JP5964485B1 - Speaker system - Google Patents

Abstract

Provided is a speaker system capable of generating sounds from a plurality of diaphragms each sharing a plurality of sound ranges from the same position and reproducing them as a sound with less distortion. A speaker magnetic circuit having a concentric circle for a voice coil gap of a tweeter and a voice coil of a squeker having a diameter larger than that of the tweeter, and a tweeter disposed in the voice coil gap of the tweeter. Voice coil, schoker voice coil arranged in the gap for the voice coil of the schoker, and tweeter diaphragm formed in a convex dome shape with the outer peripheral edge connected to the front edge of the tweeter voice coil And a schoker diaphragm disposed in front of the tweeter diaphragm and having an outer peripheral edge connected to the front edge of the schoker voice coil. A through-hole through which sound waves pass is provided in a region corresponding to the size of the tweeter diaphragm at a position facing the tweeter diaphragm. . [Selection] Figure 2

Description

  The present invention relates to a speaker system in an audio playback device, and more specifically, in a speaker system in which a playback sound range is shared and played back by a plurality of speakers for each sound range. By arranging the plates coaxially and close to each other in the front-rear direction, the position of the sound image is devised so as not to be shifted depending on the frequency, and the reproduction sound is less distorted.

  In an audio reproducing apparatus, there is a speaker system that reproduces a sound in a wide frequency band from a low sound to a high sound by sharing a reproduction sound range for each sound range by a plurality of speakers. The most common is a three-way speaker system consisting of a woofer that reproduces the low frequency range, a squawker that reproduces the mid frequency range, and a tweeter that reproduces the high frequency range, usually in one vertical speaker box (enclosure). To woofer, squawka, and tweeter.

  The higher the frequency, the sharper the directivity, so the squawker and the tweeter are placed at different locations above and below, so that the mid-range sound and the high-frequency sound are emitted from a position that is shifted up and down as seen by the listener. It can't be denied that it has the drawbacks of being felt. In other words, the localization of the sound image seen by the listener swings up and down according to the frequency band. Moreover, according to the vibration plates being arranged at different locations in the vertical direction, the height of the speaker box is increased accordingly, and the size of the speaker box must be increased. In addition, since the directivity of the sound in the low frequency range is not sharp, the position of the sound source does not matter much.

  Among the prior arts, there can be seen an invention in which a plurality of speakers that are responsible for reproducing sounds in different frequency bands are arranged on the same axis so that the localization of the sound image of the sound source does not shift. Although all the techniques are disclosed in -4, each of the techniques also includes a diaphragm, a voice coil, and a magnetic circuit in a space in front of one speaker including the diaphragm, a voice coil, and a magnetic circuit. A configuration in which different speakers with different sizes are arranged is employed, and so-called separate speakers are merely arranged in the front-rear direction. For this reason, the structure must be bulky. In addition, although arranged on the same axis, the position is shifted to the extent that it cannot be ignored in the front-rear direction. In particular, in the middle and high sound region, sound image localization is also hindered in terms of the phase of the reproduced sound.

JP 2005-277874 A JP 2005-303484 A JP 2009-5180 A JP 2012-182773 A

  Provided is a speaker system that can generate sound from a plurality of diaphragms that respectively share a plurality of sound ranges from the same position and that can be reproduced as a sound with less distortion.

  In order to solve the above-described problems, a speaker system according to the present invention includes a first voice coil gap and a second voice coil gap having a larger diameter than the first voice coil gap in the same plane. A speaker magnetic circuit, a first voice coil disposed in the first voice coil gap, a second voice coil disposed in the second voice coil gap, and a front A first diaphragm having an outer peripheral edge connected to the front edge of the first voice coil, and an outer peripheral edge formed on the front voice dome. A second diaphragm connected to the front edge and disposed in front of the first diaphragm, wherein the second diaphragm is first at a position facing the first diaphragm. Equivalent to the size of the diaphragm The range of the region waves through hole is provided for passing that, characterized in that.

  In the speaker system according to the present invention, when a set of a plurality of small holes is provided in a region around the through-hole through which the sound wave provided in the second diaphragm passes, the sound generation from the first diaphragm is blocked. Since it reduces, it is suitable. Moreover, since the fall of the bending rigidity as the whole dome shape is suppressed in the part which continues around the small hole, it is suitable also in the meaning which ensures the piston motion of a diaphragm. In that case, when the set of a plurality of small holes is more densely distributed closer to the central portion of the region and coarsely distributed further away from the central portion, the passage of sound waves from the first diaphragm and the second This is more preferable in that the bending stiffness of the diaphragm is maintained. Further, if a breathable mesh sheet having a mesh smaller than the diameter of the small hole is attached to the rear surface of the second diaphragm provided with the through hole and the plurality of small holes, the bending stiffness of the entire dome shape is reduced. Is more preferable in terms of securing

