JP2001136590A - Loudspeaker system and sound reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve input resistance performance by making the shape thin and improve heat radiation characteristics when a passive radiator Kelton type loudspeaker system is made small in size. SOLUTION: A front sealed chamber 106 is formed by fitting a loudspeaker unit 102 and a passive radiator unit 103 composed of an edge, a damper, and a diaphragm to a front baffle 104 and a plate part 108 of the loudspeaker unit 012 is exposed to the outside. Consequently, the passive radiator Kelton type loudspeaker system is made thin, the heat radiation characteristics are improved, and the input resistance performance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker device and a sound reproducing device, and more particularly to a speaker device and a sound reproducing device useful for use in a vehicle.

[0002]

2. Description of the Related Art With the spread of digital recording sources such as compact discs, MDs, and DVDs, there is a need for an audio reproducing apparatus capable of sufficiently reproducing these broadband sources. In particular, in order to improve the low-frequency reproduction capability even when the size of the speaker device is reduced, conventionally, the low-frequency reproduction capability is improved by using a passive radiator type Kelton system in which a speaker unit and a passive radiator unit are combined with the speaker device. Attempts are being made.

A conventional passive radiator type Kelton type speaker device which improves the low frequency reproduction capability even when the speaker device is miniaturized will be described below. FIG.
FIG. 1 is an exploded perspective view of a conventional passive radiator type Kelton type speaker device. In FIG. 13, reference numeral 1101 denotes a passive radiator unit that actually performs sound reproduction. A speaker unit 1102 drives the passive radiator unit. Reference numeral 1103 denotes a front baffle to which the passive radiator unit 1101 is attached and forms a part of the speaker box. Reference numeral 1104 denotes a front closed chamber for coupling the sound output of the speaker unit 1102 to the passive radiator unit 1101. 1105
Is a speaker unit 1102, and the front closed room 1
This is a sub-baffle plate that spatially divides the back chamber 104 from the rear closed chamber. Reference numeral 1106 denotes a cabinet constituting the speaker box.

The operation of the conventional passive radiator type Kelton type speaker device configured as described above will be described below. As shown in FIG. 13, the sound reproduction output radiated from the front of the speaker unit 1102 attached to the sub-baffle plate 1105 which spatially divides the front closed chamber 1104 and the rear closed chamber is supplied to the speaker unit 1102 and the front. Front sealed chamber 110 composed of baffle 1103 and sub-baffle plate 1105
By driving the passive radiator unit 1101 attached to the front baffle 1103 via the air in the passive radiator unit 110,
Sound reproduction is performed from step 1. Also, the speaker unit 1
The speaker unit 1102, the front baffle 1103, the sub-baffle plate 1105, and the cabinet 1 do not interfere with the sound reproduction output of the passive radiator unit 1101 from the sound reproduction output radiated from the back of the 102.
It is hermetically sealed by the rear closed chamber constituted by 106.

