WO2019069466A1 - Speaker drive device, speaker device and program - Google Patents

Abstract

A speaker drive device according to one embodiment of this invention comprises: a first processor which outputs a first operation signal obtained from an input signal according to response characteristics on the basis of a first parameter which stipulates the equalizing circuit for a first speaker unit; a drive signal generating unit which generates a drive signal for driving the speaker unit on the basis of the first operation signal; and a modifying unit which modifies the response characteristics of the first processor on the basis of the characteristics obtained successively from the input signal.

Description

Speaker drive device, speaker device and program

The present invention relates to a technology for driving a speaker.

There are various techniques for adding an acoustic effect to the sound output from the speaker. The acoustic effect includes, for example, giving a frequency characteristic to the input audio signal. When an audio signal to which a frequency characteristic is added is supplied to the speaker, a sound to which the frequency characteristic is added is output from the speaker. Therefore, the sound characteristics can be changed variously by changing the frequency characteristics to be applied. An equalizer device for providing such an acoustic effect is disclosed, for example, in Patent Document 1.

Unexamined-Japanese-Patent No. 2010-50875

According to the technology disclosed in Patent Document 1, the addition of an acoustic effect by convoluting an impulse response is also performed. With the technique of convoluting such an impulse response, the characteristics of the sound output from the speaker can be changed variously. On the other hand, even with such a technology, it is often impossible to realize the intended sound characteristics. For example, in the case where the sound output from a speaker is artificially brought close to the sound output using a speaker other than the speaker, it is sufficient to adjust the frequency characteristics to be applied to the audio signal. It was difficult to get.

One of the objects of the present invention is to generate a drive signal for bringing a sound output from a predetermined speaker closer to a sound output from another speaker.

According to an embodiment of the present invention, there is provided a first operation unit for outputting a first operation signal obtained from an input signal according to a response characteristic based on a first parameter defining an equivalent circuit of a first speaker unit; A drive signal generation unit that generates a drive signal for driving a speaker unit based on a signal; and a change unit that changes the response characteristic of the first calculation unit based on a characteristic value sequentially obtained from the input signal And a speaker driving device characterized by comprising:

The apparatus may further include a setting unit configured to set the first parameter.

The changing unit may change the response characteristic by correcting the first parameter set by the setting unit.

The changing unit may change the response characteristic based on a relationship between the characteristic value and a predetermined condition, and the setting unit may further set the predetermined condition.

The setting unit may set the predetermined condition based on a temperature of a speaker unit to which the drive signal is supplied.

The first operation unit may control the amplitude of the first operation signal based on the relationship between the characteristic value and the predetermined condition.

The image processing apparatus may further include a first UI providing unit that provides an interface for specifying the first parameter set in the first operation unit.

The first operation signal may include information related to the position of the diaphragm of the first speaker unit.

The characteristic value may include a value obtained based on the first operation signal.

The first operation unit may control the amplitude of the first operation signal based on the characteristic value.

The drive signal generation unit includes a second operation unit that outputs a second operation signal obtained from the drive signal according to a response characteristic based on a second parameter corresponding to a second speaker unit, and a frequency characteristic of the drive signal. The drive signal may be generated based on the first operation signal and the second operation signal.

The characteristic value may correspond to the second operation signal.

Further, according to an embodiment of the present invention, there is provided a speaker device comprising the above-described speaker drive device and a speaker unit driven by the drive signal output from the speaker drive device. Be done.

Further, according to an embodiment of the present invention, there is provided a first operation unit for outputting a first operation signal obtained from an input signal according to a response characteristic based on a first parameter defining an equivalent circuit of a first speaker unit; And d) a drive signal generation unit for generating a drive signal for driving the speaker unit based on one operation signal, wherein the response characteristic changes with the progress of time. Be done.

Further, according to an embodiment of the present invention, there is provided a first operation unit for outputting a first operation signal obtained from an input signal according to a response characteristic based on a first parameter defining an equivalent circuit of a first speaker unit; 1. A drive signal generation unit that generates a drive signal for driving a speaker unit based on one operation signal, and a change that changes the response characteristic of the first operation unit based on a characteristic value sequentially obtained from the input signal A program for functioning a computer as a part is provided.

According to one embodiment of the present invention, it is possible to generate a drive signal for bringing the sound output from a predetermined speaker closer to the sound output from another speaker.

It is a block diagram which shows the function of the speaker apparatus in 1st Embodiment. It is a figure explaining the example of the parameter which defines the equivalent circuit (Lumped Parameter Model) of a speaker unit. It is the figure which showed the change of the frequency response and step response in, when Rms (machine resistance) is changed. It is the figure which showed the change of the frequency response and step response in, when Kms (stiffness) is changed. It is the figure which showed the change of the frequency response and step response in, when Mms (mass) is changed. It is a figure explaining the example of the parameter which prescribes | regulates the equivalent circuit of the speaker unit arrange | positioned at a closed type enclosure (Closed Box). It is a figure explaining the example of the parameter which defines the equivalent circuit of the speaker unit arrange | positioned at the bass reflex type enclosure (Vented Box). It is a figure explaining the template table in a 1st embodiment. It is a figure explaining the user interface in a 1st embodiment. It is a figure which shows the example of the 2nd operation signal in the case of fixing a 1st parameter and not performing amplitude control. It is a figure which shows the signal (upper figure) at the time of performing amplitude (State x) control with respect to the 2nd calculation signal shown in FIG. 10, and a gain (lower figure). It is the figure which compared the time average value of the maximum value of the absolute value of drive signal Sd by the presence or absence of amplitude (State x) control. It is a figure which shows the frequency characteristic at the time of amplitude (State x) control by a predetermined control amount (gain). It is a figure which shows the signal (upper figure) at the time of performing mechanical resistance (Rms) change control with respect to the 2nd calculation signal shown in FIG. 10, and a gain (lower figure). It is the figure which compared the time average value of the maximum value of the absolute value of drive signal Sd by the presence or absence of mechanical resistance (Rms) change control. It is a figure which shows the frequency characteristic at the time of performing mechanical resistance (Rms) change control by a predetermined control amount (gain). It is a figure which shows the signal (upper figure) at the time of performing stiffness (Kms) change control with respect to the 2nd calculation signal shown in FIG. 10, and a gain (lower figure). It is the figure which compared the time average value of the maximum value of the absolute value of drive signal Sd by the presence or absence of stiffness (Kms) change control. It is a figure which shows the frequency characteristic at the time of performing stiffness (Kms) change control by a predetermined control amount (gain). The signal (upper figure) and gain (lower figure) at the time of performing parallel change control (amplitude (State x), mechanical resistance (Rms), stiffness (Kms)) to the 2nd operation signal shown in FIG. 10 are shown. FIG. It is the figure which compared the time average value of the maximum value of the absolute value of drive signal Sd by the presence or absence of parallel change control. It is a figure which shows the frequency characteristic at the time of performing parallel change control by a predetermined control amount (gain). FIG. 13 is a diagram showing a time average value corresponding to FIG. 12 when equal loudness (A-weight) correction is performed on the drive signal Sd. It is a block diagram which shows the function of the speaker apparatus in 2nd Embodiment. It is a block diagram which shows the function of the speaker apparatus in 3rd Embodiment. It is a block diagram which shows the function of the speaker apparatus in 4th Embodiment. It is a block diagram which shows the function of the speaker apparatus in 5th Embodiment. It is a block diagram which shows the function of the speaker system in 6th Embodiment. It is an external view which shows the tablet computer in 7th Embodiment.

Hereinafter, a speaker device according to an embodiment of the present invention will be described in detail with reference to the drawings. The embodiments shown below are merely examples of embodiments of the present invention, and the present invention is not construed as being limited to these embodiments. That is, it is possible to apply the well-known technique to several embodiment described below, to deform | transform, and to implement in a various aspect. In the drawings referred to in this embodiment, the same portions or portions having similar functions are denoted by the same reference numerals or similar reference numerals (reference numerals with A, B, etc. appended after numbers), and the repetition thereof The description of may be omitted.

