WO2019230126A1

WO2019230126A1 - Speaker device

Info

Publication number: WO2019230126A1
Application number: PCT/JP2019/010684
Authority: WO
Inventors: 裕介山本
Original assignee: ソニー株式会社
Priority date: 2018-05-30
Filing date: 2019-03-14
Publication date: 2019-12-05
Also published as: JPWO2019230126A1

Abstract

The purpose of the present invention is to ensure that an acoustic effect due to porous activated carbon is not reduced by moisture absorption. To achieve this, a speaker device is provided with: a heat dissipation unit for dissipating heat generated by a heat generating unit; and a porous activated carbon disposed inside a cabinet at a position that is dried by heat from the heat dissipation unit.

Description

Speaker device

This technology relates to the technical field of speaker devices.

With respect to the speaker device, Patent Document 1 below describes a means for realizing a small speaker capable of preventing a speaker unit from being damaged by a structure that radiates heat using a heat pipe and capable of generating a large output.
Patent Document 2 below discloses a structure in which activated carbon is arranged inside a speaker.

JP 2000-152380 A JP 2009-27526 A

Since the sealed active speaker device does not allow air to enter and exit from the outside, heat from the amplifier and the power source tends to increase and the temperature inside the cabinet tends to increase. For this reason, the output power is reduced due to the necessity of protecting the power element of the amplifier, but this limits the amplifier performance. In addition, even bass reflex type speaker devices with improved sound pressure of bass sound have little air inflow and out, and the problem of heat dissipation remains unchanged.
Further, when the size is reduced, the cabinet volume is reduced, so that f0 (minimum resonance frequency) is increased and it is difficult to produce a low sound.
Accordingly, an object of the present technology is to be able to output a sufficiently low sound even with a small speaker device and to maintain performance while solving a heat problem.

The speaker device according to the present technology includes a heat dissipating unit that dissipates heat generated by the heat generating unit, and a porous activated carbon disposed in a cabinet at a position to be dried by heat leaked from the heat dissipating unit.
For example, it arrange | positions so that a porous activated carbon may be filled in a cabinet. Moreover, a heat radiating part is provided in the cabinet, and the porous activated carbon is dried by the heat leaked from the heat radiating part.

In the above-described speaker device according to the present technology, the porous activated carbon has macropores having an opening diameter of about 1 μm on the surface of the granular material, and mesopores having an opening diameter of 2 nm to 50 nm on the inner wall portion of the macropore. It is conceivable to be a granular body having micropores having an opening diameter of 2 nm or less on the inner wall portion of the mesopores.
Porous activated carbon which is a granular body having these three types of holes hierarchically is arranged in the cabinet.

In the above-described speaker device according to the present technology, the porous activated carbon may have a surface area of about 1000 m ² / g.
That is, the porous activated carbon has a surface area far larger than the surface area of the spherical surface of the granular material due to the structure of macropores, mesopores, and micropores.

In the above-described speaker device according to the present technology, it is considered that the porous activated carbon is disposed in the cabinet in a state of being packed in a plurality of breathable bags.
As for porous activated carbon, for example, a granular material of about 2 mm is packed in a plurality of sachets, and the sachets are arranged in a cabinet.

In the above-described speaker device according to the present technology, it is conceivable that the heat generating unit is an amplifier unit arranged in the cabinet.
For example, an amplifier unit including a substrate on which an amplifier circuit is formed generates heat during speaker operation, and can be used as a heat generating portion.

In the above-described speaker device according to the present technology, it is considered that the heat radiating unit is a heat pipe.
That is, the heat generated by the heating element is released to the outside through the heat pipe.

In the above-described speaker device according to the present technology, it is conceivable that the heat dissipation portion is a hollow heat sink.
That is, for example, a cylindrical hollow heat sink in contact with the heating element is provided to release the heat accumulated in the cabinet to the outside.

In the above-described speaker device according to the present technology, the heat radiating portion may be a hollow heat sink that penetrates the cabinet in the vertical direction.
That is, a hollow heat sink in contact with the heating element is made to penetrate in the cabinet.

In the above-described speaker device according to the present technology, the cabinet may be a sealed type.
That is, it is configured as a sealed speaker.

