Microphone directivity synthesis method based on single sound head

Abstract

The invention discloses a microphone directivity synthesis method based on a single sound head, and the method comprises the steps: configuring a microphone with a single sound head to generate and output two groups of four-path signals through two paths of heart-shaped directivity signal circuits under a fixed polarization voltage; and the four paths of signals are combined to form any demand directivity. According to the microphone directivity synthesis scheme based on the single sound head provided by the invention, an existing scheme of directly realizing directivity through front-end pickup equipment is abandoned, multiple paths of audio signals are creatively formed through the front-end pickup equipment, and then the required directivity is synthesized in a later period based on the multiple paths of audio signals; therefore, the operation difficulty of pickup deployment of the front-end pickup equipment is greatly reduced, and the convenience and flexibility of realizing the directivity of the microphone are improved.

Description

Technical Field

[0001] The invention relates to the field of audio technology, and in particular to a microphone directivity synthesis technology. Background Art

[0002] Currently common multi-directional microphones (i.e., microphones) usually use dual-crystal sound capsules, and the multi-directionality of the microphone is achieved by changing the magnitude of the polarization voltage of the sound capsule diaphragm.

[0003] In this solution based on achieving multiple directivities of the microphone by changing the polarization voltage of the sound head diaphragm, the corresponding directivities are directly formed and output by the pickup circuit in the microphone, that is, the desired directional audio signal is formed directly in the microphone by changing the polarization voltage of the sound head diaphragm. In this way, the directional audio signal generated by the microphone can no longer be synthesized and processed again by the back-end tuning equipment to adjust the directivity. Therefore, in order to achieve a high-quality pickup effect, this requires the front-end multiple directional microphones to be accurate in the pickup area and orientation deployment, as well as the polarization voltage adjustment; and this requires the pickup staff to have very rich experience, which makes the use of the microphone in professional scenarios more difficult.

[0004] The existing stereo sound synthesis solution needs to obtain corresponding audio signals from different directions based on multiple microphones and then perform subsequent synthesis. Such a synthesis solution is not suitable for microphone directivity synthesis.

[0005] It can be seen that providing a flexible and convenient microphone directivity synthesis solution for a single-tone microphone is an urgent problem to be solved in the art. Summary of the invention

[0006] In view of the problems existing in the existing schemes of achieving multiple directivities of microphones based on changing the polarization voltage of the sound head diaphragm, the purpose of the present invention is to provide a microphone directivity synthesis method based on a single sound head, which forms a multi-channel cardioid directional signal based on the microphone of the single sound head, and then combines it into any required directivity by the back-end tuning equipment, thereby greatly reducing the operating difficulty of the front-end microphone used for sound pickup.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a microphone directivity synthesis method based on a single-tone head. The synthesis method configures the microphone of the single-tone head to generate and output two groups of four-way signals through two-way cardioid directivity signal circuits under a fixed polarization voltage; and then combines the four-way signals into any required directivity.

[0008] In some embodiments of the present invention, the synthesis method first fixes the polarization voltage so that the single-ended high-impedance signal is generated by the single-ended head in the microphone, and then converts each single-ended high-impedance signal into two low-impedance balanced differential signals through two cardioid directional signal circuits.

[0009] In some embodiments of the present invention, in the synthesis method, two cardioid directivity signal circuits are configured to output forward simultaneously, and a circular microphone directivity can be synthesized based on the forward output signals.

[0010] In some embodiments of the present invention, in the synthesis method, one cardioid directional signal circuit is configured as a forward output, while another cardioid directional signal circuit is configured as a reverse output, so that a figure-eight microphone directivity can be synthesized based on the output signals.

[0011] In some embodiments of the present invention, in the synthesis method, one cardioid directional signal circuit is configured to output in a positive direction, while another cardioid directional signal circuit is configured to be turned off and not output, so that a cardioid microphone directivity can be synthesized based on the output signal.

