fi + stereoscopic image) is aimed beyond the Hi-Fi reproduction of the CD sound source.
(2) A structure that generates sound not only from the speaker unit but also from the entire enclosure (housing).
(3) All “vibration energy” generated from the speaker unit is transmitted to the enclosure and converted into sound.
(4) A structure capable of sounding even fine harmonic components.
(5) In addition to the timbre of the musical instrument, the sound rise (attack), decay (decay), sustain (sustain), and mute (release) can be expressed realistically.
(6) Use a combination of materials such as spruce and bamboo used in musical instruments.
(7) In the case of wood, the sound is tuned 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 echo.
(9) A bass reflex method will be studied for bass control and tuning of the sound of the entire speaker system.
(10) A unique internal structure is used as a mid / high / low tone / internal echo control.
(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, the speaker structure is a structure that produces sound from the entire enclosure, and as a result of conducting other multifaceted studies on the basis of studying the material for that, the present inventors have found that the above problems can be solved, and based on this, the present invention has been found. It came to be completed. That is, the invention claimed in the present application, or at least the disclosed invention, as means for solving the above-described problems is as follows.

[1] a cylindrical enclosure having at least one open end;
A speaker unit disposed coaxially with the enclosure on the open end side and driven based on an audio signal;
The side surface of the enclosure is formed of a non-homogeneous thin plate,
A cylindrical speaker structure, characterized in that sound waves are transmitted to the outside through the side surface of the enclosure.
[2] The cylindrical speaker structure according to [1], wherein the thin plate member is formed using one or a plurality of sheet-like wood materials.
[3] The cylindrical speaker structure according to [2], wherein spruce (hereinafter sometimes referred to as “spruce”), bamboo, or both are used as the sheet-like wood material.
[4] The cylindrical speaker structure according to [2], wherein two spruce veneers are used as the sheet-like wood material.

[5] The cylindrical speaker structure according to [4], wherein the spruce veneer used on the inside has vertical grain and the spruce veneer used on the outside has horizontal grain.
[6] The cylindrical speaker structure according to any one of [2] to [5], wherein a reinforcing sheet is attached to the sheet-like wood material.
[7] The cylindrical speaker structure according to any one of [1] to [6], wherein the enclosure is cylindrical.
[8] The cylindrical speaker structure according to any one of [1] to [7], further including a virtual ground portion for increasing vibration efficiency of the thin plate member.

[9] The cylindrical speaker structure according to [8], wherein a bass reflex is provided in the virtual ground portion.
[10] The cylindrical speaker structure according to any one of [1] to [9], wherein a reflection portion that reflects sound waves from the speaker unit is provided in the enclosure.
[11] The cylindrical speaker structure according to [10], wherein the reflecting portion is fixed by a floating mount method.
[12] The cylinder according to any one of [1] to [11], wherein vibration propagation means (hereinafter referred to as “sound bridge”) for transmitting vibration from the speaker unit to the enclosure is provided. Speaker structure.

[13] The cylindrical speaker structure according to [12], wherein one or more additional sound bridges are provided as the sound bridge in addition to a baffle plate surrounding the speaker unit.
[14] The cylindrical speaker structure according to any one of [1] to [13], wherein one or a plurality of stabilizers are provided to divide and vibrate the thin plate member.
[15] The cylindrical speaker structure according to [14], wherein the stabilizer is in a tape shape and is attached to the thin plate body.
[16] The cylindrical speaker structure according to [14] or [15], wherein the stabilizer is made of a wood material.

[17] A speaker device including the cylindrical speaker structure according to any one of [1] to [16].
[18] A method for manufacturing the speaker device according to [17], wherein one or more stabilizers are attached to the enclosure.
[19] A method for modifying the speaker device according to [17], wherein one or a plurality of stabilizers are attached to the enclosure.
[20] An audio system including the speaker device according to [17].
[21] The configuration in which the end of the enclosure facing the speaker unit is open only in the case of a bass reflex hole when a bass reflex is provided on the bottom plate, [1] to [16] ] The cylindrical speaker structure according to any one of the above.

<Effect of the present invention>
Since the cylindrical speaker structure, speaker device, audio system, speaker device manufacturing method, and speaker device modification method of the present invention are configured as described above, according to these, a weak signal including a subtle nuance can be reproduced satisfactorily. Therefore, it is possible to obtain an excellent Hi-Fi reproducibility of the original sound such as a CD sound source without using a high-powered high-end machine, and it is possible to provide an audio environment with high reality at low cost.

  In other words, a weak signal can be reproduced well without increasing the aperture, increasing the output, and increasing the size, and high-definition reproducibility can be obtained. Moreover, it can be reduced in size, can provide a speaker structure etc. that can sufficiently enjoy high-definition audio without being limited in time and inexpensively and without excessively burdening the ear. The unnatural reproduction by only the speaker cone is eliminated, and a more natural reproduction sound can be obtained.

  According to the cylindrical speaker structure of the present invention, not only the speaker unit, but also all generated “vibration energy” is transmitted to the enclosure, and sound is produced from the entire enclosure. Up to (attack), decay (decay), sustain (sustain), and mute (release) can be expressed with good reproducibility. Furthermore, because the thin plates that make up the enclosure are non-homogeneous (eg, sheet-like wood materials such as spruce and bamboo), vibrations that could not be reproduced as sound with a cone can be reproduced with high definition. Thus, it is possible to obtain a reproduced sound that approximates the reproduction on the recording site (Hi-Fi + stereoscopic image) beyond the Hi-Fi reproduction of the CD sound source.

  Moreover, 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 played (music genre, type of musical instrument / sound, volume and sound quality characteristics, etc.), and free sound quality design for the user A speaker device having the possible specifications can be provided.

It is side sectional drawing which shows the basic structural example of this invention cylindrical speaker structure. It is a side view of the example of a structure shown in FIG. FIG. 2 is a plan view (top view) of the configuration example shown in FIG. 1. FIG. 2 is a bottom view of the configuration example shown in FIG. 1. It is explanatory drawing which shows the example of the formation method of the thin-plate body based on this invention. It is side sectional drawing which shows the structural example of this invention cylindrical speaker structure provided with the virtual ground part. It is side sectional drawing which shows the structural example of this invention cylindrical speaker structure provided with the reflection part. It is explanatory drawing of the side sectional view which shows the effect | action in the structural example shown in FIG. It is a sectional side view which shows the example of a design of the reflection part in this invention cylindrical speaker structure. It is explanatory drawing of the side sectional view which shows the example of a shape of the reflector in this invention cylindrical speaker structure. It is explanatory drawing of the partial side sectional view which shows the structural example of this invention cylindrical speaker structure which used the reflection part as the floating mount. It is explanatory drawing of the partial side sectional view which shows the sound bridge structural example in this invention cylindrical speaker structure. It is explanatory drawing which shows the structure of each sound bridge shown to the structural example of FIG. 12, and is the figure seen from the baffle board inner surface side. It is explanatory drawing of the partial side sectional view which shows the structural example of this invention cylindrical speaker structure provided with the stabilizer.