According to the present technology, the porous activated carbon can be dried so that the effects on acoustic characteristics such as f0 reduction and standing wave suppression due to the arrangement of the porous activated carbon are not hindered by the moisture absorption of the porous activated carbon.
Note that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is explanatory drawing of the structure of the speaker apparatus of 1st Embodiment of this technique. It is explanatory drawing of the porous activated carbon of embodiment. It is explanatory drawing of f0 fall by filling with the porous activated carbon of embodiment. It is explanatory drawing of sound pressure maintenance and standing wave suppression of embodiment. It is explanatory drawing of the structure of the speaker apparatus of 2nd Embodiment. It is explanatory drawing of the structure of the speaker apparatus of 3rd, 4th embodiment.

Hereinafter, embodiments will be described in the following order.
<1. Speaker device of first embodiment>
<2. Speaker Device of Second Embodiment>
<3. Speaker Device of Third Embodiment>
<4. Speaker device of fourth embodiment <5. Summary and Modification>

<1. Speaker device of first embodiment>
A speaker device 1 according to a first embodiment will be described. FIG. 1A is an explanatory diagram of the structure of the speaker device 1.
The speaker device 1 is configured as a sealed speaker in which the cabinet 2 has a relatively small rectangular parallelepiped shape and the speaker unit 3 is attached to the front opening. An acoustic drive signal is supplied to the speaker unit 3 through a wiring 4 from an external amplifier device (not shown).

In the internal space 5 of the cabinet 2, a large number of air-permeable bags filled with porous activated carbon (hereinafter referred to as “activated carbon bags 10”) are stacked on the back side of the speaker unit 3.
Note that the size and number of the bags 10, the arrangement state, the arrangement area, and the like are examples, and are not limited to those illustrated. For example, the activated carbon bag 10 may be arranged with the upper surface of the internal space 5 open, or the arrangement area in the planar direction may be changed.

The activated carbon bag 10 is, for example, non-woven fabric, and the activated carbon does not leak but has sufficient air permeability, and a large number of porous activated carbon 30 as shown in FIG. 2A is packed therein.
The porous activated carbon 30 is, for example, a triporous particle having a particle diameter of about 2 mm (TRIPOROUS \ Triporous is a registered trademark of Sony Corporation).

This porous activated carbon 30 has innumerable three types of pores with a diameter of about 2 mm.
As shown in the enlarged schematic diagram in FIG. 2B, macro holes 31 having an opening diameter of about 1 μm are formed on the surface of the granular material.
Further, the meso hole 32 having an opening diameter of 2 nm to 50 nm is provided on the inner wall portion of the macro hole 31.
Further, microholes 33 having an opening diameter of 2 nm or less are provided on the inner wall portion of the mesopores 32.
A large number of such macro holes 31, meso holes 32, and micro holes 33 are formed in the granular material.
The porous activated carbon 30 has a surface area of about 1000 m ² / g. This is the area of about four sides of a tennis doubles court.

配置 By disposing such porous activated carbon 30 in the internal space 5, sound quality deterioration due to volume reduction of the cabinet 2 due to miniaturization is improved in a small speaker. That is, by using this porous activated carbon 30 as a speaker internal filler, the f0 reduction effect and the standing wave suppression effect of the speaker device 1 are obtained.

Considering that about 80% of air is nitrogen molecules and the molecular diameter is 4 nm, it corresponds to the diameter between the mesopores 32 and the micropores 33. As described above, the porous activated carbon 30 having the macro holes 31, the meso holes 32, and the micro holes 33 has the air being meso-holes 32 at the moment when the air is compressed in the cabinet 2 according to the vibration of the cone of the speaker unit 3. And is attracted toward the micropores 33 and drawn.
By this adsorption, the air density decreases in an instant, and the capacity of the cabinet 2 appears to be equivalently increased, which is considered to reduce f0 and improve the low-frequency acoustic characteristics.

FIG. 3 shows the characteristics of the speaker device not filled with the porous activated carbon 30 (non-filling characteristic 90) and the characteristics of the speaker device filled with the porous activated carbon 30 (filling characteristic 91). The vertical axis represents impedance [Ohm], and the horizontal axis represents frequency [Hz].
As shown in the figure, in the filling characteristic 91 when the porous activated carbon 30 is filled, f0 (minimum resonance frequency) is lower by about 10 Hz than the non-filling characteristic 90, thereby improving the low-frequency reproduction characteristic. It can be said.

