JP2008048176A - Speaker apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speaker apparatus which improves sensitivity of a low-pitched sound area, reduces whistling sound, specially is a small size, and is excellent in reproduction characteristics of a low-pitched sound. <P>SOLUTION: While a bass reflection duct 15 is connected so as to pull out from a backboard of a cabinet 10; a part of the end side of the bass reflection duct 15 is curved, guided into the cabinet 10 again, penetrated, and connected to an opening of a front face side of a baffle plate 11. Moreover, cross sections of an ingress 16 of the bass reflection duct 15 and an egress 17 gradually become small in proportion to approach an intermediate part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a speaker device, and more particularly to a speaker device in which a speaker unit is mounted in a housing.

  In a speaker device using a small speaker unit, the sound output from the front and the sound output from the rear are in opposite phases particularly in a low sound range. Accordingly, the sounds in the low frequency range cancel each other out, so that there is a tendency for low frequencies to be difficult to produce, and only high sounds are produced.

  On the other hand, in a sealed speaker device in which the back side of the housing is sealed, the sound of the reverse phase from the back side of the speaker unit is not output, so the low-frequency sound coming from the front is not canceled. Therefore, in this type of sealed speaker device, not only high sounds but also low sounds are emitted.

  In order to enable the bass to be reinforced with a small speaker, bass reflexes such as those disclosed in Japanese Utility Model Publication Nos. 63-30088, 56-145183, 58-173988, etc. Type speaker devices have been proposed. The bass reflex type speaker device has a bass reflex duct, and the bass reflex duct reverses the phase of the sound emitted from the back side of the speaker unit, thereby superimposing the sound emitted from the front, thereby enhancing the reproduction of the low frequency range in particular. It is intended to plan. Here, phase inversion is performed at the resonance frequency set by the bass reflex duct, so that the sound pressure of the bass is improved and the bass is widened. Accordingly, the bass reflex type is widely used as an acoustic improvement particularly for enhancing bass. Bass reflex type bass enhancement is widely used because it can be constituted by a casing and a bass reflex port, and is inexpensive and has a high effect. Here, the bass reflex type speaker device reverses the phase of the sound emitted to the back of the speaker in the low frequency range by the resonance of the compliance (volume) of the housing and the mass (equivalent mass) of the bass reflex duct, and the front of the speaker unit. By superimposing on the sound radiated from the side, the sound pressure in the low range is improved.

  In particular, when reproducing sound up to a sufficiently low band in the low sound range with a small casing, it is necessary to set the resonance frequency of the bass reflex low. There are three methods for setting the resonance frequency of the bass reflex low. The first method is to enlarge the housing. The second method is to reduce the area of the bass reflex duct. The third method is a method of increasing the length of the bass reflex duct.

  Of the above three methods, the method of enlarging the first housing is not appropriate for reducing the size of the speaker device and improving the bass. As for the method of reducing the area of the second bass reflex duct, if the area of the bass reflex duct is reduced, the acoustic resistance increases, so the output in the low frequency range decreases and the wind noise increases. On the other hand, the method of lengthening the third bass reflex duct is an excellent method.

  FIG. 1 shows a conventional bass reflex speaker device having a long bass reflex duct. Here, the speaker unit 3 is attached to the circular opening 2 on the front surface side of the housing 1, and the bass reflex duct 4 is attached to the bottom surface portion of the housing 1. Here, the bass reflex duct 4 is a reciprocating path, which increases its overall length.

  In the configuration shown in FIG. 2, the bass reflex duct 4 disposed in the housing 1 below the speaker unit 3 has a vertical portion and a horizontal portion, thereby lengthening the length. 3, the upright bass reflex duct 4 is arranged in the speaker unit 3 of the housing 1, and the length of the bass reflex duct 4 is increased depending on the dimension in the height direction.