FIG. 14 is an example of a comparison of low-frequency reproduction characteristics showing the superiority of the conventional passive radiator type Kelton system. In FIG. 14, reference numeral 1201 denotes an output sound pressure frequency characteristic of a closed system. In the closed system, the sound reproduction output on the back of the speaker unit is sealed in the speaker box to avoid interference with the sound reproduction output on the entire surface of the speaker unit. However, reducing the size of the speaker box reduces the compliance with the speaker unit. As a result, as seen from 1201 in FIG. 14, the low-frequency reproduction capability is limited. Reference numeral 1202 denotes a phase inversion type output sound pressure frequency characteristic using a speaker unit and a speaker box of the same type. The phase inversion method is a method in which the sound reproduction output on the back of the speaker unit is resonated at a certain frequency (hereinafter referred to as an anti-resonance frequency) from the inside of the speaker box through a port, and mixed with the sound reproduction output on the front of the speaker unit. The sound reproduction output via this port has the same phase as the sound reproduction output of the speaker unit in the band above the anti-resonance frequency, so the interaction improves the radiation efficiency and extends the lower band reproduction limit compared to the sealed system. Can be. However, the sound reproduction output via this port has an opposite phase to the sound reproduction output of the speaker unit in the ultra-low range, and cancels out. For this reason, in a very low frequency band, a sharp attenuation curve of about -20 dB / oct occurs, so that there is a disadvantage that sufficient heavy bass reproduction cannot be obtained. Reference numeral 1203 denotes an output sound pressure frequency characteristic of a conventional passive radiator type Kelton system using a speaker unit and a speaker box of the same type. The passive radiator type Kelton system resonates the passive radiator unit, the speaker unit, and each closed chamber in the speaker box at a certain frequency similarly to the phase inversion system, and can extend the low-frequency reproduction limit. In addition, since the sound reproduction output of the passive radiator unit and the sound reproduction output of the speaker unit are not mixed even in the very low frequency range, the sound reproduction output similar to that of the closed system is obtained even in the ultra-low frequency band.
A gentle attenuation curve of 12 dB / oct is obtained, and sufficient heavy bass reproduction can be obtained. Further, even if the speaker unit vibrates in the frequency band higher than the specific frequency, the passive radiator diaphragm does not vibrate, so that the low band speaker reproducing device can also have excellent bandpass characteristics.

[0006] As described above, the conventional passive radiator type Kelton system is characterized by the ability to reproduce heavy bass sound due to the gradual attenuation characteristics of the ultra-low range, which is the advantage of the closed system, and the low range reproduction, which is the advantage of the phase inversion system. By combining the advantages of both types, that is, expanding the limits, the ability to reproduce low frequencies is improved.

[0007]

However, the conventional passive radiator type Kelton type speaker device has the following problems.
As described above, it is very effective as a means for improving the low-frequency reproduction capability when the size of the speaker device is reduced, but the inside of the speaker box is sealed by the sub-baffle plate with the front sealed room and the rear sealed room. Due to the special structure of dividing the room into two, the box structure is complicated and it is difficult to reduce the thickness. Also, since the speaker unit is completely stored in the speaker device, the heat radiation characteristics are poor and the input resistance is low.

The present invention solves the problems of the above-described conventional small loudspeaker apparatus such as the passive radiator type Kelton type loudspeaker apparatus, and comprises a speaker unit and a passive radiator unit comprising an edge, a damper and a diaphragm. In addition to having a simple structure in which the front closed chamber is formed by attaching to the front baffle, by exposing the plate portion of the speaker unit, the speaker device is made thinner and the input performance is improved by improving the heat radiation characteristics. The purpose is to:

[0009]

According to the present invention, there is provided a speaker device to which a sound output signal of a power amplifier is connected, a passive radiator unit including an edge, a damper, and a diaphragm. A front baffle having an opening for attaching the speaker unit and the passive radiator unit to form a part of a speaker box and exposing a plate portion of the speaker unit; a cabinet forming the speaker box; the speaker unit and the passive unit A front closed chamber, which is hermetically sealed by a radiator unit, a cushion attached to the front baffle and a magnet portion of the speaker unit, and couples an acoustic output on the back of the speaker unit to the passive radiator unit; Sealed by mosquitoes unit and the front baffle and the cabinet, provided with a rear sealed chamber enclosing the acoustic output of the front surface of the speaker unit,
The speaker unit is arranged in an inverted direction with respect to the passive radiator unit, and a plate portion of the speaker unit is exposed from an opening of the front baffle.

According to this structure, the speaker unit and
A passive radiator unit consisting of an edge, a damper, and a diaphragm is attached to the front baffle to form a simple structure that forms a front closed chamber. By exposing the plate portion of the speaker unit, the thickness of the speaker device is reduced and the heat dissipation characteristics are improved. The input resistance can be improved by the improvement.

