System and method for improving robustness of loudspeaker control in abnormal situations

Abstract

In at least one embodiment, a speaker system is provided. The speaker system includes at least one speaker, an amplifier, and at least one controller. The at least one speaker system transmits an audio output signal. The amplifier transmits a drive signal to the speaker to transmit the audio output signal in response to the first audio signal. The controller includes: a parameter estimation block that generates speaker system parameters; and a feed-forward processing block that models the loudspeaker system to provide the first audio signal to the amplifier based on the modeled loudspeaker system parameters. The controller includes an adaptive switch that controls the parameter estimation block based on at least one of: a measured characteristic of the drive signal provided by the amplifier, and a measured response associated with at least one characteristic of the at least one speaker.

Description

Technical Field

[0001] Aspects disclosed herein generally relate to systems and methods for improving the robustness of speaker control under abnormal circumstances. These and other aspects will be disclosed in greater detail herein. Background Art

[0002] Adaptive speaker control systems can operate properly under normal operating conditions. However, in situations where unexpected disturbances act on the speaker system, parameter estimation may fail to produce correct parameter feedback. Examples of such disturbances include a user touching a moving part, a vent port becoming clogged, foreign matter adhering to the speaker's diaphragm, or the speaker being exposed to water.

[0003] Such interference adds extraneous noise to the measured response obtained from the loudspeaker control system. Furthermore, the interference alters the dynamics of the model used to estimate the loudspeaker control system's parameters. This alteration renders the estimated loudspeaker parameters unreliable, and as a result, protection and compensation functions in the amplifier's feedforward processing block may not operate correctly. These effects can then lead to mechanical overshoot, excessive distortion, or even complete failure due to mechanical or thermal overload. Summary of the Invention

[0004] In at least one embodiment, a speaker system is provided. The speaker system includes at least one speaker, an amplifier, and at least one controller. The at least one speaker transmits an audio output signal. The amplifier transmits a drive signal to the speaker in response to a first audio signal to transmit the audio output signal. The at least one controller includes: a parameter estimation block that generates speaker system parameters; and a feedforward processing block that models the speaker system to generate modeled speaker system parameters and provides the first audio signal to the amplifier based on the modeled speaker system parameters. The at least one controller includes an adaptive switch that controls the parameter estimation block based on at least one of: a measured characteristic of the drive signal provided by the amplifier, and a measured response associated with at least one characteristic of the at least one speaker.

[0005] In at least one embodiment, a speaker system is provided. The speaker system includes at least one speaker, an amplifier, and at least one controller. The at least one speaker transmits an audio output signal. The amplifier transmits a drive signal to the speaker in response to a first audio signal to transmit the audio output signal. The at least one controller includes: a parameter estimation block programmed to generate speaker system parameters; and a feedforward processing block programmed to model the speaker system parameters and provide the first audio signal to the amplifier based on the modeled speaker system parameters. The at least one controller further includes a protection control block programmed to transmit a threshold to the feedforward processing block to adjust the drive signal to mechanically protect the at least one speaker.

[0006] In at least one embodiment, a method for controlling a speaker system is provided. The method includes transmitting an audio output signal via at least one speaker and providing a drive signal from an amplifier to the speaker in response to a first audio signal to transmit the audio output signal. The method further includes generating speaker system parameters via at least one controller and modeling the speaker system to provide the first audio signal to the amplifier based on the modeled speaker system parameters. The method further includes controlling the at least one controller based on at least one of: a measured characteristic of the drive signal provided by the amplifier and a measured response associated with at least one characteristic provided by the at least one speaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The embodiments of the present disclosure are particularly pointed out in the appended claims. However, other features of the various embodiments will become more apparent and will be best understood by referring to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0008] Figure 1 An example of adaptive feedforward control of a loudspeaker system is depicted;

[0009] Figure 2 Depicts the Figure 1 An example of using the parameter estimation block with adaptive feedforward control;

[0010] Figure 3 Describes experiencing disturbance Figure 1 Adaptive feed-forward control of loudspeaker systems;

[0011] Figure 4 Adaptive feed-forward control of a loudspeaker system according to one embodiment is depicted;

[0012] Figure 5 A first method for performing adaptive switching of a speaker system according to one embodiment is described;