  Further, in the speaker system of the present invention, the first diaphragm is a plate-like member formed with beryllium as a main component and having a thickness of 30 to 100 μm, and the second diaphragm is mainly composed of magnesium. A plate having a three-layer structure in which a front layer and a rear layer each having a thickness of 5 to 50 μm formed by using beryllium as a main component are laminated on the front and rear surfaces of an intermediate layer formed as an element and having a thickness of 20 to 100 μm, respectively. When configured as a shaped member, the piston movement of the diaphragm can be ensured, so that a suitable speaker system can be realized. In this case, the diameter of the first diaphragm having a convex dome shape is preferably in the range of 20 to 35 mm, and the diameter of the second diaphragm having a convex dome shape is 140 to 180 mm. The range of is preferable.

  According to the present invention, since the diaphragms having different frequency bands in the speaker system are arranged coaxially and in the front-rear direction as a convex dome shape, the sound images of these different bands can be heard from a shifted position. It is possible to eliminate the fluctuation of the sound image of the reproduced sound. Further, by forming the dome shape, the piston movement of both diaphragms is ensured, and a sound with less distortion can be reproduced.

1 is a front view of a speaker system according to an embodiment of the present invention. It is sectional drawing in the II-II line | wire (bending in the location of a central axis) of FIG. It is sectional drawing in the III-III line of FIG. It is a figure which shows the outline of the frequency characteristic of the 3 way speaker system using the speaker system by embodiment of this invention.

  Hereinafter, a speaker system realized as a combination of a squawker for reproducing mid-range sounds and a tweeter for reproducing high-frequency sounds will be described as an embodiment of the present invention with reference to the drawings. FIG. 1 is a front view of a speaker system in which a squawker and a tweeter are combined, and FIG. 2 is a cross-sectional view taken along the line II-II (bent at the central axis) in FIG.

  First, the magnetic circuit of the speaker system of this embodiment will be described. The central magnetic pole member 11 has a cylindrical magnetic pole portion 11a for forming a voice coil gap for a tweeter at the front end portion (left end portion in FIG. 2), and is integrated integrally while gradually increasing in diameter behind it. An energizing coil 19 for generating magnetic flux of the magnetic circuit is wound around the large-diameter portion 11b. An annular plate-shaped intermediate magnetic pole member 12 is supported by the support member 15 with respect to the central magnetic pole member 11 radially outward of the magnetic pole portion 11a. A tweeter voice coil gap 25 is formed between the magnetic pole portion 11 a of the central magnetic pole member 11. An annular plate-shaped inner ring portion 13 a of the outer yoke member 13 is provided facing the outer ring portion 12 b on the outer side of the intermediate magnetic pole member 12 in the radial direction. Between the inner annular portion 13a and the outer annular portion 12b of the intermediate magnetic pole member 12, a voice coil gap 35 for a squawker having a diameter larger than that of the tweeter voice coil gap 25 is formed. The outer rear portion 13b of the outer yoke member 13 has a cylindrical shape, and a disc-shaped rear yoke member 14 is connected to the rear (right side in FIG. 2). A central portion of 14 is connected to the back surface of the large diameter portion 11 b of the central magnetic pole member 11. As a result, the central magnetic pole member 11, the intermediate magnetic pole member 12, the outer yoke member 13, and the rear yoke member 14 are concentrically arranged in the same plate surface with the tweeter voice coil gap 25 and the squawker voice coil gap 35 in series. A speaker magnetic circuit having a shape is formed.

  In the illustrated embodiment, a configuration using an electromagnet in which the excitation coil 19 is wound around the central magnetic pole member 11 is employed as a magnetomotive force source for generating magnetic flux of the magnetic circuit. Instead, the central magnetic pole member 11 itself is used instead. Of course, a permanent magnet is also possible. However, the configuration with the electromagnet seems to be convenient for optimal design while changing the magnetic flux density in the experimental stage of design, and also when using the speaker system as an audio set, It seems convenient to set the speaker characteristics to the intentional characteristics according to the excitation current.

  In the tweeter voice coil gap 25, a tweeter voice coil bobbin 22 around which a tweeter voice coil 23 is wound is positioned and supported with respect to the intermediate magnetic pole member 12 by a tweeter damper 24. 25 is arranged so as to be movable in the front-rear direction (left-right direction in FIG. 2) in a suspended state. To the front edge of the tweeter voice coil bobbin 22, an outer peripheral edge 21c of a tweeter diaphragm 21 formed in a convex dome shape is connected. The tweeter diaphragm 21 vibrates in accordance with the audio current flowing through the tweeter voice coil 23 and emits sound forward (leftward in FIG. 2). The tweeter diaphragm 21 is a Be thin film with a thickness of 65 μm, and is formed in a convex dome shape with a diameter of 26 mm forward. In the experiments by the inventors, the thickness of Be was practical in the range of 30 to 100 μm, and the dome-shaped diameter was in the range of 20 to 35 mm.

