Systems and methods for calibrating speakers
Systems and method are disclosed for facilitating efficient calibration of filters for correcting room and/or speaker-based distortion and/or binaural imbalances in audio reproduction, and/or for producing three-dimensional sound in stereo system environments. According to some embodiments, using a portable device such as a smartphone or tablet, a user can calibrate speakers by initiating playback of a test signal, detecting playback of the test signal with the portable device's microphone, and repeating this process for a number of speakers and/or device positions (e.g., next to each of the user's ears). A comparison can be made between the test signal and the detected signal, and this can be used to more precisely calibrate rendering of future signals by the speakers.
1. A method for calibrating speakers for a particular environment, the method comprising:
positioning a microphone of a portable device at a first location in an environment;
initiating first playback by an audio source of a piece of audio content over a speaker;
detecting the first playback of the piece of audio content by the microphone at the first location;
positioning a microphone at a second location in the environment, the second location being different from the first location;
initiating second playback by the audio source of the piece of audio content over the speaker;
detecting the second playback of the piece of audio content using the microphone at the second location;
determining, based at least in part on the detected first playback of the piece of audio content and the detected second playback of the piece of audio content, one or more adjustments to be applied to additional audio content before additional audio content playback by the speaker, wherein determining the one or more adjustments comprises:
accessing a system information file of the portable device to determine a transfer function of the microphone; and
determining the one or more adjustments using, at least in part, the transfer function of the microphone; and
applying the one or more adjustments to the additional audio content before it is played by the speaker.
2. The method of claim 1 , wherein the first location comprises a position proximate to a first ear of a person within the environment.
3. The method of claim 2 , wherein the second location comprises a position proximate to a second ear of a person within the environment.
4. The method of claim 1 , wherein the piece of audio content comprises one or more synchronization patterns.
5. The method of claim 4 , wherein determining the one or more adjustments to be applied to the additional audio content further comprises aligning the detected first playback of the piece of audio content and the detected second playback of the piece of audio content based, at least in part, on the one or more synchronization patterns.
6. The method of claim 1 , wherein the portable device comprises a mobile phone.
7. The method of claim 1 , wherein the portable device comprises a tablet.
8. The method of claim 1 , wherein determining the one or more adjustments to be applied to the additional audio content further comprises performing spectral analysis on the detected first playback of the piece of audio content and the detected second playback of the piece of audio content.
9. The method of claim 8 , wherein determining the one or more adjustments to be applied to the additional audio content further comprises comparing a frequency response of the detected first playback of the piece of audio content with an ideal frequency response.
10. The method of claim 1 , wherein determining a transfer function of the microphone comprises:
retrieving a mobile device identifier from the system information file; and
retrieving the transfer function of the microphone from a set of microphone transfer functions using a web service.
11. A portable device for calibrating speakers for a particular environment, the portable device comprising:
a microphone;
a processor; and
a non-transitory memory storing instructions that when executed by the processor of the portable device cause the portable device to perform operations comprising:
providing instructions for positioning the microphone of the portable device at a first location in an environment;
initiating first playback by an audio source of a piece of audio content over a speaker;
detecting the first playback of the piece of audio content by the microphone at the first location;
providing instructions for positioning a microphone at a second location in the environment, the second location being different from the first location;
initiating second playback by the audio source of the piece of audio content over the speaker;
detecting the second playback of the piece of audio content using the microphone at the second location;
determining, based at least in part on the detected first playback of the piece of audio content and the detected second playback of the piece of audio content, one or more adjustments to be applied to additional audio content before additional audio content playback by the speaker, wherein determining the one or more adjustments comprises:
accessing a system information file of the portable device to determine a transfer function of the microphone; and
determining the one or more adjustments using, at least in part, the transfer function of the microphone; and
applying the one or more adjustments to the additional audio content before it is played by the speaker.
12. The portable device of claim 11 , wherein the first location comprises a position proximate to a first ear of a person within the environment.
13. The portable device of claim 12 , wherein the second location comprises a position proximate to a second ear of a person within the environment.
14. The portable device of claim 11 , wherein the piece of audio content comprises one or more synchronization patterns.
15. The portable device of claim 14 , wherein determining the one or more adjustments to be applied to the additional audio content further comprises aligning the detected first playback of the piece of audio content and the detected second playback of the piece of audio content based, at least in part, on the one or more synchronization patterns.
16. The portable device of claim 11 , wherein the portable device comprises a mobile phone.
17. The portable device of claim 11 , wherein the portable device comprises a tablet.
18. The portable device of claim 11 , wherein determining the one or more adjustments to be applied to the additional audio content further comprises performing spectral analysis on the detected first playback of the piece of audio content and the detected second playback of the piece of audio content.
19. The portable device of claim 18 , wherein determining the one or more adjustments to be applied to the additional audio content further comprises comparing a frequency response of the detected first playback of the piece of audio content with an ideal frequency response.
20. The portable device of claim 11 , wherein determining a transfer function of the microphone comprises:
retrieving a mobile device identifier from the system information file; and
retrieving the transfer function of the microphone from a set of microphone transfer functions using a web service.