musical instruments

Abstract

A musical instrument is provided that can suppress changes in the frequency characteristics of sound emitted from the acoustic section even when a vibrator is installed in the acoustic section. The instrument comprises: an acoustic section (15) that emits sound in response to vibration; a vibrator (31) having a vibrator body (33) and a vibrating part (34) that vibrates relative to the vibrator body (33), which vibrates the acoustic section (15); and a support part (32) installed in the acoustic section (15) that supports the vibrator body (33) in a manner that transmits vibration from the vibrating part (34) to the acoustic section (15). The support part (32) supports the vibrator body (33) by elastic displacement of the vibrator body (33) relative to the acoustic section (15). The resonant frequency of the vibration system formed by the vibrator body (33) and the support part (32) is lower than the lowest resonant frequency of the acoustic section (15).

Description

Technical Field

[0001] This invention relates to musical instruments. Background Technology

[0002] Traditionally, sound is produced in musical instruments by vibrating the soundboard or similar components using a vibrator. Patent Document 1 discloses an acoustic guitar with a vibrator mounted on the back of the body that vibrates in response to an input signal. The acoustic guitar in Patent Document 1 includes: a foot (support) extending from the back; and a support fixed to the front of the foot and positioned opposite the back. The vibrator is mounted on the back and the support. Furthermore, in this acoustic guitar, since the stress acting on the support is reduced due to the vibration of the back, the rigidity of the foot is set to be lower than that of the support.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6524927 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] However, if a vibrator of a specified weight is installed relative to the acoustic part, which produces sound in response to vibration, as in the back plate of an acoustic guitar, the vibration characteristics of the acoustic part are affected by the weight of the vibrator. Therefore, the vibration characteristics of the acoustic part differ from those without a vibrator. That is, there is a problem that the frequency characteristics of the sound emitted from the acoustic part through vibration (the acoustic characteristics of the instrument) change depending on the presence or absence of a vibrator.

[0008] The present invention was made in view of the above circumstances, and its object is to provide a musical instrument that can suppress changes in the frequency characteristics of the sound emitted from the acoustic part even when a vibrator is installed in the acoustic part.

[0009] Technical solutions for solving technical problems

[0010] One embodiment of the present invention comprises an instrument comprising: an acoustic section that emits sound in response to vibration; a vibrator having a vibrator body and a vibrating section that vibrates relative to the vibrator body, for vibrating the acoustic section; and a support portion mounted on the acoustic section to support the vibrator body in such a way as to transmit vibration from the vibrating section to the acoustic section; the support portion supports the vibrator body by means of elastic displacement of the vibrator body relative to the acoustic section, and the resonant frequency of the vibration system formed by the vibrator body and the support portion is lower than the lowest resonant frequency of the acoustic section.

[0011] The effects of the invention

[0012] According to the present invention, even if the vibrator is installed in the acoustic section, the frequency characteristics of the sound emitted from the acoustic section can be suppressed. Attached Figure Description

[0013] Figure 1 This is a front view of a guitar according to the first embodiment of the present invention.

[0014] Figure 2 It means Figure 1 A plan view of the inner side of the back plate of a guitar.

[0015] Figure 3 It is along Figure 2 A cross-sectional view of arrow III-III.

[0016] Figure 4 Is Figures 1-3 A graph representing an example of the frequency characteristics of the guitar body (back plate) and the vibration system consisting of the vibrator body and the support.

[0017] Figure 5 This is a cross-sectional view showing the main parts of the guitar according to the second embodiment of the present invention.

[0018] Figure 6 It means Figure 5 A three-dimensional view of the support portion.

[0019] Explanation of reference numerals in the attached figures

[0020] 1… Guitar (musical instrument), 15… Back plate (acoustic part), 31… Vibrator, 32, 32C… Support part, 33… Vibrator body, 34… Vibrating part, 35… Support foot, 36… Bracket, 36C… Bracket (elastic part). Detailed Implementation

[0021] [First Implementation]

[0022] The following is for reference Figures 1-4 The first embodiment of the present invention will be described.

[0023] like Figure 1 As shown, the musical instrument in this embodiment is an acoustic guitar 1 (hereinafter referred to as guitar 1). Guitar 1 includes a guitar body 10 (instrument body) and a vibration device 30. The guitar body 10 includes a body 11, a neck 12, and strings 13.