  In the voice coil gap 35 for the squawker, the voice coil bobbin 32 for the squawker around which the voice coil 33 for the squawker is wound is positioned and supported with respect to the outer yoke member 13 by the damper 34 for the squawker. 35 is arranged so as to be movable in the front-rear direction (left-right direction in FIG. 2) in a suspended state. Connected to the front edge of the voice coil bobbin 32 for the squawker is an outer peripheral edge 31c of a diaphragm 31 of the squawker formed in a convex dome shape. In response to the voice current flowing through the voice coil 33 for the squawker, the diaphragm 31 of the squawker vibrates and emits sound forward (to the left in FIG. 2). The squawker diaphragm 31 is made of a thin film of Be having a thickness of 15 μm on the front surface of an intermediate layer made of a thin film of a material having a main component of Mg having a thickness of 60 μm (named AZ91D containing 9% Al). A three-layer structure in which a back layer made of a Be thin film having a thickness of 15 μm is stacked on the back surface of the intermediate layer, and formed into a convex dome shape with a diameter of 160 mm in the shape of a die diaphragm. . Mg containing 9% Al has not only good workability but also moderately large internal friction, so that it has a damping effect and contributes to suppressing the divided resonance vibration and causing the diaphragm 31 to perform a piston motion. . In the experiments of the inventors, the thickness of the intermediate layer is in the range of 20 to 100 μm, the thickness of the front layer and the back layer is in the range of 5 to 50 μm, and the diameter of the dome shape is 140 It was practical in a range of ˜180 mm.

  As another embodiment, when a structure and a manufacturing method of an appropriate diaphragm usable for the speaker system of the present invention were searched, a diaphragm having a three-layer structure manufactured by the manufacturing method according to the invention of Japanese Patent No. 5324886, It was confirmed that the diaphragm can be suitably used as a diaphragm for a squawker instead of the diaphragm having the three-layer structure described in the above embodiment.

  As shown in FIG. 1, the diaphragm 31 of the squawker is provided with a through hole 31 o through which sound waves are transmitted in a region corresponding to the size (diameter) of the diaphragm 21 of the tweeter. In FIG. 2, the diaphragm 31 of the squawker is drawn in an end view, and the portion of the through hole 31o is drawn by a thin line. Further, as shown in FIG. 1, the diaphragm 31 of the squawker is provided with a plurality of small holes 31 h in a region around the through hole 31 o, and the vibration of the squawker with respect to the sound emitted from the diaphragm 21 of the tweeter. Consideration is made to reduce the shielding action by the plate 31 even slightly. The small holes 31h are more densely distributed closer to the central portion, and are distributed more coarsely further from the central portion. Furthermore, although not shown, the diaphragm 31 of the squawker has an air-permeable mesh structure cloth (cotton, chemical fiber) that is coarse to the extent of gauze in a region where the through holes 31o and the plurality of small holes 31h exist. Etc.) is preferable because it compensates for the strength reduction due to the formation of the through holes 31o and the small holes 31h, and can be expected to suppress the divided vibration by appropriate damping, and also helps prevent the intrusion of dust.

Further, as shown in FIG. 2, a long hole is formed from the front surface around the central axis of the central magnetic pole member 11 behind the diaphragm 21 of the tweeter, and a widened round hole is provided near the rear surface. The tweeter back cavity 11v is formed. Glass wool is packed in the back cavity 11v. A mounting frame 41 is provided so as to cover the entire magnetic circuit from the rear, and a space 41v is formed between the back yoke member 14 and the mounting frame 41, and the intermediate magnetic pole member 12 has a space inside the magnetic circuit. A through hole 12h is formed toward the space 41v, and the rear yoke member 14 is formed with a through hole 14h toward the space 41v. The space inside the magnetic circuit and the space 41v inside the mounting frame 41 are combined. And forming a squawker back cavity. Similarly, the space 41v is filled with glass wool. The back cavity of the tweeter and the back cavity of the squawker are provided independently from each other in order to avoid interference of atmospheric pressure fluctuations caused by mutual vibration.