[0012] The single-head-based microphone directivity synthesis solution provided by the present invention abandons the existing solution of directly realizing directivity by a front-end sound pickup device, and innovatively forms a multi-channel audio signal through the front-end sound pickup device, and then performs the required directivity for post-synthesis based on the multi-channel audio signal, thereby greatly reducing the operational difficulty of the front-end sound pickup device for sound pickup deployment and improving the convenience and flexibility of realizing the microphone directivity.

[0013] Specifically, the microphone directivity synthesis solution based on a single sound head provided by the present invention generates four-channel audio signals that can be combined into any required directional audio signals in the later stage based on a dual-crystal sound head and two-channel cardioid directional microphone circuits. As a result, the front-end microphone does not need professional polarization voltage adjustment or professional sound pickup azimuth deployment when deployed at the front end, which greatly reduces the operating requirements for the microphone and greatly improves the convenience of using the microphone.

[0014] Furthermore, the scheme of the present invention can make the later audio synthesis operation more flexible and more convenient and quick to adjust and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0016] Figure 1 It is a schematic diagram of a sound pickup circuit in a single-voice microphone in an example of the present invention;

[0017] Figure 2 This is a diagram showing an example of the structure of a sound pickup circuit in a single-voice microphone in an example of the present invention;

[0018] Figure 3 An example diagram of the directivity of a circular microphone synthesized in an example of the present invention;

[0019] Figure 4 An example diagram of the directivity of a figure-of-eight microphone synthesized in an example of the present invention;

[0020] Figure 5 This is an example diagram of the directivity of a cardioid microphone synthesized in an example of the present invention. DETAILED DESCRIPTION

[0021] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0022] Compared with the existing microphone directivity determination scheme, a variety of microphone directivities are achieved by directly changing the polarization voltage of the sound head diaphragm in the microphone; the present invention abandons this microphone directivity implementation scheme of directly adjusting the required directional audio signal in the front-end sound pickup device, and innovatively provides a post-synthesis microphone directivity scheme, thereby improving the convenience and flexibility of realizing the microphone directivity.

[0023] The microphone directivity synthesis solution provided by the present invention is aimed at a single-tone microphone, that is, is implemented based on a single-tone microphone.

[0024] The monophonic microphone is configured to generate and output two groups of four signals through two cardioid directional signal circuits under a fixed polarization voltage. The two groups of four signals are then combined into any required directivity.

[0025] In this scheme, the polarization voltage is first fixed to make the single-ended high-impedance signal in the single-tone head of the microphone generate two single-ended high-impedance signals; then, each single-ended high-impedance signal is processed by a cardioid directional signal circuit to convert the single-ended high-impedance signal into two low-impedance balanced differential signals with the same frequency, equal amplitude and a phase difference of 180 degrees, thus realizing two groups of four signals output by the microphone of the single-tone head.

[0026] In the front-end sound pickup stage of this microphone directivity synthesis solution, it is sufficient to obtain a fixed audio signal, and the final directivity will be synthesized in the later stage, which will greatly reduce the operational difficulty when the front-end microphone is deployed for sound pickup, and also bring convenience to the later synthesis adjustment.

[0027] It should be noted that the specific implementation scheme for synthesizing any required directivity based on multi-channel signals in this solution is not limited here, and can be determined according to actual needs. As an example, existing tuning equipment can be used for synthesis, but it is not limited to this.

[0028] The implementation process and corresponding technical features of the solution of the present invention are further illustrated below through specific examples.

[0029] The scheme of the present invention can be implemented based on a single-head microphone and a tuning device. The single-head microphone is used as a front-end pickup device to generate a multi-channel signal that can be synthesized into microphone directivities in the later stage; and the tuning device is used as a back-end synthesis device to synthesize the required microphone directivities, such as circular, figure-of-eight, and cardioid directivities, based on the multi-channel signals generated by the single-head microphone.

[0030] The monophonic microphone serves as the main basis for the implementation of the solution of the present invention, and its internally configured sound pickup circuit is mainly composed of a monophonic microphone and two-way cardioid directional signal circuits.

[0031] See also Figure 1 , which is a schematic diagram of the sound pickup circuit solution configured in the single-tone microphone of the present invention.

[0032] Based on the diagram, the sound pickup circuit 100 is mainly composed of an audio input module 110 , an audio amplification module 120 and an audio output module 130 that cooperate with each other.

