JP4597824B2 - Speaker diaphragm, speaker unit having the same, and speaker system - Google Patents

Description

  The present invention relates to a speaker diaphragm, and more particularly to a magnesium alloy diaphragm for a speaker, and a speaker unit and a speaker system having the diaphragm.

  Various materials such as a fiber material such as paper and a polymer material such as plastic have been used as a material for a diaphragm of a cone type speaker for music and sound reproduction. However, since these materials have low rigidity, there is a problem in that they are deformed by an excitation force applied from the voice coil, and so-called divided vibration is likely to occur. As described above, when a divided vibration mode in which the diaphragm is deformed occurs instead of a mode in which the diaphragm is translated without being deformed (pistonic motion), there is a problem in that reproduced sound by the speaker is deteriorated. That is, when the diaphragm oscillates, sound other than the input sound signal is generated, sound of a specific frequency band cannot be reproduced, or conversely, a specific frequency band is emphasized, the reproduced sound is distorted, Problems such as large peaks and dips occur in the reproduction frequency characteristics.

  Japanese Laid-Open Patent Publication No. 7-95686 describes a speaker unit in which ribs are formed on a paper diaphragm to increase rigidity and suppress occurrence of divided vibration. However, if the material of the diaphragm is a fibrous material such as paper or a polymer material such as plastic, it is difficult to sufficiently suppress the occurrence of divided vibration even if the rigidity of the entire diaphragm is increased by attaching ribs, etc. Met.

  Therefore, in order to obtain a diaphragm having higher rigidity, metals such as aluminum and titanium have been used, and in particular, they have been widely used as diaphragms for high-frequency sound reproduction speakers having a relatively small diameter.

JP-A-7-95686

  However, even in the case of a medium / low frequency sound reproduction speaker, even if a high-rigidity metal is used as the material of the diaphragm, the diameter of the diaphragm is relatively large, so that the rigidity of the diaphragm is still insufficient and split vibrations are generated. There is a problem of end. In addition, metal materials such as aluminum and titanium have a high specific strength, which is a ratio of strength to specific gravity, which is advantageous for forming a lightweight and highly rigid diaphragm, but on the other hand, the disadvantage of low internal loss There is. When a divided vibration is generated in a diaphragm formed of a material having a small internal loss, the generated divided vibration is difficult to attenuate, and there is a problem that a large peak occurs in the reproduction frequency characteristic.

  In addition, when a divided vibration occurs in a multi-way system speaker that divides the playback sound range into multiple parts using a band dividing circuit and plays back with two or more types of speakers, a frequency that is higher than the band that is handled A peak will be generated. There is a problem that the abnormal sound in the high frequency band generated by this divided vibration is superimposed on the sound of the speaker for high sound reproduction, and the sound in the high sound range cannot be accurately reproduced. On the other hand, when trying to attenuate the frequency band of abnormal sound generated by the divided vibration electrically strongly by the band dividing circuit, it is necessary to insert a complicated band dividing circuit in front of the mid-low sound reproduction speaker. There is a problem that the reproduction sound of the mid-low sound reproduction speaker deteriorates.

  Therefore, there is a strong demand for a mid / low frequency sound reproduction speaker using a magnesium alloy, which is a metal material having high specific strength and large internal loss. However, the rolled magnesium alloy sheet has a lower Young's modulus than other metals such as aluminum and titanium, and has a large anisotropy of mechanical properties such as Young's modulus between the rolling direction and the direction perpendicular thereto. There's a problem. That is, when the cone-shaped diaphragm is formed of a material with large anisotropy, for example, when an external force is applied from the outer edge toward the cone center, the rigidity varies depending on the direction in which the external force is applied, There is a problem that deformation is more likely to occur than when formed from a material with small anisotropy.

  For this reason, due to the anisotropy of the magnesium alloy diaphragm, it is difficult to make use of the superiority of the material as it is easy to generate a split vibration mode in the circumferential direction and the internal loss is large. . Therefore, even when magnesium alloy is used as the material of the diaphragm, abnormal vibration occurs in the high frequency range. For this reason, even when a magnesium alloy diaphragm is applied to the mid- and low-frequency sound reproduction speakers of the multi-way system, the same problem that an abnormal sound is generated due to superimposition with the sound of the high-frequency sound reproduction speakers. It has occurred.

