Sound-electricity recording equipment and electricity-sound equipment based on stringed musical instrument

Abstract

The invention relates to an acoustic-electric sound recording device and an electric-acoustic sound device based on a stringed musical instrument, the acoustic-electric sound recording device and the electric-acoustic sound device are formed by transforming two original stringed musical instruments with the same material property, one is used for acoustic-electric sound recording, and the other is used for an electric-acoustic sound device. Recording of the sound-electricity recording device is stored, when playing is needed, the replaced bridge of the sound-electricity sound equipment vibrates to excite resonance sound production between the strings and the guitar film or the resonance board, and the replaced bridge is composed of a piezoelectric ceramic piece or an electromagnetic loudspeaking board. The defects that sound equipment at home and abroad has no stereoscopic impression when hearing sound, a sound production material produces sound by a loudspeaker, and the sound production material produces sound by an original string material or a stereoscopic sound box are overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to a sound equipment, in particular, belongs to a kind of sound-electric recording equipment and electric sound equipment based on stringed instrument. BACKGROUND

[0002] Stringed instruments mainly include plucked string instruments and bowed string instruments. Bowed string instruments produce sound by vibrating the strings through the friction between the bow hair and the strings. A common Chinese traditional bowed string instrument is the erhu, which consists of a soundbox, neck, headstock, tuning pegs, strings, bridge, nut, and bow. Other bowed string instruments include the banhu, jinghu, quhu, gaohu, sihu, and morin khuur, each producing different timbres due to differences in structure and fingering. The bridge acts as a bridge between the strings and the soundbox, transmitting the string vibrations to the membrane of the soundbox. Western bowed string instruments mainly include the violin, viola, cello, and double bass. They vibrate by rubbing the strings with rosin-coated bow hair. The string vibrations are then transmitted through the bridge to the soundboard of the soundbox. Chinese plucked string instruments mainly include the guqin, guzheng, pipa, ruan, sanxian, liuqin, rawap, and dombra. The player, wearing artificial fingernails or using a plectrum, plucks the strings with their right hand, giving them an initial pulse of energy to vibrate. The vibration of the plucked string is transmitted through the bridge to the soundboard, causing the soundboard to vibrate, which in turn drives the resonance of the body (soundbox), amplifying the sound. The bridge serves to hold the strings in place and transmit the string vibrations to the soundboard. Western plucked string instruments include the harp, guitar, and banjo. Taking the guitar as an example, its construction consists of three parts: the headstock (tunes, nut, strings), the neck (frets, frets, fingerboard), and the body (soundholes, bridge, nut, string pin, soundboard, pickguard, back, sides). The body is also called the soundbox. The bridge serves to hold the strings in place and transmit the string vibrations to the body. As can be seen from the above, regardless of whether it is a traditional Chinese musical instrument or a Western instrument, whether it is a plucked string instrument or a stringed instrument, there is always a bridge. The bridge transmits the vibration signal of the string to the soundbox. Different shapes of strings and soundboxes produce different unique timbres. Some bridges are located between the string and the soundbox, such as the erhu; others have a bridge fixed to the soundbox, with the string fixed to the bridge, such as the pipa. Stringed instruments occupy a dominant position in most musical expressions. Stringed instruments are complex to operate; for example, the erhu has techniques such as staccato bowing, plucked bowing, vibrato, trills, glissando, soft notes, and string plucking, which cannot be learned overnight. Great Peking Opera singers have dedicated accompanists; Mei Lanfang's "Mei School" art is inseparable from his accompanists Xu Lanyuan and Wang Shaoqing. Some large-scale theater concerts with more than a thousand people rely on electronic sound equipment, with sound coming from loudspeakers and images from displays, significantly reducing the audio-visual effect. Even today, the sound produced by electroacoustic equipment is still very easy to distinguish; there's no sound system so realistic you can't tell the difference with your eyes closed. Even top celebrities using multi-million dollar sound equipment can still be identified as using artificial sound. In short, current sound equipment, both domestic and international, lacks the distinctive characteristics of traditional sound systems. To compensate for the shortcomings of electroacoustic equipment, some theaters no longer use microphones or amplifiers for accompaniment performances. Based on this, innovations have been made in accompaniment sound, resulting in sound that is more realistic than current systems, even surpassing multi-million dollar equipment. Summary of the Invention