  In any case, the cross-sectional area of the inlet portion or outlet portion of the bass reflex duct 4 is abruptly changed. Therefore, when the bass reflex duct 4 is resonated at a particularly low frequency, wind noise is generated. In addition, if the bass reflex duct 4 is configured in the housing 1, it is necessary to limit the length or to rapidly turn the bass reflex duct 4. FIG. 4 shows a structure in which two bass reflex ducts 4 and 5 having different diameters are used and a large-diameter bass reflex duct 5 is attached so as to cover from the inlet side to the middle portion of the bass reflex duct 4. With such a bass reflex duct composed of a folded duct, for example, the resonance frequency of the bass reflex can be set to about 70 Hz.

  An example of the frequency characteristics of such a speaker system is shown in FIG. Here, for example, a wind noise is generated in a low frequency range of 100 Hz or less, which obstructs the reproduced sound, which makes it difficult to reproduce high-quality low sound. Here, the wind noise is a sound generated when air passes through a narrow passage. In order to prevent the generation of wind noise, it is necessary to increase the resonance frequency of the bass reflex or to suppress the output so that the wind noise is not noticeable. The bass could not be played.

As a method for reducing wind noise, there is a method using a passive radiator instead of the bass reflex duct. This method is more costly than the bass reflex duct, and the characteristic is that the mechanical resistance component of the passive radiator is large. Therefore, the resonance Qo (resonance sharpness) is lower than that of the bass reflex type, and the bass correction effect is reduced. There is a disadvantage that the efficiency becomes worse.
Japanese Utility Model Publication No. 63-30088 Japanese Utility Model Publication No. 56-145183 Japanese Utility Model Publication No. 58-173988

  An object of the present invention is to provide a speaker device in which the output in the low sound range is particularly enhanced.

  Another object of the present invention is to provide a loudspeaker device in which a bass reflex duct is configured to be long, thereby enhancing a low sound range.

  Still another object of the present invention is to provide a small speaker device including a bass reflex duct having a large cross-sectional area.

  Still another object of the present invention is to provide a speaker device in which the acoustic resistance is reduced by reducing the flow velocity of the air passing through the bass reflex duct.

  Still another object of the present invention is to provide a speaker device in which the sensitivity in the low sound range is increased.

  Still another object of the present invention is to provide a speaker device in which the low frequency range is enhanced and the wind noise is reduced.

  The above-described problems and other problems of the present invention will be made clear by the technical idea of the present invention described below and the embodiments thereof.

The main invention of the present application is a speaker device in which a speaker unit is mounted in a housing.
A bass reflex duct that reverses the phase of the sound emitted from the rear side of the speaker unit, the bass reflex duct being connected to an opening in the wall surface of the housing, and being drawn out of the housing and then entering the housing; And a speaker device, wherein the speaker device is connected to an opening of a front plate of the housing.

  Here, the edge of the inlet portion of the bass reflex duct may be formed of a curved surface or an inclined surface, and the cross-sectional area may gradually become smaller toward the intermediate portion. Further, the edge of the outlet portion of the bass reflex duct may be formed of a curved surface or an inclined surface, and the cross-sectional area may gradually become smaller as it goes to the intermediate portion. The speaker unit may be attached to a baffle plate that covers the front side of the housing, and an outlet portion of the bass reflex duct may be connected to an opening of the baffle plate. Further, an opening may be formed in the rear plate of the housing at a position substantially rearward of the speaker unit, and an inlet portion of the bass reflex duct may be connected to the opening. The bass reflex duct may penetrate the space in the casing in the front-rear direction on the bottom side of the casing.

Another main invention of the present application is a speaker device in which a speaker unit is mounted in a housing.
Having a bass reflex duct in which the cross-sectional area of the inlet portion gradually decreases and the cross-sectional area of the outlet portion gradually increases;
The bass reflex duct is connected to the opening of the wall surface of the casing, pulled out from the casing, enters the casing, and is connected to the opening of the outer plate of the casing to which the speaker is attached. The present invention relates to a speaker device characterized in that the phase of a sound output from the back side of the speaker is inverted by a duct.