  Accordingly, the present invention provides a diaphragm for a low-frequency reproduction speaker made of magnesium alloy that can fully utilize the excellent characteristics of a material by suppressing a split vibration mode that is likely to occur due to material anisotropy. And a speaker unit and a speaker system having the same.

  In addition, the present invention, when used in a multi-way speaker system, prevents annoying metal sound due to divided vibrations from being superimposed on the reproduction sound of the high-frequency sound reproduction speaker, and band division with the high-frequency sound reproduction speaker. It is an object of the present invention to provide a magnesium alloy diaphragm for a mid-low sound reproducing speaker, a speaker unit having the same, and a speaker system.

To solve the problems described above, the diaphragm of the bass reproduction speaker in the present invention has a cone shape formed of a magnesium alloy plate, rigidity homogenizing part of the annular concentrically formed, the The rigid homogenizing part is formed by bending a magnesium alloy plate into a mountain shape by press working .

  In the present invention configured as described above, an annular rigid homogenizing portion is formed concentrically on the cone-shaped diaphragm. By this rigidity homogenization part, the rigidity of each direction of the diaphragm generally formed from the magnesium alloy plate with strong anisotropy is homogenized.

  According to the present invention configured as described above, since the rigidity in each direction of the diaphragm manufactured from the magnesium alloy sheet having strong anisotropy is homogenized by the rigidity homogenizing section, the division generated in the diaphragm Vibration can be effectively suppressed. Thereby, it is possible to prevent the annoying metal sound due to the divided vibration from being superimposed on the reproduction sound of the high sound reproduction speaker, and to facilitate the band division with the high sound reproduction speaker.

In the present invention, preferably, the number n of the annular rigid homogenization portions is 1 or more and 10 or less, and when n is 2 or more, the vibration divided by the n annular rigidity homogenization portions. the ratio of the projected area of the compartment on the plate S _1: S _2: ··: each S ₁ in _{S n + 1, S 2,} ··, S n + 1 is selected from the 1 and 43 following primes The adjacent areas have different projected areas. When n is 1, the projected area of the larger area is a non-integer multiple of the projected area of the smaller area.

  According to the present invention configured as described above, since the rigidity homogenizing portion is disposed at the predetermined position described above, the inner side of the rigidity homogenizing portion is defined by the resonance of the wave transmitted in the radial direction of the diaphragm. It is possible to prevent the occurrence of the divided vibration in the circumferential direction in both the outer section and the outer section.

In the present invention, preferably, the height of the annular stiffness homogenizing portion is not less than 2 times and not more than 30 times the thickness of the portion other than the annular stiffness homogenizing portion of the diaphragm.
According to the present invention configured as described above, a sufficient rigidity homogenizing effect can be obtained by the rigidity homogenizing portion, and at the same time, the formation of the rigidity homogenizing portion is relatively easy. The original function of the board is not impaired.

  Further, the speaker unit for middle / low tone reproduction of the present invention generates a magnetic field so that a diaphragm of the speaker for middle / low tone reproduction of the present invention, a voice coil attached to the diaphragm, and a magnetic field line across the voice coil. It has a magnetic circuit and a frame that supports the magnetic circuit.

  Furthermore, the speaker system according to the present invention includes the speaker unit for middle / low sound reproduction according to the present invention, the speaker unit for high sound reproduction, and a housing that supports the speaker unit for middle / low sound reproduction and the speaker unit for high sound reproduction. It is characterized by.

  According to the magnesium alloy diaphragm of the present invention for a low-pitched sound reproduction speaker, and the speaker unit and speaker system having the diaphragm, by suppressing the divided vibration mode that tends to occur due to anisotropy of the diaphragm material. The excellent properties of the material can be fully utilized.

  Further, according to the diaphragm of the magnesium alloy medium / low-frequency sound reproduction speaker of the present invention, and the speaker unit and speaker system having the diaphragm, the annoying metal sound due to the divided vibration is superimposed on the reproduction sound of the high-frequency sound reproduction speaker. Can be prevented, and band division with the high-frequency sound reproduction speaker can be facilitated.

Next, a speaker system according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of a speaker system according to an embodiment of the present invention. FIG. 2 is a side sectional view of the speaker unit for middle / low sound reproduction used in the speaker system according to the present embodiment. FIG. 3 is a front view of the diaphragm of the speaker unit for middle / low sound reproduction in the present embodiment, and FIG. 4 is a side view. FIG. 5 is an enlarged cross-sectional view showing a part of the diaphragm of the speaker unit for middle / low sound reproduction in the present embodiment.