[0003] The purpose of this invention is to provide an acoustic-electric recording device and an electro-acoustic sound system based on stringed instruments, enabling the stringed instruments to produce sound effects characteristic of the original sound-producing devices. The technical solution adopted by this invention to solve its technical problem is: an acoustic-electric recording device and an electro-acoustic sound system based on stringed instruments, wherein the stringed instruments include plucked and bowed string instruments from both domestic and international sources, and their structure includes a headstock, tuning pegs, strings, a neck, and a soundbox. The soundbox of the erhu, a traditional Chinese bowed string instrument, is also called the soundbox, and it has a membrane made of bark. The soundbox of the violin, a Western bowed string instrument, has a soundboard, also called the sound plate. The acoustic-electric recording device and the electro-acoustic sound system are a pair modified from two original stringed instruments with the same material properties; one is used for acoustic-electric recording, and the other for electro-acoustic sound. The acoustic-electric recording device and electro-acoustic device also include a replacement bridge, located at the original bridge position between the string and the diaphragm or resonator. The replacement bridge is composed of a piezoelectric ceramic plate or an electromagnetic speaker plate, which is a modified version of the original electromagnetic loudspeaker: a lightweight plate replaces the diaphragm of the original electromagnetic loudspeaker, the height of which is higher than the height of the electromagnetic loudspeaker support, and an elastic membrane or elastic wire exists between the support and the lightweight plate. In some plucked string instruments, such as the pipa, the bridge is fixed to the resonator. In these cases, the piezoelectric ceramic plate or electromagnetic speaker plate is fixed between the string and the resonator in front of the original bridge. On the acoustic-electric recording device, where the accompanist's fingers press the area between the string and the neck below the string, one of five recording devices is provided: one is a hollow coil fixed to the neck, adjacent to the string, with a magnetic needle fixed to the string that can be inserted halfway into the hollow coil. Secondly, a coil is fixed to the neck of the instrument, located adjacent to the string. The core of the coil contains soft iron, and a magnetic sheet or magnetic powder is fixed to the string near the coil. Thirdly, an electret microphone is fixed to the neck of the instrument, located near the string. The electret microphone has only a small gap facing the string to accommodate its vibration, with the rest covered by sound-absorbing material. Fourthly, a piezoelectric ceramic sheet is located between the string and the neck. Fifthly, an electromagnetic speaker is located between the string and the neck. The five recording devices are arranged in three ways depending on the number of strings: one is that all the strings share a single recording device; another is that each string corresponds to one recording device; and the third is that several strings correspond to one recording device. The acoustic-electric signals collected by the recording devices are amplified by amplifier circuits and stored in a storage medium such as a USB flash drive as backup signal sources. When the signal is applied, the various acoustic-electric signals extracted from the storage medium are amplified separately and then output to the input terminals of the respective electro-ceramic plates or electromagnetic speaker boards of the electro-acoustic equipment.The recording device, with the number of strings corresponding to the string position and number on the electro-acoustic device at that location, connects to an electric ceramic plate or electromagnetic speaker board to reproduce the vibration frequency of the corresponding strings for recording. The volume of the headstock, tuning pegs, strings, neck, bridge, and soundbox of the electro-acoustic device is 0.3-50 times the volume of the corresponding headstock, tuning pegs, strings, neck, bridge, and soundbox of the acoustic-electric recording device. The magnified headstock, tuning pegs, strings, neck, bridge, and soundbox are not consistently magnified by the same factor, but rather based on the frequency of the acoustic-electric recording device's soundbox being the same as the vibration frequency of the electro-acoustic device's soundbox, and the accompanist's fingers pressing the strings. The principle is that the frequency of the strings recorded below the tuning pegs should be the same as the vibration frequency of the strings below the tuning pegs when pressed by the accompanist's fingers on the corresponding electro-acoustic device. Under this principle, the thickness of the tuning pegs and neck, the thickness of the strings, the string length, the string material, the thickness of the soundbox, the material of the diaphragm or soundboard, the thickness of the diaphragm or soundboard, the tension between the diaphragm or soundboard and its surroundings, the method of fixing the diaphragm or soundboard to its surroundings, the fixing position of the piezoelectric ceramic plate or electromagnetic speaker plate, and the number of tuning pegs and strings are variable. A spring is connected in series with each string in the area from the tuning pegs to the tuning pegs. The diaphragm and the soundbox may be separate, with a tension ring added to the edge of the diaphragm, which is connected to the soundbox via a horn ring. Alternatively, one end of several small springs can be evenly fixed around the tension ring, and the other end of the small springs can be fixed to the resonator housing. If the resonator housing is a panel structure, one end of several small springs can be evenly fixed at the junction of the panel and the resonator housing, and the other end of the small springs can be fixed to the resonator housing. The replacement bridge can be structured as follows: keeping the original bridge unchanged, bonding the original bridge to the diaphragm or panel as a single unit, and attaching one end of the piezoelectric ceramic plate or electromagnetic speaker plate to the other side of the diaphragm, with the other end of the piezoelectric ceramic plate or electromagnetic speaker plate fixed to the resonator housing. When the fixed position of the electromagnetic speaker plate in the acoustic-electric recording device or electro-acoustic device is far from the other side of the diaphragm, a long, straight, lightweight rigid rod can be added and fixed between the coil of the electromagnetic speaker plate and the lightweight plate. The piezoelectric ceramic plate in the acoustic-electric recording device or electro-acoustic device can be composed of several piezoelectric ceramic plates connected in series, parallel, or in a mixed configuration.