Next, the magnetic shunt member for the voice coil gap will be described. Figure 3 is a cross-sectional view that put the line III-III in FIG. 1, this figure is a magnetic shunt member 16b of the magnetic shunt members 16a and squawker voice coil gap 35 of the voice coil gap 25 tweeter Illustrated. The magnetic shunt member 16a spans the voice coil gap 25 of the tweeter and shorts the magnetic circuit from the intermediate magnetic pole member 12 to the central magnetic pole member 11. In this embodiment, the magnetic shunt member 16a has four locations in the circumferential direction (FIG. 1). (See) The magnetic field strength of the tweeter voice coil gap 25 is adjusted to an appropriate value. The magnetic shunt member 16b spans the voice coil gap 35 of the squawker and shorts the magnetic circuit from the intermediate magnetic pole member 12 to the outer yoke member 13. In this embodiment, eight magnetic shunt members 16b are arranged in the circumferential direction (FIG. 1). Reference) is provided, and the magnetic field strength of the voice coil gap 35 of the squawker is adjusted to an appropriate value. When finished as a product, a magnetic shunt member may be provided only on the tweeter voice coil gap and the schoker voice coil gap where the magnetic flux density is too strong to the extent that adjustment is required.

  In the embodiment described above, both the tweeter and the squawker are formed in a dome shape that is convex forward with a light and highly rigid material, and the outer peripheral edge is driven by a voice coil, thereby vibrating the diaphragm. Since the plate moves its piston while maintaining its shape, it is possible to reproduce sound with less distortion. Furthermore, since the tweeter and the squawker radiate sound from the same axial position and from substantially the same position in the front-rear direction, the sound image can be expected to be reproduced without shifting according to the frequency band as viewed from the listener. Further, since the tweeter and the squawker are made as one unit, the size of the speaker box can be small.

  FIG. 4 is a diagram showing an outline of frequency characteristics for an example of a three-way speaker system configured by combining a speaker system according to an embodiment of the present invention with a separately designed woofer. The tweeter and the squawker according to the embodiment of the present invention are responsible for reproducing sounds in the range of 3 kHz to 50 kHz (Pt) and 150 Hz to 3 kHz (Ps), respectively, and the range of 30 Hz to 150 Hz (Pw) in a separate woofer. Is responsible for playing the sound.

DESCRIPTION OF SYMBOLS 11 ... Central magnetic pole member, 11a ... Magnetic pole part, 11b ... Large diameter part, 11v ... Back cavity, 12 ... Intermediate magnetic pole member, 12a ... Inner ring part, 12b ... Outer ring part, 12h ... Through-hole, 13 ... outer peripheral yoke member, 13a ... inner annular part, 13b ... outer rear part, 14 ... rear yoke member, 14h ... through hole, 15 ... support member, 16a, 16b ... magnetic shunt member, 19 ... exciting coil, 21 ... Tweeter diaphragm, 22 ... tweeter voice coil bobbin, 23 ... tweeter voice coil, 24 ... tweeter damper, 25 ... tweeter voice coil gap, 31 ... skoker diaphragm, 31o ... through hole, 31h ... small hole 32 ... Scoker voice coil bobbin, 33 ... Scoker voice coil, 34 ... Schoker damper, 35 ... Schoker voice coil gap, 41 Mounting frame.

Claims (5)

A speaker magnetic circuit having a first voice coil gap and a second voice coil gap having a larger diameter than the first voice coil gap in a concentric manner in the same plate surface;
A first voice coil disposed in the gap for the first voice coil;
A second voice coil disposed in the gap for the second voice coil;
A first diaphragm formed in a dome shape convex forward and having an outer peripheral edge connected to the front edge of the first voice coil;
A second diaphragm that is formed in a forward convex dome shape and has an outer peripheral edge connected to the front edge of the second voice coil and disposed in front of the first diaphragm;
Said second diaphragm, said first hole of acoustic waves in the area of the range corresponding to the magnitude of the first diaphragm passes is provided at a position facing the diaphragm Rutotomoni, of the through holes A speaker system comprising a set of a plurality of small holes in a surrounding area . The speaker system according to claim 1, wherein
The speaker system is characterized in that the plurality of small holes are more densely distributed closer to the central portion and coarsely distributed further from the central portion in the region. The speaker system according to claim 1 , wherein
A breathable mesh sheet having a mesh smaller than the diameter of the small holes is attached to the back surface of the region of the second diaphragm provided with the through holes through which the sound waves pass and a set of the plurality of small holes. The speaker system characterized by becoming. The speaker system according to any one of claims 1 to 3 ,
The first diaphragm is a diaphragm formed with beryllium as a main component, and is a plate member having a thickness of 30 to 100 μm. The second diaphragm has magnesium as a main component. A plate-shaped member having a three-layer structure in which a front layer and a back layer each having a thickness of 5 to 50 μm formed by using beryllium as a main component are laminated on the front and back surfaces of the formed intermediate layer having a thickness of 20 to 100 μm. The speaker system characterized by being. The speaker system according to claim 4 , wherein
The first diaphragm has a forward dome-shaped diameter of 20 to 35 mm, and the second diaphragm has a forwardly convex dome-shaped diameter of 140 to 180 mm. Speaker system.

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