  As shown in FIG. 1, a speaker system 1 according to an embodiment of the present invention includes a mid-low sound reproduction speaker unit 2, a high sound reproduction speaker unit 4, and an enclosure 6 that is a housing to which these speaker units are attached. Have. Further, a speaker terminal 8 for connecting the speaker system 1 and an amplifier (not shown) is attached to the rear surface of the enclosure 6. The electrical signal input to the speaker terminal 8 is input to the high-pitched sound reproduction speaker unit 4 via the network 10 that is a band dividing circuit. On the other hand, for the reason described later, in the present embodiment, the electric signal input to the speaker terminal 8 is directly input to the middle / low sound reproduction speaker unit 2 without going through the network.

  The network 10 includes a capacitor 10a connected in series to the loudspeaker reproducing speaker unit 4 and a coil 10b connected in parallel. Through the network 10, the electric signal input to the high-pitched sound reproduction speaker unit 4 is attenuated by 12 dB every time the frequency is lowered by one octave. In the present specification, the term “middle / low range playback speaker” means a speaker that mainly shares a range other than the highest range in the speaker system used, and includes a woofer that shares the low range, a squawker that shares the mid range, and the like. It shall be included in this. Therefore, a speaker unit to which an electric signal of the entire region is input without going through the network is also included in the middle / low sound reproducing speaker as long as it mainly shares a region other than the highest sound region.

Next, with reference to FIG. 2, the speaker unit 2 for middle / low sound reproduction used in the speaker system 1 according to the embodiment of the present invention will be described.
As shown in FIG. 2, the speaker unit 2 for middle / low sound reproduction includes a cone-shaped diaphragm 12, a voice coil 14 attached to the narrowed rear end of the cone-shaped, and a magnetic field line. And a magnetic circuit 16 for generating a magnetic field so as to cross. Further, the speaker unit 2 for middle / low sound reproduction includes a frame 18 that supports the magnetic circuit 16, a damper 20 that elastically supports the diaphragm 12, and an annular edge 22 that connects the outer periphery of the diaphragm 12 to the frame 18. Have. With this configuration, when an electrical signal input from the speaker terminal 8 flows through the voice coil 14, an electromagnetic force that moves the voice coil 14 in the front-rear direction is generated, and the diaphragm 12 is vibrated by this force, so that the electrical signal is a sound wave. Is converted to

  The voice coil 14 is formed by winding a conducting wire around the rear end of a cylindrical bobbin. The voice coil 14 has a front end joined to a rear end having a narrow inner diameter of the cone-shaped diaphragm 12.

  The magnetic circuit 16 includes an annular ferrite magnet 16a, a pole piece 16b attached to the rear side thereof, and a donut plate-like plate 16c attached to the front side of the ferrite magnet 16a. With this configuration, a strong magnetic field is generated in the annular gap that is the gap between the tip of the pole piece 16b and the plate 16c, and the cylindrical voice coil 14 is disposed in the gap so as to cross the magnetic lines of force due to this magnetic field.

The frame 18 has a mortar-like shape as a whole and is disposed so as to surround the diaphragm 12.
The damper 20 is composed of a donut-shaped member in which concentric corrugations are formed. The outer periphery of the damper 20 is attached to the inner periphery of the rear end of the frame 18, and the inner periphery of the damper 20 is attached to the tip of the voice coil 14. The damper 20 is elastically supported by the damper 20 so as to be movable in the front-rear direction (the axial direction of the voice coil 14) at a predetermined position in the gap, and the diaphragm 12 attached to the front end of the voice coil 14 Is also elastically supported.
The edge 22 is an annular flexible member, and connects the outer peripheral portion of the front end of the diaphragm 12 and the inner peripheral portion of the front end of the frame 18.

Next, the configuration of the diaphragm 12 will be described with reference to FIGS. 3 to 5.
As shown in FIGS. 3 to 5, the diaphragm 12 has a cone shape as a whole and is formed of a rolled magnesium alloy plate. Furthermore, in the present embodiment, AZ31 is used as the magnesium alloy. In addition to AZ31, magnesium alloys usually used for industrial products such as AZ61 and AZ91 can be used. Further, in this specification, the cone type means a general shape extending from a thin inner periphery at the rear end toward an outer periphery at the front end, and does not mean only a conical shape. Therefore, the shape of a so-called curved cone in which a conical bus bar is curved is also included in the cone shape in this specification.