<Basic configuration of the present invention>
Hereinafter, the present invention will be described in detail with reference to the drawings. Each figure is an example, and the present invention is not strictly limited to the configuration, 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 show configuration examples according to the present invention.
FIG. 1 is a side sectional view showing a basic configuration example of a cylindrical speaker structure of the present invention. Also,
2, 3 and 4 are a side view, a plan view (top view) and a bottom view of the configuration example shown in FIG. 1, respectively. As shown in these figures, the present cylindrical speaker structure 10 has a cylindrical enclosure 1 with at least one end side 2 opened, and is disposed on the open end 2 side coaxially with the enclosure 1 and driven based on an audio signal. And the speaker unit 4 is formed by a non-homogeneous thin plate member 5 so that sound waves are transmitted through the side surface of the enclosure 1 and radiated to the outside. Is the main configuration.

  Each figure is a basic configuration example of the cylindrical 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 a plurality of bass reflex structures 6 (bass reflex port 6P, bass reflex hole 6H), but a configuration in which no bass reflex structure 6 is provided is within the scope of the present invention. The same applies to the spike 7. Of course, as described above, the present invention is not limited by the illustrated shapes, proportions, and the like. The present invention is not limited to the illustrated configuration, and the same applies to the description to be described later in FIG.

  With this configuration, in the cylindrical 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 also propagates inside the enclosure 1 behind the speaker unit 4. The latter sound wave is transmitted through the non-homogeneous thin plate member 5 constituting the side surface of the enclosure 1 and radiated to the outside. In this way, the sound emitted from the speaker unit 4 is sounded forward and from the entire thin plate member 5 forming the side surface of the enclosure 1.

  The “tubular shape” of the enclosure 1 in the present invention is not limited to the cross-sectional shape. Accordingly, the cross-sectional shape includes all of circles, ellipses, regular triangles and other triangles, squares and other quadrangles, other polygons, semicircles, and other figures. It should be noted that the cylindrical enclosure is one of the excellent examples that can sufficiently obtain the effects of the present invention, and can constitute an omnidirectional speaker. One example is mainly performed. Moreover, the case where the diameter is expanded toward one of the end portions 2 and 3 is also included. The enclosure 1 fulfills three functions: a housing of the speaker structure 10, a vibrating body, and a 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 back sound source. That is, the vibration from the speaker unit 4 propagates as follows.
Vibration: Speaker unit vibration-> Baffle plate->Enclosure-> Convert to sound Back sound: Speaker unit back sound-> Enclosure internal sound pressure-> Enclosure (side)-> Convert to sound Enclosure (side) 1 or thin plate 5 Functions as a passive radiator. In other words, the principle is close to the mechanism by which the vibrations of strings such as guitars and violins vibrate the surface plate through the bridge to generate sound.

<Effect of making a cylindrical enclosure with thin plate>
The effects of forming the side surface of the enclosure 1 with the thin plate member 5 to be cylindrical (particularly cylindrical) will be listed.
(1) When the enclosure is cylindrical, tension is generated by bending the thin plate into a cylindrical shape, and the strength of the casing can be secured.
(2) It becomes a sounding body having optimum vibration characteristics and transmission characteristics that are thin and light.
(3) The sound resolution is high (the sound of each instrument can be heard individually).
(4) Produces a sense of realism with a moderate internal response.
(5) Since the direct sound of the speaker unit spreads upward and is sounded 360 degrees horizontally from the surface of the cylindrical enclosure, a three-dimensional sound image is formed.
(6) Since all the thin plate cylinders are 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 gentle to the ear and can listen for a long time in the near field (short distance).

(8) When a wood board is used as the thin plate body, it has compression and extension strength in the annual ring direction and is flexible in the direction perpendicular to the annual ring.
(9) By combining the plates together with the thickness of the plates and combining the length and width of the annual rings, a thin and strong structure and a vibrating body capable of controlling sound quality can be obtained.
(10) The conventional passive radiator (thought to increase the bass by driving a passive cone without a drive function by the internal pressure of the enclosure) is aimed at enhancing the bass part. Output from high to low is possible.
(11) When the enclosure is cylindrical, the sound from the side of the cylinder diffuses as a cylindrical wave, so that the listener receives a sound with pressure, and a clear sound reaches far from the characteristics of the cylindrical wave even at low volumes. 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) The vibration of the sound can be experienced more clearly than when a light cone such as paper vibrates due to the vibration of the wooden board. In other words, it sounds like a musical instrument.
(14) Sound in the enclosure is transmitted with high efficiency and pronounced. Since this transmission is attenuated, a standing wave (standing wave) is less likely to occur, and the sound is less turbid.

  By the way, in the present invention, the configuration in which the end 3 of the enclosure 1 facing the speaker unit 4 is opened is only in the case of the bass reflex hole 6H when the bass reflex 6 is provided at the end. That is, in the cylindrical speaker structure 10 of the present invention, the end 2 where the speaker unit 4 is provided is naturally an open end, but the opposed end 3 is not an open end in principle, and the bass reflex 6 The bass reflex hole 6 </ b> H forms an open portion at the end portion 3 only in the configuration in which is provided. A bass reflex can also be installed on the cylinder and baffle.

This is different from the technique disclosed in Patent Document 4 in which not only the end portion where the speaker unit is provided, but also the opposite end portion facing this is completely opened. That is, in the prior art, the open end opposite to the speaker unit is originally configured as an end where sound is radiated, and a thin enclosure made of polycarbonate or the like is required to obtain a sound image with a sense of spaciousness. However, in the present invention, the side portion of the enclosure 1 by the thin plate member 5 is the medium from which the sound is radiated, and it is necessary that the end 3 facing the speaker unit 4 is an open end. is not. 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 characteristics from the open end of the prior art. is there. The general definition for bass reflex is as follows.
Bass reflex port: Hole opened to the outside Bass reflex duct: Pipe bass reflex duct length: Pipe length Bass reflex duct diameter: Inner diameter: Inner diameter of pipe, outer diameter: Outer diameter of duct

<Structure of thin plate>
In the cylindrical speaker structure 10 of the present invention, the non-homogeneous thin plate member 5 can be formed using one or a plurality of sheet-like wood materials. One or two sheets of woody material may be used, but three or more are within the scope of the present invention. When a plurality of sheet-like wood materials are used, these can be suitably used by being bonded together. As plant materials, spruce of various tree species such as spruce and bamboo can be preferably used, but is not limited thereto. Not only the veneer but also a cut sheet material or other sheet 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, whether woody or not. In this respect, among the plant materials, a wood material, particularly a wood veneer or a sliced material is preferable. Due to the non-homogeneity, that is, the wide range of characteristics related to resonance, the width of the portion where each sound wave having a specific frequency is likely to vibrate is widened. Each sound can be reproduced more naturally.

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

  Further, a reinforcing sheet can be attached to the sheet-like wood material. For example, in the case of a projecting plate, the 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 suitably used.