First Embodiment
[1. Outline of Speaker Device]
FIG. 1 is a block diagram showing the function of the speaker device in the first embodiment. The speaker device 1 includes a speaker drive device 10, an operation unit 60, a display unit 70, and a speaker unit 80. The speaker drive device 10 receives the audio signal Sin, converts the signal into a drive signal Sd for driving the speaker unit 80, and outputs the drive signal Sd. The speaker unit 80 outputs a sound corresponding to the drive signal Sd supplied from the speaker drive device 10. In the speaker device 1, although it is possible to output a sound according to the characteristic of the speaker unit 80, a speaker unit having a characteristic different from the characteristic of the speaker unit 80 (hereinafter sometimes referred to as a target speaker unit) It is also possible to output a pseudo-reproduced sound.

The operation unit 60 is a device that receives an input operation of a user such as a touch sensor, a keyboard, and a mouse, and outputs an operation signal according to the input operation to the speaker driving device 10. The display unit 70 is a display device such as a liquid crystal display or an organic EL display, and displays a screen based on control of the speaker drive device 10. The operation unit 60 and the display unit 70 may be integrated to constitute a touch panel. Hereinafter, the configuration of the speaker device 1, in particular, the configuration of the speaker driving device 10 will be described in detail.

[2. Speaker drive device]
As shown in FIG. 1, the speaker driving device 10 includes an acquisition unit 110, a first calculation unit 130, a change unit 140, a drive signal generation unit 150, and a setting unit 170. The acquisition unit 110 acquires an audio signal Sin supplied from the outside of the speaker driving device 10 as an input signal. In this example, the acquisition unit 110 is a terminal to which a device for supplying the audio signal Sin is connected. The acquiring unit 110 may acquire the audio signal Sin by receiving the audio signal Sin from an external device such as a server via a network.

[2-1. First operation unit]
The first operation unit 130 performs an operation based on the electro-mechanical model of the speaker unit using the audio signal Sin acquired by the acquisition unit 110, and outputs a first operation signal Sc1 indicating the operation result. This speaker unit is not the above-described speaker unit 80 but a target speaker unit (first speaker unit). The calculation performed by the first calculation unit 130 calculates an operation (internal state) of the target speaker unit using the audio signal Sin as an input signal, using a parameter specifying the structure of the target speaker unit. This parameter is set as the set value 130s. Further, in this example, the first calculation unit 130 includes an amplitude control unit 135 that controls the amplitude of the first calculation signal Sc1. Note that, as described later, the setting value 130s and the control amount in the amplitude control unit 135 are sequentially changed by the changing unit 140. Therefore, it can be said that the structure of the target speaker unit to be calculated, that is, the response characteristic of the target speaker unit is changed as time progresses.

The operation of the target speaker unit is, in this example, a time change of the position of the diaphragm. Therefore, in this example, the first calculation signal Sc1 corresponds to the position of the diaphragm of the target speaker unit. As a result, frequency characteristics (response characteristics) according to the target speaker unit are given to the audio signal Sin. Note that this parameter may not be a value that directly specifies the structure, but may be a parameter that indicates a characteristic obtained according to the structure of the speaker unit. Hereinafter, the parameter used in the first operation unit 130, that is, the parameter specifying the structure of the target speaker unit is referred to as a first parameter.

The first parameter is, for example, at least one of parameters defining an equivalent circuit of a target speaker unit (or each of the structures constituting the same). For example, mass, spring constant of damper, magnetic flux density, inductance, stiffness, It is a mechanical constant such as mechanical resistance. Examples of parameters that define the equivalent circuit of the speaker unit will be described later. The first parameter may be a damping factor, a resonance frequency or the like which can be calculated by combining these parameters. The first parameter may be a characteristic in the time domain (time domain) or a value for controlling this. The first parameter is a value for calculating the position (or velocity) of the diaphragm of the target speaker unit, the maximum value of the position of the diaphragm, the impulse response characteristic of the diaphragm, the step response characteristic of the diaphragm, the diaphragm The impulse response characteristic of the position of, the step response characteristic of the position of the diaphragm, or the like may be used, or the characteristic of the reproduction sound pressure may be used instead of the above-mentioned characteristics related to the diaphragm. In any case, it may be a parameter that affects the position of the diaphragm of the target speaker unit by calculation rather than parameters on a simple frequency domain (center frequency, Q, cut-off, and gain).

The first calculation signal Sc1 corresponds to the position of the diaphragm of the target speaker unit, but may be a value corresponding to the information related to this position. For example, the information related to the position may be, for example, the velocity of the diaphragm, the current, or the like. The calculation in the first calculation unit 130 uses the electro-mechanical model of the target speaker unit, but may use an acoustic (radiation characteristic) model or a space propagation model. In this case, the first calculation signal Sc1 does not indicate the position of the diaphragm of the target speaker unit, but may indicate the vibration of air at a predetermined position. Even in this case, it can be said that the calculation result relates to the position of the diaphragm. The model used for the calculation may include not only linear characteristics but also operations regarding non-linear characteristics.

As a specific content of the model used for the above-mentioned operation, any known operation method can be applied. Examples of known calculation methods are given in the following documents.
Karsten Oyen, "Compensation of Loudspeaker Nonlinearities-DSP implementation", [online], Master of Science in Electronics, University of Science and Technology Department of Electronics and Telecommunications, August 2007, p. 21-27, [April, 2016] 11th Search], Internet <URL: http://www.diva-portal.org/smash/get/diva2:347578/FULLTEXT01.pdf>

[2-2. Example of parameter defining equivalent circuit of speaker unit]
Here, the first parameter will be described in more detail. The first parameter is at least one of parameters (sometimes referred to as TS parameters) defining an equivalent circuit of the speaker unit. The specific example (Lumped Parameter Model) of the parameter which prescribes | regulates the equivalent circuit of this speaker unit is demonstrated. The second parameter described later is also the same as the first parameter.

[2-2-1. Speaker unit only]
FIG. 2 is a diagram for explaining a specific example of parameters that define an equivalent circuit (Lumped Parameter Model) of the speaker unit. The contents of each parameter shown in FIG. 2 are also shown in FIG. Here, an example of the characteristic change of the speaker unit when the values of these parameters are changed will be described. For example, when the value of the set value 130s set in the first calculation unit 130 is changed, the response characteristic of the target speaker unit can be changed.

FIG. 3 is a diagram showing changes in frequency response and step response when Rms (mechanical resistance) is changed. FIG. 3 shows changes in frequency response and step response when the value of Rms is a predetermined reference value, 0.2 times the reference value, and 5 times the reference value. By changing Rms (mechanical resistance), at least the frequency response (especially the strength of the resonant frequency) and the step response can be changed. As shown in FIG. 3, for example, if Rms is increased, the intensity at the resonance frequency (amplitude of the diaphragm) can be suppressed, and the intensity swings with little change in the rise of the vibration (rise of the sound). The time to hold back can be shortened.

FIG. 4 is a diagram showing changes in frequency response and step response when Kms (stiffness) is changed. FIG. 5 is a diagram showing changes in frequency response and step response when Mms (mass) is changed. FIG. 4 shows changes in the frequency response and the step response when the value of Kms is a predetermined reference value, 0.5 times the reference value, and 2 times the reference value. FIG. 5 shows changes in the frequency response and the step response when the value of Mms is a predetermined reference value, 0.5 times the reference value, and 2 times the reference value. As shown in FIGS. 4 and 5, changing the Kms (stiffness) or Mms (mass) can change the resonance frequency. For example, the resonance frequency can be lowered by decreasing Kms or increasing Mms. In the speaker unit, the lower limit frequency is determined by the resonance frequency in relation to the radiation impedance.