[0024] The body 11 is formed as a box shape with an internal cavity. The body 11 has a top plate 14, a back plate 15, and side plates 16. The top plate 14 and back plate 15 are flat plates of the same shape. The top plate 14 and back plate 15 are spaced apart from each other in their thickness direction. The side plates 16 extend from the periphery of the back plate 15 to the periphery of the top plate 14. These top plates 14, back plates 15, and side plates 16 together form the internally cavity-filled body 11. In the following description, the direction in which the top plate 14 and back plate 15 are arranged (Z-axis direction) is referred to as the up-down direction.

[0025] A sound hole 17 is formed in the soundboard 14, extending through its thickness. The sound hole 17 connects the cavity in the body 11 to the space outside the body 11. Furthermore, a bridge 18 is provided on the outer surface of the soundboard 14 to fix the first end of the string 13 along its length.

[0026] The neck 12 extends from the body 11 in a direction approximately orthogonal to the vertical direction (Z-axis). A headstock 19 is located at the front end of the neck 12 for winding around the second end of the string 13 along its length. In the following description, the direction orthogonal to the vertical direction and in which the neck 12 primarily extends (Y-axis) may be referred to as the front-back direction. Furthermore, the direction orthogonal to both the vertical and front-back directions may be referred to as the left-right direction (X-axis).

[0027] String 13 is strung across the body 11 and neck 12 in the front-to-back direction. Specifically, the first end of string 13 is fixed to the bridge 18 of the body 11, and the second end of string 13 is wound around the headstock 19. Thus, string 13 is strung between the bridge 18 and the headstock 19.

[0028] A vibration conduction section 20 (bridge) is provided between the string 13 and the outer surface of the soundboard 14. As a result, in the guitar 1, the vibration of the string 13 is conducted to the soundboard 14 through the vibration conduction section 20, causing the soundboard 14 to vibrate, and the back plate 15 and the side plates 16 also vibrate. As a result, the air inside (the cavity) of the body 11 resonates, and the sound radiates to the outside of the body 11.

[0029] The back plate 15 of the body 11 has an inner side 15a that faces the front plate 14 in the vertical direction. For example... Figure 2 As shown, a fixing strip 23 and four sound beams 24 are installed on the inner side 15a of the back plate 15. The fixing strip 23 and the sound beams 24 are fixed in a specified position relative to the inner side 15a by means of adhesive or the like. Figure 2 The shape, number, and position of the fixed strip 23 and the sound bar 24 are examples. Their positions can be appropriately changed to improve the rigidity of the back plate 15 or to adjust the tone of the guitar 1.

[0030] exist Figure 2In this back panel 15, the fixing strip 23 is formed as a strip extending along the inner side surface 15a. The fixing strip 23 is positioned at the center of the inner side surface 15a of the back panel 15 in the left-right direction, with its length direction facing the front-back direction. The fixing strip 23 prevents the adhesive of the back panel 15, which is formed by bonding two pieces of material together in the left-right direction, from peeling off.

[0031] The four sound beams 24 are each formed as rods extending along the inner side 15a. Each sound beam 24 is arranged with its length direction facing left and right. The four sound beams 24 are arranged with gaps in the front-to-back direction. The portion of the back plate 15 containing the sound beams 24 is more rigid than the other parts of the back plate 15. Therefore, the portion of the back plate 15 containing the sound beams 24 is less likely to vibrate than the other parts of the back plate 15, and is more likely to become a vibrating joint.

[0032] like Figure 3 As shown, the vibration device 30 includes a vibrator 31 and a support 32. The vibrator 31 vibrates the back plate 15 of the aforementioned instrument body 11. The vibrator 31 has a vibrator body 33 and a vibrating part 34 that vibrates in the same direction relative to the vibrator body 33. The vibrator 31 is connected to an output device (not shown). The vibrator 31 can be wired to the output device, or it can be wirelessly connected to the output device by receiving signals from the output device via a wireless unit provided in the vibrator 31. The output device stores musical data or acoustic / sound data and outputs a vibration signal (electrical signal) based on this data. The output device outputs a vibration signal, and the vibrator 31 receives the vibration signal, thereby causing the vibrating part 34 to vibrate relative to the vibrator body 33 based on the vibration signal. The vibrator 31 can be, for example, a voice coil type actuator. In this case, the vibrator body 33 can have a magnetic part, and the vibrating part 34 can have a voice coil. The weight of the vibrator body 33 is much heavier than the weight of the vibrating part 34. As a result, the vibrating part 34 can vibrate relative to the vibrator body 33.