[0013] Figure 6 A method for performing protection control of a loudspeaker system according to one embodiment is described;

[0014] Figure 7 Depicted according to one embodiment Figure 6 Example of error-threshold mapping for the method;

[0015] Figure 8 depicts an example of fitting error of parameter estimates according to one embodiment;

[0016] Figure 9 depicts an example of displacement thresholds for a loudspeaker driver and a passive radiator according to one embodiment; and

[0017] Figure 10 Speaker system parameters according to one embodiment are depicted. DETAILED DESCRIPTION

[0018] As required, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to illustrate details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0019] Aspects disclosed herein provide for robust operation of adaptive loudspeaker control algorithms. For example, the disclosed systems and methods can adjust various parameters of a parameter estimation block in a loudspeaker system by checking the level, continuity, and coherence of measured voltage and response signals to facilitate updates under abnormal conditions. If modeling errors are large, the disclosed systems and methods can adaptively reduce mechanical protection thresholds. Using the disclosed systems and methods, a loudspeaker control system (or loudspeaker system) can be more robust under abnormal conditions (e.g., when operating under external interference or when parameters have not yet converged).

[0020] In principle, the measured response can be any physical quantity that contains information about the state of the loudspeaker system. For example, voice coil current, cabinet pressure, displacement, velocity, or acceleration of the loudspeaker driver, passive radiator (PR), and ventilation air. The overall concept of protection threshold control can be summarized as equipping the loudspeaker system with a sensor that reduces its output if an external disturbance is applied to the loudspeaker system.

[0021] Generally speaking, adaptive loudspeaker control systems can function as expected under normal operating conditions. However, in situations where unexpected external disturbances act on the loudspeaker system, parameter estimation may fail to produce correct parameter feedback. Examples of disturbances include a user touching a moving part of the loudspeaker system, a blocked port on a vented box, an object adhering to the diaphragm, or the loudspeaker being exposed to water. These disturbances add irrelevant noise to the measured response or alter the dynamics of the physical system, making it impossible for the model within the parameter estimation block to capture them. The estimated parameters may be unreliable, and as a result, the protection and compensation functions within the feedforward processing block will not operate correctly, leading to mechanical overshoot, excessive distortion, or even complete failure due to mechanical or thermal overload. The disclosed system and method make the loudspeaker protection and compensation system more robust under abnormal conditions. More specifically, the parameter feedback is more stable and less sensitive to short-term, irrelevant external disturbances. Additionally, the risk of mechanical overshoot and excessive distortion caused by incorrect parameters is reduced. Such incorrect parameters can occur under external disturbances or when the parameters have not yet converged.

[0022] Figure 1 An example of adaptive feedforward control of a speaker system 100 is depicted. System 100 generally includes at least one digital signal processor (DSP) 102 (or at least one controller 102 (hereinafter referred to as "controller 102")), an amplifier 104, at least one speaker 106 (hereinafter referred to as "speaker 106"), and at least one sensor 108 (hereinafter referred to as "sensor 108"). In one example, sensor 108 can be a microphone. Controller 102 includes a feedforward processing block 120 and a parameter estimation block 122. Feedforward processing block 120 and parameter estimation block 122 form a control block within controller 102 for controlling the audio transmitted by speaker 106.

[0023] Generally speaking, model-based speaker control algorithms are becoming increasingly popular due to their ability to improve the sound quality of a given speaker system. An example of such a model-based speaker control algorithm is the SmartPA technology that has been widely used for micro speakers on mobile devices. In general, the control algorithm usually follows Figure 1The framework of the adaptive feedforward control shown. The feedforward processing block 120 provides sound enhancement functions, which may include mechanical and thermal protection, nonlinear compensation and automatic equalization of the speaker 106 (or system 100). The feedforward processing block 120 can be based on modeling the speaker system 100, and the performance of the feedforward processing block 120 can depend on the accuracy of the model. On the other hand, the transmission characteristics of a real speaker system have large uncertainties due to production differences and time-varying effects. For this reason, the parameter estimation block 122 may need to update the parameters of the model in real time to ensure alignment between the feedforward processing block 120 and the actual speaker system being controlled. The embodiments disclosed herein can improve the robustness of the system 100.