  In the case where a sheet-like wood material is used as the thin plate member 5, particularly spruce, bamboo, or both can be suitably used. Spruce will be described in more detail. Depending on the type of tree, the specific properties such as density and specific gravity differ, and even wood of the same type varies depending on the weather conditions of the habitat, but spruce is a suitable material for pianos, guitars and violins. It is wood that has been used as. Spruce has a sound (vibration) propagation speed of 5,500 m / s and is faster than iron. Moreover, specific gravity is 0.45, and it is the lightness which cannot be compared with 7.9 of iron. The characteristics of wood required for musical instruments include high vibration propagation speed, low specific gravity, flexibility, elasticity, and good timbre, but in all of these, spruce is a highly rated wood. Also in the present invention, it can be most suitably used as a sheet-like wood material.

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

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

  On the other hand, because bamboo has high strength, it is effective for increasing the strength of the enclosure. Hard maple is often used for the violin back plate, but its purpose is considered to be support of the front plate and reflection of sound from the front plate. Therefore, it is desirable to use a hard maple projecting plate for the reflecting portion described later.

<Experimental_Investigation of projecting plate for forming thin plate>
Of the experiments conducted in the process of completing the present invention, the results of studies on spruce and bamboo will be described. It is an experimental result using the following two types of protruding plates.
A 0.05 mm thick Japanese paper was affixed to a 0.25 mm thick spruce grid veneer to obtain a sheet-like wood material having a thickness of 0.3 mm. Hereinafter, it is simply referred to as “spruce”.
Moreover, 0.05 mm thick Japanese paper 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. Depending on the type of sheet used on the inside and outside of the enclosure, four types of thin plate bodies were produced: inside and outside “spruce”, inside and outside “bamboo”, inside “spruce” outside “bamboo”, and inside “bamboo” outside “spruce”. In addition, a combination of vertical and horizontal grain was produced, and a cylindrical speaker structure using such a thin plate as an enclosure was made as a prototype, and its sounding characteristics were evaluated.

As a result, the following tendency was found.
(1) About bamboo When bamboo is used as the inside of a thin plate, the internal response becomes stronger. In addition, it is difficult for the sound to fail even in the case of a large volume. On the other hand, when bamboo is used as the outside, the impact of the emitted sound becomes strong. In addition, the sound is clear with a clear outline at low volume, but the echo inside the enclosure may become large at high volume.

(2) About Spruce When spruce is used as the inside of a thin plate, internal reverberation is appropriate. In the stage before fixing the baffle, the bass may fail when the volume is large, but this is because the strength is complemented by applying a tape-shaped protruding plate inside the enclosure, and the bass is increased. There is no problem. On the other hand, when spruce is used as the outside, a soft and natural sound is emitted. Of course, the clearness tends to decrease slightly compared to bamboo, but it does not get tired of listening even at medium volumes, and is suitable for long-term listening and BGM playback.

(3) Vertical and horizontal grain The bamboo, spruce, and any tree species have a sense of speed and impact when the grain is vertical (axial direction of the enclosure). In the vertical direction of bamboo, the characteristics are particularly strong.

(4) Specification Example of Product Level As a result of the above experiment, an enclosure specification example in the case of parameters: H260 mm, W120 mm, speaker: ˜20 W, caliber 6 cm-8 cm can be as follows, for example.
Two sheet-like wood materials having a thickness of 0.3 mm (projection plate 0.25 mm + reinforcing Japanese paper 0.05 mm) are laminated to a thickness of 0.6 mm. In addition, as for a sheet-like wooden material, one side is the grain vertical and the other side is horizontal. This specification is one of the best balance of vibration transmission due to thinness, fineness of transmitted sound, strength maintenance necessary for products, and aesthetics. Also, the combination of spruce length inside and spruce width outside gives excellent acoustic characteristics. In addition, since “brightness” is generated on the surface by setting the outside to be side of the spruce, the beauty is improved.
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 according to the present invention. The spruce protruding plates 15a and 15b shown above are bonded together to form a thin plate body 15 shown as a developed view below. Both vertical spruce veneer 15a (upper left) and horizontal spruce veneer 15b (upper right) are reinforced with Japanese paper as described above. An appropriate adhesive such as a bond for woodworking can be used as the adhesive, and the adhesive is formed by the following procedure.
(1) Both the projecting plates 15a and 15b are cut in a dimension of the circumference of the finally formed cylinder + 1 cm.
(2) The two projecting plates 15a and 15b are bonded with a shift of 1 cm in the rounding direction.
(3) The sheet (thin plate body) 15 formed by laminating is rounded, and the shifted two sides of 1 cm width become the margins Wa and Wb.
(4) The margins Wa and Wb are bonded together to form a cylinder.
The margins Wa and Wb of 1 cm inside and outside at the joint are overlapped for convenience, and the inside and outside of the joint are covered by the margins Wa and Wb, respectively. As a result, the strength of the joined portion is maintained, and the cylinder is retained even if it is left as it is.

<Non-homogeneity of thin plates constituting the enclosure>
As described above, the cylindrical speaker structure of the present invention is characterized in that the thin plate member constituting the enclosure is non-homogeneous. Although there is some overlap, this will be explained supplementarily.
In the cylindrical speaker structure of the present invention, sound is generated by transmitting vibration from the speaker unit to the thin plate enclosure, and sound is generated by transmitting the sound inside the thin plate enclosure generated from the back of the speaker unit through the enclosure. That is, the enclosure is a sounding body. A non-homogeneous material is used as the thin plate, and a woody material such as wood or bamboo is particularly suitable. In particular, an optimum result can be obtained by using a spruce thin plate.

  Woody materials such as wood and bamboo are non-homogeneous materials having structures such as annual rings, wood grain, and conduits. For this reason, acoustic characteristics such as vibration propagation speed, transmission characteristics, resonance characteristics, and the like differ depending on the type of wood and the like, as well as the annual rings, the appearance of grain, and the thickness. Therefore, these combinations become acoustic characteristic variables, and in the enclosure which is a sounding body according to the present invention, the acoustic characteristics differ depending on the part. That is, in the speaker device of a thin plate enclosure made of a 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, excellent characteristics as a sounding body and an enclosure that a standing wave and a resonance point with a specific frequency are hardly generated can be obtained. In addition, since the structure in which different physical properties are distributed in this thin plate body is also a structure that easily receives divided sounds and vibrations from the speaker unit, and thus is easily divided, the non-homogeneous thin plate body according to the present invention has various sound generations. It is also suitable for materials and structures.

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

  In this way, since homogeneous materials such as metals, rubber, and plastics literally have a homogeneous molecular structure, the acoustic characteristics such as natural frequency and resonance frequency of the material are likely to appear sharply. It will be perceived as the “sound” of the sound of the speaker. From the above, in the present invention, a non-homogeneous material is selected as a loudspeaker material for outputting a variety of musical instruments and sounds faithfully to the original sound and more naturally.