When the impedance decreases, the sound pressure often decreases. In this case, the impedance is reduced in the filling characteristic 91.
Therefore, frequency-sound pressure characteristics were measured. FIG. 4 shows the measurement results. The vertical axis represents sound pressure [dBV] and the horizontal axis represents frequency [Hz].
As can be seen from FIG. 4, there is almost no difference in sound pressure between the filling characteristic 91 and the non-filling characteristic 90 in a low frequency range of 100 Hz or less. In other words, it was found that by disposing the porous activated carbon 30 of the embodiment in the internal space 5, f0 can be reduced without lowering the sound pressure, and the output in the low range can be enhanced.

Further, in the non-filling characteristic 90, there is a sudden characteristic change 95 due to the vibration (standing wave) peculiar to the cabinet around about 500 to 2K, but it can also be seen that the characteristic change is suppressed in the filling characteristic 91. . In other words, the frequency characteristics from the middle range to the high range are also stable.
This is presumably because excess reflection is absorbed by the meso hole 32 and the macro hole 31, and the disturbance of the frequency characteristics due to the standing wave is reduced.

FIG. 1B shows a mechanical equivalent circuit of the speaker device 1 (sealed speaker) of the embodiment. here,
Rms: damper of speaker unit 3 + air resistance Cms: ease of movement of the edge of the speaker unit 3 and the damper (= 1 / Kms: reverse of spring constant)
Mms: Weight of vibration system such as cone and bobbin of speaker unit 3 Cmb: Air volume of cabinet 2 Rmb: Resistance of sound absorbing material (porous activated carbon 30) and the like.

The mechanical impedance Zms of the sealed speaker is obtained by the following (Equation 1).

However, “||” represents series.
“Ω” is 2πf0, and f0 can be obtained from the minimum mechanical impedance of the sealed speaker.

From the above, as an effect of the porous activated carbon 30,
-Cmb (the air volume of the cabinet 2) increases and f0 decreases.
・ Rmb (resistance of sound absorbing material, etc.) is slightly increased and standing waves are suppressed.
I understand that.

That is, in the speaker device 1 according to the present embodiment, the use of porous activated carbon having the macro hole 31, the meso hole 32, and the micro hole 33 as a special structure can suppress the standing wave and reduce the f0 resonance frequency. can get. Thereby, even if the speaker device 1 is small, a low sound comes out favorably.

<2. Speaker Device of Second Embodiment>
By the way, it is thought that the performance deterioration of the porous activated carbon 30 occurs due to moisture absorption over time. In the second embodiment, in addition to the improvement of acoustic characteristics by using the porous activated carbon 30 as in the first embodiment, the improvement effect is maintained.

FIG. 5A is an explanatory diagram of the structure of the speaker device 1A according to the second embodiment. In this example, a small sealed active speaker is used.
For example, the cabinet 2 of the speaker device 1 </ b> A has a relatively small rectangular parallelepiped shape, and is configured as a sealed speaker in which the speaker unit 3 is disposed in the front opening and the amplifier unit 6 is disposed in the cabinet 2.
The amplifier unit 6 contains a substrate 7 therein, and a power circuit, a power amplifier amplifier circuit, and the like are formed on the substrate 7.
A speaker wiring 4 is formed between the speaker unit 3 and the amplifier unit 6 (substrate 7), and the acoustic drive signal amplified by the power amplifier amplifier circuit is supplied to the speaker unit 3.
A power cord 8 is derived from the amplifier unit 6 so that, for example, driving power can be obtained from a commercial power source.

In the speaker device 1A, for example, the amplifier unit 6 is provided with a wireless communication unit using a short-range wireless communication method such as Bluetooth (registered trademark), so that an audio signal from an external music player or the like is received. The sound output is performed by receiving and demodulating and supplying the amplified sound drive signal to the speaker unit 3.
Alternatively, the speaker device 1A may be connected to an audio signal wiring (not shown) to input an audio signal from an external music player or the like by wire.

In consideration of heat generated by the amplifier unit 6, the speaker device 1 </ b> A is provided with a heat pipe 20, and a mechanism for releasing the heat to the outside through the heat pipe 20 is formed.
As is well known, the heat pipe 20 is a pipe made of a material having high thermal conductivity, in which a volatile liquid is enclosed. One of the pipes is heated and the other is cooled to move the liquid. Move. In this case, for example, one of the pipes is arranged in contact with or near the amplifier unit 6 so that the liquid inside is heated. The other pipe is provided with a heat radiating fan, a heat radiating fin, or the like as the cooling unit 21.
This prevents the inside of the cabinet 2 from becoming hot due to heat from the amplifier unit 6.