[0024] Controller 102 provides a first audio signal to amplifier 104. Amplifier 104 amplifies the first audio signal to provide a drive signal (or stimulus voltage), which is provided to speaker 106. Amplifier 104 provides a measured voltage corresponding to the drive signal transmitted to speaker 106. Generally speaking, amplifier 104 provides the stimulus voltage (or drive signal) to drive speaker 106 to generate an audio output signal. Sensor 108 picks up or senses a characteristic associated with speaker 106 and transmits a signal as a measured response to parameter estimation block 122. When the stimulus voltage is being applied, the measured response generally corresponds to the response signal of speaker 106. Sensor 108 generally detects any one or more characteristics, such as voice coil current, chamber pressure, displacement, velocity, the driver of speaker 106, the passive radiator (PR) of speaker 106, and acceleration of the air venting speaker 106. Therefore, in this regard, any one or more of the above-mentioned characteristics can correspond to the measured response.

[0025] Depending on which response signal or speaker characteristic is measured, sensor 108 may correspond to circuitry for sensing current, a microphone, a vibration sensing laser, a vibration sensing capacitor, or an accelerometer. Parameter estimation block 122 models various transfer characteristics between the measured voltage and the measured response.

[0026] Figure 2 Depicts the Figure 1 The parameter estimation block 122 of the controller 102 is an example of a controller 102 used in conjunction with adaptive feedforward control of the speaker system 100. The parameter estimation block 122 includes a minimization block 150, a modeling block 152, and an adder block 154. The parameter estimation block 122 takes as input a voltage and at least one measured response of the speaker system 100. The parameter estimation block 122 uses the modeling block 152 to calculate the voltage between the two measured signals (e.g., Figure 2The parameters (or transfer characteristics) of the loudspeaker 106 are modeled between x and y as shown in FIG. The parameters of the model are estimated by the modeling block 152 through an algorithm, and at least one output is provided as an error signal to the minimization block 150 to minimize the error between the modeled output and the measured output. It should be appreciated that with respect to Figure 2 As shown, the voltage can be switched and the response signal measured.

[0027] Figure 3 Describing the experience of disturbance Figure 1 Adaptive feedforward control of the speaker system 100. The system 100 generally performs quite well under normal conditions. However, in some cases, the system 100 experiences external disturbances, and the parameter estimation block 122 may generate incorrect parameters for controlling various aspects (e.g., parameters) of the speaker 106. Examples of disturbances may include a user touching a moving part of the speaker 106, a port of a ventilation box associated with the speaker 106 becoming blocked, the speaker 106 being exposed to water, etc. These disturbances may add irrelevant noise to the measured response of the speaker system 100. In addition, the disturbances may change the dynamics of the physical system (e.g., the speaker 106) such that the model of the parameter estimation block 122 may not be able to correctly adapt the parameters of the speaker 106. As a result, the estimated speaker parameters may be unreliable, and as a result, the feedforward processing block 120 may not operate correctly, resulting in mechanical overshoot, excessive distortion, or even complete failure due to mechanical or thermal overload. Various mechanisms may be required to ensure robust operation under such disturbances.

[0028] The SmartPA technology described above can be used in microspeakers on smartphones, tablets, and laptops, where the speaker housing is typically a closed box with the front outlet protected by a grille. External interference is minimized, and the most likely scenario involves a blocked outlet grille. In this case, the diaphragm displacement may actually be smaller, so this may not pose any serious problems.

[0029] However, this isn't the case for larger products, where the radiating surfaces (loudspeaker diaphragm, passive radiators, port outlets) are often directly exposed, making these larger products more susceptible to interference. This can be even more problematic for higher-order systems, such as ventilated boxes and passive radiator systems. For example, a blocked vent in a ventilated box can increase the displacement of the loudspeaker diaphragm within a certain frequency range. This can also alter the system's dynamics, making parameter convergence impossible.

[0030] Figure 4 Adaptive feed-forward control of a loudspeaker system 200 according to one embodiment is depicted. The system 200 includes the above combined Figure 1The controller 102, amplifier 104, speaker 106, and sensor 108 are shown. The system 200 also includes an adaptive switch 202 and a protection control block 204 within the controller 102. The adaptive switch 202 is operatively coupled to the parameter estimation block 122 and receives the voltage from the amplifier 104 and the measured response from the sensor 108.