  Here, it is preferable that the cross-sectional shape in the axial direction of the inlet portion and the outlet portion of the bass reflex duct is curved, and the curvature radius of the curve is not less than ½ of the radius of the intermediate portion of the bass reflex duct. Further, it is preferable that the inlet portion and the outlet portion of the bass reflex duct are tapered, and the dimension of the maximum diameter portion of the inlet portion and the outlet portion is not less than three times the radius of the intermediate portion of the bass reflex duct. Preferably, the cross-sectional shape in the axial direction of the inlet portion and the outlet portion of the bass reflex duct is curved, and the radius of curvature of the curvature is not less than ½ of the radius of the intermediate portion of the bass reflex duct. Further, it is preferable that the inlet portion and the outlet portion of the bass reflex duct are tapered, and the dimension of the maximum diameter portion of the inlet portion and the outlet portion is not less than three times the radius of the intermediate portion of the bass reflex duct.

  A preferred embodiment of the present invention comprises a speaker unit that constitutes an electroacoustic transducer and a casing that houses the speaker unit. The casing is configured as a bass reflex type, and the duct of the bass reflex extends outward from the casing. The bass reflex duct, which has been reduced to a predetermined cross-sectional area while gradually reducing the cross-sectional area and has a predetermined cross-sectional area, is bent in the middle and penetrates into the casing again. It is designed to be connected in the outward direction (outside air direction) of the housing while gradually increasing the area.

  According to such a configuration, the bass reflex duct can be configured to be long and the cross-sectional area thereof is increased, so that the flow velocity of the air passing through the bass reflex duct is reduced and the acoustic resistance is reduced. For this reason, the sensitivity of the low frequency range increases. Wind noise is also reduced. Furthermore, the change in the cross-sectional area of the joint between the casing and the duct can be configured gently, and the change in the flow velocity in the duct is reduced to reduce wind noise.

  A main invention of the present application is a speaker device in which a speaker unit is mounted in a housing, and includes a bass reflex duct that reverses the phase of sound emitted from the back side of the speaker unit, and the bass reflex duct is connected to an opening on the wall surface of the housing Then, after being pulled out from the casing, it enters into the casing and penetrates to be connected to the opening of the front plate of the casing.

  Therefore, according to such a speaker device, the sound output from the back side of the speaker unit is phase-inverted by the bass reflex duct and superimposed on the sound output from the front side of the speaker unit, thereby enhancing the reproduction sound particularly in the low frequency range. It becomes possible. In addition, since the bass reflex duct once comes out of the casing and then enters the casing again and penetrates through the casing, the length of the bass reflex duct can be made sufficiently long. Moreover, since the cross-sectional area can be enlarged, the flow velocity of the air passing through the duct becomes slow, and the acoustic resistance is reduced. Therefore, the sensitivity in the low sound range is increased and the wind noise is reduced.

  The present invention will be described below with reference to embodiments shown in the drawings. FIG. 6 shows a housing of the speaker device according to the present embodiment, and this housing is a rectangular parallelepiped box made of, for example, a synthetic resin molded body. A front plate of the housing 10 is composed of a baffle plate 11, and a speaker mounting opening 12 is formed in the baffle plate 11. The speaker mounting opening 12 has a substantially square shape, and a screw insertion hole 13 for fixing the speaker is formed around the opening.

  A bass reflex duct 15 is attached to the housing 10. The bass reflex duct 15 has an inlet portion 16 having a trumpet shape and is connected to a circular opening portion of the back plate of the housing 10. The outlet portion 17 of the bass reflex duct 15 also has a trumpet shape and is connected to a circular opening portion below the speaker mounting opening 12 of the baffle plate 11. Here, in particular, the bass reflex duct 15 is attached to the back plate of the housing 10 and then pulled out from the housing 10. The bass reflex duct 15 extends downward, and the lower end side of the vertical portion is curved so that the bottom surface of the housing 10 is curved. The baffle plate 11 of the housing 10 is connected to the circular opening portion below the speaker mounting opening 12.