[0033] The audio input module 110 includes a dual crystal sound head 111 and a polarization voltage circuit 112, wherein the polarization voltage circuit 112 is configured to connect the middle plate of the dual crystal sound head and provide a fixed polarization voltage for the dual crystal sound head 111. The audio input module 110 thus formed can pick up audio signals based on the dual crystal sound head 111 under the condition of a fixed polarization voltage, and simultaneously generate two audio signals, which are output to the audio amplification module 120.

[0034] The audio amplifier module 120 in the pickup circuit 100 includes a first audio amplifier circuit 121 and a second audio amplifier circuit 122. In coordination therewith, the audio output module 130 in the pickup circuit 100 includes a first audio output circuit 131, a second audio output circuit 132 and an output terminal 133.

[0035] On this basis, the signal input end of the first audio amplifier circuit 121 in the audio amplifier module 120 is connected to the forward diaphragm of the dual crystal sound head 111, and the signal output end of the first audio amplifier circuit 121 is connected to the input end of the first audio output circuit 131, and the output end of the first audio output circuit 131 is connected to the output terminal 133, thereby forming a first cardioid directional signal circuit as a first audio output channel.

[0036] The first audio output circuit 131 is configured such that the output end forms two signal output ports and is simultaneously connected to the output terminal 133 .

[0037] In the first cardioid directional signal circuit formed here, the first audio amplifier circuit 121 is configured to receive the first audio signal output by the forward diaphragm of the dual-crystal sound head 111, amplify it and output it to the first audio output circuit 131, and the first audio output circuit 131 processes the received first audio signal to form two first cardioid directional audio signal outputs.

[0038] As a further explanation, the first audio amplifier circuit 121 is specifically configured to convert the single-ended (forward) high-impedance signal of the sound head into a low-impedance balanced differential signal, and output two signals. The two differential signals after conversion have the same frequency, equal amplitude and a phase difference of 180 degrees.

[0039] In coordination therewith, the first audio output circuit 131 is configured to perform 0dB voltage gain processing on the input signal, and the first audio output circuit 131 is also configured to output low impedance and enhance load capacity. After performing corresponding output processing on the two differential signals formed by the first audio amplifier circuit 121, the first audio output circuit 131 can output to the back-end MIX stage.

[0040] At the same time, the signal input end of the second audio amplifier circuit 122 in the audio amplifier module 120 is connected to the reverse diaphragm of the dual crystal sound capsule 111, and the signal output end of the second audio amplifier circuit 122 is connected to the input end of the second audio output circuit 132, and the output end of the second audio output circuit 132 is connected to the output terminal 133, thereby forming a second cardioid directional signal circuit as a second audio output channel.

[0041] The second audio output circuit 132 is configured such that the output end forms two signal output ports and is simultaneously connected to the output terminal 133 .

[0042] In the second cardioid directional signal circuit formed here, the second audio amplifier circuit 122 receives the second audio signal output by the reverse diaphragm of the dual-crystal sound head 111, amplifies it and outputs it to the second audio output circuit 132, and the second audio output circuit 132 processes the received second audio signal to form two second cardioid directional audio signal outputs.

[0043] As a further explanation, the second-stage audio amplifier circuit 122 is specifically configured to convert the single-ended (reverse) high-impedance signal of the sound head into a low-impedance balanced differential signal, and output two signals. The two differential signals after conversion have the same frequency, equal amplitude and a phase difference of 180 degrees.

[0044] In coordination therewith, the second audio output circuit 132 is configured to perform 0dB voltage gain processing on the input signal, and the second audio output circuit 132 is also configured to output low impedance and enhance load capacity. After performing corresponding output processing on the two differential signals formed by the second-stage audio amplifier circuit 122, the second audio output circuit 132 can output to the back-end MIX stage.

[0045] Based on the above-mentioned four-way output signal, the directivity can be adjusted timely at the MIX level according to the user's demand for directivity or conveniently during post-music production, thereby solving the problem in existing solutions that the directivity adjustment is not suitable on site and cannot be changed later.