[0031] The adaptive switch 202 checks whether the voltage from the amplifier 104 and the measured response from the sensor 108 are suitable for updating the model parameters provided by the parameter estimation block 122. If the adaptive switch 202 determines that the measured response and voltage are not suitable, the adaptive switch 202 controls the parameter estimation block 122 to freeze the adaptation and output the parameters from the previous frame. Although not shown, it should be appreciated that the voltage and measured response can be transmitted as digital inputs (or frames) to the parameter estimation block 122 and the adaptive switch, and an analog-to-digital converter (ADC) (not shown) can be positioned between the parameter estimation block 122 and the amplifier 104 and the sensor 108 to convert the analog variants of the measured response and voltage into digital data for processing by the parameter estimation block 122 and the adaptive switch 202.

[0032] The protection control block 204 calculates or determines the machine protection threshold for the feedforward processing block 120 in response to the model fitting error signal (or model fitting error). The parameter estimation block 122 determines and provides the model fitting error, as combined with the Figure 2 , which is shown as provided from the output of the adder block 154. If the protection control block 204 determines that the fitting error is large (e.g., above a threshold), such a large fitting error indicates that the model is unreliable. In this case, the protection control block 204 reduces the protection threshold for the protection system 200.

[0033] Figure 5 A first method 250 for performing adaptive switching of the speaker system 200 according to one embodiment is depicted. The controller 102 performs the first method 250 to determine whether the current frame of the input signal (e.g., the voltage from the amplifier 104 or the measured response from the sensor 108) is suitable for parameter updating. The first method 250 shown in conjunction with the adaptive switch 202 may require the conditions set forth in operations 256, 262, and 268. These aspects will be discussed in more detail below. In operation 252, the controller 102 obtains (or acquires) a data frame corresponding to the voltage from the amplifier 104 and the measured response from the sensor 108 (or microphone).

[0034] In operation 254, the controller 102 calculates the root mean square (RMS) value of the measured voltage and the measured response. The controller 102 calculates the RMS value of the measured voltage and the measured response to ensure that the stimulation voltage and / or the measured response are large. For example, the controller 102 may calculate the RMS value based on the following equation:

[0035] ,in is the sample index in the data frame.

[0036] It will be appreciated that the variable x set forth above may correspond to a measured voltage output by the amplifier 104 or a measured response provided by the sensor 108 .

[0037] In operation 256, the controller 102 compares the calculated RMS value to a threshold value. For example, the controller 102 compares the calculated RMS value of the voltage to a first threshold value and compares the calculated RMS value of the measured response to a second threshold value. It should be appreciated that the first threshold value and the second threshold value may correspond to the same value or be relative to each other, or may be equal to different values. If any one or more of the measured voltage or the calculated RMS value of the measured response is less than the first threshold value or the second threshold value, respectively, the method 250 moves to operation 258. If not, the method 250 moves to operation 260.

[0038] In operation 258 , the controller 102 determines that the signal (eg, measured voltage and / or measured voltage response) is too low and controls the parameter estimation block 122 to freeze or stop calculating parameter estimates for the feedforward processing block 120 until new data is available.

[0039] In operation 260, the controller 102 calculates a second derivative test. For example, the controller 102 calculates a second derivative test to determine if there are any discontinuities in the measured voltage or the measured response. Such discontinuities correspond to the result of a software problem or may otherwise be attributed to a software problem associated with the controller 102 that may negatively impact the parameter estimation block 122. For example, the controller 102 may calculate a second (2nd) derivative test (e.g., d2(n)) based on the following equation:

[0040] ,

[0041] where h is the sample interval.

[0042] It will be appreciated that the variable x set forth above may correspond to a measured voltage output by the amplifier 104 or a measured response provided by the sensor 108 .

[0043] In operation 262, the controller 102 compares the calculated second-order derivative to a threshold value. For example, the controller 102 compares the second-order derivative of the voltage to a first threshold value and compares the second-order derivative of the measured response to a second threshold value. It should be appreciated that the first threshold value and the second threshold value may correspond to the same value or be relative to each other, or may be equal to different values. If any one or more of the measured voltage or the calculated second-order derivative of the measured response is greater than the first threshold value or the second threshold value, respectively, the method 250 moves to operation 264. If not, the method 250 moves to operation 266.