  However, in the present invention, it is not denied that a homogeneous material and a non-homogeneous material are used in combination. Even if a homogeneous material such as resin or metal is bonded to a thin plate that is a non-homogeneous material because of the desired acoustic characteristics, the entire thin plate is a non-uniform material. It is within the scope of the present invention. If non-homogeneous material is used as a thin plate, there may be problems with strength, durability, quality advancement, and uniformity in product production. It can be solved without problems by attaching them together and installing a stabilizer described later.

<About the thickness of the thin plate>
Although the specification example etc. were mentioned above about the thickness of a thin-plate body, it demonstrates further.
The thickness of the thin plate body is a major parameter depending on the tree species, the direction of annual rings when using a sheet-like wood material as the thin plate body, and the method of bonding when using two or more projecting plates. In addition, the thickness of the thin plate is also a major parameter in the required sound quality and acoustic characteristics. In consideration of these, it can be said that the thickness of the thin plate member according to the present invention is desirably 0.1 mm or more and 5 mm or less. More preferably, it is 0.3 mm or more and 1 mm or less, More preferably, it is 0.5 mm or more and 0.8 mm or less.

The reason why it is desirable to set the thickness to 0.1 mm or more and 5 mm or less is that the range of the thin plate body which the present invention aims at when the range is the thinnest level of the projecting plate and the material other than the projecting plate such as paper (void tube) or wood is used. This is because the desired effect can be obtained. For example, when a medium-sized unit and a void tube are used, the effect of the present invention can be obtained even when the thickness is as large as 5 mm. Of course, the thickness may be 3 mm.
Further, the grounds that it is more desirable that the thickness be 0.3 mm or more and 1 mm or less are that when a thin plate is used with a projecting plate, a configuration with a single projecting plate in the specification using a small unit, and a projecting plate 3 in a specification with a larger size. This is because it is desirable to use a single-sheet configuration.
In addition, it is more desirable that the thickness is 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 or the like on the basis of the thickness of 0.6 mm in the embodiment of the present invention. is there.

<Virtual ground>
FIG. 6 is a side sectional view showing a configuration example of the cylindrical 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 member 25 is provided as a characteristic configuration. The virtual ground portion 2VG can be formed by providing virtual grounding means 29 as shown in the figure. As the virtual grounding means 29, a material made of a material that can obtain a greater inertia by the mass and a greater deformation prevention effect by the hardness can be suitably 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 it is of course not limited thereto. However, when the bass reflex structure 26 is provided, it is desirable to provide the virtual grounding means 29 as shown in the figure. In the following drawings, there is an example in which an iron weight is used as virtual grounding means.

  With this configuration, the space between the upper surface of the virtual grounding means 29 and the ground speaker structure 210 ground plane GND can be set as the virtual ground 2VG. That is, by fixing as the virtual ground 2VG, this range can prevent vibration due to inertia due to mass and deformation due to hardness. Therefore, the enclosure 21 made of the thin plate member 25 receives the vibration received by itself from the virtual ground 2VG. Propagation cannot be made, and it is inevitably necessary to vibrate itself. As a result, the vibration efficiency and tone of the seat (enclosure) 21 are increased. In other words, the virtual ground 2VG forms a “semi-insulating” structure for further improving the vibration efficiency of the seat (enclosure) 21.

<Reflecting part>
FIG. 7 is a side sectional view showing a configuration example of the cylindrical speaker structure of the present invention provided with a reflecting portion. FIG. 8 is an explanatory diagram of a side sectional view showing the operation of the configuration example shown in FIG. As shown in these figures, the cylindrical speaker structure 310 of the present invention has a characteristic configuration in which a reflection portion 3 </ b> R for reflecting sound waves from the speaker unit 34 is provided in the enclosure 31. The figure shows an example of a reflector 3R composed of a tower-like reflector (hereinafter also referred to as “reflector”) 3R1 and an umbrella-shaped nose portion (hereinafter also referred to as “reflector 2”) 3R2. The invention is not limited to this. A configuration in which the nose portion 3R2 is not provided may be employed, and the reflector 3R1 and the nose portion 3R2 may have different shapes.

  The reflector 3R1 reflects the standing wave (stationary wave) in the enclosure 31 through the sheet by reflection, and increases the transmission efficiency of internal sound. On the other hand, when the bass reflex 36 is provided, the nose portion 3R2 functions to prevent middle and high sounds from entering the bass reflex port. As a material of the reflecting portion 3R, any material having a high sound reflectance can be used as appropriate. For example, hard maple can be suitably used in the case of wood, and aluminum can be suitably used in the case of metal. Moreover, it is good also as sticking those materials on HDF (High compression wood fiber board, High Density Fiberboard). Also, when reducing the reflectivity of the reflector 3R or reducing the reverberation sound of the internal sound of the enclosure 31, use MDF (Middle Density Fiberboard), the reflectivity, internal sound Can be controlled.

The sound generation principle of the cylindrical speaker structure of the present invention is the following three.
(1) Reflection and transmission of sound inside enclosure → Sound transmission (drawing below)
(2) Change in internal pressure by speaker diaphragm → sheet vibration → sound transmission (3) seat vibration by sound bridge mechanism → sound transmission Among these, (1) will be described with reference to FIG.

Speaker vibration → Internal air density wave → Sound generated by sound is transmitted to the outside through the enclosure 31 (sheet) as shown in the figure.
<1> Direct transmission (3Rs1 in the figure): Internal sound → Sheet vibration → Sound transmission (External air density wave)
<2> Reflection and transmission (in the figure, 3Rs2): Internal sound → Reflector → Sheet vibration → Sound transmission (external air compaction wave)
<3> Reflection and transmission 2 (prevention of internal irregular reflection, 3Rs3 in the figure): Internal reflection sound->Reflector-> Sheet vibration-> Sound transmission (external air density wave)
Without a reflector, diffuse reflection occurs even in a sheet. Diffuse reflections cause excessive echoes, impairing the purity of the sound that occurs sequentially. 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 need not be provided. Regardless of whether or not a bass reflex port is installed, the reflection and transmission functions by the reflecting portion 3R are not changed. Further, the virtual grounding by the virtual grounding means 39 maximizes the vibration of the sheet by “the structure of the sheet” while the members and the sheet below the reflector 3R1 constitute and maintain the structure as the same speaker device. It is a “semi-insulating” structure for sounding.

  The baffle plate 38 can be said to be one of “sound bridges” as an element for transmitting vibration. Usually, the term sound bridge is mainly used for soundproofing buildings and rarely for instruments. However, there is no precedent that uses this concept in speakers. The sound bridge will be described in detail later.

  FIG. 9 is an explanatory view of a partial cross-sectional view showing a design example of a reflecting portion in the cylindrical speaker structure of the present invention. Although the basic function of the reflection part is as described with reference to FIG. 7 and the like, it is possible to design the reflection part 4R and determine its property, thereby controlling the timbre. Specifically, high-medium-bass balance, sustain, bass-reflex effect, bass-reflex phase (control of the phase of the sound coming out of the speaker, thin plate and the phase of bass-reflex (whether it is delayed or not) It can be controlled by the design of the reflecting portion 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 (kind), metal, resin, etc. The tone can be controlled by the material.
P2: Material of the surface material of the reflector 4R1 MDF, HDF, wood (kind), metal, resin, etc. The tone can be controlled by the material. However, P2 may not be provided.
P3: Reflector shape This will be described later with reference to FIG.