Also, in a closed speaker system or a phase inversion speaker system, by exposing the plate portion of the speaker unit, it is possible to improve the input resistance performance by making the speaker system thinner and improving heat radiation characteristics.

When the above-mentioned speaker device is combined with a full-range speaker device, an audio signal having a phase opposite to that of the sound signal to the full-range speaker device is added. On the other hand, the phase relationship can be optimized when the above-mentioned loudspeaker devices having sound outputs of opposite phases in combination are combined.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to claim 1 of the present invention provides a speaker unit to which an acoustic output signal of a power amplifier is connected, a passive radiator unit including an edge, a damper, and a diaphragm; A front baffle having an opening for attaching the passive radiator unit to form a part of the speaker box and exposing a plate portion of the speaker unit, a cabinet forming the speaker box, the speaker unit, the passive radiator unit, and A front closed chamber, which is hermetically sealed by a front baffle and a cushion attached to a magnet section of the speaker unit, and couples an acoustic output on the back surface of the speaker unit to the passive radiator unit; A speaker device which is closed by a baffle and the cabinet, includes a back sealing chamber for sealing an acoustic output on a front surface of the speaker unit, and the speaker unit is arranged in an upside down direction with respect to the passive radiator unit. By attaching a passive radiator unit consisting of an edge, a damper, and a diaphragm to the front baffle, the front baffle is formed to form a simple structure, and by exposing the plate portion of the speaker unit, the thickness of the speaker device is reduced and the heat dissipation characteristics are reduced. Has the effect of improving the input resistance performance due to the improvement of.

According to a second aspect of the present invention, a speaker unit to which an acoustic output signal of a power amplifier is connected, a passive radiator unit including an edge, a damper, and a diaphragm, and the speaker unit and the passive radiator unit are mounted. Form part of the speaker box,
A front baffle having an opening for exposing a plate portion of the speaker unit, a cabinet forming a speaker box, a cushion attached to the speaker unit, the passive radiator unit, the front baffle, and a magnet attached to the magnet unit of the speaker unit; Sealed by a sealing bracket,
A front closed chamber for coupling the sound output on the back of the speaker unit to the passive radiator unit, and a back closed by the speaker unit, the front baffle, the cabinet, and the ceiling bracket to seal the sound output on the front of the speaker unit. A speaker device comprising a closed chamber, wherein the speaker unit is disposed in an inverted direction with respect to the passive radiator unit, wherein a frame margin of the speaker unit is small, and the speaker unit includes a speaker unit, an edge, a damper, and a diaphragm. Even if it is not possible to form a front closed chamber simply by attaching it to the front baffle, it is possible to simplify the structure by using a ceiling angle and expose the plate portion of the speaker unit, making the speaker device thinner. It has the effect of improving the resistance to input performance by improving the thermal characteristics.

According to a third aspect of the present invention, there is provided a speaker unit to which an acoustic output signal of a power amplifier is connected, and an opening for mounting the speaker unit to form a part of a speaker box and exposing a plate portion of the speaker unit. A front baffle having an opening and a sound opening, and a cabinet forming a speaker box, wherein the speaker unit and the front baffle seal the sound output on the front of the speaker unit to provide a sound output on the back of the speaker unit. This is a speaker device that reproduces sound, and has an effect of improving the input resistance by exposing the plate portion of the speaker unit upward, thereby making the speaker device thinner and improving heat dissipation characteristics.

According to a fourth aspect of the present invention, there is provided a speaker unit to which a sound output signal of a power amplifier is connected, a port for obtaining a phase-reversed sound output, and a speaker box having the speaker unit and the port attached thereto. A front baffle having an opening for exposing a plate portion of the speaker unit, an acoustic opening, and the port opening, and a cabinet forming a speaker box, and a sound output on the back surface of the speaker unit. The speaker device performs sound reproduction with the sound output of the port, and has an effect of exposing a plate portion of the speaker unit to an upper portion, thereby making the speaker device thinner and improving heat radiation characteristics to improve input resistance.