[0044] In operation 264, the controller 102 determines that there is a discontinuity in the measured voltage and / or the measured response and freezes the adaptation. In this case, the controller 102 determines that the signal (e.g., the measured voltage and / or the measured voltage response) indicates a discontinuity in the system 200 and controls the parameter estimation block 122 to freeze or stop calculating the parameter estimate values ​​of the feedforward processing block 120 until new data is available.

[0045] In operation 266, the controller 102 performs a coherence test. For example, the controller 102 calculates the coherence of the measured voltage and the measured response. . Coherence Corresponds to an estimate of the degree to which signal y (e.g., the signal corresponding to the measured response) is linearly correlated with signal x (e.g., the signal corresponding to the measured voltage). It is usually a function of frequency and can be defined as:

[0046] ,

[0047] in 、 and It is the signal (e.g., measured voltage) and Estimates of the power spectrum and cross-power spectrum of (e.g., the measured response). These values ​​can be calculated using various methods (e.g., exponentially averaged periodogram):

[0048] ;

[0049] ,

[0050] in is the index of each input frame (e.g., of measured voltage and measured response), and is the frequency spectrum of the frame of x and y obtained by discrete Fourier transform, and 𝛼 is the factor controlling the average velocity.

[0051] Under normal conditions, Close to 1. In the presence of external disturbances, especially when the disturbance initially starts acting on the system 200, the coherence will drop significantly due to the irrelevant components added to the response 𝑦. The coherence test detects this situation and freezes the parameter update.

[0052] In operation 268, the controller 102 determines the coherence Is greater than a threshold. If this condition is true, the method 250 proceeds to operation 270. If not, the method 250 proceeds to operation 272. In operation 270, the controller 102 allows the parameter estimation block 122 to perform adaptation (e.g., provide the speaker parameters to the feedforward processing block 120). In operation 272, the controller 102 determines that the interference noise is too large and controls the parameter estimation block 122 to freeze or avoid updating the speaker parameters. In this case, the controller 102 determines that the measured response (i.e., signal y) has a signal component that is not from the measured voltage (i.e., signal x), and such a signal component can be attributed to interference.

[0053] Figure 6 A method 300 for performing protection control of the speaker system 200 is depicted, according to one embodiment. Generally, the operations identified in connection with the method 300 can be performed by the protection control block 204. Generally, when performed by the feedforward processing block 120, the controller 102 utilizes the fitting error to generate a safe protection threshold for a mechanical protection parameter of the speaker 106. The feedforward processing block 120 can generally reduce the gain of the first audio signal in response to the feedforward processing block 120 detecting that the predicted (or modeled) mechanical characteristic exceeds the threshold set forth by the protection control block 204. The feedforward processing block 120 includes a digital speaker model stored within the controller 102 to generate the predicted mechanical characteristic. The parameter estimation block 122 generates the fitting error based on the measured voltage and the measured response.

[0054] In operation 302, the controller 102 obtains the fitting error provided by the parameter estimation block 122. In operation 304, the controller 102 maps the fitting error obtained in operation 302 to Figure 7 , as shown in the error-threshold mapping table 350. A large fitting error generally indicates that the model provided by the system 200 is unreliable. In operation 306, the controller 102 smoothes (or moves) the protection threshold. For example, the higher the fitting error, the more the controller 102 reduces the threshold, as shown in the table 350 (note that a high fitting error (see x-axis) produces a smaller protection threshold, as shown on the y-axis). In this case, the system 200 operates within a more conservative range due to the reduced threshold. Conversely, the lower the fitting error, the higher the threshold, also as shown in FIG. Figure 7. Generally, controller 102 averages a predetermined number of samples of the fitted error signal. Method 300 can be performed regardless of the state of adaptive control. In addition to protecting system 200 from incoherent interference, method 300 also functions during the convergence phase, for example, when system 200 is just turned on and the exact parameters are uncertain (or unpredictable).