G1: Gap between reflector main body and nose part The degree of function of the bass reflex 46 (generation of bass by the bass reflex) and the degree of vibration energy transmission to the thin plate can be adjusted. The escape of sound pressure to the outside can be adjusted by G1.
G2: Nose part diameter Together with G1, sound diffraction from the speaker unit can be prevented. If G2 is large, the sound from the unit is difficult to be diffracted, and accordingly, the sound that escapes to the bass reflex port 46P is reduced, and the sound can be transmitted more through the thin plate.

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

  In addition, installation of nose part 4R2 is not essential. When seeking a releasable sound or for the purpose of positively producing medium and high sounds from the bass reflex port 46P, it is better not to install the nose portion 4R2. Although the structure of the floating mount is also shown in the figure (fixing portion 4S, buffer material 4F, etc.), the floating mount will be described again with reference to FIG.

<Example of reflector formation>
FIG. 10 is a side sectional view showing an example of the shape of the reflector in the tubular speaker structure of the present invention, and is a variation example for controlling reflection according to the incident angle of sound. From left to right, (a) strong reflection type, (b) weak reflection type, and (c) balance type.
(A) Strongly reflective type By providing one or more parts (convex parts) with a short distance between the reflector and the thin plate, and making it a two-stage type or multi-stage type, the separability of the mid-high range and low range is improved. While improving, each permeability can be improved. Can produce sharp and energetic sounds.

(B) Weakly reflective type By making the reflector thin (slim) so that the internal space of the enclosure can be widened, the sound pressure inside the enclosure of the back sound of the speaker unit is moderated. Also, the reflection of internal sound by the reflector is weakened. As a result, a delicate sound that reproduces the room tone at the time of recording, and a pleasant sound with less stimulation can be generated.
(C) Balanced type It is an intermediate form between a strong reflection type and a weak reflection type, and a 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 diagram of a partial cross-sectional view illustrating a configuration example of the cylindrical speaker structure of the present invention in which the reflection portion is a floating mount. As shown in the figure, the present cylindrical speaker structure 510 has a characteristic configuration in which the reflecting portion 5R is fixed by a floating mount method and is independent of other components. In the illustrated example, when the reflector 5R1 is fixed to the bottom plate 50 using the fixing means 5S, the buffer means 5F such as a soft cushioning material (layer) is interposed between the reflector bottom plate 5R10 and the bottom plate 50 and fixed. The reflection part 5R is made to be a floating mount by interposing a buffer means 5E such as a buffer material between the means 5S and each fixing point. The gap between the fixing means 5S and the buffer means 5F is filled with silicon resin or the like.

  In the illustrated example, a virtual grounding means 59 such as an iron weight is bonded and fixed on the reflector bottom plate 5R10, and the fixing means 5S is fixed through the fixing means 5S. A bolt or the like can be suitably used as the fixing means 5S, and a synthetic rubber or the like can be suitably used as the buffer means 5E or 5F, but is not limited thereto. Moreover, what is shown 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 sound reflection inside the enclosure 51 of the sound emitted from the back surface of the speaker unit 54 and reflecting the sound inside the enclosure 51 and transmitting the thin plate, but the reflector 5R1 is 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, and the sound transmitted through the enclosure 51 and the thin plate member becomes turbid. However, by fixing by the floating mount method, the reflector 5R1 becomes less susceptible to the vibration of the speaker unit 54 and other casing components. That is, by making the floating mount, it is possible to enhance each function of the reflection portion 5R such as reflection, transmission, sound generation, and reduction of internal echo of internal sound.

<Sound Bridge>
The cylindrical speaker structure 510 can be configured to be provided with 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 bonding 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 is vibrated positively, and sound is radiated well outside the enclosure 51. In particular, medium and high sounds can be transmitted well to the enclosure 51, and vibration can be transmitted dynamically 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) is reflected from the bottom plate 50 and the spike 57 by the reaction force of the vibration of the enclosure 51. This is because the enclosure 51 using a thin plate body is in a semi-insulated state as vibrations below the bottom plate 50. Thereby, the vibration of the enclosure 51 is increased and the sound generation to the outside of the enclosure 51 is clarified. In this figure, the virtual ground portion 5VG is formed by the virtual grounding means 59 (iron weight), so that the semi-insulating structure is further solidified and the vibration of the enclosure 51 is maximally enhanced. is there.

  FIG. 12 is an explanatory diagram of a partial cross-sectional view showing a sound bridge configuration example in the cylindrical speaker structure of the present invention. 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 seen from the inner surface side of the baffle plate. As shown in these figures, the cylindrical speaker structure 610 can be provided with one or a plurality of 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 by direct contact with the speaker unit or indirectly through a speaker unit fixing bolt or the like, and transmits the vibration to the enclosure 61. In the figure, an example of an umbrella 6B2 and a rod 6B3 as additional sound bridges is shown. These examples will be described.

(1) Umbrella body Umbrella body 6B2 is provided so as to contact the entire circumference of enclosure 61 from above speaker unit 64. The umbrella body 6B2 can be made of, for example, aluminum, copper, or steel plate, but is not limited thereto. Also, the shape and other specifications are not limited to this example. The umbrella body 6B2 assists the sound bridge function of the baffle plate 68 and acts to transmit medium and high sounds to the enclosure 61, and in particular, can transmit delicate medium and high sounds. Moreover, according to this structure, since it contacts the whole inner periphery of the enclosure 61, a vibration can be transmitted equally.

(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 back surface of the speaker magnet 64M of the speaker unit 64 is configured by eight rod-like bodies 6B3 extending radially from the center. Each rod-shaped body 6B3 is provided in contact with the enclosure 61. The rod-like body 6B3 can be made of stainless steel, for example, but is not limited thereto. Also, the shape and other specifications are not limited to this example. Since the rod-like body 6B3 assists the sound bridge function of the baffle plate 68 and can obtain particularly high vibration energy because it is close to the speaker unit vibration source, it enhances the action transmitted to the enclosure 61 over low, medium and high sounds. Can do.

  By the way, in the figure, 6BV: a part for transmitting vibration from each sound bridge to the cylinder, 6BVl: an area extending from 6BV to the bottom of the cylinder. The vibration caused by the sound bridge is attenuated by the distance propagating through the thin plate as a medium. In 6BV, the tube vibrates with vibration close to that of the speaker unit, but attenuates from the high pitched part as it goes to the lower end of 6BVl. There are two types of attenuation. One is attenuation due to diffusion (sounding), and the other is attenuation due to absorption of the thin plate (heat conversion). The fact that the treble attenuates at the upper part of 6BVl is turbid from the thin plate. It can be inferred that a sound with less modification is emitted.