[0004] Adding an operator to the electro-acoustic device is a means of improving its audiovisual effects; the electro-acoustic device is preferably controlled by a robot. Based on this, several fixed pulleys are fixed at the top and bottom of the stringed instrument. A closed thin rope passes over the fixed pulleys around the front and back of the stringed instrument. A restraint strap for securing the robot's hand is attached to the rope in front of the strings. The rope behind the strings is also wrapped around and connected to a drive wheel, which is driven by a fourth stepper motor. The fourth stepper motor can move along the direction of the strings according to the pitch of the music, thus adjusting the restraint strap. A spring rod is extended from the string and pressed onto it, achieving the effect of a real person pressing the string to change the pitch. The robot's wrist is equipped with the first stepper motor, the elbow and wrist with the second stepper motor, and the shoulder with the third stepper motor. The control process of the first to fourth stepper motors is as follows: In addition to serving as the vibration signal to excite the strings of the electro-acoustic device, the audio signal is also divided into two paths. One path is the audio intensity signal. After full-wave rectification and filtering, the audio signal is then divided into three levels (high, medium, and low) by a voltage comparator and input to the core control logic module of the circuit. The intensity signal has an adjustable knob to control its magnitude. The circuit achieves the following: When the intensity signal is low, the first stepper motor is controlled to reciprocate at a certain frequency (manually adjustable, equivalent to the frequency of a violin bow); when the intensity signal is medium, the first and second stepper motors are controlled to reciprocate simultaneously at a certain frequency (manually adjustable, equivalent to the frequency of a medium-amplitude violin bow); when the intensity signal is high, the first to third stepper motors are controlled to reciprocate simultaneously at a certain frequency (manually adjustable, equivalent to the frequency of a large-amplitude violin bow). Another path of the input audio signal is used for frequency analysis. The instantaneous audio signal is converted from frequency to voltage and input to the core control logic module of the circuit. Based on the frequency, the output controls the rotation angle of the fourth stepper motor, so that when the frequency is high, this stepper motor rotates a large angle, and when the frequency is low, it returns to a smaller angle. This section can be omitted if the operator of the electro-acoustic device has no specific requirements.

[0005] The working principle of this invention is as follows: Currently, domestic and international audio equipment that reproduces the original sound is based on electro-acoustic principles, lacking the characteristics of the original sound-producing device. Although the accompanying instruments in large concerts are expensive, they still produce sound from electro-acoustic speakers. The voice coil drives the speaker's diaphragm to vibrate, forcing the surrounding air to vibrate. Because the speaker's voice coil vibrates in one direction, the sound produced is a plane wave in one direction, lacking a sense of depth. Furthermore, the sound-producing material is emitted by the speaker's diaphragm. Even if the main frequencies of the original strings are imitated, the timbre of the original string material cannot be completely replicated. Therefore, people can easily distinguish the sound from a speaker that is not made of strings, resulting in a poor listening experience. To address this, the audio equipment of this invention still uses stringed instruments. The live accompanist operates the original stringed instrument to produce sound through two parts: firstly, the strings, driven by the bridge, vibrate the resonator; secondly, the accompanist's fingers press the strings to produce sound. Therefore, this invention still sets two vibration sources at these two locations, with the vibration source signal taken from another stringed instrument. At the corresponding two locations of this other stringed instrument, piezoelectric ceramic plates, electromagnetic speaker boards, or cylindrical microphones are added to acquire the acoustic-electric signal of the stringed instrument, which is then amplified and stored for later use. When the strings need to produce sound, only an electro-acoustic device is needed. Even if the string resonant frequency of the electro-acoustic device is not the same as the vibration frequency of the strings pressed by a live accompanist, since the electrical signal driving the electro-acoustic device is taken from the vibration frequency of the strings pressed by a live accompanist, the forced vibration frequency of the strings in this invention must be the same as the vibration frequency of the strings pressed by a live accompanist. Similarly, the forced vibration frequency of the bridge-driven resonator in this application must be the same as the vibration frequency of the bridge-driven resonator when the strings are manipulated by a live accompanist. Therefore, the synthesis of the string frequency and the resonator frequency in this invention truly reproduces the timbre of the strings played by a live accompanist.