[0055] Figure 8 Corresponding to graph 400, this graph shows an example of the fitting error of parameter estimation according to one embodiment. As shown in graph 400, when the interference is applied at 5.2s (see x-axis), the fitting error increases and the protection threshold begins to decrease (see y-axis). During the time interval of the interference, the estimated parameters provided by parameter estimation block 122 are obviously "wrong", especially for those parameters directly associated with passive radiators (PR). Although the model cannot fully capture the dynamics, the model attempts to fit the measurement results as much as possible. In this case, after the initial application of the interference, the fitting error drops to about 20%. The protection threshold is also released at a more moderate pace. At 12.5s, the interference is removed. The threshold is not released to its maximum value until the parameters are converged at about 15s.

[0056] Figure 9 An example of displacement thresholds for a loudspeaker driver and a passive radiator according to an embodiment is depicted. The thresholds shown are generated by the protection control block 204 according to the method 300 described above.

[0057] Figure 10 Depicted are speaker system parameters 452 through 474 according to one embodiment. The illustrated system parameters 452 through 474 are consistent with the thresholds shown in graph 400. Parameter 452 corresponds to the voice coil resistor, parameter 454 corresponds to the voice coil inductance, parameter 456 corresponds to the stiffness of the speaker suspension system, parameter 458 corresponds to the moving mass of the speaker driver, parameter 460 corresponds to the mechanical resistance of the speaker driver, parameter 462 corresponds to the resonant frequency of the speaker driver, parameter 464 corresponds to the Q factor, parameter 466 corresponds to the mechanical stiffness of the passive radiator, parameter 468 corresponds to the moving mass of the passive radiator, parameter 470 corresponds to the mechanical resistance of the passive radiator, parameter 472 corresponds to the resonant frequency of the passive radiator, and parameter 474 corresponds to the Q factor of the passive resistor. For each of the parameters 452 through 474, and as combined Figure 8 As can be seen, the interference is applied at approximately 5.2 seconds. In addition, the interference is removed at approximately 12.5 seconds, and thereafter, as time increases, the parameters 452 to 474 begin to stabilize.

[0058] It should be recognized that the controllers disclosed herein may include various microprocessors, integrated circuits, memory devices (e.g., FLASH, random access memory (RAM), read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or other suitable variations thereof) and software that cooperate with each other to perform the operations disclosed herein. In addition, such controllers disclosed utilize one or more microprocessors to execute computer programs embodied in non-transitory computer-readable media that are programmed to perform any number of the disclosed functions. In addition, the controllers provided herein include a housing and various numbers of microprocessors, integrated circuits, and memory devices (e.g., FLASH, random access memory (RAM), read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) positioned within the housing. The disclosed controllers also include hardware-based inputs and outputs, which are used to receive data from and transmit data to other hardware-based devices discussed herein, respectively.

[0059] While exemplary embodiments have been described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are descriptive rather than limiting, and it should be understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, features of the various implemented embodiments may be combined to form further embodiments of the invention.

Claims

1. A speaker system comprising: at least one speaker, the at least one speaker transmitting an audio output signal; an amplifier for transmitting a drive signal to the speaker in response to a first audio signal to transmit the audio output signal; and At least one controller, the at least one controller comprising: a parameter estimation block programmed to generate loudspeaker system parameters; a feedforward processing block programmed to model the speaker system to provide modeled speaker system parameters and to provide the first audio signal to the amplifier based on the modeled speaker system parameters; and An adaptive switch programmed to control the parameter estimation block based on at least one of: a measured characteristic of the drive signal provided by the amplifier, and a measured response associated with at least one characteristic of the at least one loudspeaker.

2. The speaker system of claim 1 , wherein the adaptive switch is further programmed to control the parameter estimation block by one of enabling the parameter estimation block to generate the speaker system parameters and refraining from generating the speaker system parameters based on at least one of: the measured characteristic of the drive signal provided by the amplifier, and a measured response associated with the at least one characteristic of the at least one speaker.

3. The speaker system of claim 2 , wherein the adaptive switch is further programmed to cause the parameter estimation block to generate the speaker system parameters by enabling the parameter estimation block to generate a previous set of speaker system parameters based on at least one of: a previously measured characteristic of the drive signal provided by the amplifier, and a previously measured response associated with the at least one characteristic of the at least one speaker.