As described above, when it is intended to change the characteristics such as the frequency response of the speaker unit, in general, the thickness and weight of the diaphragm will be adjusted. Changes in conjunction with each other, and very complex design changes are required to obtain the desired characteristics. For example, in order to suppress the influence of divided vibration in the middle and high frequencies, it is desirable that the diaphragm be thick, high in rigidity, be lightweight, have a large internal loss, and have a small diameter. Moreover, in the low region, it is advantageous that the aperture is large and the distortion free amplitude is large. Furthermore, processing difficulty and durability must be taken into consideration, and it is generally difficult to simultaneously satisfy them. On the other hand, for example, by changing the value (set value 130s) of the parameter of the equivalent circuit of the target speaker unit set in the first operation unit 130, some parameters can be controlled independently from other parameters. It is possible to make adjustments such as changing the mechanical resistance without changing the weight of the diaphragm. Therefore, while using a thick diaphragm to reduce the influence of divided vibration, it is light and has good transient characteristics, large mechanical resistance, so that unnecessary vibration is less likely to occur, stiffness is small, and bass is easily produced, etc. Properties that are physically difficult to realize are easily realized, and can be adjusted later by signal processing.

2-2-2. Speaker unit arranged in a closed enclosure]
FIG. 6 is a diagram for explaining a specific example of parameters defining an equivalent circuit of the speaker unit arranged in the closed type enclosure (closed box). The contents of each parameter shown in FIG. 6 are also shown in FIG. The parameters shown in FIG. 2 are not shown in this figure. Here, the influence of Ka (stiffness) according to the capacity of the enclosure is added. As shown in FIG. 6, this parameter can also be calculated from parameters related to the shape of the enclosure, such as Sd and Cb. Therefore, Ka may be set indirectly by setting the capacity (Cb) of the enclosure instead of directly setting Ka. That is, the parameter defining the equivalent circuit is not limited to the case of being set directly, but may be set indirectly through the parameter necessary to obtain this parameter. Therefore, parameters can be set assuming enclosures of various sizes without actually making the enclosures.

2-2-3. Speaker unit arranged in a bass reflex (bus reflex) type enclosure]
FIG. 7 is a diagram for explaining a specific example of parameters defining an equivalent circuit of the speaker unit arranged in the bass reflex type enclosure (Vented Box). The contents of each parameter shown in FIG. 7 are also shown in FIG. The parameters shown in FIG. 2 are not shown in this figure. In this example, the properties of the duct section are added. Such equivalent circuits are exemplified in the following documents.
Wolfgang Klippel, "Direct Feedback Linearization of Nonlinear Loudspeaker Systems", JAES Volume 46 Issue 6 pp. 499-507; June 1998

In general, bass reflex enclosures have difficulty achieving the designed acoustic characteristics. On the other hand, in this example, the values of the parameters shown in FIG. 7 are changed assuming a bass reflex type enclosure having desired characteristics, without producing a large number of enclosures in which the shape of the duct portion is actually changed. be able to.

As described above, the parameters defining the equivalent circuit of the speaker unit can be variously taken according to the calculation model in the first calculation unit 130. All of these parameters may be changeable, or only some of them may be changeable, and the rest may be predetermined values. As described later, the second operation unit 153 is also similar to the first operation unit 130. In addition, as described later, these parameters may be sequentially changed by the changing unit 140.

As a prior art, there is also a method of realizing a response characteristic of a predetermined speaker unit using an impulse response, a transfer function or the like. However, when such a calculation method is used, in order to change the response characteristic of the speaker unit, it is necessary to prepare a separate impulse response, transfer function and the like each time. On the other hand, the response characteristic of the speaker unit can be easily changed by changing the value of the parameter that defines the equivalent circuit of the speaker unit, as in the case of the first operation unit 130.

[2-3. Amplitude control unit]
Returning to FIG. 1, the description will be continued. The amplitude control unit 135 controls the amplitude before the first operation unit 130 outputs the first operation signal Sc1. That is, amplitude control is performed on a signal obtained by adding the response characteristic by the arithmetic processing in the first arithmetic unit 130. The control amount of the amplitude is changed by the changing unit 140. As described later, the control amount of the amplitude is determined by the changing unit 140 based on the intensity of the second operation signal Sc2 (corresponding to the displacement amount in the case of the position of the diaphragm), as described later.

The amplitude control unit 135 may perform amplitude control based on the intensity of the first operation signal Sc1. In addition, the amplitude control unit 135 may be, for example, a gain that compresses / expands at a constant ratio, or suppresses values outside the range between the first threshold level and the second threshold level to a constant value (amplitude It may be a limiter (which limits the maximum value and the minimum value), or may be a compressor which compresses / decompresses values outside the range between the first threshold level and the second threshold level at a constant ratio.

[2-4. Drive signal generator]
The drive signal generation unit 150 includes a signal control unit 151, a second calculation unit 153, and an output unit 155. The signal control unit 151 receives the first operation signal Sc1 and the second operation signal Sc2, and outputs the drive signal Sa to the second operation unit 153 and the output unit 155. The drive signal Sa is generated and output so that the first operation signal Sc1 and the second operation signal Sc2 coincide with each other. The second operation signal Sc2 is a signal generated by the second operation unit 153 based on the drive signal Sa. The second operation signal Sc2 will be described later.

The output unit 155 outputs the acquired drive signal Sa to the speaker unit 80 as a drive signal Sd. In this example, the output unit 155 is a terminal to which the speaker unit 80 is connected. Further, the drive signal Sa and the drive signal Sd are the same signal. The output unit 155 may transmit the drive signal Sd to an external device via the network. The drive signal Sa and the drive signal Sd may not be the same signal. For example, the output unit 155 may adjust the dynamic range of the drive signal Sa and output it as the drive signal Sd. The drive signal Sd may be a signal obtained by amplifying the drive signal Sa. The drive signal Sa obtained as described above may have an output level larger than that of the audio signal Sin depending on the content of the calculation. In such a case, the drive signal Sd may be a signal obtained by compressing the dynamic range of the drive signal Sa.

The second operation unit 153 performs an operation based on the electro-mechanical model of the speaker unit using the drive signal Sa output from the signal control unit 151 as an input signal, and outputs a second operation signal Sc2 indicating the operation result. The speaker unit is hereinafter referred to as a drive speaker unit (second speaker unit). The calculation performed by the second calculation unit 153 calculates the operation of the drive speaker unit using the drive signal Sa as an input signal, using a parameter that specifies the structure of the drive speaker unit. This parameter is set as the set value 153s. The operation of the drive speaker unit is, in this example, a time change of the position of the diaphragm. Therefore, in this example, the second operation signal Sc2 corresponds to the position of the diaphragm of the drive speaker unit. Thus, frequency characteristics (response characteristics) corresponding to the drive speaker unit are given to the drive signal Sa.

The first operation signal Sc1 and the second operation signal Sc2 basically indicate the time change of the same physical quantity. As in the case of the first operation unit 130, this parameter may not be a value that directly specifies the structure, but may be a parameter that indicates a characteristic obtained according to the structure of the speaker unit. Hereinafter, the parameter used in the second calculation unit 153, that is, the parameter specifying the structure of the drive speaker unit is referred to as a second parameter.

The drive speaker unit assumes the above-described speaker unit 80. Therefore, the second parameter is a value related to the speaker unit 80. As described later, by making such settings, the sound output from the speaker unit 80 can be made closer to the sound of the target speaker unit. The second parameter is set to the set value 153s with the drive speaker unit as a speaker unit other than the speaker unit 80 in order to apply various unintended acoustic effects although the sound of the target speaker unit is different. May be

The second parameter is exemplified with the same contents as the above-described first parameter, and thus the description thereof is omitted. The calculation in the second calculation unit 153 may also be performed using a model similar to that of the first calculation unit 130. That is, the calculation process in the first calculation unit 130 and the calculation process in the second calculation unit 153 have the same model used for the calculation process. Although it is not necessary to use the same model for these arithmetic processing, even in this case, the second arithmetic signal Sc2 is the same as the first arithmetic signal Sc1 in order to facilitate comparison in the signal control unit 151. It is desirable that the signal is a signal that indicates the time change of physical quantity. That is, as with the first operation signal Sc1, the second operation signal Sc2 is not limited to the position of the diaphragm, but may be a value corresponding to information related to the position of the diaphragm.