[0006] Stringed instruments vary in the number of strings; for example, the guzheng typically has 21 strings, the guitar 6, and the pipa 4. Each string has a different pitch. To reproduce the timbre, all the strings can share a single acoustic-electric recording device, and there can be only one corresponding electronic sound-emitting device. Alternatively, each string can have its own recording device, such as the erhu, where two strings correspond to two recording and two playback devices. Or, several strings can share one recording device, such as the guzheng, where every seven strings share a single acoustic-electric recording device, resulting in three recording devices and three corresponding electronic sound-emitting devices. Due to the different applications of electronic sound-emitting devices, the volume of these devices can be 0.3 to 50 times that of the original acoustic-electric recording strings. For example, a resonator (bore) 50 times larger than that of an acoustic-electric recording erhu would be roughly the size of a bass drum. To reduce the size of this invention, the strings can be shorter, for example, reduced by half or several times the amplification factor. This is because triggering string vibration at a certain position can produce overtones, which are notes higher than the fundamental frequency produced by string vibration. The frequency of overtones is an integer multiple of the fundamental frequency. Therefore, a shortened string can still produce the original frequency sound. A larger resonator (borebox) results in a larger amplitude and a louder sound. The vibration frequency of the resonator (borebox) originates from the vibration frequency of the acoustic-electric recording erhu resonator (borebox), and the vibration frequency of the strings originates from the vibration frequency of the acoustic-electric recording erhu strings below the strings pressed by the accompanist's fingers. This means that even if the frequency of the electro-acoustic device differs from the original frequency, the electro-acoustic device is under forced vibration, and its vibration frequency still follows the original frequency, being 50 times louder than the original acoustic-electric recording erhu. The electro-acoustic erhu resonator (borebox) and strings reproduce the vibration and sound production of the original acoustic-electric recording erhu. Therefore, the frequency of the sound that vibrates in the air is realistic, and it is the erhu that produces the sound, not the paper cone. The timbre of the sound is realistic and three-dimensional—such an electro-acoustic effect is unprecedented. Originally, the erhu's soundbox membrane was made of rough skin, but for an erhu with 50 times the electro-acoustic volume, the rough skin might not be large enough. Therefore, other artificial synthetic diaphragms of comparable size can be used. Furthermore, the amplitude of large loudspeakers can reach several centimeters. To accommodate such amplitude, the membrane is not fixed to the edge of the soundbox, but rather a pleated ring similar to that of an internal magnet loudspeaker is added around the diaphragm. A tension ring is added to the edge of the membrane, and this tension ring is connected to the soundbox body through the pleated ring. Alternatively, the tension ring is connected to one end of several small springs, and the other ends of these small springs are fixed to the soundbox body. With such a large amplitude vibration, the driving source has also been modified accordingly: keeping the original bridge unchanged, the original bridge is bonded to the diaphragm or resonator as one piece, and one end of the piezoelectric ceramic sheet or electromagnetic speaker plate is added to the other side of the diaphragm, with the other end of the piezoelectric ceramic sheet or electromagnetic speaker plate fixed to the resonator box.The length of the driving source has also been modified accordingly: when the distance between the fixed position and the control position of the electromagnetic speaker plate of the acoustic-electric recording device or electro-acoustic device is far, a long, straight, and lightweight rigid rod is added and fixed between the coil and the lightweight plate of the electromagnetic speaker plate. The tension bearing capacity of the strings has also been modified accordingly: a spring is connected in series on the strings in the area from the jack to the tuning pegs to prevent the strings from breaking under large amplitude. Such a large amplitude sound is suitable for use in large concerts. If the concert venue is even larger, this invention can be placed at a distance, and the sound emitted by two or more of these inventions will still be stereo sound produced by real strings.

[0007] The electrical signals of the electro-acoustic device of this invention originate from the recording signals of strings of the same nature and location. Therefore, it is necessary to design an acoustic-electric recording device suitable for the electro-acoustic device of this invention, and the principles are similar. This is the reason why the electro-acoustic device and the acoustic-electric recording device of this invention are applied for together. A concert may use more than one stringed instrument. For example, a symphony orchestra may have dozens of violins, and this invention also has dozens of instruments with different timbres. The "principal musician" is in the center position of the orchestra. By recording his accompaniment using the acoustic-electric recording device of this invention, the musician can leave after recording the music and play it back using the electro-acoustic device of this invention, thus achieving the performance level of the "principal musician." For another example, a Peking Opera performance may require six string players to play the jinghu and erhu. This invention only requires six instruments. Moreover, with this invention and the corresponding string instrument software, the six string players can be laid off, or Peking Opera actors without string players can perform independently using this invention. Some factories have used robots, resulting in a significant reduction in factory labor. Similarly, this invention is a product of modern technological development. Applying this invention reduces the need for professional performers, lowers concert costs, and overcomes the shortcomings of traditional theater accompaniment bands. This invention preferably utilizes robots or concert stagehands for operation, combined with the inventor's patented use of robots for percussion. Thus, the entire band is a robot band. Furthermore, the singers utilize the inventor's patented stereo system, making the entire performance team primarily robotic, yet the sound is remarkably realistic and louder than the original instruments and performers. A single concert can feature robots imitating numerous (even deceased) stars, allowing audiences to enjoy a technologically advanced concert experience. Compared to current large-scale concerts where viewing performers requires binoculars or displays, and sound is limited to flat speakers, the auditory effect of this invention is significantly stronger. The robots' or stagehands are guided by straps to synchronize with the music; for example, on the erhu, they move upwards for low notes and downwards for high notes, ensuring flawless imitation of accompanying instruments.

