How to create a cal file?

Compare against reference mic with same pink noise source. Calculate dB difference per frequency. Save as text with freq/magnitude columns. Comments with * or ;. Software applies inverse correction.

Can smartphones be calibrated?

Against reference: ±2-3 dB within 200-8000 Hz achievable. Lack low-frequency extension, dynamic range, omnidirectional pattern per IEC 61672. Use for screening, not compliance.

How often recalibrate?

IEC 61672-3: annual verification. Pistonphone before/after every session. Full frequency after damage, capsule change, or when verification shows drift above 0.5 dB.

Free-field vs pressure-field?

Free-field: anechoic, direct wave only. Pressure: sealed cavity uniform pressure. Free-field for source-pointed mics. Pressure for flush-mounted or random-incidence use.

How to create a cal file?

Compare against reference mic with same pink noise source. Calculate dB difference per frequency. Save as text with freq/magnitude columns. Comments with * or ;. Software applies inverse correction.

Can smartphones be calibrated?

Against reference: ±2-3 dB within 200-8000 Hz achievable. Lack low-frequency extension, dynamic range, omnidirectional pattern per IEC 61672. Use for screening, not compliance.

How often recalibrate?

IEC 61672-3: annual verification. Pistonphone before/after every session. Full frequency after damage, capsule change, or when verification shows drift above 0.5 dB.

Free-field vs pressure-field?

Free-field: anechoic, direct wave only. Pressure: sealed cavity uniform pressure. Free-field for source-pointed mics. Pressure for flush-mounted or random-incidence use.

Microphone Calibration for Audio Measurement

Microphone Calibration for Measurement

Microphone calibration applies frequency-dependent corrections to compensate for response deviations. Professional measurement microphones ship with individual calibration data. Applying corrections ensures accuracy traceable to IEC 61094 national metrology standards.

IEC 61094-1:2000IEC 61672-1:2013§5.3IEC 61672-3:2013

Why Calibrate

No mic is flat. Measurement mics deviate ±1-2 dB. MEMS ±5-10 dB. Without correction, deviations contaminate every measurement systematically across all frequencies.

File Formats

.cal/FRD: frequency-magnitude pairs, comments start * or ;. Software applies inverse. Log-frequency interpolation between points.

Reference Mics

IEC 61094 defines standards. GRAS 46AE, Earthworks M30, Behringer ECM8000 (budget). Individual certificates required.

MEMS

Roll-off below 100 Hz, peaks 8-12 kHz, noise 30-35 dBA. Calibrated against reference: ±2-3 dB within 200-8000 Hz achievable.

Field Calibration

Pistonphone at 94/114 dB, 1 kHz. Single-point sensitivity only. Full frequency requires reference comparison. Annual per IEC 61672-3.

Try It Now

Import calibration files in the workspace

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