  The trumpet shape of the inlet portion 16 and the outlet portion 17 of the bass reflex duct 15, and the curvature radius of the curved shape in the cross section as shown in FIG. 8 is not less than ½ of the diameter of the intermediate portion of the bass reflex duct 15. Preferably there is. This is because when the radius of curvature is 1/2 or less, the effect of reducing wind noise due to a sudden change in the cross-sectional area is lost.

  Next, a speaker unit 20 that is combined with the casing 10 and constitutes a speaker device will be described with reference to FIG. The speaker unit 20 is a small speaker and includes a cup-shaped yoke 21, and disk-shaped magnets 23 and 24 are vertically arranged inside the yoke 21. A sub plate 25 is disposed above the upper magnet 23, and a main plate 26 is disposed between the magnets 23 and 24 on both sides. A bobbin 27 is arranged on the outer periphery of the magnets 23 and 24, and a voice coil 28 is wound around the outer periphery of the bobbin 27. Since the voice coil 28 is linked to the magnetic flux in the gap portion between the outer peripheral portions of the sub-plate 25 and the main plate 26 and the yoke 21, the voice coil 28 receives an axial force.

  A dish-shaped frame 30 having an opening at the center is disposed at the upper end of the yoke 21. A diaphragm 32 is attached to the front end side of the frame 30 on the outer peripheral side via an edge 31. The central portion of the diaphragm 32 is coupled to the bobbin 27. A damper 33 having a zigzag cross section is disposed between the bobbin 27 and the frame 30. A dome-shaped center cap 34 is attached to the front end of the bobbin 27.

  Here, when a signal current is passed to the voice coil 28 wound on the bobbin 27, the coil 28 is linked to the magnetic flux generated from the magnets 23 and 24 in the air gap. The wound bobbin 27 receives an axial force, which causes the bobbin 27 to vibrate. The vibration of the bobbin 27 is transmitted to the diaphragm 32, and sound is emitted forward by the diaphragm 32.

  In the bass reflex type speaker device in which the bass reflex duct 15 is provided in the housing 10, the bass reflex speaker 15 is discharged to the back side of the speaker unit 20 due to the resonance of the compliance (volume) of the housing 10 and the mass (equivalent mass) of the bass reflex duct 15. The phase of the sound is reversed, and the sound is emitted from the outlet portion 17 to the front of the baffle plate 11. Therefore, the sound that is phase-inverted by the bass reflex duct 15 and goes forward has the same phase as the sound that goes directly forward from the speaker unit 20, thereby improving the sound pressure at the low-frequency side.

  FIG. 10 particularly shows the characteristics of such a bass reflex type speaker in terms of sound pressure in comparison with the characteristics of a sealed type speaker. In the case of a sealed speaker, since the casing is sealed, sound from the back side of the speaker unit does not leak to the outside, and only sound from the front side of the speaker unit 20 is emitted. Accordingly, the output of the sealed speaker particularly in the low sound range is lowered. On the other hand, in the case of the bass reflex type, it is shown that the sound pressure in the low sound range is greatly improved. That is, a portion indicated by a chain line in FIG. 10 is a region where sound pressure is improved.

  Next, a reduction in wind noise due to the trumpet shape or curved shape of the inlet portion 16 and the outlet portion 17 of the bass reflex duct 15 in the speaker device including such a bass reflex duct 15 will be described with reference to FIG. As described above, the bass reflex duct 15 has an inlet portion 16 and an outlet portion 17 having a trumpet shape and a sectional shape as shown in FIG. Therefore, such a curved shape avoids a sudden change in the cross-sectional area at the inlet portion 16 and the outlet portion 17 of the bass reflex duct 15 and reduces wind noise. Here, if the inlet portion 16 and the outlet portion 17 are straight and wind noise is generated in these portions, the bass reflex duct 15 emits wind noise as indicated by a chain line in FIG. However, according to the structure in which the cross-sectional shapes of the inlet portion 16 and the outlet portion 17 are curved as in the present application, since the wind noise is reduced, a synthesized sound as shown by a solid line in FIG. Will be demonstrated.