  In the present embodiment, the surface of the diaphragm 12 is anodized. In general, a magnesium alloy is inferior in corrosion resistance, so it is better to use it after surface treatment. As the surface treatment, any method such as anodic oxidation or application of a thin resin can be adopted, but when the coating film becomes thick, the original properties of the magnesium alloy cannot be exhibited. It is preferable not to exceed half of the thickness t of the diaphragm 12.

As shown in FIGS. 3 and 4, the diaphragm 12 has two annular rigidity homogenizing portions 12 a and 12 b formed concentrically. The diaphragm 12 is divided into three sections 12c, 12d, and 12e by two rigid homogenizing sections 12a and 12b. In the present embodiment, these sections 12c, 12d, S ₁ 12e to the ratio of the vibration area ratio S ₁ that respectively projected onto a plane orthogonal to the direction, S _2, S ₃ of the diaphragm 12: S _2: S The space | interval L and position between the rigid homogenization parts 12a and 12b are determined so that ₃ may be 1: 2: 3.

  Further, as shown in FIG. 5, the rigid homogenizing portions 12 a and 12 b are formed by curving the cross section of the diaphragm 12 in a mountain shape toward the front by pressing. In the present embodiment, the outer diameter of the diaphragm 12 is 160 mm, the plate thickness t is 0.2 mm, and the height h of the rigid homogenizing portions 12a and 12b is about 1 mm. Preferably, the height h of the rigid homogenized portion is at least twice the plate thickness t of the flat portion where the rigid homogenized portion is not formed. This is because if it is less than twice, there is no effect of increasing the rigidity and suppressing the divided vibration. In addition, the effect of suppressing the split vibration is improved as the height h is increased. However, if the height h exceeds 30 times the plate thickness t, the original performance of the diaphragm cannot be exhibited, and processing becomes difficult and industrial productivity. Therefore, the height h is preferably 30 times or less of the plate thickness t.

  Preferably, the number n of the rigid homogenizing portions is 1 or more and 10 or less. The effect of homogenizing the rigidity of the diaphragm is recognized even if only one of the rigidity homogenizing portions is formed, and when the number exceeds 10, the effect is saturated and the rigidity of the diaphragm is made uniform. This is because it hardly changes.

  When the number n of rigid homogenizing parts is 1, the rigid homogenizing parts are arranged so that the projected area of the larger one of the two sections is a non-integer multiple of the projected area of the smaller one. Good to do.

Further, when the number n of the rigid homogenizing part is two or more, the ratio S ₁ of the projected area of each _{compartment: S 2: ····: S 1} , S 2 in the S _{n + 1,} · · · -It is good to arrange | position a rigid homogenization part so that Sn _{+ 1} is selected from the prime numbers of 1 and 43 or less, and the area of the mutually adjacent division differs.

This is because, when the projected areas between adjacent rigid homogenizing parts are equal, due to the resonance of the waves transmitted in the radial direction of the diaphragm, both the inner and outer compartments with respect to the rigid homogenizing part as a boundary. This is because the split vibration is likely to occur. In order to avoid this phenomenon, the rigid homogenizer is arranged so that the projected areas of adjacent sections are different. Furthermore, the ratio S ₁ : S ₂ :...: S _{n + 1} of the sections between the rigid homogenization sections is an integer ratio selected from prime numbers of 1 and 43 or less. The divided vibration in the circumferential direction due to the resonance of the waves in the radial direction can be more effectively suppressed.

  In addition, selecting the area ratio from prime numbers less than 43 means that when the prime number exceeds 43, the ratio between adjacent prime numbers approaches 1, and the projected areas of substantially adjacent sections differ. This is because there is no more. Furthermore, it is preferable that the projected areas of adjacent sections are different, but sections having the same area may exist as long as they are not adjacent to each other.