  In addition, as illustrated in FIG. 12 and FIG. 14 to be described later, a plurality of additional sound bridges may be provided in combination. In FIG. 12 and the like, an example in which the umbrella body 6B2 and the rod body 6B3 are used together is shown. Further, the virtual grounding means 69 in the configuration example shown in FIG. 12 is different in installation position from that shown in FIG. The virtual grounding means can also be designed as appropriate in consideration of the virtual ground function, sound bridge function, manufacturing method, and the like.

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

The stabilizer controls vibration and adjusts the sound quality, but specifically, it has the following actions.
(1) Split vibration By installing the stabilizer 7Z1 and the like, the enclosure 71 can easily split and vibrate, so it is easy to produce high sounds on the speaker unit 74 side of the enclosure 71 (thin plate) and low sounds on the opposite side. . As shown in the figure, when the enclosure 71 is divided into three regions by the two stabilizers 7Z1 and 7Z2, it becomes easy to generate a medium sound from the center. A structure that easily undergoes divided vibration can increase the resolution of vibration caused by an audio signal. That is, since the low sound that tends to remain as vibration does not affect the middle sound and the high sound, a clean medium sound and high sound can be produced.

(2) Vibration Suppression It is possible to suppress the enclosure 71 from vibrating excessively, continuing to vibrate, and resonating at a specific frequency. Thereby, it is possible to linearly follow the change in vibration from the speaker unit 74.
(3) Complementation of stress with respect to internal pressure The enclosure 71 is expanded by sound pressure (internal pressure) from the back surface of the speaker, and stress (strain) is generated. This stress (strain) becomes sound, but excessive stress on the input signal hinders faithful reproduction of the original sound. By installing the stabilizer 7Z1 or the like, it is possible to obtain a vibrating body having a moderately high stress while ensuring sensitivity to a weak signal.

Note that the high, middle, and low tone range will be further described.
The high sound is generated by the vibration of the enclosure 71 due to the sound of each sound bridge and the back of the speaker. Since the treble and treble vibrations have a higher attenuation rate and higher straightness than the bass vibrations, it is desirable that the treble and treble vibrations be emitted as sound at the upper portion of the enclosure 71. On the other hand, since the bass pressure wave is mainly the pressure wave of the air from the speaker cone, it reaches the bottom mainly through the air inside the enclosure, but the pressure wave loses its place by the reflector 7R1 and vibrates up to the bottom of the enclosure 71. It attenuates by.

  The stabilizer 7Z1 is installed in order to completely attenuate the vibration caused by the pressure wave at the bottom so as not to transmit bass to the top of the enclosure 71. Further, since the low pressure wave has high dynamic energy, the stabilizers 7Z1 and 7Z2 function so as to be reproduced as a tight bass even at a high volume or when a sound source rich in bass is reproduced.

The effects and advantages of providing a stabilizer are as follows.
(1) A bass with a clear outline can be generated.
(2) The mid-high sound clearness is improved.
(3) The sound generation power of the entire speaker system is improved. That is, when the stress with respect to the internal pressure of the enclosure is increased, the distortion of the portion other than the stabilizer installation location and the pressure to the bass reflex port are increased, and the operation of the bass reflex mechanism is enhanced.
(4) High input resistance is improved. In other words, even if the volume of the amplifier is increased, the sound is less likely to fail.
(5) Enclosure strength and durability are improved.

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

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

Tape stabilizer specifications and installation method / thickness: about 0.3 mm for wood (may be thinner depending on the material)
・ Width: about 10mm (Depending on the material, it can be made thinner)
Installation method ・ Stabilizer is affixed to the inner circumference of the enclosure using woodworking bond (1 round + margin).
Note that the stabilizer can be installed in the vertical direction instead of in the horizontal direction, and the sound quality can be freely changed by parameters such as the number, installation interval, and material.

  A speaker device including any of the above-described cylindrical speaker structures is also within the scope of the present invention. Also, 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 to which one or more stabilizers are attached to the enclosure Modification methods are also within the scope of the present invention.

<Direction of speaker>
As shown in each figure, since the speaker unit is installed upward in the present invention, the initial vibration (first amplitude) is difficult to move upward due to inertia and gravity. Insensitive to structure (damper, braking force by edges). After the signal ends, inertia is easily canceled by the braking force and gravity. Thereby, the following effects can be obtained.
(1) Attack becomes stronger (2) Sustain becomes stable.
(3) Fine sound can be expressed even at a low volume.
(4) Silence can be instantaneous.

<Supplementary: The way to the invention of the tubular speaker structure>
Hereinafter, based on the confirmation of the basic idea of the present invention, the process of completing the invention will be supplementarily described.
(1) Fundamental idea of the tubular speaker structure of the present invention In the conventional speaker, in order to suppress unnecessary vibration as much as possible, a strong material has been used for the enclosure and the baffle plate to prevent vibration of the enclosure itself. In addition, due to the necessity of preventing the turbidity and resonance of the sound inside the enclosure due to the sound coming out from the back of the speaker unit from affecting the vibration of the cone caused by the signal, measures have been taken with a silencer. On the other hand, in the present invention, not only the speaker unit but also the enclosure is used as a sounding body. It tries to convert all the vibrations, waves, and other energy generated from the speaker unit into sound as much as possible without taking it as unnecessary vibrations. This is incompatible with the conventional way of thinking, and yet it achieves an acoustic characteristic that cannot be produced by a conventional speaker.

(2) Construction of the Principle of the Present Invention Based on the Physical Law (2) -1 Law of Inertia A thing that is easy to move and stops is optimal as a vibrating body of a speaker. Ease of movement is the specific gravity of the vibrating body and vibration transmission speed, and ease of stopping is flexibility (loss characteristics) and conversion rate from vibration energy to sound. Wood, especially spruce, is excellent as a material having these conflicting characteristics. Also, it is considered that the output sound quality can be controlled by the difference in wood type, size, thickness and joining method.

  In addition, when a speaker unit is installed, the initial motion vibration (initial amplitude) becomes difficult to move upward due to the influence of inertia and gravity. However, after the second amplitude, it becomes difficult to be affected by the structure of the speaker (damper, braking force by the edge), and after the end of the signal, inertia is easily canceled by the braking force and gravity. As a result, even in the case of a low volume, it is possible to obtain an effect for fine expression of sound, from 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 proportional to the force applied in the direction of the force and inversely proportional to the mass m of the object is generated. That is, it is as the following formula.
External force F = mass m x acceleration a
Here, external force F: electromagnetic force generated by current to the voice coil, mass m = mass of the speaker swinging portion (voice coil, cone paper), acceleration a = acceleration of cone motion. Thus, cones move faster when lighter and slower when heavy. Further, if the external force F, that is, the impact of the signal or the current is large, the cone acceleration a 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 tube of the speaker and is pushed back as a reaction force at the bottom plate. If the bottom is solid as a base, the cylinder part will have to vibrate. Therefore, the sound quality also changes depending on the material and weight below the bottom. If the material is soft, the force escapes in both the action and reaction, so the force is absorbed by the softest part. Further, since gravity is added to the downward acceleration, it is considered that the downward action on the cylinder is further strengthened.