[0033] A support portion 32 exists between the back plate 15 and the vibrator body 33. The support portion 32 is mounted on the inner surface 15a of the back plate 15. The support portion 32 supports the vibrator body 33 by contacting the vibrating part 34 with the inner surface 15a of the back plate 15 and by elastically displacing the vibrator body 33 relative to the back plate 15. The specific configuration of the support portion 32 will be described below.

[0034] The support portion 32 includes support feet 35 and brackets 36. The support feet 35 extend upward (in the positive Z-axis direction) from the inner side 15a of the back plate 15. In this embodiment, the two support feet 35 are respectively fixed to two adjacent sound beams 24 in the front-rear direction on the inner side 15a of the back plate 15. The support feet 35 can be fixed to the sound beams 24 by adhesive (not shown) or the like.

[0035] The bracket 36 is a component used to fix the vibrator body 33. The bracket 36 is formed as a plate or sheet with its thickness along the vertical direction. The bracket 36 is located at the front end of the support foot 35. Specifically, the edge portion of the bracket 36 is supported by the support foot 35. Thus, the bracket 36 is positioned with a gap relative to the inner side surface 15a of the back plate 15 in the vertical direction. The bracket 36 can be fixed to the front end of the support foot 35 by screws or adhesive (not shown).

[0036] The vibrator body 33 is fixed to the opposing surface 36a of the bracket 36, which is opposite to the inner surface 15a of the back plate 15. The vibrator body 33 can be fixed to the bracket 36 by screws or adhesive (not shown). With the vibrator body 33 fixed to the bracket 36, the vibrating part 34 is in contact with the inner surface 15a of the back plate 15. In fact, the vibrating part 34 is fixed to the inner surface 15a of the back plate 15 by adhesive or the like.

[0037] In the guitar 1 of this embodiment configured as described above, the vibrator 31 receives a vibration signal (electrical signal) output from an output device (not shown), and the vibrating part 34 vibrates in the vertical direction relative to the vibrator body 33. As a result, the back plate 15 vibrates in the vertical direction, converting the vibration of the vibrator 31 into sound radiation. In this embodiment, an acoustic part is configured to emit sound in response to the vibration of the back plate 15.

[0038] The support portion 32 is configured such that the resonant frequency of the vibration system formed by the support portion 32 and the vibrator body 33 is lower than the resonant frequency of the back plate 15. The "resonant frequency" can be expressed as the natural frequency or the frequency of the vibration peak.

[0039] In this embodiment, the bracket 36 of the support portion 32 is flexible. That is, the bracket 36 is easily deformable. To make the bracket 36 flexible, for example, the thickness of the bracket 36 can be set to be relatively thin (e.g., less than 1 mm). The material constituting the bracket 36 can be resin or metal, etc. Furthermore, the bracket 36 is more easily deformable than the support foot 35, that is, the rigidity of the bracket 36 is lower than the rigidity of the support foot 35.

[0040] By employing a flexible bracket 36 as a component of the support portion 32, the resonant frequency of the vibration system formed by the support portion 32 and the vibrator body 33 becomes lower than the resonant frequency of the back plate 15. Furthermore, because the bracket 36 is flexible, the vibrator body 33, which is fixed to the bracket 36, can elastically displace relative to the back plate 15.

[0041] For a point in the vibration system formed by the support 32 and the vibrator body 33 where the resonant frequency is lower than the resonant frequency of the back plate 15, refer to Figure 4 Explanation will be provided. In Figure 4The graph shows the frequency characteristics of the guitar body 10, and an example of the frequency characteristics of the vibration system composed of the support 32 and the vibrator body 33 in this embodiment.

[0042] The frequency characteristics of the guitar body 10 are measured as follows: First, in an anechoic chamber, the guitar body 10 is suspended with the headstock 19 at the top, and a microphone is placed near the soundhole 17 on the body 11 to measure the sound (sound pressure level) produced by the guitar body 10. In this state, vibration signals of various frequencies are input to the actuator mounted on the back plate 15, and the frequency characteristics of the guitar body 10 are measured based on the sound pressure level of the guitar body 10 obtained by the microphone. At this time, the second-order harmonics can be measured simultaneously. The actuator used here can be, for example, the vibration device 30 of this embodiment.

[0043] In the frequency characteristics of the guitar body 10 as measured above, such as Figure 4 As shown, a primary resonant frequency F1 and a secondary resonant frequency F2, which is higher than the primary resonant frequency F1, appear. It should be noted that although a resonant frequency F0, lower than the primary resonant frequency F1, appears in the frequency characteristics of the guitar body 10, this resonant frequency F0 is a peak frequency caused by the actuator's resonance and is therefore not included in the frequency characteristics of the guitar body 10. It should also be noted that in the vibration of the guitar body 10, since the vibration of the top plate 14 and the back plate 15 is the main component, the frequency characteristics of the guitar body 10 can be considered to be substantially the same as the frequency characteristics of the back plate 15.