The signal control unit 151 outputs the drive signal Sa such that the first operation signal Sc1 and the second operation signal Sc2 coincide with each other. This may use a general feedback control (PID control, optimal control, application control, etc.) technique for generating the drive signal Sa, or a technique similar to digital power control. The feedback gain set at the time of feedback control may be updated according to the value (set value 153 s) of the second parameter when the second parameter set in the second calculation unit 153 is changed. At this time, the feedback gain may be set to a value determined in advance according to the second parameter to be set, or may be obtained by a configuration that automatically calculates an appropriate value according to the set second parameter. The set value may be set. As a result, the drive signal Sa is output such that the second operation signal Sc2 corresponding to the drive speaker unit matches the first operation signal Sc1 corresponding to the target speaker unit.

When the drive signal Sa is supplied to the actual drive speaker unit, the drive speaker unit can be driven by the same operation as when the target speaker unit is driven by the audio signal Sin. Therefore, when the drive speaker unit is designated by the second parameter of the speaker unit 80, the sound when the audio signal Sin is output using the target speaker unit is reproduced in the sound output from the speaker unit 80. become.

As described above, when the drive speaker unit is designated by the second parameter according to the structure other than the speaker unit 80, the sound effect when the audio signal Sin is output using the target speaker unit is further enhanced ( It is also possible to output from the speaker unit 80 a sound to which an effect according to the second parameter is given.

[2-5. Setting section]
The setting unit 170 includes a parameter storage unit 171, a first UI providing unit 173, a second UI providing unit 175, a setting updating unit 177, and a threshold setting unit 179. Each parameter described above can be designated by the setting unit 170. The parameter storage unit 171 stores a template table.

FIG. 8 is a diagram for explaining a template table in the first embodiment. The template table includes a setting reference value 130sb (combination of first parameters) as a reference of the setting value 130s used in the first calculation unit 130, and a setting value 153s (combination of second parameters) used in the second calculation unit 153. It prescribes. In the example shown in FIG. 8, the template “AAA” defines a combination of the parameter A “a1”, the parameter B “b1”,. “AAA” is information corresponding to, for example, the model number of the speaker unit. The combination of parameters defined by the template “AAA” is the value of each parameter corresponding to the speaker unit of the model number. In this example, the parameters A, B,... Become the first parameter when they are set as the reference (setting reference value 130sb) of the parameter of the target speaker unit, and become the parameter (setting value 153s) of the driving speaker unit. In the case of being set in the second calculation unit 153, this is the second parameter.

Returning to FIG. 1, the description will be continued. The first UI providing unit 173 provides a user interface for specifying a first parameter to be set as the setting reference value 130sb. The second UI providing unit 175 provides a user interface for specifying a second parameter set as the setting value 153 s of the second calculation unit 153. This user interface is realized by the display of the display unit 70 and the reception of the input operation from the operation unit 60.

FIG. 9 is a diagram for explaining a user interface in the first embodiment. As shown in FIG. 9, on the display unit 70, the first user interface D1 provided by the first UI providing unit 173 and the second user interface D2 provided by the second UI providing unit 175 are displayed. The first user interface D1 is an area for designating a parameter (first parameter) related to the target speaker unit. The second user interface D2 is an area for specifying a parameter (second parameter) related to the driving speaker unit. In this example, the second user interface D2 can specify a predetermined threshold. The predetermined threshold value is a value corresponding to the maximum displacement amount of the position of the diaphragm of the drive speaker unit (for example, the range in which the diaphragm can linearly operate) in this example. In the following description, the threshold specified here is referred to as a threshold Dth.

These parameters are specified by, for example, inputting numerical values using the input box BN, the slider SL, or the dial DA. Further, the selection box SB is an interface capable of selecting a template defined in the template table. When a template is selected using the selection box SB, parameters corresponding to the template are read from the template table and automatically input. It is also possible to correct the read value. Before reading out the parameter corresponding to the template, a predetermined value such as a recommended value may be input in advance.

In the user interface, it may be possible to input information in which the deterioration of the speaker unit is assumed. For example, by inputting the use period (for example, year unit) of the speaker unit, the set parameter is corrected to correct the arithmetic processing. For example, the arithmetic processing may be corrected so as to reproduce the phenomenon that the damper becomes harder as the use period becomes longer. Not limited to the use period, a user interface may be presented which can input correction information for correcting arithmetic processing by changing parameters such as barometric pressure and humidity.

The save button BS is an interface for storing values input corresponding to each parameter in the memory as a combination of parameters as in the template. The load button BL reads the parameters stored in the memory, and inputs them in correspondence to the respective parameters of the first user interface D1 and the second user interface D2.

When the set button BT is operated, the setting updating unit 177 updates the setting of the first parameter in the setting reference value 130sb based on the value input in the first user interface D1, and inputs the setting in the second user interface D2. The setting of the second parameter in the setting value 153s is updated based on the calculated value. The value set to the setting reference value 130sb is first set to the setting value 130s by the changing unit 140.

When the set button BT is operated, the threshold setting unit 179 sets the threshold Dth input in the second user interface D2 in the changing unit 140.

By variously changing the setting reference value 130sb (the initial value of the setting value 130s) and the parameter to be set to the setting value 153s using the user interface shown in FIG. 9, the characteristics of the sound output from the speaker unit 80 are variously changed. It can be changed. For example, the target speaker unit can be changed by changing the setting reference value 130sb. When the speaker unit 80 is connected to another speaker unit X, the setting value 153s can be changed to a parameter corresponding to the speaker unit X.

[2-6. Change section]
Returning to FIG. 1, the description will be continued. The changing unit 140 acquires the second operation signal Sc2, and changes the set value 130s for the first operation unit 130 and the amplitude control amount in the amplitude control unit 135 based on the relationship between the second operation signal Sc2 and the threshold Dth. Do. Since the first operation signal Sc1 and the second operation signal Sc2 are, for example, predetermined characteristic values such as the position of the diaphragm, they can be said to be characteristic values sequentially obtained according to the audio signal Sin which is an input signal. Therefore, it can be said that the changing unit 140 changes the set value 130s to the first calculation unit 130 and the amplitude control amount in the amplitude control unit 135 based on the characteristic value when sequentially obtained from the input signal. Specifically, the change unit 140 operates as follows.

When the first parameter is set to the setting reference value 130 sb as described above, the changing unit 140 sets the same value to the setting value 130 s. After that, the changing unit 140 refers to the second operation signal Sc2 which changes sequentially, and when the position of the diaphragm indicated by the second operation signal Sc2 exceeds the threshold Dth, the position does not exceed the threshold Dth. The set value 130 s and the amplitude control amount of the amplitude control unit 135 are changed. As a result, the first operation signal Sc1 is changed, and as a result, the second operation signal Sc2 is changed so as to approach the threshold value Dth. As described above, it can be said that the changing unit 140 is a limiter for preventing the second operation signal Sc2 from exceeding the threshold value Dth. In this example, the changing unit 140 determines the setting value 130s and a parameter (a gain in this example) for changing the amplitude control amount of the amplitude control unit 135 so that the position of the diaphragm does not exceed the threshold Dth.

For example, the setting value 130s is determined by giving a predetermined gain to the setting reference value 130sb. The larger the gain, the larger the set value 130s for the set reference value 130sb. If the gain is "0", the set reference value 130sb and the set value 130s are the same. Further, with regard to the amount of amplitude control, the larger the gain, the larger the amount by which the amplitude of the first operation signal Sc1 is compressed. If the gain is "0", the amplitude control is not performed.

At this time, if the change in gain is rapid, noise may be induced. Therefore, the changing unit 140 determines the gain so as to be a change using an attack time and a release time as used in a general compressor. For example, the attack time corresponds to the time from when the signal exceeds a threshold to compression, that is, the time until control begins. The release time corresponds to the time from the signal falling below the threshold to the end of the compression, ie the time to the end of the control.

The changing unit 140 may not use the attack time / release time to control the gain. Although the control of the gain using such attack time and release time may be specifically performed using a known method, for example, a method shown in the following document may be used.
Giannoulis, Dimitrios, Michael Massberg, and Joshua D. Reiss. "Digital Dynamic Range Compressor Design? A Tutorial And Analysis". Journal of Audio Engineering Society. Vol. 60, Issue 6, pp. 399? 408.