[0008] The beneficial effects of this invention are as follows: the forced vibration frequency of the strings is the same as the vibration frequency of the strings pressed by the accompanist's fingers, and the forced vibration frequency of the resonator is the same as the vibration frequency of the resonator driven by the bridge operated by the accompanist. The synthesis of the string frequency and the resonator frequency realistically reproduces the tone of a live accompanist operating the strings. Furthermore, it can increase the string volume several times or even dozens of times, overcoming the lack of stereo amplification in the nearly ten million yuan loudspeakers used in large concerts. Moreover, it overcomes the shortcomings of using a backing band for performers in grand theaters, saving a significant amount of manpower and concert costs. Attached Figure Description

[0009] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0010] Figure 1 This is a schematic diagram of the structure of the erhu of the present invention.

[0011] Figure 2 A schematic diagram of the electromagnetic speaker board.

[0012] Figure 3 This is a schematic diagram of the structure of a high-power electro-acoustic device, using the erhu as an example.

[0013] Figure 4 This invention uses a violin as an example to illustrate the structure of an electro-acoustic device.

[0014] Figure 5 This is a structural diagram showing the position of the electro-ceramic sheet or electromagnetic speaker plate when the bridge of the present invention is fixed on the resonating plate.

[0015] Figure 6 This is a block diagram illustrating the principle of an audio signal-controlled stepper motor circuit.

[0016] Figure 7 This is a schematic diagram of an electro-acoustic device for which the operator of the present invention is a robot.

[0017] In the diagram: 1. Headstock; 2. Tuning pins; 3. Strings; 4. Neck; 5. Soundbox; 6. Piezoelectric ceramic plate; 7. Electromagnetic speaker board; 8. Lightweight flat plate; 9. Support; 10. Elastic wire; 11. Coil; 12. Centering support; 13. Rigid rod; 14. Permanent magnet; 15. Membrane; 16. Small spring; 17. Jack; 18. Another small spring; 19. Soundboard; 20. Bridge; 21. Backplate; 22. First stepper motor; 23. Second stepper motor; 24. Third stepper motor; 25. First stepper motor; 26. Violin; 27. Fixed pulley. Detailed Implementation

[0018] Figure 1This is a schematic diagram of the structure of the erhu of the present invention, including a headstock 1, tuning pegs 2, strings 3, neck 4, and a soundbox 5. The soundbox 5 is usually called the soundbox body. The bridge is replaced by a piezoelectric ceramic plate 6. Of course, an electromagnetic speaker plate can also be used. An electromagnetic speaker plate 7 is used on the neck 4. Of course, a piezoelectric ceramic plate 6 can also be used. The choice is made based on factors such as effect and cost. Figure 1 This invention can be used as an acoustic-electric recording device, where a live musician plays the strings, causing the strings 3 and the resonator 5 to vibrate. The vibrational audio signals received by the piezoelectric ceramic plate 6 and the electromagnetic speaker plate 7 are amplified and stored in a storage medium (e.g., a USB flash drive). The choice between the piezoelectric ceramic plate 6 and the electromagnetic speaker plate 7 for the recording device can be made arbitrarily as needed. Alternatively, a post-electroplated microphone can be used. To reduce interference, the electret microphone has only a small gap facing the strings 3 to accommodate their vibrations, with the rest covered with sound-insulating material. Figure 1 It can also be used as an electro-acoustic device. A pre-recorded electrical signal from the resonator 5 is input to the piezoelectric ceramic plate 6, while the electrical signal from the accompanist's fingers pressing the strings is input to the electromagnetic speaker plate 7. The combined vibration of the piezoelectric ceramic plate 6 and the electromagnetic speaker plate 7 reproduces the sound of the accompanist's actual string manipulation. In this case, the piezoelectric ceramic plate 6 and the electromagnetic speaker plate 7 function as sound reproduction devices, and their technical parameters (e.g., impedance) may differ from those of the piezoelectric ceramic plate 6 and the electromagnetic speaker plate 7 used in the aforementioned recording devices.

