A measurement microphone has an omnidirectional polar pattern and a frequency response that is as flat as possible. The difference between cheap and expensive lies less in the sound than in the variation between units, the maximum SPL, the self-noise – and whether a calibration is supplied.
Entry level: measurement microphones without a stated standard, usually with an electret capsule.
The low-cost measurement microphone with XLR connection that has been widespread for years. The manufacturer states basic data, but not calibration data.
Low-cost XLR measurement microphone with individual calibration file – the usual next step after a microphone without calibration.
USB version of the EMM-6: microphone and converter in one, without an audio interface and without phantom power.
The widespread USB measurement microphone with calibration file; the REW developer names it as the simplest configuration together with his software.
Low-cost measurement microphone with XLR connection and an individual measurement report included; widespread in the German-speaking region.
Professional: microphones whose manufacturer guarantees a standard or tightly toleranced, tested data.
Measurement microphone with a very wide, tightly toleranced frequency response and 140 dB maximum SPL – designed for loud measurements in everyday sound reinforcement.
Class 1 measurement microphone according to IEC 61672 – needed when measured values must comply with a standard, for instance with level requirements.