Systems and methods for protecting a speaker

1. A system comprising:

a controller configured to be coupled to an audio speaker, wherein the controller processes an audio input signal based on a displacement transfer function associated with the audio speaker to generate an output audio signal communicated to the audio speaker, wherein the displacement transfer function correlates an amplitude and a frequency of the audio input signal to an expected displacement of the audio speaker in response to the amplitude and the frequency of the audio input signal, and wherein the controller adaptively modifies the displacement transfer function based on one or more parameters of the audio speaker.

2. The system of claim 1 , wherein the controller further predicts a predicted displacement associated with the audio speaker based on the audio input signal and the displacement transfer function, determines if the predicted displacement is greater than a displacement threshold, and modifies the audio input signal to generate the output audio signal in response to a determination that the predicted displacement is greater than a displacement threshold.

3. The system of claim 1 , wherein the controller further determines which ranges of the frequency of the audio input signal correlate to expected displacements greater than a displacement threshold and attenuates portions of the audio input signal within such ranges of frequency to generate the output audio signal such that actual displacement associated with the audio speaker is less than the displacement threshold.

4. The system of claim 1 , wherein the amplitude comprises a voltage.

5. The system of claim 1 , wherein the displacement transfer function is based on offline testing of one or more audio speakers similar to the audio speaker.

6. The system of claim 1 , wherein the controller measures an actual displacement of the displacement in response to the audio input signal and modifies the displacement transfer function based on the actual displacement.

7. The system of claim 1 , wherein the controller generates one or more modeled parameters for the audio speaker and modifies the displacement transfer function based on the one or more modeled parameters.

8. The system of claim 7 , wherein the controller generates the one or more modeled parameters by receiving a current signal indicative of an electrical current associated with the audio speaker and a voltage signal indicative of an electrical voltage associated with the audio speaker, and in response to the current signal and the voltage signal, generates the one or more modeled parameters for the audio speaker.

9. The system of claim 8 , wherein the one or more modeled parameters are based on discrete-time domain information and displacement domain information and the discrete-time domain information and the displacement domain information are used to update the one or more modeled parameters.

10. The system of claim 7 , wherein the one or more modeled parameters comprises a modeled displacement associated with the audio speaker.

11. The system of claim 3 , wherein attenuating portions of the audio input signal within such ranges of frequency comprises high-pass filtering the audio input signal below a cutoff frequency to generate the output audio signal such that actual displacement associated with the audio speaker is less than the displacement threshold.

12. The system of claim 11 , wherein the controller is further configured to generate corresponding signals at harmonic frequencies of low-frequency signal components attenuated by the high-pass filtering, such that the harmonic frequency signals cause the attenuated low-frequency signal components to be psychoacoustically perceived by a listener of the audio speaker.

13. The system of claim 3 , wherein attenuating portions of the audio input signal within such ranges of frequency comprises attenuating signals within a range of a resonant frequency of the audio speaker to generate the output audio signal such that actual displacement associated with the audio speaker is less than the displacement threshold.

14. The system of claim 1 , wherein processing the audio input signal comprises modifying a gain of the audio signal based on the displacement transfer function such that actual displacement associated with the audio speaker is less than the displacement threshold.

15. A method comprising:

processing an audio input signal to generate an output audio signal communicated to an audio speaker based on a displacement transfer function associated with the audio speaker, wherein the displacement transfer function correlates an amplitude and a frequency of the audio input signal to an expected displacement of the audio speaker in response to the amplitude and the frequency of the audio input signal, and wherein the displacement transfer function is adaptively modified based on one or more parameters of the audio speaker.

16. The method of claim 15 , further comprising:

predicting a predicted displacement associated with the audio speaker based on the audio input signal and the displacement transfer function;

determining if the predicted displacement is greater than a displacement threshold; and

modifying modifies the audio input signal to generate the output audio signal in response to a determination that the predicted displacement is greater than a displacement threshold.

17. The method of claim 15 , further comprising:

determining which ranges of the frequency of the audio input signal correlate to expected displacements greater than a displacement threshold; and

attenuating portions of the audio input signal within such ranges of frequency to generate the output audio signal such that actual displacement associated with the audio speaker is less than the displacement threshold.

18. The method of claim 15 , wherein the amplitude comprises a voltage.

19. The method of claim 15 , wherein the displacement transfer function is based on offline testing of one or more audio speakers similar to the audio speaker.

20. The method of claim 15 , further comprising:

measuring an actual displacement of the displacement in response to the audio input signal; and

modifying the displacement transfer function based on the actual displacement.

21. The method of claim 15 , further comprising:

generating one or more modeled parameters for the audio speaker; and

modifying the displacement transfer function based on the one or more modeled parameters.

22. The method of claim 21 , wherein generating the one or more modeled parameters comprises:

receiving a current signal indicative of an electrical current associated with the audio speaker and a voltage signal indicative of an electrical voltage associated with the audio speaker; and

in response to the current signal and the voltage signal, generating the one or more modeled parameters for the audio speaker.

23. The method of claim 22 , wherein the one or more modeled parameters are based on discrete-time domain information and displacement domain information and the discrete-time domain information and the displacement domain information are used to update the one or more modeled parameters.

24. The method of claim 21 , wherein the one or more modeled parameters comprises a modeled displacement associated with the audio speaker.

25. The method of claim 17 , wherein attenuating portions of the audio input signal within such ranges of frequency comprises high-pass filtering the audio input signal below a cutoff frequency to generate the output audio signal such that actual displacement associated with the audio speaker is less than the displacement threshold.

26. The method of claim 25 , further comprising generating corresponding signals at harmonic frequencies of low-frequency signal components attenuated by the high-pass filtering, such that the harmonic frequency signals cause the attenuated low-frequency signal components to be psychoacoustically perceived by a listener of the audio speaker.

27. The method of claim 17 , wherein attenuating portions of the audio input signal within such ranges of frequency comprises attenuating signals within a range of a resonant frequency of the audio speaker to generate the output audio signal such that actual displacement associated with the audio speaker is less than the displacement threshold.

28. The method of claim 15 , wherein processing the audio input signal comprises modifying a gain of the audio signal based on the displacement transfer function such that actual displacement associated with the audio speaker is less than the displacement threshold.