  FIG. 12 shows a result of measuring a frequency characteristic of a speaker device having the following specifications.

1. Housing volume 390cc (excluding duct part)
Method Bass reflex type Equivalent mass of duct Approx. 1.9g (φ14 x 200mm)
2. Speaker unit Diameter Outer diameter 48mm
Diaphragm Cone paper made in Japan Magnetic circuit Inner magnet type double magnet fo (minimum resonance frequency): 115Hz
a (effective vibration radius of vibration system): 1.85 cm
md (equivalent mass of vibration system): 1.2 g
Qo (resonance sharpness): 0.45
As described above, the speaker according to the present embodiment includes the speaker unit 20, the housing 10, and the bass reflex duct 15. The bass reflex duct 15 is extended outward from the housing space at the rear of the speaker unit 20 of the housing 10. The joint between the housing 10 and the bass reflex duct 15 in the outward direction is configured so that the cross-sectional area gradually decreases. Then, the duct extending in the outward direction and having a constant cross-sectional area is bent by a large arc and enters the interior space of the housing 10 again to penetrate therethrough. The bass reflex duct 15 that penetrates is opened and connected to the baffle plate 11. The bass reflex duct 15 is configured so that the cross-sectional area of the inlet portion 16 and the outlet portion 17 gradually increases.

  According to such a configuration, since the bass reflex duct 15 can be particularly long, the cross-sectional area can be widened, and the flow velocity of the air passing through the bass reflex duct 15 is slowed to reduce acoustic resistance. Accordingly, the sensitivity in the low sound range is particularly increased (see FIG. 12). Further, since the cross-sectional area of the bass reflex duct 15 is increased, wind noise is reduced. In addition, the change in the cross-sectional area of the joint between the casing 10 and the bass reflex duct 15 becomes gradual, which reduces the change in the flow velocity in the bass reflex duct 15 and reduces wind noise.

  In such a speaker device, in particular, the cross-sectional shape of the bass reflex duct 15 for reversing the phase of the low frequency sound emitted from the back side of the speaker unit 20 is a circular shape as shown in FIG. 13A. It is not always necessary, and for example, it may have a rectangular cross section as shown in FIG. 13B. Alternatively, as shown in FIG. 13C, it may have a substantially rectangular cross section with a curved corner.

  Also, the cross-sectional shapes of the inlet portion 16 and the outlet portion 17 of the bass reflex duct 15 do not necessarily have the curved cross-sectional shape as shown in FIG. 8, and may have a tapered shape as shown in FIG. That is, the inlet portion 16 connected to the back plate of the housing 10 of the bass reflex duct 15 may be tapered, and the outlet portion 17 connected to the baffle plate 11 may be tapered. Here, the diameter D of the maximum diameter portion of the inlet portion 16 and the outlet portion 17 is preferably set to a value that is three times or more the radius R of the straight portion that is an intermediate portion of the bass reflex duct 15. This is because the effect of reducing wind noise at the inlet portion 16 and the outlet portion 17 is not sufficiently exhibited when the value of D is three times or less of R.

  Although the present invention has been described above with reference to the illustrated embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea of the present invention. For example, the speaker unit 20 disposed in the housing 10 does not necessarily have to be an internal magnet type double magnet type speaker as shown in FIG. 9, and various types of speakers can be used. In addition, with respect to the outward drawing size and the like of the bass reflex duct 15 attached to the housing 10, the length and diameter can be appropriately changed in order to adjust the resonance frequency for phase inversion.

  The present invention can be applied to a speaker device that is particularly compact and has improved sound pressure in the low frequency range.