Around the heat pipe 20 thus arranged, the activated carbon bag 10 containing the porous activated carbon 30 shown in FIG.
A part of the activated carbon bag 10 arranged around the heat pipe 20 is schematically shown in FIG. 5B. The activated carbon bag 10 has, for example, an elongated cylindrical shape, and is arranged so that the activated carbon bag 10 is arranged around the heat pipe 20 in a vertical posture.
As a result, the heat generated inside the speaker device 1A is released to the outside by the heat pipe 20, and the heat pipe 20 has an action of drying the porous activated carbon 30.

The main components of the speaker device 1 </ b> A are a power amplifier amplifier circuit, a power supply circuit, and the speaker unit 3 in the amplifier unit 6. These components generate heat during use. In particular, since the heat generated from the power amplifier amplifier circuit is large, it is assumed that the power element is destroyed by high temperature.
Therefore, in the present embodiment, a structure for radiating heat to the outside with the heat pipe 20 is added as a cooling device.
However, the cabinet 2 that was originally small is further reduced in space due to its components. Therefore, an effect equivalent to that obtained by expanding the space by packing the porous activated carbon 30 described in FIG. 2 into the cabinet is obtained. That is, it is the effect of the above-mentioned f0 reduction and standing wave suppression.
However, these effects are gradually lost due to moisture absorption of activated carbon over time. Therefore, by adopting a structure in which the porous activated carbon 30 is wrapped around the heat pipe 20, the porous activated carbon 30 is dried by the heat generated by the heat pipe 20 to avoid moisture absorption. This makes it possible to maintain the effect over a long period of time.
That is, the speaker device 1A that conducts heat to the porous activated carbon 30 and eliminates clogging of the micropores 33 due to moisture adsorption, and has excellent sound quality over a long period of time is realized.
The increase in the volume of the heat pipe 20 is canceled out by the cabinet volume expansion effect by the porous activated carbon 30 without greatly sacrificing the design.

<3. Speaker Device of Third Embodiment>
A speaker device 1B according to a third embodiment will be described with reference to FIG. 6A. Note that parts similar to those in FIG. 5A are denoted by the same reference numerals, and redundant description is avoided.
The speaker device 1B shown in FIG. 6A is also a small sealed active speaker. In this example, a hollow heat sink 25 is used instead of the heat pipe 20 described above, and a mechanism for radiating heat from the heat generating amplifier unit 6 through the hollow heat sink 25 is formed.

The hollow heat sink 25 has a cylindrical shape with a flange portion 25 a at one end, for example, and is disposed in a state where the flange portion 25 a is in contact with the amplifier unit 6.
The opening on the upper end side of the hollow heat sink 25 reaches the upper surface of the cabinet 2.
Around the hollow heat sink 25, the activated carbon bag 10 containing the porous activated carbon 30 of FIG.

In the case of this configuration, the heat generated by the power amplifier amplifier circuit in the amplifier unit 6 is conducted to the hollow heat sink 25, and is transmitted through the hollow heat sink having a large surface area, whereby cooling by heat radiation proceeds. At that time, the porous activated carbon 30 is also heated so that the dry state can be maintained.
The increase in the volume of the hollow heat sink 25 is canceled out by the cabinet volume expansion effect by the porous activated carbon 30 without greatly sacrificing the design.
The hollow heat sink 25 radiates heat by forming a convection due to heat like a chimney, but the activated carbon bag 10 is arranged around so as not to disturb heat radiation.

<4. Speaker Device of Fourth Embodiment>
A speaker device 1C according to a fourth embodiment will be described with reference to FIG. 6B. Note that parts similar to those in FIG. 6A are denoted by the same reference numerals, and redundant description is avoided.
The speaker device 1C of FIG. 6B is also a small sealed active speaker. In this example, a vertically penetrating hollow heat sink 26 is used.
The vertical through-hole type hollow heat sink 26 is formed in a cylindrical shape, and the lower end side is formed so as to penetrate the housing of the amplifier unit 6 and the hole formed in the substrate 7.
Further, the activated carbon bag 10 containing the porous activated carbon 30 is arranged around the upper and lower penetrating hollow heat sink 26 so as to be wound around.

In the case of the vertically penetrating hollow heat sink 26, the cold air in the lower part of the cabinet 2 is taken in by convection and flows upward, and a large convection occurs in the entire speaker device 1C. This allows efficient cooling. Further, the porous activated carbon 30 can also be heated to maintain a dry state.