According to a fifth aspect of the present invention, there is provided the speaker device according to any one of the first to fourth aspects, wherein the rear surface of the plate portion of the speaker unit is provided with irregularities acting as a heat sink. Has the function of further improving the heat radiation characteristics of the device.

According to a sixth aspect of the present invention, there is provided a speaker device according to any one of the first to fourth aspects, wherein a radiation fin is added to the back of the plate portion of the speaker unit. It has the function of further improving.

According to a seventh aspect of the present invention, there is provided a differential amplifier provided before a power amplifier, a microphone for detecting a sound output signal radiated from a speaker unit or a passive radiator unit of a speaker device, and a microphone for detecting the sound output signal. Microphone amplifier for electrically amplifying the amplified signal, power amplifying means for connecting the output signal of the microphone amplifier to the differential amplifier for acoustic feedback, and reproducing the acoustic output signal of the power amplifying means by the speaker device. A sound reproducing device using the speaker device according to any one of claims 1 to 6 as the speaker device, wherein the speaker device is downsized by acoustic feedback control using a microphone. Suppress the rise of the quality factor, which is an issue, and launch the speaker device It has the effect of improving falling characteristics Ri.

The invention according to claim 8 comprises a combination of a full-range loudspeaker device to which an audio signal is added and a low-frequency sound reproduction device. 8. The sound reproducing device according to claim 7, wherein the sound signal having an opposite phase relationship is added, and the low-frequency sound reproducing device is configured to be opposite in structure to the full-range speaker device. When the low-frequency speaker device that outputs a phase sound is combined with the low-frequency speaker device, the phase relationship is optimized.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIGS. 1 and 2 show an exploded perspective view and a sectional view of a speaker device according to Embodiment 1 of the present invention. In FIGS. 1 and 2, reference numeral 101 denotes a power amplifier for amplifying an acoustic input signal. It is. Reference numeral 102 denotes a speaker unit to which the sound output signal of the power amplifier 101 is connected. 103
Is a passive radiator unit comprising an edge, a damper and a diaphragm. 104 is a speaker unit 102
And a front baffle having an opening 104a for mounting a passive radiator unit 103 and a part of a speaker box and exposing a plate portion 108 of the speaker unit 102. Numeral 105 denotes a cabinet constituting a speaker box, and numeral 106 denotes a speaker unit 102, a passive radiator unit 103, a front baffle 104, and a cushion 10 attached above a magnet unit 109 of the speaker unit 102.
9a is a front closed chamber in which the sound output on the back of the speaker unit 102 is coupled to the passive radiator unit 103. 107 is a speaker unit 102,
This is a rear closed chamber which is sealed by the front baffle 104 and the cabinet 105 and seals the sound output on the front of the speaker unit 102. The speaker unit 102 is disposed upside down with respect to the passive radiator unit 103 to constitute a passive radiator type Kelton type speaker device.

The operation of the loudspeaker of the first embodiment configured as described above will be described below.

In the speaker device according to the first embodiment shown in FIGS. 1 and 2, the sound signal from the sound source device or the like is amplified by the power amplifier 101. The acoustic signal whose power has been amplified by the power amplifier 101 is connected to the speaker unit 102 and converted into an acoustic output. The sound output on the back of the speaker unit 102 is based on the speaker unit 102 and the passive radiator unit 103.
And front baffle 104 and speaker unit 10
Since the sound is transmitted to the passive radiator unit 103 through air in the front sealed chamber 106 sealed by a cushion attached above the second magnet unit 109 and an actual acoustic output can be obtained from the passive radiator unit 103, In addition to having a simple structure that does not require a sub-baffle plate, which is indispensable, in addition to exposing the plate portion 108 of the speaker unit 102, the speaker device is made thinner and the heat dissipation characteristics are improved so that the input resistance is improved. Can be improved.