[2-7. Example of gain control by change unit]
The changing unit 140 changes the set value 130s for one parameter in principle. That is, the gain is determined for one parameter as a change target. When changing a plurality of parameters at the same time, gain weighting is set in advance for each parameter. Then, the changing unit 140 determines one basic gain based on the second operation signal Sc2 on the assumption that the setting values 130s of the respective parameters are changed in conjunction with each other according to the predetermined weighting. It may be possible to specify which parameter is to be changed in the first user interface D1. In addition, in the case where a plurality of parameters are to be changed, the setting of weighting may also be made to be able to be specified in the first interface D1.

In the following, in the case of amplitude (State x) control in the amplitude control unit 135, the changing unit 140 changes the set value 130s of the mechanical resistance (Rms) as the first parameter as a case of changing one parameter. And three types of control for changing stiffness (Kms) will be described. In addition, a control case in which these three parameters are changed in parallel in accordance with predetermined weighting will also be described.

FIG. 10 is a diagram showing an example of the second operation signal when the first parameter is fixed and the amplitude control is not performed. The figure shows an example of the second operation signal Sc2 obtained from the input signal (audio signal Sin) in the case where the gain in the changing unit 140 is set to “0” and the setting value 130s and the amplitude control in the amplitude control unit 135 are not performed. . The horizontal axis indicates time (time), and the vertical axis indicates the maximum displacement of the diaphragm at predetermined time intervals (eg, every 0.16 s), ie, the intensity of the second operation signal Sc2 at predetermined time intervals. The maximum value of (amplitude) is shown. It also shows the set threshold Dth.

[2-7-1. Amplitude (State x) Control: State x Limiter]
FIG. 11 is a diagram showing a signal (upper figure) and a gain (lower figure) when amplitude (State x) control is performed on the second operation signal shown in FIG. This figure shows an example in which the changing unit 140 changes only the control amount of the amplitude in the amplitude control unit 135 without changing the set value 130s. As shown in FIG. 11 (upper view), the portion exceeding the threshold Dth in FIG. 10 is compressed. FIG. 11 (lower diagram) shows the gain used for the amplitude control amount in this example. In the upper and lower figures, the horizontal axis indicates the same time. As described above, since the gain is determined using the attack / release time, in FIG. 11 (upper diagram), the strength of the second operation signal Sc2 is not completely lower than the threshold Dth. Absent.

FIG. 12 is a diagram comparing the time average value of the maximum value of the absolute value of the drive signal Sd with and without the amplitude (State x) control. The solid line shown in FIG. 12 indicates the time average value from t = 0 for the maximum value of the absolute value of the drive signal Sd (without amplitude (State x) control). On the other hand, the broken line shown in FIG. 12 indicates the time average value from t = 0 for the maximum value of the absolute value of the drive signal Sd (with amplitude (State x) control). As in the comparison result, by controlling the amplitude (State x), the time average output of the absolute value of the drive signal Sd can be suppressed.

FIG. 13 is a diagram showing frequency characteristics when amplitude (State x) control is performed with a predetermined control amount (gain). In FIG. 13, the horizontal axis represents frequency (logarithmic axis) and the vertical axis represents gain. "Fres" indicates a resonant frequency. According to the amplitude (State x) control, the output on the low frequency side where the vibration tends to be large can be suppressed. If the control amount (gain) of the amplitude (State x) changes, the frequency characteristic changes, but the basic characteristics do not change significantly.

[2-7-2. Machine resistance (Rms) change control: Rms Limiter]
FIG. 14 is a diagram showing a signal (upper figure) and a gain (lower figure) when the mechanical resistance (Rms) change control is performed on the second operation signal shown in FIG. This figure shows an example in which the changing unit 140 does not perform the above-described amplitude (State x) control and performs control to change only the mechanical resistance (Rms) in the set value 130s. As shown in FIG. 14 (upper view), the portion exceeding the threshold Dth in FIG. 10 is compressed. FIG. 14 (lower view) shows the gain used to change the mechanical resistance (Rms) in this example. In the upper and lower figures, the horizontal axis indicates the same time. As described above, since the gain is determined using the attack / release time, in FIG. 14 (upper diagram), the strength of the second operation signal Sc2 is not completely lower than the threshold Dth. Absent.

FIG. 15 is a diagram comparing the time average value of the maximum value of the absolute value of the drive signal Sd with and without the mechanical resistance (Rms) change control. The solid line shown in FIG. 15 indicates the time average value from t = 0 for the maximum value of the absolute value of the drive signal Sd (without mechanical resistance (Rms) control). On the other hand, the broken line shown in FIG. 15 indicates the time average value from t = 0 for the maximum value of the absolute value of the drive signal Sd (with mechanical resistance (Rms) control). As in the comparison result, by performing the mechanical resistance (Rms) control, the time average output of the absolute value of the drive signal Sd can be suppressed.

FIG. 16 is a diagram showing frequency characteristics when mechanical resistance (Rms) change control is performed with a predetermined control amount (gain). In FIG. 16, the horizontal axis represents frequency (logarithmic axis) and the vertical axis represents gain. "Fres" indicates a resonant frequency. As understood from the difference in frequency characteristics shown in FIG. 3, the control of the mechanical resistance (Rms) (control to increase Rms) suppresses the output in the vicinity of the resonance frequency. If the control amount (gain) of the mechanical resistance (Rms) changes, the frequency characteristic changes, but the output near the resonance frequency decreases as the control amount increases.

[2-7-3. Stiffness (Kms) Change Control: Kms Limiter]
FIG. 17 is a diagram showing a signal (upper diagram) and a gain (lower diagram) when stiffness (Kms) change control is performed on the second operation signal shown in FIG. This figure shows an example in which the changing unit 140 does not perform the above-described amplitude (State x) control, and performs control to change only the stiffness (Kms) in the set value 130s. As shown in FIG. 17 (upper view), the portion exceeding the threshold Dth in FIG. 10 is compressed. FIG. 17 (lower view) shows the gain used to change the stiffness (Kms) in this example. In the upper and lower figures, the horizontal axis indicates the same time. As described above, since the gain is determined using the attack / release time, in FIG. 17 (upper diagram), the strength of the second operation signal Sc2 is not completely lower than the threshold Dth. Absent.

FIG. 18 is a diagram comparing the time average value of the maximum value of the absolute value of the drive signal Sd with and without the stiffness (Kms) change control. The solid line shown in FIG. 18 indicates the time average value from t = 0 for the maximum value of the absolute value of the drive signal Sd (without stiffness (Kms) control). On the other hand, the broken line shown in FIG. 18 indicates the time average value from t = 0 with respect to the maximum value (having stiffness (Kms) control) of the absolute value of the drive signal Sd. As in the comparison result, by performing the stiffness (Kms) control, the time average output of the absolute value of the drive signal Sd can be suppressed.

FIG. 19 is a diagram showing frequency characteristics when stiffness (Kms) change control is performed with a predetermined control amount (gain). In FIG. 19, the horizontal axis represents frequency (logarithmic axis), and the vertical axis represents gain. "Fres" indicates a resonant frequency. As understood from the difference in frequency characteristics shown in FIG. 4, according to the control of the stiffness (Kms) (control to increase Kms), the output on the low frequency side from the vicinity of the resonance frequency can be suppressed while The output increases at slightly higher frequencies. If the control amount (gain) of stiffness (Kms) changes, the frequency characteristics change, but the larger the control amount, the higher the resonance frequency and the smaller the output at the original resonance frequency, and the movement destination The output changes at the resonance frequency. The resonance frequency in FIG. 19 corresponds to the resonance frequency before control.