<5. Summary and Modification>
According to the above embodiment, the following effects can be obtained.
The speaker devices 1A, 1B, and 1C according to the second, third, and fourth embodiments include a heat radiating unit that radiates heat generated by the heat generating unit (a heat pipe 20, a hollow heat sink 25, and a vertically penetrating hollow heat sink. 26) and a porous activated carbon 30 arranged in a position to be dried by heat from the heat radiating section in the cabinet 2.
By arranging the porous activated carbon 30 in the cabinet 2, an effect on acoustic characteristics can be obtained. That is, the effect of reducing the f0 of the speaker and the effect of suppressing the standing wave can be obtained. As a result, even in the case of a small cabinet with a particularly small capacity, it is possible to realize a full acoustic output in a low frequency range and to realize characteristic deterioration due to an unnecessary standing wave.
Such an effect is considered to be the effect of the pores of the porous activated carbon 30, but in that case, the effect is reduced when the pores are blocked by moisture due to moisture absorption of the porous activated carbon. Therefore, the porous activated carbon is dried by the heat dissipation part. As a result, the effect of filling the porous activated carbon can be continuously exhibited.
In particular, even in the case of a small speaker, a sufficient sound output can be obtained and maintained. Further, in the case of a small active speaker, the heat buildup in the cabinet becomes remarkable, but problems such as device malfunctions due to it are also eliminated by heat dissipation.
In the case of the speaker device 1 according to the first embodiment, the heat dissipation part is not provided, but the effect on the acoustic characteristics by the porous activated carbon 30 can be similarly obtained.

The porous activated carbon 30 in the embodiment includes a macropore 31 having an opening diameter of about 1 μm on the surface of the granular material, and has a mesopore 32 having an opening diameter of 2 nm to 50 nm on the inner wall portion of the macropore 31. It was set as the granule provided with the micropore 33 whose opening diameter is 2 nm or less in the inner wall part.
By arranging the porous activated carbon 30 which is a granular material (specifically, triporous particles) having these three types of pores in the cabinet 2, the f0 reduction effect and the standing wave suppression effect were obtained satisfactorily. .
The porous activated carbon 30 has a surface area of about 1000 m ² / g.
In the case of triporous particles, it was confirmed that the f0 reduction effect and the standing wave suppression effect can be obtained satisfactorily in this case.

In the embodiment, an example in which the porous activated carbon 30 is disposed in the cabinet 2 in a state of being packed in a plurality of breathable bags (activated carbon bag 10) has been described.
Since the porous activated carbon 30 is packed in a plurality of sachets and arranged in the internal space 5 of the cabinet 2, the sound pressure is applied to the particles of the porous activated carbon 30 of each activated carbon bag 10 by the gap between the activated carbon bag 10 and the activated carbon bag 10. Is easy to reach. Thereby, the adsorption / desorption of air in the internal space 5 is widely performed with a large number of particles, and the acoustic effect by the porous activated carbon 30 can be promoted.

In the second, third, and fourth embodiments, the heating unit is the amplifier unit 6 disposed in the cabinet 2.
In the case of an active speaker, the speaker unit 3 and the amplifier unit 6 including a substrate 7 on which an amplifier circuit and a power supply circuit are formed are main components for speaker operation. In this case, since the amplifier circuit generates a large amount of heat, it is assumed that the power element is destroyed due to a high temperature. For this reason, a heat pipe 20 and

heat sinks

25 and 26 are provided as a heat radiating part for cooling to radiate heat to the outside. Then, the heat pipe 20 and the heat sinks 25 and 26 can be used as they are as a heat source for drying the porous activated carbon 30. That is, a structure for drying the porous activated carbon 30 can be realized by utilizing a necessary configuration.
The amplifier unit 6 can be considered as a unit including at least a substrate 7 on which a power amplifier amplifier circuit is formed. Although the substrate 7 is stored in the case body, it is also conceivable that the substrate 7 is directly disposed in the internal space 5.

In the second embodiment, the heat radiating portion is the heat pipe 20.
By using the heat pipe 20, the heat accumulated in the cabinet 2 can be dissipated. In this case, by disposing the porous activated carbon 30 (activated carbon bag 10) around the heat pipe 20, the porous activated carbon 30 can be dried by heat convected in the heat pipe 20.
In the third embodiment, the heat radiating portion is the hollow heat sink 25.
By using the hollow heat sink 25, the heat accumulated in the cabinet 2 can be radiated. In this case, by disposing the porous activated carbon 30 (activated carbon bag 10) around the hollow heat sink 25, the porous activated carbon 30 can be dried by the heat of the heat dissipation process.
In the fourth embodiment, the heat radiating portion is a through-type hollow heat sink 26.
That is, a hollow heat sink in contact with the heating element is made to penetrate in the cabinet.
In the case of the vertically penetrating hollow heat sink 26, the cold air in the lower part of the cabinet 2 is taken in by convection and flows upward, and a large convection occurs in the entire speaker device 1C. This allows efficient cooling. And it becomes possible to maintain a dry state by heating the porous activated carbon 30 also.