Here, with reference to FIG. 6 thru | or FIG. 8, the aspect of the division vibration of a diaphragm is demonstrated.
6 and 7 are diagrams illustrating an example of the divided vibration of the diaphragm that does not have the rigidity homogenizing portion. In the diaphragm not provided with the rigidity homogenizing portion, the rigidity against the load in the radial direction is small, and divided vibrations in modes as shown in FIGS. 6 and 7 are generated at a predetermined mode frequency. FIG. 6 shows a divided vibration mode in which the outer shape of the circular diaphragm shown by a solid line is alternately deformed into an ellipse shown by a broken line and a one-dot chain line. FIG. 7 shows a divided vibration mode in which each part of the diaphragm is deformed so as to alternately form peaks and valleys. The solid line in the figure indicates the contour line of the mountain portion, and the broken line indicates the contour line of the valley portion. In this divided vibration mode, these peaks and valleys vibrate so that they are alternately reversed.

  6 and FIG. 7 can be suppressed by providing a rigid homogenizing portion on the diaphragm. However, as shown in FIG. 8, even when the rigidity homogenizing portion is provided on the diaphragm, the divided vibration is suppressed when the arrangement of the rigidity homogenizing portion does not satisfy the above-described conditions. The effect to do becomes small. FIG. 8 is a schematic diagram showing a vibration mode when the projected area of one of the two sections divided by the rigidity homogenizing unit is an integral multiple of the projected area of the other section. In the example of FIG. 8, due to the resonance of the wave transmitted in the radial direction of the diaphragm, the divided vibration in the circumferential direction is generated in both the inner section and the outer section with the rigidity homogenizing portion as a boundary.

  Next, with reference to FIG. 9, the rigidity homogenization effect by forming a rigidity homogenization part is demonstrated. FIG. 9 shows the rigidity in each direction of the diaphragm according to the present embodiment (corresponding to Example 2 in Table 1 described later) and a similar diaphragm having no rigidity homogenizing part (Comparative Example 1 in Table 1 described later). This is a graph comparing the rigidity in each direction. In this graph, the load applied in the diameter direction of each diaphragm is shown on the vertical axis, and the amount of deformation at that time is shown on the horizontal axis. Solid lines A and B in the figure show the diaphragm in the present embodiment, and broken lines C and D show the diaphragm without the rigid homogenizing portion. Moreover, each line A and C has shown the case where a load is applied to the rolling direction of the magnesium plate which formed the diaphragm, and each line B and D has shown the case where a load is applied to the direction orthogonal to a rolling direction.

  As shown in FIG. 9, it can be seen that the diaphragm provided with the rigidity homogenizing portion has a smaller deformation amount and higher rigidity for the same load regardless of which direction the load is applied. Further, it should be noted that the rigidity of the rolling plate and the direction perpendicular to the rolling direction are greatly different in the diaphragm not provided with the rigidity homogenizing portion, while the vibration plate provided with the rigidity homogenizing portion is different in each direction. There is not much difference in rigidity. That is, it can be seen that by providing the rigidity homogenizing portion, the rigidity of each direction of the diaphragm is homogenized even though the rolled magnesium plate has anisotropy.

  In general, in a member whose rigidity is increased by forming an axially symmetric shape such as a cone-shaped diaphragm, the collapse of the axial symmetry of the strength due to anisotropy causes a significant decrease in strength. In other words, the rigidity homogenizing unit in this embodiment is more than the effect of suppressing the divided vibration by preventing the deformation of the diaphragm itself, but rather the axial symmetry of the strength of the diaphragm by homogenizing the rigidity. Is to suppress the split vibration of the diaphragm by suppressing the collapse of the diaphragm and thereby exhibiting the original strength of the axisymmetric shape.

  Note that the effect of the present invention is exhibited even when the position where the rigid homogenizing portion is arranged is shifted by about ± 3% of the distance L between the rigid homogenizing portions from the position where each section has a predetermined projected area. The Therefore, it is also within the scope of the present invention that the rigidity homogenizing portion is arranged with such an error.

  By arranging the rigid homogenization section in this way, the sound pressure level in the high sound range of the mid-low sound reproduction speaker gradually decreases as the frequency increases, and the high sound reproduction speaker in the multi-way system This makes it easier to share the sound range.

Next, with reference to Tables 1 and 2 and FIGS. 10 and 11, examples will be described in which the diaphragm according to the embodiment of the present invention is created with various specifications and the characteristics thereof are evaluated. Here, Examples 1 to 7 in Table 1 are diaphragms which are determined and determined based on the present invention, and Comparative Examples 1 to 3 are prepared based on specifications outside the scope of the present invention. Diaphragm.

