Granted Patent B2

US 12,659,663 · App. 18/545,366 · Granted Jun 16, 2026

Inventor: Nicholas C. Ames (Tempe, AZ)

Assignee: Garmin International, Inc.

H04R3/12H04R1/22H04S7/30

Abstract

Claims (51)

1 . A method for phase alignment of audio signals using a first impulse response signal associated with a first frequency range and a second impulse response signal associated with a second frequency range, the method comprising:

determining a first start time for the first impulse response and a second start time for the second impulse response, wherein determining the first start time includes:

determining a baseline noise level associated with the first frequency range; and

detecting a rise in the first impulse response signal above the baseline noise level, the rise being at least as large as a predetermined threshold value, wherein a time corresponding to the detected rise defines the first start time;

determining a delay based at least in part on a difference between the second start time and the first start time; and

adjusting at least one audio signal phase for a first audio driver operating in the first frequency range with respect to a second audio driver operating in the second frequency range, the adjusting of the at least one audio signal phase being based at least in part on the determined delay.

2 . The method of claim 1 , wherein the method further comprises:

equalizing a magnitude of the first impulse response and a magnitude of the second impulse response prior to determining the delay.

3 . The method of claim 1 , wherein the delay is further determined based on a difference between the first start time and a reference start time of a model impulse response associated with at least one of the first frequency range and the second frequency range.

4 . The method of claim 1 , wherein the first frequency range is a subwoofer frequency range, and the second frequency range is a midrange frequency range.

5 . The method of claim 1 , wherein the method further comprises:

generating a first reference audio signal associated with the first frequency range for playback on a first loudspeaker associated with the first audio driver and a second reference audio signal associated with the second frequency range for playback on a second loudspeaker associated with the second audio driver; and

measuring the playback of the first loudspeaker to determine the first impulse response and measuring the playback of the second loudspeaker to determine the second impulse response.

6 . A system for phase alignment of audio signals using a first impulse response signal associated with a first frequency range and a second impulse response signal associated with a second frequency range, the system comprising:

a calibration device, the calibration device comprising processing circuitry configured to:

determine a first start time for the first impulse response and a second start time for the second impulse response, wherein determining the first start time includes:

determining a baseline noise level associated with the first frequency range; and

detecting a rise in the first impulse response signal above the baseline noise level, the rise being at least as large as a predetermined threshold value, wherein a time corresponding to the detected rise defines the first start time; and

determine a delay based at least in part on a difference between the second start time and the first start time;

cause transmission of a configuration to a receiver indicating the delay; and

a receiver, the receiver comprising processing circuitry configured to:

receive the configuration from the calibration device; and

responsive to receiving the configuration, adjust at least one audio signal phase for a first audio driver operating in the first frequency range with respect to a second audio driver operating in the second frequency range, the adjusting of the at least one audio signal phase being based at least in part on the delay.

7 . The system of claim 6 , wherein the processing circuitry of the calibration device is further configured to:

equalize a magnitude of the first impulse response and a magnitude of the second impulse response prior to determining the delay.

8 . The system of claim 6 , wherein the delay is further determined based on a difference between the first start time and a reference start time of a model impulse response associated with at least one of the first frequency range and the second frequency range.

9 . The system of claim 6 , wherein the first frequency range is a subwoofer frequency range, and the second frequency range is a midrange frequency range.

10 . The system of claim 6 , wherein:

the processing circuitry of the calibration device is further configured to:

generate a first reference audio signal associated with the first frequency range for playback on a first loudspeaker associated with the first audio driver and a second reference audio signal associated with the second frequency range for playback on a second loudspeaker associated with the second audio driver;

the processing circuitry of the receiver being further configured to:

receive the first reference audio signal and the second reference audio signal; and

cause playback of the first reference audio signal on the first loudspeaker and the second reference audio signal on the second loudspeaker; and

the processing circuitry of the calibration device being further configured to:

measure the playback of the first loudspeaker to determine the first impulse response; and

measure the playback of the second loudspeaker to determine the second impulse response.

11 . A calibration device for phase alignment of audio signals using a first impulse response signal associated with a first frequency range and a second impulse response signal associated with a second frequency range, the calibration device comprising processing circuitry configured to:

determine a first start time for the first impulse response and a second start time for the second impulse response, wherein determining the first start time includes:

determining a baseline noise level associated with the first frequency range; and

detecting a rise in the first impulse response signal above the baseline noise level, the rise being at least as large as a predetermined threshold value, wherein a time corresponding to the detected rise defines the first start time;

determine a delay based at least in part on a difference between the second start time and the first start time; and

cause transmission of a configuration to a receiver indicating the delay and enabling the receiver to adjust at least one audio signal phase for a first audio driver operating in the first frequency range with respect to a second audio driver operating in the second frequency range, the adjusting of the at least one audio signal phase being based at least in part on the delay.

12 . The calibration device of claim 11 , wherein the processing circuitry of the calibration device is further configured to:

equalize a magnitude of the first impulse response and a magnitude of the second impulse response prior to determining the delay.

13 . The calibration device of claim 11 , wherein the delay is further determined based on a difference between the first start time and a reference start time of a model impulse response associated with at least one of the first frequency range and the second frequency range.

14 . The calibration device of claim 11 , wherein the first frequency range is a subwoofer frequency range, and the second frequency range is a midrange frequency range.

15 . The calibration device of claim 11 , wherein the processing circuitry of the calibration device is further configured to:

generate a first reference audio signal associated with the first frequency range for playback a first loudspeaker associated with the first audio driver and a second reference audio signal associated with the second frequency range for playback on a second loudspeaker associated with the second audio driver;

cause transmission of the first reference audio signal and the second reference audio signal to the receiver enabling the receiver to cause playback of the first reference audio signal on the first loudspeaker and the second reference audio signal on the second loudspeaker;

measure the playback of the first loudspeaker to determine the first impulse response; and

measure the playback of the second loudspeaker to determine the second impulse response.

Assignments (2)

Continuity (2)

References Cited (26)