FIG. 12 shows the saturation temperature 1002 of the plate portion 108 of the speaker unit 102 of the speaker device of the first embodiment and the saturation temperature of the plate portion of the speaker unit 1102 of the conventional passive radiator type Kelton type speaker device. Reference numeral 1001 denotes a conventional passive radiator-type Kelton-type speaker device, in which the speaker unit is completely stored in the speaker device, so that heat dissipation characteristics are poor and input resistance is low. By exposing the plate portion of the speaker unit, the heat radiation characteristics of the speaker device can be greatly improved, and the input resistance can be improved.

FIG. 3 is an exploded perspective view of a modification of the speaker device according to the first embodiment. The difference from the first embodiment is that a speaker unit 301 having a small margin is used. In this case, the speaker unit 301 is attached to the front baffle 104 using a ceiling angle 305. Therefore, the acoustic output on the back of the speaker unit 301 is
01, the passive radiator unit 103, the front baffle 104, the ceiling angle 305, and air transmitted to the passive radiator unit 103 via the air in the front sealed room sealed by the cushion attached above the magnet unit 309 of the speaker unit 301, and the passive radiator An actual sound output can be obtained from the unit 103. Even in the case where the frame margin of the speaker unit 301 is small and the speaker unit 301 and the passive radiator unit 103 including the edge, the damper, and the diaphragm cannot be simply formed on the front baffle 104 to form the front closed chamber, the sealing as in this example is possible. By using the angle 305, a simple structure can be obtained. By exposing the plate portion of the speaker unit 301, the input resistance can be improved by making the speaker device thinner and improving the heat radiation characteristics.

FIGS. 4 and 5 are an exploded perspective view and a sectional view of a modification of the speaker device according to the first embodiment. The difference from the first embodiment is that the passive radiator unit 10
In this case, the speaker unit 102 is mounted on the front baffle 402 in the reverse direction, and the sound output on the front of the speaker unit 102 is
2, the front baffle 402 and the cabinet 403, and the sound output on the back of the speaker unit 102 is sealed by the cushion 109a attached above the magnet 109 of the speaker unit 102, and the sound is output through the sound opening 402b of the front baffle 402. Get output. The plate portion 108 of the speaker unit 102 can be exposed from the opening 402a of the front baffle 402, and the input resistance can be improved by reducing the thickness of the speaker device and improving the heat radiation characteristics.

6 and 7 show an exploded perspective view and a sectional view of a modified example of the speaker device according to the first embodiment. The difference from the first embodiment is that a front baffle 503 with a port 502 is used. In this case, the speaker unit 102 is attached to the front baffle 503 in an inverted direction, and the sound output on the front of the speaker unit 102 is a speaker. Unit 102 and front baffle 503
And the cabinet 504 and the port 502 resonate,
At the same time as the resonance sound output is obtained from the port 502, the sound output on the back of the speaker unit 102 is also obtained through the sound opening 503b of the front baffle 503 sealed by the cushion 109a. The plate portion 108 of the speaker unit 102 can be exposed from the opening 503a of the front baffle 503, and the input resistance can be improved by making the speaker device thinner and improving the heat radiation characteristics.

FIG. 8 is a perspective view of a speaker unit of a modified example of the speaker device according to the first embodiment. The difference from the first embodiment is that irregularities 601 acting as a heat sink are provided on the back surface of the plate portion 108 of the speaker unit 102. The unevenness 601 is exposed from the opening at the time of assembly to the front baffle, so that the heat radiation characteristics of the speaker device can be further improved.

FIG. 9 is a perspective view of a speaker unit of a modified example of the speaker device of the first embodiment. The difference from the first embodiment is that a radiation fin 702 is added to the back surface of the plate portion 108 of the speaker unit 102. Radiating fins 702 when assembled to the front baffle
Is exposed through the opening, so that the heat radiation characteristics of the speaker device can be further improved.