[0044] The frequency characteristics of the vibration system consisting of the support portion 32 and the vibrator body 33 are measured, for example, as described below. First, the vibration device 30, which includes the support portion 32 and the vibrator body 33, is measured as follows. Figure 3 The back plate 15 is mounted on the guitar body 10 as shown. Next, with the guitar body 10 suspended, vibration signals of various frequencies are input to the vibrator 31 of the vibration device 30 to cause the vibrating part 34 and the back plate 15 to vibrate. In this state, the absolute value [Ω] of the impedance of the structure including the support part 32 and the vibrator body 33 is measured by an impedance analyzer. Figure 4 The frequency characteristics of the vibration system consisting of the support 32 and the vibrator body 33 are represented by the measured absolute value of the electrical impedance [Ω].

[0045] In the frequency characteristics of the vibration system consisting of the support 32 and the vibrator body 33 obtained as described above, its resonant frequency f0 becomes lower than the primary resonant frequency F1 of the guitar body 10 (back plate 15).

[0046] As explained above, in the guitar 1 of this embodiment, the resonant frequency of the vibration system formed by the vibrator body 33 and the support 32 is lower than the lowest resonant frequency (first resonant frequency F1) of the back plate 15 (acoustic part). Therefore, even if the back plate 15 vibrates at this resonant frequency, the vibration of the vibrator 31 following the vibration of the back plate 15 can be suppressed. That is, the influence of the weight of the vibrator 31 (especially the vibrator body 33) on the vibration characteristics of the back plate 15 can be reduced. Therefore, even if the vibrator 31 is mounted on the back plate 15, changes in the frequency characteristics of the sound emitted from the back plate 15 can be suppressed.

[0047] Furthermore, in the guitar 1 of this embodiment, the support portion 32 has a support foot 35 extending from the back plate 15 and a bracket 36 provided at the front end of the support foot 35 for fixing the vibrator body 33. Moreover, the bracket 36 is flexible. The flexibility of the bracket 36 allows for a lower rigidity. By reducing the rigidity of the bracket 36, the resonant frequency of the vibration system formed by the vibrator body 33 and the support portion 32 can be reliably reduced.

[0048] Furthermore, in the guitar 1 according to this embodiment, the support foot 35 of the support portion 32 is fixed to the portion of the back plate 15 where the sound bar 24 is provided. As a result, with the provision of the support portion 32 relative to the back plate 15, changes in the vibration characteristics of the back plate 15 can be suppressed.

[0049] [Second Implementation]

[0050] Next, the main references are... Figure 5 , Figure 6 The second embodiment of the present invention will be described. In the second embodiment, the same reference numerals are used to refer to the same constituent elements as in the first embodiment, and their descriptions are omitted.

[0051] The guitar in the second embodiment Figure 1 The guitar 1 shown in the first embodiment also includes a guitar body 10 and Figure 5 The vibration device 30C shown is an example. Figure 5 As shown, the support portion 32C of the vibration device 30C in the second embodiment, like that in the first embodiment, includes multiple support feet 35 and a bracket 36C. However, the bracket 36C in the second embodiment functions as an elastic part that elastically deforms to allow relative displacement between the back plate 15 and the vibration unit 33 in the vibration direction (Z-axis direction) of the vibration unit 31. The specific configuration of the bracket 36C will be described below.

[0052] The support 36C, like in the first embodiment, is a plate or sheet with its thickness along the vertical direction (Z-axis direction). For example... Figure 6As shown, the support 36C has an outer peripheral portion 37C, an inner peripheral portion 38C, and a wrist portion 39C. Viewed from the thickness direction (Z-axis direction) of the support 36C, the outer peripheral portion 37C is formed in a ring shape. Figure 6 The center is circular. Support feet 35 are mounted on the outer periphery 37C, and multiple support feet are arranged at intervals along the circumference of the outer periphery 37C. Figure 6 (There are three in the middle).