  As shown in Table 1, in these examples and comparative examples, AZ31 or AZ61 magnesium alloy plates having a thickness of 0.08 mm, 0.1 mm, 0.2 mm, and 0.3 mm were used, and the outer diameter was 120 mm or 160 mm. The diaphragm is manufactured. Further, in the diaphragm of each example, 1 to 7 rigid homogenizing portions having a height of 1 to 3 mm are formed at the positions shown in Table 1. Moreover, in the comparative example, a diaphragm having the same projected area of two sections formed by one rigid homogenizing portion having a height of 1 mm and that having no rigid homogenizing portion was prepared. Each diaphragm is subjected to a surface treatment by an anodic oxidation method or a polyimide resin coating method.

  A loudspeaker unit for middle / low sound reproduction was produced by combining a voice coil or the like with each of the diaphragms thus produced. FIG. 10 and FIG. 11 are graphs showing the reproduction frequency characteristics of the speaker unit for middle / low sound reproduction produced in this way. The graphs of FIGS. 10 and 11 show the frequency of the signal input to the speaker unit on the horizontal axis and the sound pressure level of the reproduced sound on the vertical axis. FIG. 10 shows the characteristics of the speaker unit using the diaphragm of Example 1 in Table 1 as a solid line, and the characteristics of the speaker unit according to Comparative Example 1 as a broken line. FIG. 11 shows Example 2 as a solid line and Comparative Example 2 as a broken line.

  As shown in FIGS. 10 and 11, when the diaphragms of the comparative examples not provided with the rigidity homogenizing portion are used, the sound pressure level becomes low near 5 kHz, and the sound pressure level becomes abnormally high near 10 kHz. I understand that. On the other hand, when using the diaphragm having the rigidity homogenizing part of each embodiment, as shown by the solid line in FIG. 10 and FIG. 11, a dip of frequency characteristics indicating an abnormally low sound pressure level, It can be seen that the occurrence of a peak of the frequency characteristic indicating an abnormally high sound pressure level is suppressed. This is considered to be because the rigidity of the entire structure is increased and the anisotropy of the rigidity is extremely reduced by providing the rigidity homogenizing portion.

  Further, in the middle / low sound reproducing speaker unit using the diaphragm of each embodiment, the sound pressure level in the high sound range gradually decreases as the frequency increases. Thereby, in a multi-way system to which a high-frequency sound reproduction speaker unit is added, a high-frequency sound reproduction speaker and a band dividing circuit for dividing a band can be easily designed. Further, in the multi-way system according to the embodiment shown in FIG. 1, the band dividing circuit of the middle / low frequency reproduction speaker is omitted by using this characteristic of the middle / low frequency reproduction speaker unit.

  Next, a two-way speaker system was constructed by combining a speaker unit for middle / low sound reproduction using the diaphragms of the examples and comparative examples and a speaker unit for high sound reproduction having a dome-shaped magnesium diaphragm having a diameter of 36 mm. Table 2 shows the evaluation results of the sensory test of this 2-way speaker system. The sensory test was conducted by five subjects who were familiar with daily music.

  As can be seen from Table 2, in the two-way speaker system using the diaphragms of the comparative examples in which a large peak occurred in the high frequency range in the measurement of the frequency characteristics of the mid-low sound reproduction speaker unit alone, the sensory evaluation by the subject Was evaluated as having an annoying abnormal sound in the high frequency range. On the other hand, in any of the speaker systems using the diaphragms of the examples, no annoying abnormal sound in the high sound range was recognized in the sensory evaluation by the subject.

  As described above, in the speaker system according to the embodiment of the present invention, the problem of causing the divided vibration, which was observed when using the magnesium alloy diaphragm, was solved. Further, according to the middle / low sound reproduction speaker unit of the present embodiment, it can be easily combined with the high sound reproduction speaker unit, and a speaker system excellent in sound reproducibility can be constructed.

  Further, in the speaker unit for middle / low sound reproduction according to the embodiment of the present invention, in the case of constructing a multi-way speaker system, it has been desired to easily share a sound range with the speaker unit for high sound reproduction. The characteristic that the sound pressure level in the above high range gradually decreases as the frequency increases is made possible for the first time by a metal diaphragm.