[0046] As can be seen from the above, the pickup circuit 100 forms a parallel first cardioid directional signal circuit and a second cardioid directional signal circuit through the cooperation of the audio amplifier module 120 and the audio output module 130, and is connected in parallel to the dual crystal sound head 111 in the audio input module 110, and can process the two audio signals output by the dual crystal sound head 111 at the same time, and generate and output two groups of four-way signals. These two groups of four-way signals can be input to the back-end tuning equipment and randomly combined into the required directional signals, such as circular, figure eight, heart-shaped, etc.

[0047] See also Figure 2 , which shows a specific implementation circuit example of the above-mentioned pickup circuit 100 when in application.

[0048] Based on the diagram, in the specific implementation of the pickup circuit 100, the audio input module is mainly composed of a dual-crystal sound head, a high resistor R6, and a high resistor R19; the formed audio input module can output two-way sound head single-ended high impedance signals.

[0049] The audio amplifier module is mainly composed of two parallel first audio amplifier circuits and second audio amplifier circuits formed by high resistors R7 and R18, FET tubes T2 and T4, and resistors R2, R10, R11, R12, R14, R21, R22, and R23.

[0050] The audio output module is mainly composed of resistors R1, R3, R4, R5, R8, R9, R13, R15, R16, R17, R20, R21, capacitors C3, C4, C5, C6, C10, C11, C12, C13, transistors T1A, T1B, T3A, T3B, inductors L1, L2 and output terminal XLR1, and forms two parallel first audio output circuits and second audio output circuits.

[0051] As a further explanation, in the specific construction of the pickup circuit, the middle plate 1 of the dual-crystal sound head is connected to a polarization voltage, where the polarization voltage is a fixed value.

[0052] The positive diaphragm (Pin0) in the dual crystal sound head is connected to one end of the high resistance R6, and the other end of the high resistance R6 is connected to the ground. The positive diaphragm (Pin0) is connected to one end of the coupling capacitor C2, and the other end of the coupling capacitor C2 is connected to the gate of the FET tube T2. The gate of T2 is also connected to one end of the high resistance R7. The other end of the high resistance R7 is connected to one end of the resistor R12. The other end of the resistor R12 is grounded. The other end of the high resistance R7 is also connected to one end of the resistor R10. The other end of the resistor R10 is connected to the source of T2. The source of T2 is connected to one end of the resistor R11, and the other end of one end of the resistor R11 is grounded; the source of T2 is also connected to one end of the capacitor C7, and the other end of C7 is connected to the base of the transistor T1A. The base of T1A is respectively connected to one end of the resistors R5 and R8. The other end of R5 is connected to the collector of T1A, and the other end of R8 is connected to the emitter of T1A. The emitter of T1A is connected to the One end of resistor R9, the other end of R9 is connected to the 4th pin of inductor L1, the 4th pin of L1 is connected to capacitor C4, the other end of C4 is grounded, the 3rd pin of L1 is also connected to capacitor C6 to ground, the 3rd pin of L1 is connected to the 3rd pin of output terminal XLR1 to output a negative signal; the drain of T2 is connected to the power supply VCC through resistor R2, the drain of T2 is also connected to the base of transistor T1B through capacitor C1, the base of T1B is respectively connected to one end of resistors R1 and R4, the other end of R4 is connected to the collector of T1B, the collector of T1B is also connected to the collector of T1A; the other end of R1 is connected to the emitter of T1B, the emitter of T1B is connected to one end of resistor R3, the other end of R3 is connected to the 1st pin of L1, the 1st pin of L1 is connected to capacitor C3, the other end of C3 is grounded, the 2nd pin of L1 is also connected to capacitor C5 to ground, the 23rd pin of L1 is connected to the 2nd pin of output terminal XLR1 to output a positive signal.