[0053] The inner circumferential portion 38C is spaced apart from the inner side of the outer circumferential portion 37C. Figure 6 In the middle, the inner circumference 38C is formed into a circular shape, but is not limited to this. The wrist 39C is formed in a way that allows for elastic expansion and contraction, connecting the outer circumference 37C and the inner circumference 38C. Multiple wrists 39C are arranged with gaps around the outer circumference 37C and the inner circumference 38C. Figure 6 (There are three in the middle). Therefore, the inner peripheral portion 38C can elastically displace relative to the outer peripheral portion 37C in the thickness direction (Z-axis direction) of the support 36C. Figure 6 In the support portion 32C, the support foot 35 and the wrist portion 39C are arranged at positions offset from each other in the circumferential direction of the outer peripheral portion 37C, but for example, they can also be arranged at positions at the same circumferential direction.

[0054] like Figure 5 As shown, in the second embodiment, the support portion 32C is mounted on the back plate 15 such that the bracket 36C (particularly the inner peripheral portion 38C) faces the inner side surface 15a of the back plate 15 in the vertical direction. The vibrator body 33 is fixed to the opposing surface 38Ca of the inner peripheral portion 38C, which faces the back plate 15. With the vibrator body 33 fixed to the inner peripheral portion 38C, the vibration direction of the vibrator 31 is in the vertical direction. Therefore, by elastically deforming the wrist portion 39C, the inner peripheral portion 38C of the bracket 36C and the vibrator body 33 can be elastically displaced relative to the back plate 15 in the vibration direction of the vibrator 31.

[0055] In the second embodiment, by making the bracket 36C of the support portion 32C function as an elastic part, the resonant frequency of the vibration system composed of the support portion 32C and the vibrator body 33 becomes lower than the resonant frequency of the back plate 15.

[0056] The guitar according to the second embodiment can achieve the same effect as the first embodiment.

[0057] Furthermore, according to the guitar of the second embodiment, the support portion 32C includes an elastic portion that causes the vibrator body 33 to elastically displace relative to the back plate 15 in the vibration direction of the vibrator 31, which can reliably make the resonant frequency of the vibration system composed of the vibrator body 33 and the support portion 32C lower than the lowest resonant frequency (first resonant frequency F1) of the back plate 15.

[0058] In the second embodiment, the elastic portion of the support 32C may be, for example, an adhesive (not shown) capable of elastic expansion and contraction of the support 32C. The adhesive of the support 32C may be, for example, an adhesive used to bond the support foot 35 to the back plate 15 or the sound beam 24, an adhesive used to bond the front end of the support foot 35 to the bracket 36C, or an adhesive used to bond the bracket 36C to the resonator body 33. In this case, the elastic expansion and contraction of the adhesive allows the resonator body 33 to elastically displace relative to the back plate 15 in the vibration direction of the resonator 31.

[0059] The present invention has been described in detail above, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0060] In this invention, the vibration part 34 of the vibrator 31 may, for example, not be in contact with the back plate 15, but can be configured in such a way that the vibration is at least transmitted from the vibration part 34 to the back plate 15.

[0061] In this invention, the guitar may be, for example, an electric acoustic guitar. In this case, the guitar may, for example, use a pickup to convert the vibration of the string 13 into an electrical signal and input it to the vibrator 31 of the vibration device 30, 30C, thereby causing the back plate 15 to vibrate.

[0062] The musical instrument of this invention is not limited to a guitar, but can also be other stringed instruments, pianos, percussion instruments, etc. The acoustic part of this invention can be, for example, the soundboard of a piano, drumhead (diaphragm), etc., which radiates sound in response to vibration.

Claims

1. A musical instrument, characterized by, Possessing: an acoustic section that emits sound in correspondence with vibration; a vibration applicator that has a vibration applicator body and a vibration section that vibrates relative to the vibration applicator body, and applies vibration to the acoustic section; a support section that is mounted to the acoustic section, and supports the vibration applicator body in a manner that transmits vibration from the vibration section to the acoustic section; the support section supports the vibration applicator body in a manner that elastically displaces the vibration applicator body relative to the acoustic section, a resonance frequency of a vibration system composed of the vibration applicator body and the support section is lower than a lowest resonance frequency of the acoustic section, the support section possesses: a support leg that extends from the acoustic section; a support bracket that is provided to a front end of the support leg, and fixes the vibration applicator body; the support bracket has a rigidity that is lower than a rigidity of the support leg.

2. The musical instrument according to claim 1, wherein the support section includes an elastic section that elastically deforms in a manner that relatively displaces the vibration applicator body and the acoustic section in a vibration direction of the vibration applicator.

3. The musical instrument according to claim 2, wherein the elastic section is composed of the support bracket.

4. The musical instrument according to claim 2 or 3, wherein the elastic section is composed of an adhesive.

Images