SPEAKERS WITH A DIGITAL SIGNAL PROCESSOR

• US 20090225996A1
• Filed: 03/21/2008
• Published: 09/10/2009
• Est. Priority Date: 03/07/2008
• Status: Active Grant

• Current Assignee: KSC Industries Inc.
• Original Assignee: KSC Industries Inc.
• Inventors: Brooking, Eric Blackwell
• Granted Patent: US 8,401,202 B2
• Time in Patent Office: Days
• US Class Current: 381/59
• CPC Class Codes: H04R 1/323 for loudspeakers H04R1/34 and H04R1/40 take precedence
• CPC Class Codes: H04R 29/001 for loudspeakers H04R29/007 takes precedence
• CPC Class Codes: H04R 3/04 for correcting frequency response
• CPC Class Codes: H04S 7/305 Electronic adaptation of stereophonic audio signals to reverberation of the listening space H04S7/301 takes precedence

Abstract

A speaker with a digital signal processor is disclosed. In one aspect, a speaker comprises at least one electromechanical transducer configured to convert an electrical audio signal into sound and a digital signal processor configured to process an audio signal and send the processed audio signal to the electromechanical transducer directly or indirectly.

Claims

1. A speaker comprising:

at least one electromechanical transducer configured to convert an electrical audio signal into sound; and

a digital signal processor configured to process an audio signal and send the processed audio signal to the electromechanical transducer directly or indirectly.

2. The speaker of claim 1 further comprising a secondary reflection correction unit configured to correct secondary reflections off an object near the speaker or a listening position.

3. The speaker of claim 2, wherein the secondary reflection correction unit is configured to cancel only reflected waves arriving in a predetermined time.

4. The speaker of claim 2, wherein the secondary reflection correction unit comprises at least one finite impulse response filter with phase inverted band limited impulses.

5. The speaker of claim 4, wherein the finite impulse response filter comprises at least one tunable coefficient.

6. The speaker of claim 1 further comprising a standing wave room correction unit configured to correct for room modes standing waves.

7. The speaker of claim 6, wherein the standing wave room correction unit comprises a set of infinite impulse response (IIR) bi-quad filters.

8. The speaker of claim 7, wherein the IIR bi-quad filters comprise at least one tunable coefficient.

9. The speaker of claim 6, wherein the standing wave room correction unit is configured to correct at least three standing wave frequencies.

10. The speaker of claim 6, wherein the standing wave room correction unit is configured to correct peaks of the standing waves and not to correct holes of the standing waves.

11. The speaker of claim 1 further comprising a speaker placement room correction unit configured to correct for boundary effects and/or bass loading effects due the proximity of the speaker relative to boundaries of a room in which the speaker is placed.

12. The speaker of claim 11, wherein the speaker placement room correction unit comprises at least a parametric shelving filter.

13. The speaker of claim 12, wherein the parametric shelving filter comprises at least one tunable parameter.

14. The speaker of claim 12, wherein the parametric shelving filter is configured to correct for boundary gain of bass frequencies caused by proximity of the speaker to the walls, floor, or ceiling of a room in which the speaker is placed.

15. The speaker of claim 1, wherein the at least one electromechanical transducer includes a tweeter and a woofer, the tweeter being disposed in the woofer.

16. The speaker of claim 15, wherein the digital signal processor is configured to line up the acoustic wave fronts of the tweeter and of the woofer along the axis parallel to a line connecting a center of the tweeter and of the woofer.

17. The speaker of claim 15 further comprising a high-frequency time delay correction unit and a low-frequency time delay correction unit configured to introduce appropriate time delay so that sound from the tweeter and the woofer arrives at the same time.

18. The speaker of claim 17, wherein the time delay correction units comprises at least one tunable parameter.

19. The speaker of claim 1, wherein the digital signal processor further comprises a set of driver correction filters for each of the at least one electromechanical transducers, the driver correction filters being configured to remove peaks and poles in a transfer function of the electromechanical transducers.

20. The speaker of claim 19, wherein the driver correction filters comprise at least one tunable coefficient.

21. The speaker of claim 19, wherein the driver correction filters comprise at least one bi-quad infinite impulse response filter.

22. The speaker of claim 1 further comprising a horn and a compression driver, and wherein the digital signal processor comprises a set of driver correction filters configured to remove both peaks and poles in a transfer function of the horn.