In each embodiment, the cabinet 2 is a sealed type.
In the case of a sealed speaker, the acoustic effect by the porous activated carbon 30, that is, the f0 lowering effect and the standing wave suppressing effect can be obtained satisfactorily.

The speaker device of the present technology is suitable for a small speaker. In addition to a single speaker device, the present technology is also suitable as a speaker device incorporated in, for example, a television device, a smartphone, a tablet device, a personal computer device, or the like.
The speaker device of the present technology is not limited to a sealed speaker, and can be applied to, for example, a bass reflex speaker device.

It should be noted that the effects described in this specification are merely examples and are not limited, and other effects may be obtained.

In addition, this technique can also take the following structures.
(1)
A heat dissipating part that dissipates heat generated by the heat generating part;
A speaker device, comprising: a porous activated carbon disposed at a position to be dried by heat from the heat radiating portion in a cabinet.
(2)
The porous activated carbon is
Provided with macropores with an opening diameter of about 1 μm on the surface of the granular material,
Provided with mesopores having an opening diameter of 2 nm to 50 nm on the inner wall portion of the macropores,
The speaker device according to (1), wherein the speaker device is a granular body provided with micropores having an opening diameter of 2 nm or less on an inner wall portion of the mesopores.
(3)
The speaker device according to (2), wherein the porous activated carbon has a surface area of about 1000 m ² / g.
(4)
The said activated carbon is the speaker apparatus in any one of said (1) thru | or (3) arrange | positioned in the said cabinet in the state packed with the some air permeable bag.
(5)
The speaker device according to any one of (1) to (4), wherein the heat generating unit is an amplifier unit disposed in the cabinet.
(6)
The speaker device according to any one of (1) to (5), wherein the heat dissipation unit is a heat pipe.
(7)
The speaker device according to any one of (1) to (5), wherein the heat dissipation unit is a hollow heat sink.
(8)
The speaker device according to any one of (1) to (5), wherein the heat dissipating unit is a hollow heat sink that penetrates the cabinet in a vertical direction.
(9)
The speaker device according to any one of (1) to (8), wherein the cabinet is a sealed type.

DESCRIPTION OF

SYMBOLS

1,1A, 1B, 1C ... Speaker apparatus, 2 ... Cabinet, 3 ... Speaker unit, 4 ... Speaker wiring, 5 ... Internal space, 6 ... Amplifier unit, 7 ... Substrate, 8 ... Power cord, 10 ... Activated carbon bag, 20 DESCRIPTION OF SYMBOLS ... Heat pipe, 25 ... Hollow type heat sink, 26 ... Vertical penetration hollow heat sink, 30 ... Porous activated carbon, 31 ... Macro hole, 32 ... Meso hole, 33 ... Micro hole

Claims

A heat dissipating part that dissipates heat generated by the heat generating part;
A speaker device, comprising: a porous activated carbon disposed at a position to be dried by heat from the heat radiating portion in a cabinet.
The porous activated carbon is
Provided with macropores with an opening diameter of about 1 μm on the surface of the granular material,
Provided with mesopores having an opening diameter of 2 nm to 50 nm on the inner wall portion of the macropores,
The speaker device according to claim 1, wherein the speaker device is a granular body provided with micropores having an opening diameter of 2 nm or less on an inner wall portion of the mesopores.
The speaker device according to claim 2 , wherein the porous activated carbon has a surface area of about 1000 m 2 / g.
The speaker device according to claim 1, wherein the porous activated carbon is arranged in the cabinet in a state of being packed in a plurality of breathable bags.
The speaker device according to claim 1, wherein the heat generating unit is an amplifier unit disposed in the cabinet.
The speaker device according to claim 1, wherein the heat radiating unit is a heat pipe.
The speaker device according to claim 1, wherein the heat dissipation unit is a hollow heat sink.
The speaker device according to claim 1, wherein the heat dissipating part is a hollow heat sink that penetrates the cabinet in the vertical direction.
The speaker device according to claim 1, wherein the cabinet is a sealed type.