Measurement Microphones Compared: From Phone to Professional

Every modern smartphone contains a MEMS (Micro-Electro-Mechanical Systems) microphone designed for voice capture. These capsules are remarkably consistent within a model line and provide flat response within plus or minus 3 dB from 200 Hz to 8 kHz. Self-noise is typically 25-30 dB SPL, and maximum SPL is 115-120 dB.

The key advantage is that you already own one. No additional hardware is needed. With a calibration correction curve (available for many popular phone models), accuracy improves to within 1-2 dB, sufficient for most practical audio engineering tasks. SonaVyx supports importing phone-specific calibration files.

USB measurement microphones in the $50-150 range provide significantly better performance than phone MEMS capsules, particularly below 200 Hz and above 10 kHz. The MiniDSP UMIK-1 ($100) comes with an individual calibration file and is widely used with REW. The Dayton Audio UMM-6 ($80) offers similar performance.

These microphones plug directly into a computer via USB, providing their own ADC. They typically offer 20 Hz to 20 kHz response within plus or minus 2 dB without calibration and plus or minus 0.5 dB with individual calibration. Self-noise is around 15-20 dB SPL, enabling measurements in quieter environments.

Professional measurement microphones from manufacturers like Earthworks (M23, $500), Audix (TM1, $300), and Josephson (C550H, $900) provide laboratory-grade accuracy with response flat within plus or minus 1 dB from 20 Hz to 20 kHz. These require phantom power and an audio interface.

The top tier includes Bruel and Kjaer (4190, $3,000+) and GRAS capsules used for IEC 61672 Type 1 compliance measurement. These offer accuracy within 0.1 dB and come with individually serialized calibration certificates traceable to national standards laboratories.

For live sound system tuning: phone MEMS with calibration or budget USB mic. The relative measurement accuracy (comparing before and after, or position to position) is more important than absolute accuracy, and both options provide excellent relative accuracy.

For room acoustic consulting: budget to mid-range measurement mic ($100-500) with individual calibration. Clients expect documented accuracy, and a calibrated measurement mic provides the credibility and accuracy needed for professional reports.

For compliance testing (IEC 61672, ISO 3382): professional calibrated capsule with current calibration certificate. Regulatory and legal compliance requires traceable measurement accuracy, which only certified equipment provides.