4. The speaker system of claim 1, wherein the measured characteristic of the drive signal provided by the amplifier is a voltage of the drive signal driving the at least one speaker.

5. The speaker system of claim 1, further comprising a protection control block programmed to transmit a threshold value to the feedforward processing block to adjust the first audio signal to mechanically protect the at least one speaker.

6. The speaker system of claim 5, wherein the protection control block is further programmed to adjust the threshold based on a fitting error signal.

7. The speaker system of claim 6 , wherein the fitting error signal is based at least on the modeled speaker system parameters and one of: the measured characteristics of the drive signal provided by the amplifier, and the measured response associated with the at least one characteristic of the at least one speaker.

8. The speaker system of claim 6, wherein the protection control block is further programmed to adjust the threshold by one of increasing or decreasing the threshold based on a value of the fitting error signal.

9. The speaker system of claim 6, wherein the fitting error signal increases in response to the at least one speaker exhibiting a jamming condition.

10. A speaker system comprising: at least one speaker, the at least one speaker transmitting an audio output signal; an amplifier for transmitting a drive signal to the at least one speaker in response to a first audio signal to transmit the audio output signal; At least one controller, the at least one controller comprising: a parameter estimation block programmed to generate loudspeaker system parameters; a feedforward processing block programmed to model the speaker system to provide modeled speaker system parameters and to provide the first audio signal to the amplifier based on the modeled speaker system parameters; and A protection control block is programmed to transmit a threshold value to the feedforward processing block to adjust the drive signal to mechanically protect the at least one loudspeaker.

11. The speaker system of claim 10, wherein the protection control block is further programmed to adjust the threshold based on a fitting error signal.

12. The speaker system of claim 11 , wherein the fitting error signal is based at least on the modeled speaker system parameters and one of: a measured characteristic of the drive signal provided by the amplifier, and a measured response associated with at least one characteristic of the at least one speaker.

13. The speaker system of claim 11, wherein the protection control block is further programmed to adjust the threshold by one of increasing or decreasing the threshold based on a value of the fitting error signal.

14. The speaker system of claim 11, wherein the fitting error signal increases in response to the at least one speaker exhibiting a jamming condition.

15. The speaker system of claim 11 , further comprising an adaptive switch programmed to control the parameter estimation block based at least on the modeled speaker system parameters and at least one of: a measured characteristic of the drive signal provided by the amplifier, and a measured response associated with at least one characteristic of the at least one speaker.

16. The speaker system of claim 15, wherein the at least one characteristic of the at least one speaker corresponds to one of: voice coil current, cabinet pressure, displacement of the speaker, velocity of the speaker, a driver of the speaker, a passive radiator (PR) of the speaker, and acceleration of ventilation air of the speaker.

17. The speaker system of claim 15 , wherein the adaptive switch is further programmed to control the parameter estimation block by either enabling the parameter estimation block to generate the speaker system parameters or refraining from generating the speaker system parameters based on at least one of the modeled speaker system parameters and: a measured characteristic of the drive signal provided by the amplifier, and the measured response associated with the at least one characteristic of the at least one speaker.

18. A speaker system as described in claim 17, wherein the adaptive switch is further programmed to enable the parameter estimation block to generate the speaker system parameters by enabling the parameter estimation block to generate a previous set of speaker system parameters based at least on a previously measured characteristic of the drive signal provided by the amplifier and a previously measured response associated with the at least one characteristic of the at least one speaker.

19. The speaker system of claim 15, wherein the measured characteristic of the audio output signal provided by the amplifier is a voltage of the drive signal delivered by the amplifier for driving the at least one speaker.

20. A method for controlling a speaker system, the method comprising: transmitting an audio output signal via at least one speaker; providing a drive signal from an amplifier to the speaker to transmit the audio output signal in response to a first audio signal; generating speaker system parameters via at least one controller; modeling the speaker system to provide modeled speaker system parameters, and providing the first audio signal to the amplifier based on the modeled speaker system parameters; as well as The at least one controller is controlled based on at least one of: a measured characteristic of the drive signal provided by the amplifier and a measured response associated with at least one characteristic provided by the at least one speaker.

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