[0019] Figure 2 A schematic diagram of the electromagnetic speaker plate 7. It is modified from an electromagnetic loudspeaker, with a lightweight plate 8 replacing the diaphragm of the loudspeaker. The height of the lightweight plate 8 is higher than the height of the electromagnetic loudspeaker support 9. An elastic wire 10 connects the support 9 and the lightweight plate 8, serving to balance external pressure. Without the elastic wire 10, when subjected to inward external pressure, the lightweight plate 8 would cause the coil 11 to move inward, resulting in the centering support 12 losing its balance. With the elastic wire 10, the external pressure is applied to the support 9 through the elastic wire 10. The external pressure experienced by the electromagnetic speaker plate 7 in this invention refers to the static pressure of the string 3 on the lightweight plate 8. When the electromagnetic speaker plate 7 is used as an acoustic-electric recording device, the vibration of the string 3 is transmitted to the lightweight plate 8, which in turn transmits it to the rigid rod 13. The rigid rod 13 then transmits it to the coil 11. The electromagnetic induction between the coil 11 and the permanent magnet 14 generates an acoustic-electric signal, which is then output, amplified, and stored. The structure of the electromagnetic speaker board 7 is similar to that of a dynamic microphone. The reason why this invention does not use a dynamic microphone is that the dynamic microphone is too sensitive and can receive all sounds, while the electromagnetic speaker board 7 only receives the vibration signal of the string 3, and then restores the vibration through the electromagnetic speaker board or piezoelectric ceramic in the electro-acoustic equipment, thereby reducing distortion.

[0020] Figure 3This invention uses the erhu as an example to illustrate the structure of a high-power electro-acoustic device. The resonator 5 is significantly larger, but the strings 3 and neck 4 are not increased proportionally to the size of the resonator 5. Compared to the resonator 5, the sound of the resonator 5 is louder, and the overtones of the strings 3 can compensate for the high frequencies. The upper electromagnetic speaker 7 represents the frequency of the strings below the accompanist's fingers pressing the strings, while the lower electromagnetic speaker 7 represents the frequency at the original bridge position. These are two vibration sources, and the electrical signal strength and timbre input to the two electromagnetic speaker 7s are different; the input signals cannot be interchanged. In this high-power electro-acoustic device, knobs for adjusting the volume and pitch of the excitation electromagnetic speaker 7 can be added. The high-power electromagnetic speaker 7 excites the diaphragm 15 to an amplitude that reaches the centimeter level. To prevent damage to the diaphragm 15, a tension ring is added to the edge 15 of the diaphragm. The tension ring is connected to the resonator 5 in two ways: one is by using a folding ring from the electromagnetic speaker to connect the tension ring to the resonator 5; the other is by evenly fixing one end of several small springs 16 around the tension ring, with the other ends of the springs 16 fixed to the resonator 5. To fine-tune the overtones of the string 3, there are jacks 17 at both ends of the string 3. To prevent the string 3 of the high-power electro-acoustic equipment from breaking, another small spring 18 is connected in series on each string 3 in the area from the jack 17 to the tuning peg 2.

[0021] Figure 4 This invention uses a violin as an example to illustrate the structure of an electro-acoustic device. The electro-acoustic device below where the accompanist's fingers press the strings is a piezoelectric ceramic plate 6. The original bridge 20 of the violin remains unchanged. Several small springs 16 are evenly distributed along the edge of the resonator plate 19 below the bridge 20. The other ends of these small springs 16 are fixed to the housing 5 of the resonator box. Each string 3 is connected to another small spring 18, thus accommodating large-amplitude vibrations without damaging the resonator plate 19 and the strings 3. On the other side of the resonator plate 19 is a lightweight flat plate 8 of an electromagnetic speaker plate 7, which is fixed to the inside of the violin's back plate 21. This makes the entire structure robust and reasonable. Of course, the preceding... Figure 3 The electromagnetic speaker board 7 in the middle can also be used with Figure 4 In a similar configuration, there is a lightweight flat plate 8 with an electromagnetic speaker plate 7 on the other side of the original piano membrane. The electromagnetic speaker plate 7 is fixed to a separate longitudinal plate inside the resonating box 5.

[0022] Figure 5This is a structural diagram showing the position of the electro-ceramic plate 6 or the electromagnetic speaker plate 7 when the bridge 20 of the musical instrument of the present invention is fixed on the resonating plate 19. For example, in the case of a pipa, the original bridge 3 remains unchanged, and the electro-ceramic plate 6 or the electromagnetic speaker plate 7 is fixed between the strings 3 and the resonating plate 19 in front of the bridge 3. Alternatively, the electromagnetic speaker plate 7 can be fixed to the other side of the resonating plate 19 and the inside of the back plate 21. Both methods, when used as an electro-acoustic device structure, can cause the resonating plate 19 and strings 3 of the pipa to vibrate; and when used as an acoustic-electronic recording device structure, can record the vibration of the pipa's resonating plate 19 and strings 3.