FIG. 10 shows a sound reproducing apparatus to which the speaker device according to the first embodiment is applied. In FIG. 10, an acoustic output signal actually radiated from the speaker unit 102 or the passive radiator unit 103 of the speaker device 801 is picked up by a microphone 802, and a sound input signal from a sound source device or the like is added via a microphone amplifier 803. Differential amplifier 80
4 is amplified by the power amplifying unit 805 and supplied to the speaker device 801. As a result, acoustic feedback control for performing correction according to the ambient noise is performed, which is advantageous as a low-frequency sound reproduction device. Therefore, it is possible to suppress the rise of the quality factor due to the miniaturization of the speaker device, and to improve the rising and falling characteristics of the speaker device. Here, the speaker device shown in FIGS. 1 to 9 is used.

FIG. 11 shows an example of use of the low-frequency sound reproduction apparatus described with reference to FIG. In FIG. 11, a sound signal from a sound source device 903 including a sound source device 903a such as a compact disk player, a cassette player, and a tuner, a voltage amplifier 903b, and a power amplifier 903c is reproduced in a full-range speaker device 9 for reproducing mainly in a middle and high frequency range.
02, and is also supplied to the sound reproducing device 901 which is the low-frequency sound reproducing device shown in FIG.
In this combination, the full-range speaker device 90
An embodiment in which a sound signal having a phase opposite to that of the sound signal applied to the sound reproduction device 2 is added to the sound reproduction device 901, so that a sound output having a structure opposite to that of the full-range speaker device 902 is obtained. It is possible to optimize the phase relationship with the sound reproducing device 901 using the one speaker device.

[0033]

As described above, according to the present invention, in the passive radiator type Kelton type loudspeaker device, the loudspeaker unit and the passive radiator unit including the edge, the damper, and the diaphragm are attached to the front baffle to thereby close the front closed chamber. In addition to the simple structure of forming the speaker unit, by exposing the plate portion of the speaker unit, it is possible to improve the input resistance performance by making the speaker device thinner and improving the heat radiation characteristics. Also, in a closed speaker device or a phase inversion speaker device, by exposing the plate portion of the speaker unit, the input resistance can be improved by making the speaker device thinner and improving heat radiation characteristics.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a speaker device according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view showing the speaker device according to the first embodiment;

FIG. 3 is an exploded perspective view showing a modification of the speaker device according to the first embodiment.

FIG. 4 is an exploded perspective view showing a modified example of the speaker device according to the first embodiment.

FIG. 5 is a sectional view showing a modification of the speaker device according to the first embodiment;

FIG. 6 is an exploded perspective view showing a modification of the speaker device according to the first embodiment.

FIG. 7 is a sectional view showing a modification of the speaker device according to the first embodiment;

FIG. 8 is a perspective view showing a modification of the speaker device according to the first embodiment.

FIG. 9 is a perspective view showing a modification of the speaker device according to the first embodiment.

FIG. 10 is an electric block diagram of a sound reproducing apparatus to which sound feedback control is applied using the speaker device according to the first embodiment;

FIG. 11 is a system diagram of the sound reproducing device when the speaker device according to the first embodiment is used as a sound reproducing device dedicated to low frequencies.

FIG. 12 is a comparison diagram of the saturation temperature of the plate part of the speaker unit of the speaker device of the first embodiment and the speaker unit of the conventional passive radiator type Kelton type speaker device.

FIG. 13 is an exploded perspective view showing a conventional passive radiator type Kelton type speaker device.