23. The speaker of claim 22, wherein the horn is a constant directivity horn with no harsh diffraction edges.

24. The speaker of claim 22, wherein the driver correction filters comprises at least one tunable coefficient.

25. The speaker of claim 22, wherein the driver correction filters comprise at least one bi-quad infinite impulse response filter.

26. The speaker of claim 1, wherein the speaker is a co-axial speaker.

27. A method of configuring a speaker to compensate for room anomalies, the speaker comprising a digital signal processor having tunable room anomaly correction filters, the method comprising:

generating room anomaly correction coefficients to optimize the speaker response for a particular listening position in a room; and

saving the generated coefficients into the digital signal processor to configure the room anomaly correction filters.

28. The method of claim 27, wherein the coefficients are generated to optimize the speaker response for at least two positions in the room.

29. The method of claim 27, wherein the test audio signal comprise sine-wave stimulus.

30. The method of claim 27 further comprising:

sending a test audio signal to the speaker for playing; and

measuring the sound of the speaker, wherein the room anomaly correction coefficients are generated based at least in part on the measured sound of the speaker.

31. The method of claim 30 further comprising receiving information indicative of room anomalies, wherein the room anomaly correction coefficients are generated at least in part on the received information.

32. The method of claim 31, wherein the received information comprises a room dimension.

33. A device for configuring a speaker to compensate for room anomalies, the speaker comprising a digital signal processor and tunable room anomaly correction filters, the device comprising:

a storage unit having stored therein a software module; and

a control unit configured to perform the software module configured to;

generate room anomaly correction coefficients to optimize the speaker response for a particular listening position in the room; and

save the generated coefficients into the digital signal processor to configure the room anomaly correction filters.

34. A method of configuring a speaker to compensate for secondary reflections off an object in a room, the speaker comprising a digital signal processor which comprises tunable secondary reflection correction filters, the method comprising:

identifying secondary reflections;

generating secondary reflection correction coefficients to cancel secondary reflections arriving within a particular time limit; and

saving the generated coefficients into the digital signal processor to configure the secondary reflection correction filters.

35. The method of claim 34, wherein the test audio signal comprises test chirp stimulus.

36. The method of claim 34 further comprising:

sending a test audio signal to the speaker; and

measuring the sound of the speaker, wherein the identifying of secondary reflections is based on the measured sound.

37. The method of claim 34 further comprising receiving information indicative of secondary reflections, wherein the identifying of secondary reflections is based on the received information.

38. The method of claim 37, wherein the information received comprises measurement of direct and reflected path lengths.

39. A device for configuring a speaker to compensate for secondary reflections, which are reflections off an object in a room, the speaker comprising a digital signal processor which comprises tunable secondary reflection correction filters, the device comprising:

a storage unit having stored therein a software module; and

a control unit configured to perform the software module configured to;

identify secondary reflections;

generate secondary reflection correction coefficients to cancel secondary reflections arriving within a particular time limit; and

store the generated coefficients into the digital signal processor to configure the secondary reflection correction filters.

40. A method of testing a speaker, comprising:

sending a test audio signal to the speaker,

measuring an acoustic response of the speaker; and

storing a profile associated with the speaker into a database, the profile comprising information related to the measured acoustic response.

41. A device for testing a speaker, comprising:

a storage unit having stored therein a software module; and

a control unit configured to perform the software module configured to;

send a test audio signal to the speaker;

measuring an acoustic response of the speaker; and

storing a profile associated with the speaker into a database, the profile comprising information related to the measured acoustic response.

42. A method of configuring a speaker, the method comprising:

retrieving a profile associated with the speaker from a database, the profile comprising information related to an acoustic response of the speaker; and

configuring the speaker based on the retrieved profile.

43. A device for configuring a speaker, comprising:

a storage unit having stored therein a software module; and

a control unit configured to perform the software module configured to;

retrieve a profile associated with the speaker from a database, the profile comprising information related to the speaker'"'"'s acoustic response; and

configure the speaker based on the retrieved profile.

44. A method of configuring a speaker, the method comprising:

measuring and saving the acoustic response of a speaker at a first location;

delivering the saved acoustic response to a second location; and

configuring the speaker based on the saved acoustic response at the second location.