[0023] Figure 6 This is a block diagram of the audio signal-controlled stepper motor circuit. The robot's feet, body, head, violin, and stool are all fixed together. When entering the stage, it can be pushed up using pulleys installed under the stool. The robot's right wrist has a first stepper motor 22, its elbow has a second stepper motor 23, and its shoulder has a third stepper motor 24. It can perform periodic bowing movements 25 with varying amplitudes according to the music intensity. The bow 25 may not have bow hair and does not contact the violin 26. Several fixed pulleys 27 are fixed at both ends of the violin, and a closed thin rope passes over the pulleys 27. A thin restraint strap (very thin) is attached to the rope in front of the violin 26 to secure the robot's hand. Figure 6 (Not shown), the string behind violin 26 is also wrapped around and straddled a drive wheel, which is driven by a fourth stepper motor.

[0024] Figure 7 This is a schematic diagram of the electro-audio system controlled by a robot, as described in this invention. The input audio signal is divided into two channels. One channel is an audio intensity signal, with three levels: high, medium, and low. The intensity signal has an adjustable knob for control. This signal is input to the core control logic module of a PLC or microcontroller. Based on the high, medium, and low amplitude of the audio intensity signal, the first to third stepper motors are controlled, controlling the periodic bow stroke amplitude of the robot's right arm. The fourth stepper motor's rotation angle is controlled based on the audio frequency, so that at high frequencies, this stepper motor rotates a large angle, and at low frequencies, it returns to a smaller angle, controlling the position of the strings in the robot's hand according to the frequency. A remote control receiver module can (start / stop) or (pause) the electro-audio system, which is crucial for directors or singers, enabling them to handle unexpected situations on set. Remote control methods include infrared, wireless, and Bluetooth. When the robot completes a long and complex accompaniment piece, the audience is impressed by the robot's "brain memory," unaware that it is playing a recorded USB signal, thus enhancing the artistic effect. Another remote control can be used to add actions such as the robot raising its head, smiling, and waving to the audience in real time, further enhancing the robot's performance and showcasing its intellectual content.