[0053] The reverse diaphragm (Pin2) in the dual crystal sound head is connected to one end of the high resistance R19, the other end of the high resistance R19 is connected to the ground, the reverse diaphragm (Pin2) is connected to one end of the coupling capacitor C9, the other end of C9 is connected to the gate of the FET tube T4, the gate of T4 is also connected to one end of the high resistance R18, the other end of the high resistance R18 is connected to one end of the resistor R24, the other end of the resistor R24 ​​is grounded, the other end of the high resistance R18 is also connected to one end of the resistor R22, the other end of the resistor R22 is connected to the source of T4, the source of T4 is connected to one end of the resistor R23, the other end of one end of the resistor R23 is grounded, and the source of T4 is also connected to one end of the capacitor C14; the other end of C14 is connected to the base of the transistor T3A, the base of T3A is respectively connected to one end of the resistors R17 and R20, the other end of R17 is connected to the collector of T3A, and the other end of R20 is connected to the emitter of T3A; the emitter of T3A is connected to the one end; the other end of R21 is connected to the 4th pin of inductor L2, the 4th pin of inductor L2 is connected to capacitor C11, the other end of C11 is grounded, and the 3rd pin of L2 is also connected to capacitor C13 to ground; the 3rd pin of L2 is connected to the 5th pin of output terminal XLR1 to output a negative signal; the drain of T4 is connected to the power supply VCC through resistor R14, the drain of T4 is also connected to the base of transistor T3B through capacitor C8, the base of T3B is respectively connected to one end of resistors R13 and R16, the other end of R16 is connected to the collector of T3B, the collector of T3B is also connected to the collector of T3A, the other end of R13 is connected to the emitter of T3B, the emitter of T3B is connected to one end of resistor R15, the other end of R15 is connected to the 1st pin of L2, the 1st pin of L2 is connected to capacitor C10, the other end of C10 is grounded, the 2nd pin of L2 is also connected to capacitor C12 to ground, and the 2nd pin of L2 is connected to the 4th pin of output terminal XLR1 to output a positive signal.

[0054] In the pickup circuit thus formed, the dual crystal sound head picks up the audio signal, and outputs two audio signals from the front and back sides of the sound head respectively (that is, outputs two single-ended high-impedance signals of the sound head), and the two signals are processed by two parallel audio amplification circuits respectively, and each signal is processed by the corresponding amplification circuit and converted into two low-impedance balanced differential signals with the same frequency, equal amplitude and a phase difference of 180 degrees; in this way, the four signals generated by the two parallel audio amplification circuits are output to the two parallel audio output circuits at the same time, and then processed by the two parallel audio output circuits to output two groups of four signals, which are the signals of channel 1 (2+, 3-) picked up by the front side of the sound head and channel 2 (4+, 5-) picked up by the back side.

[0055] The specific structure of the tuning device will not be described here, and can be determined according to actual needs.

[0056] When synthesizing the microphone directivity later based on the above-mentioned combination of the monophonic microphone and the tuning device, the two audio output channels of the monophonic microphone are configured to output the Cardioid signal simultaneously, and then the required microphone directivity is synthesized by the tuning device. The two audio output channels here are: channel 1 (2+, 3-) picked up from the front and channel 2 (4+, 5-) picked up from the back.

[0057] The following example illustrates the implementation process of synthesizing circular, figure-of-eight, and heart-shaped directivities based on the above example scheme.

[0058] (1) Based on the above-mentioned monophonic microphone, the audio output channel 1 (2+, 3-) and the audio output channel 2 (4+, 5-) of the monophonic microphone can be configured to output in the forward direction at the same time, and then the circular directivity can be synthesized by the tuning device, such as Figure 3 described.

[0059] Specifically, the dual-crystal sound head in the pickup circuit of the single-head microphone outputs two single-ended high-impedance signals of the sound head simultaneously based on a fixed polarization voltage; the two parallel groups of audio amplification circuits in the pickup circuit respectively process and convert the single-ended high-impedance signals of each sound head into two low-impedance balanced differential signals of the same frequency, equal amplitude and 180 degrees phase difference, thereby forming two groups of four-way differential signals; the two groups of four-way differential signals are simultaneously output to the subsequent two parallel audio output circuits, and then processed by the two parallel audio output circuits and output to the back end, thereby forming the forward output of audio channel 1 (2+, 3-) and audio output channel 2 (4+, 5-), and then the circular directivity is synthesized by the tuning equipment.