[2-7-4. Parallel Change Control: State x + Rms + Kms Limiter]
FIG. 20 shows signals (upper diagram) and control amounts (upper figure) when parallel change control (amplitude (State x), mechanical resistance (Rms), stiffness (Kms)) is performed on the second operation signal shown in FIG. And the lower figure). This figure shows an example in which the changing unit 140 performs control to change the amplitude (State x), the mechanical resistance (Rms) and the stiffness (Kms) using one gain. As mentioned above, these three parameters are interlocked and changed by the preset weighting. As shown in FIG. 20 (upper view), the portion exceeding the threshold Dth in FIG. 10 is compressed. FIG. 20 (lower view) shows one gain in this example, that is, a gain for changing the amplitude (State x), the mechanical resistance (Rms) and the stiffness (Kms) in conjunction. In the upper and lower figures, the horizontal axis indicates the same time. As described above, since the gain is determined using the attack / release time, in FIG. 20 (upper diagram), the strength of the second operation signal Sc2 is not completely lower than the threshold Dth. Absent.

FIG. 21 is a diagram comparing the time average value of the maximum value of the absolute value of the drive signal Sd with and without parallel change control. The solid line shown in FIG. 18 indicates the time average value from t = 0 for the maximum value (without parallel change control) of the absolute value of the drive signal Sd. On the other hand, the broken line shown in FIG. 21 indicates the time average value from t = 0 for the maximum value (with parallel change control) of the absolute value of the drive signal Sd. As in the comparison result, by performing parallel change control, the time average output of the absolute value of the drive signal Sd can be suppressed.

FIG. 22 is a diagram showing frequency characteristics when parallel change control is performed with a predetermined control amount (gain). In FIG. 22, the horizontal axis represents frequency (logarithmic axis) and the vertical axis represents gain. "Fres" indicates a resonant frequency. According to the parallel change control, the output from the vicinity of the resonance frequency to the low frequency side is suppressed. If the control amount (gain) of the parallel change control changes, the frequency characteristic changes, but the basic characteristics do not change significantly. On the other hand, if the weightings set for the amplitude (State x), the mechanical resistance (Rms) and the stiffness (Kms) are changed, the characteristics of the frequency characteristics can be largely changed. For example, as shown in FIG. 22, the frequency characteristics can be made as flat as possible (frequency dependence can be reduced). Also, the frequency characteristic is not flat and can be made to have large frequency dependency.

[2-7-5. Relationship to Equal Loudness Correction]
FIG. 23 is a diagram showing a time average value corresponding to FIG. 12 when equal loudness (A-weight) correction is performed on the drive signal Sd. The solid line shown in FIG. 23 indicates the time average value from t = 0 for the maximum value of the absolute value of the drive signal Sd (without amplitude (State x) control). On the other hand, the broken line shown in FIG. 23 represents the time average value from t = 0 for the absolute value of the signal obtained by equal loudness correction with respect to the maximum value of the absolute value of drive signal Sd (with amplitude (State x) control). It shows. As shown in FIG. 23, all the time average values are almost the same. Although FIG. 23 shows the comparison based on the presence or absence of the amplitude (State x) control corresponding to FIG. 12, similar results can be obtained by the comparison based on the presence or absence of various change control in FIGS. 15, 18 and 21.

As described above, by performing the change control in any of FIG. 12, FIG. 15, FIG. 18, and FIG. 21, the time average output is suppressed and amplitude control of the speaker can be performed. On the other hand, as shown in FIG. 23, in the signal in which the equal loudness correction has been performed on the drive signal Sd, the time average output is almost the same even when the various change control described above is performed or the control is not performed. Does not occur. This indicates that the amplitude control of the speaker is possible with little reduction in the aural volume.

As described above, the speaker drive device 10 according to the first embodiment of the present invention has various advantages as follows. In general, if the amplitude of the diaphragm in the speaker unit becomes large, non-linear distortion increases, and if the maximum amplitude is exceeded, noise may be generated, which may cause a failure. In order to suppress the occurrence of such a phenomenon, the amplitude of the drive signal itself is limited by a limiter or a compressor for the waveform signal of the sound supplied to the speaker unit. This limitation limits the amplitude of the full wavelength band. Therefore, the phenomenon that the whole sound pressure is largely reduced occurs because the amplitude is limited also in the band where the limitation is unnecessary. Even if the amplitude is limited by dividing the band, the same phenomenon occurs in that band, and the sound quality is also deteriorated in the process of band division and synthesis.

On the other hand, the amplitude of the first operation signal Sc1 is limited by the first parameter (set value 130s) used in the first operation unit 130 and the amplitude control in the amplitude control unit 135 as described above. When the amount of displacement is limited, the amplitude can be limited not by the entire wavelength band but by the desired frequency characteristics. As a result, when the drive signal Sa is provided to the speaker unit 80, it is possible to prevent the sound pressure on the auditory sense from being lowered much while suppressing the maximum amplitude of the diaphragm of the speaker unit 80.

Since the first calculation signal Sc1 may be information related to the position of the diaphragm of the speaker unit, the limitation of the amplitude by the amplitude control unit 135 may be a process of limiting the displacement amount of the diaphragm. The processing may be processing of limiting the amount of current, or processing of limiting the acceleration of the diaphragm. Also, the control of the amplitude may include not only the limitation of the amplitude but also the expansion of the amplitude. For example, if a process (amplification) is performed so as to restore the peak level to the maximum amplitude after performing a process (a compression of the dynamic range) that limits the amplitude by the compressor, the audibly sound pressure may also be increased. it can.

Second Embodiment
In the second embodiment, a speaker device 1A that measures the operation of the speaker unit 80 and generates a second operation signal Sc2 will be described.

FIG. 24 is a block diagram showing the function of the speaker device in the second embodiment. The speaker device 1A includes a speaker drive device 10A, a speaker unit 80, and a sensor 58. The sensor 58 is a detection unit that detects information related to the position of the diaphragm of the speaker unit 80 and outputs a detection signal according to the detected information. The information related to the position of the diaphragm is the position of the diaphragm in this example, but may be the velocity of the diaphragm or the acceleration of the diaphragm. The speaker driving device 10A includes an acquisition unit 110, a first calculation unit 130, a change unit 140, a drive signal generation unit 150A, and a setting unit 170A. The configuration of the speaker drive device 10A other than the drive signal generation unit 150A and the setting unit 170A is the same as that of the first embodiment, and thus the description thereof is omitted. The setting unit 170A has the same configuration as that of the first embodiment except that the second UI providing unit 175 is not present, and thus the description thereof will be omitted.

The drive signal generation unit 150A includes a signal control unit 151, an output unit 155, and a measurement unit 158. About the signal control part 151 and the output part 155, since it is the structure similar to 1st Embodiment, the description is abbreviate | omitted. The measurement unit 158 measures the position of the diaphragm of the speaker unit 80 based on the detection signal from the sensor 58. The measurement unit 158 generates a second operation signal Sc2 corresponding to the measured position of the diaphragm, and outputs the second operation signal Sc2 to the signal control unit 151. The signal control unit 151 outputs the drive signal Sa such that the first operation signal Sc1 and the second operation signal Sc2 coincide with each other.

In the first embodiment, the position of the diaphragm of the drive speaker unit is obtained by arithmetic processing using the second parameter, but in the second embodiment, it is obtained by measuring the position of the diaphragm of the speaker unit 80 There is. Also by this method, the sound when the audio signal Sin is output using the target speaker unit is reproduced in the sound output from the speaker unit 80.

Third Embodiment
In the third embodiment, a speaker device 1B will be described which automatically changes the second parameter set in the second calculation unit 153 in accordance with the connected speaker unit 80.

FIG. 25 is a block diagram showing the function of the speaker device in the third embodiment. The speaker device 1B includes a speaker drive device 10B, an operation unit 60, a display unit 70, and a speaker unit 80B. The speaker unit 80B includes, for example, a memory 85 recording identification information for identifying a model number or the like as information related to the speaker unit 80B. The speaker driving device 10B includes an acquisition unit 110, a first calculation unit 130, a change unit 140, a drive signal generation unit 150, and a setting unit 170B. The configuration of the speaker drive device 10B other than the setting unit 170B is the same as the configuration described in the first embodiment, and thus the description thereof is omitted.