(2) -4 Law of Conservation of Energy Within an independent system, the overall energy remains unchanged regardless of any physical or chemical changes. 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> Back air vibration → Tube vibration → Tube sound (some from bass reflex port to air vibration)
<3> Reaction force of cone vibration → baffle plate vibration → tube vibration → tube sound.

(2) -5 Mass Law, Transmission Loss Transmission loss occurs when the sound inside the enclosure is transmitted through the thin plate and sounded outside. This is called the law of mass, and the transmission loss is proportional to the product of the material mass (surface density) (kg / m ² ) and frequency. That is, the transmission loss increases as the mass increases. This is the reason why conventional speakers use heavy wood to block the sound inside the enclosure. The present invention considered how to make an enclosure using a material having a low transmission loss and transmit sound inside the enclosure. In addition, a thin plate was devised and designed to satisfy these two elements in terms of sound quality, which is a material with excellent characteristics in the propagation of vibration from the sound bridge and sound generation.
As described above, these physical laws are applied to the concept construction, the hypothesis construction, the trial production, the evaluation, the problem construction, and the like in the present invention.

(3) Excellent speaker conditions Musical instruments vary in sound by type and by individual. Therefore, in order to faithfully reproduce the sound of one instrument, it is ideal that a speaker dedicated to that instrument is designed. However, even with a single instrument, the conditions are different if it reproduces the environment such as a feeling of air, reverberation, and the voice of the audience, as in a live performance at a large venue. Also, the sound quality of the sound source varies depending on the position, type, manufacturer, engineering, and recording equipment of the microphone. Even for vocals, there are conditions such as shouting voices, whispering voices, reverberating voices, voices with odd overtones, and differences between male and female voices.

In view of these, excellent speakers, ideal speaker conditions,
<1> As the final stage of audio playback, all kinds of sound sources can be targeted for optimal playback.
<2> Excellent player and musical instrument presence, formation of sound field to play, and reproduction of player's feelings,
<3> Comfortable for long-term listening,
<4> Even when playing from a high volume to a very low volume, the balance is not lost.
<5> Compact and cost-effective,
<6> You can own it with attachment,
<7> Produced by someone who knows all about sound and music.
<8> It can be said that this is a speaker that allows users to maximize the enjoyment and excitement of music.

(4) Utilization of unnecessary vibration Conventionally, unnecessary vibration has been considered as 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 of sound elimination inside the speaker enclosure, and a high value means that there is little echo sound inside the enclosure. In the past, thick and heavy wood was used, unnecessary vibrations were not leaked to the outside, and reverberant sound that was unnecessary vibrations inside the enclosure was lost by the sound absorbing material.

  As a result, in principle, a sound faithful to the signal should be generated from the front of the speaker. However, if too much sound-absorbing material was added, there was a phenomenon that the “sound” of the sound was lost and the sound became dull. Therefore, both manufacturers and users have tried tuning by changing the amount, quality, and location of the sound absorbing material. (In the self-made bass reflex, take a policy not to add sound absorbing material in order to take advantage of the “sound”. Even users exist). Further, as described above, it is known that the quality of the wood used for the enclosure also affects the sound quality of the speaker.

  Overall, it was speculated that the vibration of the enclosure itself also affected the sound quality in the speaker. If so, it was thought that a speaker without any loss could be constructed by positively making the sound inside the enclosure, which has been regarded as unnecessary vibration, and the vibration of the speaker unit. In other words, I thought that the internal loss of the speaker should be converted to sound by actively transmitting internal vibrations to the cylinder and converting it to sound, rather than converting it into heat energy by the sound-absorbing material.

  Conventionally, a solution for unwanted vibration has been mainly to make the baffle plate and the enclosure plate thicker and heavier. However, the vibration energy of the speaker unit is quite 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 of transmitting the vibration of the unit to all or part of the enclosure, vibrating it, and making it sound positive. That is, the principle feature of this speaker is to use these two vibration elements, which have been regarded as negative, and to release them as sound.

(5) Components of this speaker and their functions Based on the above considerations, we decided to construct a 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> Tube: Main component of the enclosure (secondary sound generator) Uses a thin plate cylinder
<4> Bottom plate: Main components of the enclosure (Reaction force base (as ground for vibration source))
<5> Spike: Support for speakers (support for reaction force base)
<6> Bass reflex port: Bass reflex port (bass reflex and internal echo control)

(6) Sound characteristics of this speaker The following characteristics were recognized in the prototype speaker.
(6) -1 When a vibration from the unit is transmitted to the cylinder, a powerful attack such as a musical instrument is reproduced.
(6) -2 Various vibrations that cannot be reproduced by the speaker unit alone are generated and reproduced in the body (cylinder). That is, with respect to each vibration from the unit, a portion of the cylinder that is likely to vibrate vibrates (free vibration) and becomes a sound.

(6) -3 Various features by making the enclosure into a cylindrical structure
<1> The internal reverberation sound moderately controlled by the reflector sounds like an actual performance sound field (sustain effect).
<2> Although it is a thin plate that has a high acoustic effect, such as reacting to weak vibrations, it is also required to function as an enclosure at the same time. We can make weak vibrations that cannot be converted into sound (sensitivity).
<3> Since the sound diverges as a cylindrical wave outside, the 3D sound image (depth, height) can be reproduced with the upper speaker and the lower bass reflex, and the localization is clear. That is, the main musical instrument or vocal with a relatively high output vibrates the tube strongly, and the back sound is emitted gently. This may be due to the nature of the cylindrical wave.

<4> Cylindrical waves are diffused in a plane shape compared to the sound wave vibration from the unit, and the vibrating body is a sheet made of wood, etc., so the vibration pressure is high, and the audible and bodily sensation close to the actual sound field is obtained It is done. The characteristics of these cylindrical waves are considered to depend on the characteristic of “surface sound source” that “a constant sound field is produced on the surface of the sound source regardless of the distance and no distance attenuation occurs”. At the same time, I think that it is due to the characteristics of this surface sound source that it is not harsh when listening in the near field.
<5> The sound radiated by the cylinder spreads over the entire reproduction field, and has an excellent sound field forming ability compared to ordinary speakers that are surface or point sound sources. In addition, the directivity is determined by the relationship between the vibration surface area of the sound source and the wavelength, and the sharper directivity is obtained as the area of the vibration surface is larger than the wavelength and as the wavelength is shorter. In particular, high directivity high sound propagates to the vibration surface expanded by the cylinder by the sound bridge, and vibrates and produces sound, unlike a general surface or a point sound source speaker, enabling natural sound field formation.
<6> The cylindrical wave (radiation of sound from the surface) by the sheet passes well. Especially strongly recognized for pianos, violins, guitars and drums.
<7> A good sound field can be felt even in the near field (close to the speakers).
<8> The sound field is not destroyed or broken by the volume, and the sound field is maintained.

(7) Member and structure of the trunk portion The cylinder (trunk) of the enclosure, 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 the strength, and the surface is covered with guitar and violin manufacturing materials such as spruce, rice pine, etc., and tested to adjust the characteristics of the sound by changing the thickness and size (vertical and horizontal, capacity). Good results were obtained.
<3> The same or similar effects were observed with other wood thin plates, but the one with the best sound was an enclosure made by bonding two spruce pieces vertically and horizontally.