It is a longitudinal cross-sectional view which shows the conventional bass-reflex type speaker apparatus. It is a longitudinal cross-sectional view of another conventional bass reflex type speaker device. It is a longitudinal cross-sectional view of another conventional bass reflex type speaker device. It is a longitudinal cross-sectional view of another conventional bass reflex type speaker device. It is a graph which shows the frequency characteristic of the bass-reflex type speaker apparatus shown in FIG. It is the front view and back view of the housing | casing of the bass-reflex type speaker apparatus which concern on one embodiment of this application. It is a top view of the housing | casing of the speaker apparatus. It is a longitudinal cross-sectional view of the speaker device. It is a longitudinal cross-sectional view of the speaker unit incorporated in this housing | casing. It is a graph when the characteristic of a bass-reflex type speaker device is compared with a sealed speaker device. It is a graph of the sound pressure which shows the influence of a wind noise. It is a graph which shows the frequency characteristic of the speaker apparatus actually manufactured. It is sectional drawing which shows the cross-sectional shape of a bass-reflex duct. It is a longitudinal cross-sectional view of the speaker apparatus which has the bass-reflex duct of a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Circular opening, 3 ... Speaker unit 4, 5 ... Bass reflex duct, 10 ... Housing, 11 ... Baffle plate (front plate), 12 ... Speaker mounting opening, 13 ... Screw insertion hole, DESCRIPTION OF SYMBOLS 15 ... Bass reflex duct, 16 ... Inlet part, 17 ... Outlet part, 20 ... Speaker unit, 21 ... Yoke, 23 ... Magnet (upper), 24 ... Magnet (lower), 25 ... Subplate, 26 ... Main plate, 27 ... Bobbin, 28 ... Voice coil, 30 ... Frame, 31 ... Edge, 32 ... Diaphragm, 33 ... Damper, 34 ... Center cap

Claims (9)

In a speaker device in which a speaker unit is mounted in a housing,
A bass reflex duct that reverses the phase of the sound emitted from the rear side of the speaker unit, the bass reflex duct being connected to an opening in the wall surface of the housing, and being drawn out of the housing and then entering the housing; And a speaker device, wherein the speaker device is connected to the opening of the front plate of the housing.   The speaker device according to claim 1, wherein an edge of the inlet portion of the bass reflex duct is formed of a curved surface or an inclined surface, and the cross-sectional area gradually decreases as it goes to the intermediate portion.   The speaker device according to claim 1, wherein an edge of an outlet portion of the bass reflex duct is configured by a curved surface or an inclined surface, and a cross-sectional area gradually decreases as it goes to an intermediate portion.   2. The speaker device according to claim 1, wherein the speaker unit is attached to a baffle plate that covers a front side of a housing, and an outlet portion of the bass reflex duct is connected to an opening of the baffle plate.   The speaker device according to claim 1, wherein an opening is formed in a rear plate of the housing at a position substantially rearward of the speaker unit, and an inlet portion of the bass reflex duct is connected to the opening.   The speaker device according to claim 1, wherein the bass reflex duct penetrates a space in the casing in the front-rear direction on the bottom side of the casing. In a speaker device in which a speaker unit is mounted in a housing,
Having a bass reflex duct in which the cross-sectional area of the inlet portion gradually decreases and the cross-sectional area of the outlet portion gradually increases;
The bass reflex duct is connected to the opening of the wall surface of the casing, pulled out from the casing, enters the casing, and is connected to the opening of the outer plate of the casing to which the speaker is attached. A speaker device characterized in that the phase of a sound emitted from the back side of the speaker is inverted by a duct.   8. An axial cross-sectional shape of an inlet portion and an outlet portion of the bass reflex duct is curved, and a curvature radius of the curve is 1/2 or more of a radius of an intermediate portion of the bass reflex duct. The speaker device according to 1. The inlet portion and the outlet portion of the bass reflex duct are tapered, and the dimension of the largest diameter portion of the inlet portion and the outlet portion is three times or more the radius of the intermediate portion of the bass reflex duct. Item 8. The speaker device according to Item 7.

Images