The setting unit 170B includes a specifying unit 176 instead of the second UI providing unit 175 in the first embodiment. The configuration of the setting unit 170B other than the designation unit 176 is the same as the configuration described in the first embodiment, and thus the description thereof will be omitted. The designation unit 176 acquires identification information from the memory 85 in the connected speaker unit 80B, and designates the value of the second parameter based on the identification information. The designation unit 176 may acquire the identification information by wire connection such as a cable, may acquire it by wireless communication, or may acquire it by photographing an image such as a two-dimensional code. Also, the identification information may be information indicating the value of the second parameter.

When the value of the second parameter is designated by the designation unit 176, the setting update unit 177 changes the setting value 153s in the second calculation unit 153 to the value designated by the designation unit 176. By doing this, the setting value 153 s can be set even if the user does not individually input the parameter value.

Fourth Embodiment
In the fourth embodiment, the drive signal Sa can be recorded in a storage device, and a speaker device 1C will be described.

FIG. 26 is a block diagram showing the function of the speaker device in the fourth embodiment. The speaker device 1C includes a speaker drive device 10C, an operation unit 60, a display unit 70, and a speaker unit 80. Further, the storage device 50 can be connected to the speaker driving device 10C. The storage device 50 is, for example, a non-volatile memory such as a USB memory or a memory card, and can be removed from the speaker driving device 10C and connected to another device. The speaker driving device 10C and the storage device 50 may be connected by wire or may be connected wirelessly.

The speaker driving device 10C includes an acquisition unit 110, a first calculation unit 130, a change unit 140, a drive signal generation unit 150, a setting unit 170C, and a signal recording unit 190. The configuration of the speaker drive device 10C other than the setting unit 170C and the signal recording unit 190 is the same as the configuration described in the first embodiment, and thus the description thereof is omitted.

The setting unit 170C outputs, to the signal recording unit 190, information related to the parameter changed in the setting update unit 177 or the parameter that has already been set. When the parameter is set using a template, this information may be the name of the template or a value corresponding to each parameter. Here, in particular, information corresponding to the setting value 153s set in the second operation unit 153, that is, information for specifying a drive speaker unit (hereinafter referred to as drive speaker unit information) is output to the signal recording unit 190. Ru. Information corresponding to the set value 130s set in the first operation unit 130, that is, information for specifying a target speaker unit (hereinafter referred to as target speaker unit information) is added to the drive speaker unit information and a signal recording is made. It may be output to the unit 190.

The signal recording unit 190 acquires a user's instruction (recording start, end, and the like) from the operation unit 60, acquires the drive signal Sa to be recorded, and data of a predetermined file format (for example, WAVE, MP3, MP4, etc.) , And recorded in the storage device 50. At this time, drive speaker unit information is associated with the drive signal Sa and recorded. If the drive signal obtained by reading out and decoding the data recorded in the storage device 50 is supplied to the speaker unit corresponding to the drive speaker unit information, the target speaker unit set when generating the drive signal is output. Sound can be reproduced. If target speaker unit information is associated, it is also possible to confirm what this target speaker unit is like.

In the fifth embodiment, the case where the speaker unit 80 is connected to the speaker drive device 10D is exemplified. However, the speaker unit 80 may not be connected as long as it is stored in the storage device 50.

Fifth Embodiment
In the fifth embodiment, a speaker drive device 10D will be described in which the threshold Dth is determined by the temperature of the drive speaker unit.

FIG. 27 is a block diagram showing the function of the speaker device in the fifth embodiment. The speaker device 1D includes a speaker drive device 10D, an operation unit 60, a display unit 70, and a speaker unit 80D. The speaker unit 80D includes a thermometer 87 that measures the temperature of the speaker unit 80D (for example, the temperature near the voice coil). The speaker drive device 10D includes an acquisition unit 110, a first calculation unit 130, a change unit 140, a drive signal generation unit 150, and a setting unit 170D. The configuration of the speaker drive device 10D other than the setting unit 170D is the same as the configuration described in the first embodiment, and thus the description thereof is omitted.

The setting unit 170D includes a parameter storage unit 171, a first UI providing unit 173, a second UI providing unit 175, a setting updating unit 177, and a threshold setting unit 179D. The configuration of the setting unit 170D other than the threshold setting unit 179D is the same as the configuration described in the first embodiment, and thus the description thereof will be omitted. The threshold setting unit 179D acquires the temperature information of the speaker unit 80D from the thermometer 87, and changes the threshold Dth set in the changing unit 140 based on the temperature information. For example, the threshold setting unit 179D may change the setting so as to reduce the threshold Dth as the temperature rises. As a result, the intensity of the second operation signal Sc2 is controlled to be small, and as a result, the temperature of the speaker unit 80D can be lowered.

Sixth Embodiment
In the sixth embodiment, a speaker driving device 10E to which a speaker unit 80 is connected via a network will be described.

FIG. 28 is a block diagram showing a speaker system according to the sixth embodiment. The speaker system is the same as the speaker drive device 10 described in the first embodiment except that the drive signal Sd to be output is not a signal for directly driving the speaker unit, so the speaker system 10E is described. Omit.

The speaker driving device 10E encodes the driving signal Sd into data of a predetermined communication standard, and transmits the data to an external device via the network. The network is, for example, the Internet, a LAN or the like. The external device is, for example, the speaker device 8 or the server 90. The speaker driving device 10E transmits the driving signal Sd in a streaming format, but may transmit data encoded into a predetermined file format as shown in the fifth embodiment.

The speaker device 8 includes a receiving unit 83 and a speaker unit 80. The receiving unit 83 receives and decodes the drive signal Sd transmitted from the speaker drive device 10E, and supplies the drive signal Sd to the speaker unit 80.

When receiving the drive signal Sd transmitted from the speaker drive device 10E, the server 90 registers it in the database 95. At this time, as shown in the fifth embodiment, at least one of the drive speaker unit information and the target speaker unit information may be registered in the database 95 in association with the drive signal Sd.

Seventh Embodiment
In the seventh embodiment, an example will be described in which the speaker device in the above embodiment is realized on software by a computer. In this example, an example in which the speaker device 1 in the first embodiment is applied to a tablet computer 1000 will be described.

FIG. 29 is an external view showing a tablet computer according to the seventh embodiment. The tablet computer 1000 includes an input / output terminal 11, an operation unit 60, a display unit 70, and a speaker unit 80. Further, the tablet computer 1000 includes a control unit 100 and a storage unit 500. The control unit 100 has an arithmetic processing circuit such as a CPU, executes a program stored in the storage unit 500, and implements each function of the speaker driving device 10 shown in FIG. 1 on software. That is, this program causes the tablet computer 1000 to function as the speaker drive device 10. The program may be installed in advance on the tablet computer 1000, may be acquired from an external memory, or may be downloaded via a network.

The acquisition unit 110 may acquire the audio signal Sin from the input / output terminal 11, or may acquire the audio signal Sin generated by the control unit 100. When a headphone is connected to the input / output terminal 11, the output unit 155 may output the drive signal Sd to the input / output terminal 11 instead of the speaker unit 80. At this time, the set value 153s set in the second calculation unit 153 may be automatically changed. The second parameter after the change may be set to a value corresponding to the headphones. At this time, the second parameter may not necessarily be a value corresponding to the headphones connected to the input / output terminal 11. In this example, the input and output terminals 11 share the input and output terminals, but may be separately provided. As described in the third embodiment, as long as identification information can be acquired from headphones, the setting value 153s may be changed based on the identification information.

Here, although the example which implement | achieves each function of a speaker drive device on software was demonstrated, you may implement | achieve by DSP etc. FIG.

<Modification>
As mentioned above, although one Embodiment of this invention was described, each embodiment mentioned above can be combined and substituted mutually, and it is possible to apply. Moreover, in each embodiment mentioned above, it is also possible to deform | transform as follows and to implement.

(1) Each function of the speaker drive device in each embodiment may be realized by an analog circuit or may be realized by a digital circuit.

(2) The speaker driving device described above may be realized in a server connected to a network. In this case, the speaker drive device may receive the audio signal Sin via the network and transmit the drive signal Sa or the drive signal Sd via the network. In this configuration, it can be said that the server has the function of the speaker driving device 10E described in the sixth embodiment (FIG. 28).

