Calibration Method and Device in an Audio System

• US 20100303250A1
• Filed: 03/22/2007
• Published: 12/02/2010
• Est. Priority Date: 03/28/2006
• Status: Active Grant

• Current Assignee: Genelec Oy
• Original Assignee: Genelec Oy
• Inventors: Goldberg, Andrew, Makivirta, Aki, Urhonen, Juha, Tikkanen, Jussi
• Granted Patent: US 8,798,280 B2
• Time in Patent Office: Days
• US Class Current: 381/59
• CPC Class Codes: H04R 29/001 for loudspeakers H04R29/007 takes precedence
• CPC Class Codes: H04R 29/002 Loudspeaker arrays

Abstract

The present publication describes a calibration method and apparatus, in which an electrical calibration signal is formed, an audio signal is formed in the loudspeaker from the calibration signal, the response of the audio signal is measured and analysed, and the system is adjusted on the basis of the measurement results. The calibration signal is formed in the loudspeaker in such a way that it is essentially a sinusoidal signal, the frequency of which scans at least substantially through the entire audio frequency range.

Claims

1. A calibration method in a sound-reproduction system, in which an electrical calibration signal is formed, an audio signal is formed in the loudspeaker from the calibration signal, the response of the audio signal is measured and analysed outside the loudspeaker, and the system is adjusted on the basis of the measurement results, wherein:

the calibration signal is formed in the loudspeaker in such a way that it is essentially a sinusoidal signal, the frequency of which scans at least substantially through the entire audio frequency range.

2. The method according to claim 1, wherein the scanning speed of the calibration signal is logarithmic.

3. The method according to claim 1, wherein the scanning of the calibration signal is started from the lowest frequencies.

4. The method according to claim 1, wherein the method is used to calibrate an unknown sound card.

5. The method according to claim 4, wherein the response of the sound card is modelled using the frequency response.

6. The method according to claim 1, wherein the method is used to determine the amplification of the sound card.

7. The method according to claim 1, wherein the method is used to determine the distance of the loudspeaker.

8. The method according to claim 1, wherein the method is used to set the phase of the subwoofer and the main loudspeaker to be the same at the crossover frequency.

9. The method according to claim 1, wherein the method is used for equalizing, i.e. calibrating the response of all the loudspeakers in the listening room.

10. A calibration apparatus in a sound-reproduction system, which comprises a loudspeaker, control apparatus for the loudspeaker, signal and control connections to the loudspeaker, a microphone for measuring the response of the loudspeakers, and analysis and control apparatuses outside the loudspeaker for analysing and setting the signal obtained from the microphone, on the basis of the analysis results, wherein:

the loudspeaker has means for forming an essentially sinusoidal electrical variable-frequency calibration signal, so that the calibration signal scans essentially through the entire audio-frequency range.

11. The apparatus according to claim 10, wherein the scanning speed of the calibration signal is logarithmic.

12. The apparatus according to claim 10, wherein the scanning by the calibration signal is started from the lowest frequencies.

13. The apparatus according to claim 10, wherein the apparatus is used for calibrating the frequency response of an unknown sound card.

14. The apparatus according to claim 13, wherein the response of the sound card is modelled using the frequency response.

15. The apparatus according to claim 10, wherein the apparatus is used to determine the amplification of the sound card.

16. The apparatus according to claim 10, wherein the apparatus is used to determine the distance of the loudspeaker.

17. The apparatus according to claim 10, wherein the apparatus is used to set the phase of the subwoofer and the main loudspeaker to be the same, at the crossover frequency.

18. The apparatus according to claim 10, wherein the apparatus is used for equalizing, i.e. calibrating the response of all the loudspeakers of the system, in the listening room.

19. The apparatus according to claim 10, wherein the loudspeaker is an active loudspeaker, i.e. it contains an amplifier.

20. A loudspeaker, which comprises an element producing sound, adjustment and control devices for controlling the sound-producing element, and signal and control connections to the loudspeaker, wherein:

the loudspeaker has means for forming an essentially sinusoidal electrical variable-frequency calibration signal, so that the calibration signal scans at least substantially over the entire audio frequency range.

21. The loudspeaker according to claim 20, wherein the loudspeaker is an active loudspeaker.

22. The loudspeaker according to claim 20, wherein the loudspeaker comprises means for implementing essentially logarithmic frequency scanning.

23. The loudspeaker according to claim 20, wherein the loudspeaker comprises means for implementing frequency scanning starting from the lowest frequencies.

24. The loudspeaker according to claim 20, wherein the loudspeaker has an unequivocal identity, which can be read through the control network.

25. A computer-readable data structure, which contains the settings data of the loudspeaker system.