[0025] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sound-to-electric recording device and an electro-sound device based on stringed musical instruments, wherein the stringed musical instruments include plucked and bowed string instruments from both domestic and international sources, and their structure includes a headstock, tuning pegs, strings, a neck, and a soundbox; the soundbox of the erhu, a traditional Chinese bowed string instrument, is also called the soundbox, and the soundbox has a membrane made of bark; the soundbox of the violin, a Western bowed string instrument, has a soundboard, also called the soundboard; characterized in that: The aforementioned acoustic-electric recording device and electro-acoustic sound device are a pair modified from two original stringed instruments with the same material properties. One is used for acoustic-electric recording, and the other is used for electro-acoustic sound. The acoustic-electric recording device and electro-acoustic sound device also include a replacement bridge. The replacement bridge is located at the original bridge position between the strings and the diaphragm or resonating plate. It is composed of a piezoelectric ceramic plate or an electromagnetic speaker plate. The electromagnetic speaker plate is modified from the original electromagnetic loudspeaker: a lightweight plate replaces the diaphragm of the original electromagnetic loudspeaker. The height of the lightweight plate is higher than the height of the electromagnetic loudspeaker support. There is also an elastic membrane or elastic wire between the support and the lightweight plate. In some plucked string instruments, the bridge is fixed to the resonating plate, such as the pipa. In this case, the piezoelectric ceramic plate or electromagnetic speaker plate is fixed between the strings and the resonating plate in front of the original bridge. On an acoustic-electronic recording device, where the accompanist's fingers press the area between the strings and the neck of the instrument, one of the following five recording devices is provided: First, a hollow coil fixed to the neck is located adjacent to the strings, and a magnetic pin fixed to the strings can be inserted halfway into the hollow coil; second, a coil fixed to the neck is located adjacent to the strings, the coil's core containing soft iron, and a magnet or magnetic powder is fixed to the strings near the coil; third, an electret microphone fixed to the neck is located near the strings, the electret microphone having only a slit facing the strings to accommodate string vibrations, the rest covered with soundproofing material. Fourthly, there is a piezoelectric ceramic sheet between the strings and the neck; fifthly, there is an electromagnetic speaker between the strings and the neck; the five recording devices are arranged in three ways according to the number of strings: one is that all the strings share only one recording device, the second is that each string corresponds to one recording device, and the third is that several strings correspond to one recording device; the sound-electric signals collected by the recording devices are amplified by the amplification circuit and stored in a storage medium such as a USB flash drive as a backup signal source; when the signal is used, the sound-electric signals of each channel in the storage medium are extracted, amplified separately, and output to the input terminals of the piezoelectric ceramic sheets or electromagnetic speaker of the electro-acoustic device; the recording devices are connected to the piezoelectric ceramic sheets or electromagnetic speaker to reproduce the vibration frequency of the strings corresponding to the recording, based on the correspondence between the number of strings and the string position and number of the electro-acoustic device at that position. The volume of the headstock, tuning pegs, strings, neck, bridge, and soundbox of the electro-acoustic device is 0.3-50 times the volume of the corresponding headstock, tuning pegs, strings, neck, bridge, and soundbox of the acoustic-electronic recording device. The magnified headstock, tuning pegs, strings, neck, bridge, and soundbox are not fixed at the same magnification factor, but rather based on the frequency of the soundbox of the acoustic-electronic recording device being the same as the vibration frequency of the soundbox of the electro-acoustic device, and the accompanist's fingers pressing the strings... The principle is that the frequency of the string recorded below the string is the same as the vibration frequency of the string below the string when the accompanist's finger presses the corresponding string in the electro-acoustic device; under this principle, the thickness of the tuning peg and neck, the thickness of the string, the string length, the string material, the thickness of the soundbox, the material of the diaphragm or soundboard, the thickness of the diaphragm or soundboard, the tension between the diaphragm or soundboard and its surroundings, the fixing method of the diaphragm or soundboard and its surroundings, the fixing position of the piezoelectric ceramic sheet or electromagnetic speaker plate, and the number of the neck and strings are variable; On each string in the area from the nut to the tuning peg, a spring is connected in series; the membrane and the resonator box are either separate, with a tension ring added to the edge of the membrane and connected to the resonator box via a horn ring; or one end of several small springs is evenly fixed around the tension ring, and the other end of the several small springs is fixed to the resonator box; if the resonator box is a panel structure, one end of several small springs is evenly fixed at the junction of the panel and the resonator box, and the other end of the several small springs is fixed to the resonator box. The replacement bridge may be structured as follows: keeping the original bridge unchanged, bonding the original bridge to the diaphragm or soundboard as a single unit, and attaching one end of the piezoelectric ceramic plate or electromagnetic speaker plate to the other side of the diaphragm; the other end of the piezoelectric ceramic plate or electromagnetic speaker plate is fixed to the resonator housing; when the fixed position of the electromagnetic speaker plate of the acoustic-electric recording device or electro-acoustic device is far from the other side of the diaphragm, a long, straight, lightweight rigid rod is added and fixed between the coil of the electromagnetic speaker plate and the lightweight plate; the piezoelectric ceramic plate of the acoustic-electric recording device or electro-acoustic device may be composed of several piezoelectric ceramic plates connected in series, in parallel, or in a mixed configuration. Adding an operator to the electro-acoustic device is a means to improve its audio-visual effects. The electro-acoustic device is preferably controlled by a robot. Based on this, several fixed pulleys are fixed at the top and bottom of the stringed instrument. A closed thin rope passes over the pulleys around the front and back of the instrument. A restraint strap for securing the robot's hand is attached to the rope in front of the strings. The rope behind the strings is also wrapped around and connected to a drive wheel, which is driven by a fourth stepper motor. The fourth stepper motor can move along the direction of the strings according to the pitch of the music, leading an elastic rod from the restraint strap to press on the strings, thus achieving the effect of a human pressing the strings to change the pitch. A first stepper motor is installed on the robot's wrist, a second stepper motor on its elbow and wrist, and a third stepper motor on its shoulder. The control process of the first to fourth stepper motors is as follows: the audio signal, in addition to being used as the upper... In addition to the vibration signal that excites the strings, the signal is divided into two paths. One path is the audio intensity signal. After full-wave rectification and filtering, the audio signal is then divided into three levels (large, medium, and small) by a voltage comparator and input to the core control logic module of the circuit. The intensity signal has an adjustable knob to control its magnitude. When the intensity signal is small, the first stepper motor is controlled to reciprocate at a certain frequency. When the intensity signal is medium, the first and second stepper motors are controlled to reciprocate at a certain frequency simultaneously. When the intensity signal is large, the first to third stepper motors are controlled to reciprocate at a certain frequency simultaneously. The other path of the audio signal is used for frequency analysis. The instantaneous audio signal is converted from frequency to voltage and input to the core control logic module of the circuit. Based on the frequency, the output controls the rotation angle of the fourth stepper motor, so that when the frequency is high, the stepper motor rotates a large angle, and when the frequency is low, it returns to a small angle.

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