(3) The audio signal Sin may have a plurality of channels. When one speaker unit is used in one channel, a plurality of speaker driving devices may be used according to the number of channels.

(4) In the digital speaker device, there may be a case where one speaker unit is driven by a plurality of voice coils or a plurality of speaker units are driven. When one speaker unit is driven by a plurality of voice coils, a plurality of drive signals Sd are used for one speaker unit. In this case, the drive signal Sa generated by the signal control unit may have a plurality of channels. The second calculation unit may obtain the position of the diaphragm corresponding to the drive speaker unit using the drive signals Sa of the plurality of channels. Then, the speaker unit 80 may be driven by drive signals Sd of a plurality of channels.

On the other hand, when a plurality of speaker units are used, the first calculation signal Sc1, the second calculation signal Sc2, and the drive signal Sa may be generated for the number of channels corresponding to each speaker unit. In this case, a plurality of target speaker units need to be provided, and the first calculation unit obtains the position of the diaphragm in the plurality of target speaker units based on the audio signal Sin.

As described above, with regard to the digital speaker device which drives one speaker unit with a plurality of voice coils or the digital speaker device which drives a plurality of speaker units, known techniques may be used. As the known techniques, for example, the techniques disclosed in US Pat. Nos. 8423165, 8306244, 9219960, and 9303010 can be used. According to this technique, a noise shaper using a ΔΣ modulator and a mismatch shaper that selects a voice coil that distributes drive signals so as to reduce variations are used.

On the other hand, when the drive speaker unit to be connected is changed, it is also easy to change the value of the parameter set in the second calculation unit 153. Further, although the drive speaker unit is described as a single unit, in the case where there are a plurality of channels such as stereo 2ch, it is set in the second calculation unit 153 corresponding to the drive speaker unit corresponding to each channel. You can also change the value of the For example, even if the same drive speaker unit is used for a plurality of channels, the drive speaker units have differences in characteristics due to manufacturing variations, or differences due to the environment (such as the peripheral structure) in which the speaker units are arranged And may have. In such a case, the parameters set in the second operation unit 153 may be made different for each channel according to the respective conditions.

(5) The drive signal generation unit 150 may not have the second calculation unit 153. In this case, the signal control unit 151 may perform a process of converting the first operation signal Sc1 indicating the position of the diaphragm into the drive signal Sa. This conversion process may use a known technique (for example, radiation characteristic, model operation using space propagation), or may be a process simply converting into velocity.

(6) In the embodiment described above, although the target driven by the target of the electro-mechanical model and the electrical signal (drive signal) in the first computing unit and the second computing unit was the speaker unit, It may be any object that can be described by a differential equation, such as an object that converts signals into motions, such as machine position or velocity. As an object that can be described by a differential equation, for example, an electromechanical transducer such as a motor, a piezoelectric element, a magnetostrictive element, or an electrostatic actuator is applicable to the present invention. Therefore, the speaker drive device can be said to be an example of a drive device for an electromechanical transducer. The electromechanical transducer as described above may be included in the configuration for displacing the diaphragm of the speaker unit.

(7) In the embodiment described above, an example in which both the setting reference value 130 sb and the setting value 153 s can be set is shown, but at least one or both may have a configuration that can not be changed from preset values. . If the setting reference value 130 sb and the setting value 153 s are values set in advance, for example, in the first embodiment, the speaker driving device 10 may not have the setting unit 170.

(8) In the embodiment described above, the threshold Dth is a value corresponding to the maximum displacement amount of the position of the diaphragm of the drive speaker unit, but is not necessarily limited to such a value. Various values can be taken depending on the characteristic values of the first operation signal Sc1 and the second operation signal Sc2. That is, as long as it indicates a predetermined condition, it is not limited to the threshold Dth.

(9) In the embodiment described above, the change unit 140 uses the second calculation signal Sc2 when changing the set value 130s to the first calculation unit 130 and the amplitude control amount in the amplitude control unit 135. The operation signal Sc1 may be used.

1, 1A, 1B, 1C, 1D, 8: speaker device, 10, 10A, 10B, 10C, 10D, 10E: speaker drive device, 11: input / output terminal, 50: storage device, 58: sensor, 60: operation unit , 70: display unit, 80, 80B, 80D: speaker unit, 83: reception unit, 85: memory, 87: thermometer, 90: server, 95: database, 100: control unit, 110: acquisition unit, 130: 130th 1 operation unit, 130s ... setting value, 130sb ... setting reference value, 135 ... amplitude control unit, 140 ... changing unit, 150, 150A ... drive signal generating unit, 151 ... signal control unit, 153 ... second operation unit, 153s ... Setting value 155: Output unit 158: Measurement unit 170, 170A, 170B, 170C, 170D: Setting unit 171: Parameter storage unit 173: First UI providing unit 17 ... The 2UI providing unit, 176 ... designation unit, 177 ... setting updating unit, 179,179D ... threshold setting section, 190 ... signal recording unit, 500 ... storage unit, 1000 ... tablet computer

Claims (15)

1. A first operation unit that outputs a first operation signal obtained from an input signal according to a response characteristic based on a first parameter that defines an equivalent circuit of the first speaker unit;
   A drive signal generator configured to generate a drive signal for driving the speaker unit based on the first operation signal;
   A changing unit that changes the response characteristic of the first operation unit based on a characteristic value sequentially obtained from the input signal;
   A speaker driving device comprising:
2. The speaker drive device according to claim 1, further comprising a setting unit configured to set the first parameter.
3. The speaker drive device according to claim 2, wherein the change unit changes the response characteristic by correcting the first parameter set by the setting unit.
4. The changing unit changes the response characteristic based on a relationship between the characteristic value and a predetermined condition,
   The said setting part further sets the said predetermined condition, The speaker drive device of Claim 2 or Claim 3 characterized by the above-mentioned.
5. The said setting part sets the said predetermined condition based on the temperature of the speaker unit to which the said drive signal is supplied, The speaker drive device of Claim 4 characterized by the above-mentioned.
6. The speaker drive device according to claim 4, wherein the first operation unit controls an amplitude of the first operation signal based on a relationship between the characteristic value and the predetermined condition.
7. The speaker drive device according to any one of claims 2 to 6, further comprising a first UI providing unit which provides an interface for specifying the first parameter set in the first operation unit. .
8. The speaker driving device according to any one of claims 1 to 7, wherein the first operation signal includes information related to a position of a diaphragm of the first speaker unit.
9. The speaker drive device according to any one of claims 1 to 8, wherein the characteristic value includes a value obtained based on the first operation signal.
10. The speaker driving device according to any one of claims 1 to 9, wherein the first operation unit controls the amplitude of the first operation signal based on the characteristic value.
11. The drive signal generation unit includes a second operation unit that outputs a second operation signal obtained from the drive signal according to a response characteristic based on a second parameter corresponding to a second speaker unit, and a frequency characteristic of the drive signal.
    The speaker drive device according to any one of claims 1 to 10, wherein the drive signal is generated based on the first operation signal and the second operation signal.
12. The speaker driving device according to claim 11, wherein the characteristic value corresponds to the second operation signal.
13. The speaker drive device according to any one of claims 1 to 12.
    A speaker unit driven by the drive signal output from the speaker drive device;
    A speaker device comprising:
14. A first operation unit that outputs a first operation signal obtained from an input signal according to a response characteristic based on a first parameter that defines an equivalent circuit of the first speaker unit;
    A drive signal generator configured to generate a drive signal for driving the speaker unit based on the first operation signal;
    Equipped with
    The speaker drive device characterized in that the response characteristic changes with the progress of time.
15. A first operation unit that outputs a first operation signal obtained from an input signal according to a response characteristic based on a first parameter that defines an equivalent circuit of the first speaker unit;
    A drive signal generator configured to generate a drive signal for driving the speaker unit based on the first operation signal;
    A program for causing a computer to function as a changing unit that changes the response characteristic of the first calculation unit based on a characteristic value sequentially obtained from the input signal.

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