FIG. 14 is a comparison diagram of low-frequency reproduction characteristics of the speaker device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 101 power amplifier 102 speaker unit 103 passive radiator unit 104 front baffle 104 a opening 105 cabinet 106 front sealed room 107 rear sealed room 108 speaker unit plate portion 109 speaker unit magnet portion 109 a cushion 301 speaker unit 305 ceiling angle 402 front baffle 402 a Opening 402b Sound opening 403 Cabinet 502 Port 503 Front baffle 503a Opening 503b Sound opening 504 Cabinet 601 Unevenness 702 Radiation fin 801 Speaker device 802 Microphone 803 Microphone amplifier 804 Differential amplifier 805 Power amplifier 901 Low-frequency sound reproduction Device 902 Full-range speaker device 903 Sound source device

Claims (8)

[Claims] 1. A speaker unit to which a sound output signal of a power amplifier is connected, a passive radiator unit including an edge, a damper, and a diaphragm, and a part of a speaker box formed by mounting the speaker unit and the passive radiator unit. A front baffle having an opening for exposing a plate portion of the speaker unit, and a cabinet forming a speaker box;
A front sealed chamber that is sealed by the speaker unit, the passive radiator unit, the front baffle and a cushion attached to a magnet unit of the speaker unit, and couples an acoustic output on the back of the speaker unit to the passive radiator unit; A speaker device, comprising: a speaker unit, a rear closed chamber that is hermetically sealed by the front baffle and the cabinet, and seals a sound output on a front surface of the speaker unit, wherein the speaker unit is arranged in an inverted direction with respect to the passive radiator unit. 2. A speaker unit to which a sound output signal of a power amplifier is connected, a passive radiator unit including an edge, a damper and a diaphragm, and a part of a speaker box formed by mounting the speaker unit and the passive radiator unit. A front baffle having an opening for exposing a plate portion of the speaker unit, and a cabinet forming a speaker box;
A front closed chamber that is sealed by the speaker unit, the passive radiator unit, the front baffle, and a cushion and a sealing bracket attached to a magnet unit of the speaker unit, and couples an acoustic output on a back surface of the speaker unit to the passive radiator unit; And a rear closed chamber that is sealed by the speaker unit, the front baffle, the cabinet and the sealing bracket, and seals a sound output on a front surface of the speaker unit, wherein the speaker unit is inverted with respect to the passive radiator unit. The placed speaker device. 3. A speaker unit to which an acoustic output signal of a power amplifier is connected, an opening for attaching the speaker unit to form a part of a speaker box and exposing a plate portion of the speaker unit, and an acoustic opening. A front baffle, and a cabinet forming a speaker box, wherein the speaker unit and the front baffle seal the sound output on the front of the speaker unit, and reproduce sound with the sound output on the back of the speaker unit. Speaker device. 4. A speaker unit to which a sound output signal of a power amplifier is connected, a port for obtaining a phase-reversed sound output, the speaker unit and the port being attached to form a part of a speaker box, and the speaker unit is formed. A front baffle having an opening for exposing a plate portion of the speaker unit, a sound opening and the port opening, and a cabinet forming a speaker box, and reproduces sound with a sound output on the back of the speaker unit and a sound output on the port. Speaker device configured to perform the following. 5. The speaker unit according to claim 1, wherein a concave and convex portion that functions as a heat sink is provided on the back surface of the plate portion of the speaker unit.
The speaker device according to any one of 2, 3, and 4. 6. The speaker device according to claim 1, wherein a radiation fin is added to a back surface of the plate portion of the speaker unit. 7. A differential amplifier provided before a power amplifier, a microphone for detecting an acoustic output signal radiated from a speaker unit or a passive radiator unit of a speaker device, and a signal detected by the microphone is electrically amplified. A microphone amplifier for connecting the output signal of the microphone amplifier to the differential amplifier to perform acoustic feedback, and a sound reproducing device for reproducing the sound output signal of the power amplifier with the speaker device. Claims 1 and 2, wherein the speaker device is
An audio reproducing device using the speaker device according to any one of 3, 4, 5, and 6. 8. A low-frequency sound reproduction device comprising a combination of a full-range speaker device to which an audio signal is added and a low-frequency sound reproduction device, wherein the low-frequency sound reproduction device has a sound having an opposite phase to the sound signal of the full-range speaker device. A sound reproducing device configured to add a signal, wherein the sound reproducing device according to claim 7 is used as the low-frequency sound reproducing device.