[0060] (2) Based on the above-mentioned single-head microphone, the audio output channel 1 of the single-head microphone can be configured as a forward output (2+, 3-); at the same time, the audio output channel 2 (4+, 5-) can be configured as a reverse output (4-, 5+), and then the tuning equipment can synthesize the figure-eight directivity, such as Figure 4 described.

[0061] Specifically, the dual-crystal sound head in the pickup circuit of the single-head microphone outputs two single-ended high-impedance signals of the sound head simultaneously based on a fixed polarization voltage; the two parallel groups of audio amplification circuits in the pickup circuit respectively process and convert the single-ended high-impedance signals of each sound head into two low-impedance balanced differential signals with the same frequency, equal amplitude and a phase difference of 180 degrees, thereby forming two groups of four-way differential signals; the two groups of four-way differential signals are simultaneously output to the subsequent two parallel audio output circuits, and then processed by the two parallel audio output circuits and output to the back end, thereby forming the forward output of audio channel 1 (2+, 3-) and audio output channel 2 (4+, 5-).

[0062] On this basis, keep the audio output channel 1 forward (2+, 3-) configured as forward output, and at the same time, configure the output signal of audio output channel 2 (4+, 5-) to reverse and become (4-, 5+) output through hardware devices or software at the back end, and then synthesize the figure eight directivity by the tuning equipment.

[0063] (3) Based on the above-mentioned monophonic microphone, the audio output channel 1 (2+, 3-) of the monophonic microphone can be configured as a positive output; at the same time, the audio output channel 2 (4+, 5-) can be configured to be closed and not output, and then the tuning device can synthesize a cardioid directivity, such as Figure 4 described.

[0064] Specifically, the dual-crystal sound head in the pickup circuit of the single-head microphone outputs two single-ended high-impedance signals of the sound head simultaneously based on a fixed polarization voltage; the two parallel groups of audio amplification circuits in the pickup circuit respectively process and convert the single-ended high-impedance signals of each sound head into two low-impedance balanced differential signals with the same frequency, equal amplitude and a phase difference of 180 degrees, thereby forming two groups of four-way differential signals; the two groups of four-way differential signals are simultaneously output to the subsequent two parallel audio output circuits, and then processed by the two parallel audio output circuits and output to the back end, thereby forming the forward output of audio channel 1 (2+, 3-) and audio output channel 2 (4+, 5-).

[0065] On this basis, keep the audio output channel 1 positive (2+, 3-) configured as positive output, and at the same time, configure the audio output channel 2 (4+, 5-) to be closed and not output through the background hardware device or software; then the tuning equipment will synthesize the cardioid directivity.

[0066] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for synthesizing microphone directivity based on a single-tone head, characterized in that: The synthesis method configures a single-voice microphone to generate and output two groups of four-way signals through two-way cardioid directional signal circuits under a fixed polarization voltage; and then combines the four-way signals into any required directivity.

2. The method for synthesizing microphone directivity based on a single-tone head according to claim 1, characterized in that: In the synthesis method, a polarization voltage is first fixed so that a single-ended high-impedance signal is generated by a single-ended head in a microphone, and then each single-ended high-impedance signal is converted into two low-impedance balanced differential signals through two cardioid directional signal circuits.

3. The method for synthesizing microphone directivity based on a single-tone head according to claim 1, characterized in that: In the synthesis method, two cardioid directivity signal circuits are configured to output forward simultaneously, and circular microphone directivity can be synthesized according to the forward output signals.

4. The method for synthesizing microphone directivity based on a single-tone head according to claim 1, characterized in that: In the synthesis method, one cardioid directional signal circuit is configured as a forward output, and another cardioid directional signal circuit is configured as a reverse output, so that the figure-eight microphone directivity can be synthesized according to the output signals.

5. The method for synthesizing microphone directivity based on a single-tone head according to claim 1, characterized in that: In the synthesis method, one cardioid directional signal circuit is configured to output in a positive direction, while another cardioid directional signal circuit is configured to be closed and not output, so that the cardioid microphone directivity can be synthesized according to the output signal.

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