The M31 is a low voltage electret condenser microphone specifically designed for the measurement of transducers, loudspeaker systems, room response, ａnd other similar acoustic characteristics. The M31 provides a very cost effective solution to many general purpose acoustic measurements. This microphone features low cost, wide smooth frequency response, small size, ａnd easy interface/power requirements.

The small diameter （0.3 Inches） ａnd size of this microphone makes this an excellent choice for near field measurements ａnd in other locations where space is at a premium. The small diameter also produces less directional sensitivity for high frequency measurements. The low voltage ａnd current requirements of the microphone/preamp allow for easy setup ａnd operation from a wide variety of power supplies, ａnd can even be powered using a standard 9V battery.