  In addition, according to the embodiment of the present invention, it is possible to provide a speaker system with extremely good sound reproducibility, which can be a means for faithfully reproducing music recorded in the past or music recorded in the future. It can contribute widely to society, such as protecting musical heritage.

  As mentioned above, although preferable embodiment of this invention was described, a various change can be added to embodiment mentioned above. In particular, in the embodiment described above, the shape of the diaphragm is circular, but the diaphragm may be elliptical or oval. In this case, the shape of the rigid homogenizing portion can also be an elliptical or oval annular shape instead of an annular shape.

Further, in the embodiment described above, the rigidity homogenizing unit, which had been formed by convexly curved cross section of the diaphragm towards the front, as a modified example, as shown in FIG. 12, the diaphragm The rigid homogenizing portion may be formed by curving the cross section in a convex shape toward the rear, that is, in a concave shape when viewed from the front.

It is sectional drawing of the speaker system by embodiment of this invention. It is side surface sectional drawing of the speaker unit for middle-low sound reproduction | regeneration used for the speaker system by embodiment of this invention. It is a front view of the diaphragm of the speaker unit for middle-low sound reproduction in the embodiment of the present invention. It is a side view of the diaphragm of the speaker unit for middle / low sound reproduction in the embodiment of the present invention. It is sectional drawing which expands and shows a part of diaphragm of the speaker unit for middle-low sound reproduction | regeneration in embodiment of this invention. It is a figure which shows an example of the division vibration of the diaphragm which does not have the conventional rigid homogenization part. It is a figure which shows an example of the division vibration of the diaphragm which does not have the conventional rigid homogenization part. It is the schematic which shows the vibration mode when the projection area of one division is made into the integral multiple of the projection area of the other division among two divisions divided by the rigidity homogenization part. It is the graph which compared the rigidity of each direction of the diaphragm in embodiment of this invention, and the rigidity of each direction of the conventional diaphragm which does not have a rigidity homogenization part. 4 is a graph in which the horizontal axis represents the frequency of a signal input to the speaker unit and the vertical axis represents the sound pressure level of the reproduced sound. 4 is a graph in which the horizontal axis represents the frequency of a signal input to the speaker unit and the vertical axis represents the sound pressure level of the reproduced sound. It is sectional drawing of the diaphragm which shows the modification of a rigidity homogenization part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Speaker system by embodiment of this invention 2 Speaker unit for middle / low sound reproduction 4 Speaker unit for high sound reproduction 6 Enclosure 8 Speaker terminal 10 Network 10a Capacitor 10b Coil 12 Diaphragm 12a, 12b Rigid homogenization part 12c, 12d, 12e Partition 14 Voice coil 16 Magnetic circuit 18 Frame 20 Damper 22 Edge

Claims (5)

It has a cone shape formed from a magnesium alloy plate , a concentric annular rigid homogenization part is formed , and this rigidity homogenization part is formed by bending the magnesium alloy plate into a mountain shape by pressing. A diaphragm for a speaker for low / mid-range reproduction. When the number n of the annular rigidity homogenizing portions is 1 or more and 10 or less, and n is 2 or more, each of the sections on the diaphragm divided by these n annular rigidity homogenizing portions. the ratio of the projected area S _1: S _2: ··: each S ₁ in _{S n + 1, S 2,} ··, S n + 1 is selected from the 1 and 43 following prime and adjacent compartments 2. The diaphragm of a low-pitched sound reproducing speaker according to claim 1, wherein when n is 1, the projected area of the larger section is a non-integer multiple of the projected area of the smaller section. .   The height of the annular rigidity homogenizing portion is not less than 2 times and not more than 30 times the thickness of a portion other than the annular rigidity homogenizing portion of the diaphragm. Diaphragm. The diaphragm of the speaker for middle / low sound reproduction according to any one of claims 1 to 3,
A voice coil attached to this diaphragm,
A magnetic circuit that generates a magnetic field so that the magnetic field lines cross the voice coil;
A frame that supports this magnetic circuit;
A speaker unit for middle and low-pitched sound reproduction characterized by comprising: A speaker unit for middle / low sound reproduction according to claim 4,
A speaker unit for high sound reproduction;
A housing that supports these low and middle sound reproduction speaker units and a high sound reproduction speaker unit;
A speaker system characterized by comprising:

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