Sound calibration - Revision history

Lof at 09:39, 8 June 2026

2026-06-08T09:39:11Z

← Older revision		Revision as of 09:39, 8 June 2026
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	==Introduction==		==Introduction==
	~~% todo~~		For continuous sounds the dBspl is normally determined by the rms of the signal. Because of the silence periods in speech there is a special way to determine the dBspl.

			==Speech==
			The standard for speech is called Active Speech Level. It determines the dBspl by removing the silent parts from the speech.

			There are two ways to do this:
			*More precise: Sum the rms only over the parts above a certain power threshold.
			*More easy: Take the rms over the total sound and estimate the percentage of silence in the speech and correct for it.

			ITU-T P.56 (Active Speech Level): This is the gold standard within speech science and telecommunications. This algorithm utilizes a dynamic threshold. Silences and background noise falling below this threshold are filtered out of the calculation. The $\text{dB SPL}$ is then calculated exclusively over the periods where speech energy is actually present.

	==Sensitivity of speakers==		==Sensitivity of speakers==

2025-04-25T12:12:53Z

Sensitivity of speakers

← Older revision		Revision as of 12:12, 25 April 2025
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	==Sensitivity of speakers==		==Sensitivity of speakers==
	*In all our labs we use the Cambridge Audio MINX MIN12 speaker.		*In all our labs we use the Cambridge Audio MINX MIN12 speaker.
	*The speaker has a specified sensitivity of 86 dB SPL (@2.83 Vrms input)		*The speaker has a specified sensitivity of 86 dB SPL (@2.83 Vrms input and @ 1 kHz)
	*The calibration is calculated @ 1Vrms input and depends one over the square of the distance of the speaker to the center of the subjects head.		*The calibration is calculated @ 1Vrms input and depends one over the square of the distance of the speaker to the center of the subjects head.

2025-04-25T12:12:17Z

Sensitivity of speakers

← Older revision		Revision as of 12:12, 25 April 2025
Line 5:		Line 5:
	*In all our labs we use the Cambridge Audio MINX MIN12 speaker.		*In all our labs we use the Cambridge Audio MINX MIN12 speaker.
	*The speaker has a specified sensitivity of 86 dB SPL (@2.83 Vrms input)		*The speaker has a specified sensitivity of 86 dB SPL (@2.83 Vrms input)
	*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.		*The calibration is calculated @ 1Vrms input and depends one over the square of the distance of the speaker to the center of the subjects head.

	Calibration = mag2db(db2mag(Sens@1V)/Distance^2)		Calibration = mag2db(db2mag(Sens@1V)/Distance^2)

2025-04-25T12:11:30Z

Sensitivity of speakers

← Older revision		Revision as of 12:11, 25 April 2025
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	Calibration = mag2db(db2mag(Sens@1V)/Distance^2)		Calibration = mag2db(db2mag(Sens@1V)/Distance^2)

	Table of calibration (@ 1Vrms and 1kHz) in different labs.		Table: calibration (@ 1Vrms and 1kHz) in different labs.

	{\| class="wikitable"		{\| class="wikitable"

2025-04-25T12:11:11Z

Sensitivity of speakers

← Older revision		Revision as of 12:11, 25 April 2025
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	*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.		*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.

	Calibration = mag2db(db2mag(Sens@1V)/Distance^2)		Calibration = mag2db(db2mag(Sens@1V)/Distance^2)

			Table of calibration (@ 1Vrms and 1kHz) in different labs.

	{\| class="wikitable"		{\| class="wikitable"

2025-04-25T12:09:17Z

Sensitivity of speakers

2025-04-25T12:09:01Z

Sensitivity of speakers

← Older revision		Revision as of 12:09, 25 April 2025
Line 7:		Line 7:
	*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.		*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.

	Calibration = mag2db(db2mag(Sens)~~/Vrms~~/Distance^2)		Calibration = mag2db(db2mag(Sens@1V)/Distance^2)

	{\| class="wikitable"		{\| class="wikitable"

2025-04-25T12:08:04Z

Sensitivity of speakers

← Older revision		Revision as of 12:08, 25 April 2025
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	*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.		*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.

	~~Calculation:~~
	Calibration = mag2db(db2mag(Sens)/Vrms/Distance^2)		Calibration = mag2db(db2mag(Sens)/Vrms/Distance^2)

2025-04-25T12:07:51Z

Sensitivity of speakers

← Older revision		Revision as of 12:07, 25 April 2025
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	*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.		*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.

	~~Calibration == sensitivity @ 1.00 Vrms @ Distance^2~~		Calculation:
	Calibration = mag2db(db2mag(Sens)/Vrms/Distance^2)		Calibration = mag2db(db2mag(Sens)/Vrms/Distance^2)

2025-04-25T12:06:33Z

Sensitivity of speakers

← Older revision		Revision as of 12:06, 25 April 2025
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	*In all our labs we use the Cambridge Audio MINX MIN12 speaker.		*In all our labs we use the Cambridge Audio MINX MIN12 speaker.
	*The speaker has a specified sensitivity of 86 dB SPL (@2.83 Vrms input)		*The speaker has a specified sensitivity of 86 dB SPL (@2.83 Vrms input)
	*The calibration is ~~dependent~~ on the distance of the ~~centre~~ of the subjects head ~~to the speaker~~.		*The calibration is calculated @ 1Vrms input and depends on the distance of the speaker to the center of the subjects head.

	Calibration == sensitivity @ 1.00 Vrms @ Distance^2		Calibration == sensitivity @ 1.00 Vrms @ Distance^2