<4> It was confirmed that sound quality can be controlled by combining the same or different types of veneers (rise, sustain, internal resonance, frequency characteristics, input resistance).
<5> Although this speaker is basically one that does not have a front (all directions are front), the direction in which it is provided by attaching a projecting plate vertically to a part of the trunk or attaching a reflector With the back side, it was possible to clarify the front and back orientations.
<6> It was also confirmed that sound quality can be corrected by installing a thin tape-like plate inside the cylinder, such as bracing used for guitars and violins.

(8) Guidance_Possibility of Shock Wave Generation Why can the speaker of the present invention produce a sound with a reality as never before?
At the time of starting the trial production of this speaker, it was assumed that sound of the conventional level could be obtained. However, when the sound was actually produced after the completion of the prototype, it was felt that the sound was beyond imagination, the sound rises like a live musical instrument, and the reproduction of minute signals. Considering the cause of the difference in sound from the conventional speaker, one of the causes may be the generation of a shock wave.

  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 the sound source (object) exceeds the speed of sound, a shock wave is generated around the sound source. If the principle of the generation of this sonic boom (large acoustics caused by shock waves) is used, it is considered that “shock waves are generated from objects that transmit vibrations exceeding the speed of sound”. For example, even a concert hall full of seats with a thick audience in the winter, the sound of a single soloist violin echoes the venue. This is hard to imagine with the general concept of “sound”. If the sound has shock wave properties, it may not be within the radiant energy law of “attenuates by the square of distance”, and may be close to a shock wave that is difficult to attenuate.

  In this speaker, the vibration from the speaker unit is transmitted downward at a vibration propagation speed of 5,500 m / s of spruce (simply below, but it is thin but thick, so it also has a horizontal vibration vector. ). The generation condition of the shock wave is “the sound source (substance) exceeds the speed of sound”, but the sound wave of the vibration from the unit is synonymous with “the sound source (substance) exceeds the speed of sound” if these horizontal vibrations. There is a possibility. (Even the vibration transmitted down produces a horizontal vibration as long as it is a vibration).

  In fact, this speaker can realize that there is less energy loss of sound due to distance than conventional speakers. Also, it can be felt that the vibration of furniture during performance is very high compared to the conventional method. Therefore, it is considered that there is a high possibility that shock-wave-like air vibrations are generated from the cylinder portion. In any case, the vibration propagation method of this speaker is similar to that of violin, drums, and other musical instruments that have the same structure as the conditions that generate shock waves, so it reproduces attack, sustain, attenuation, and even harmonics with high reality. I think I can do it.

<Conclusion>
According to the cylindrical 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 type high-end machine can be obtained. Without using it, it is possible to obtain an excellent Hi-Fi reproducibility of the original sound such as a CD sound source, and it is possible to provide an audio environment with high reality at low cost. Therefore, the invention is highly industrially applicable in the audio equipment field and all related fields.

0, 20, 40, 50, 60, 70 ... bottom plates 1, 21, 31, 41, 51, 61, 71 ... enclosure 2, 22 ... end of enclosure (open end)
3, 23 ... End of enclosure (other side)
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 ... Baffle plate 10, 210, 310, 510 , 610, 710 ... cylindrical speaker structures 15a, 15b ... projecting plates 29, 39, 49, 59, 69, 79 ... virtual grounding means 2VG, 3VG, 5VG, 6VG, 7VG ... virtual ground portions 3R, 4R, 5R, 6R , 7R: Reflector 3R1, 4R1, 5R1, 6R1, 7R1 ... Reflector 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 2 of internal sound
4F, 5E, 5F, 6E, 6F, 7F ... buffer means 4S, 5S, 6S, 7S ... fixing means 5R10 ... reflector bottom plates 5T, 6T, 7T ... terminals 6B2, 7B2 ... umbrella-like body 6B3 ... rod-like body 6BV ... each Part 6BVl that transmits vibration from the sound bridge to the tube 64B from the 6BV to the bottom of the tube 64F speaker frame 64M speaker magnet 64N speaker mounting nuts 7Z1, 7Z2 stabilizer GND ... ground Wa, Wb ... margin

Claims (21)

A cylindrical enclosure having at least one open end; and a speaker unit disposed coaxially with the enclosure on the open end side and driven on the basis of an audio signal, the side of the enclosure being non-homogeneous A cylindrical speaker structure, characterized in that it is formed of a thin plate body, and sound waves are transmitted to the outside through the side surface of the enclosure. 2. The cylindrical speaker structure according to claim 1, wherein the thin plate is formed using one or a plurality of sheet-like wood materials. The cylindrical speaker structure according to claim 2, wherein spruce, bamboo, or both are used as the sheet-like wood material. The tubular speaker structure according to claim 2, wherein two spruce veneers are used as the sheet-like wood material. 5. The cylindrical speaker structure according to claim 4, wherein the spruce veneer used on the inside is a vertical grain and the spruce veneer used on the outside is a horizontal grain. 6. The cylindrical speaker structure according to claim 2, wherein a reinforcing sheet is attached to the sheet-like wood material. The cylindrical speaker structure according to any one of claims 1 to 6, wherein the enclosure is cylindrical. The cylindrical speaker structure according to any one of claims 1 to 7, further comprising a virtual ground portion for increasing vibration efficiency of the thin plate member. 9. The cylindrical speaker structure according to claim 8, wherein a bass reflex is provided in the virtual ground portion. The cylindrical speaker structure according to any one of claims 1 to 9, wherein a reflection portion that reflects sound waves from the speaker unit is provided in the enclosure. The cylindrical speaker structure according to claim 10, wherein the reflection part is fixed by a floating mount method. The cylindrical speaker structure according to any one of claims 1 to 11, further comprising vibration propagation means (hereinafter referred to as "sound bridge") for transmitting vibration from the speaker unit to the enclosure. The cylindrical speaker structure according to claim 12, wherein one or a plurality of additional sound bridges are provided as the sound bridge in addition to a baffle plate surrounding the speaker unit. The cylindrical speaker structure according to any one of claims 1 to 13, wherein one or a plurality of stabilizers are provided to divide and vibrate the thin plate member. The cylindrical speaker structure according to claim 14, wherein the stabilizer is in a tape shape and is used by being stuck to the thin plate member. The cylindrical speaker structure according to claim 14 or 15, wherein the stabilizer is made of a wood material. A speaker device comprising the cylindrical speaker structure according to any one of claims 1 to 16. 18. A method of manufacturing a speaker device according to claim 17, wherein one or more stabilizers are attached to the enclosure. 18. A method for modifying a speaker device according to claim 17, wherein one or more stabilizers are attached to the enclosure. An audio system including the speaker device according to claim 17. 17. The structure according to claim 1, wherein the end of the enclosure facing the speaker unit is open only in the case of a bass reflex hole when a bass reflex is provided on the bottom plate. The cylindrical speaker structure described.