The microphone capsule MK 211 has a free-field response with a frequency range up to 40 kHz and is therefore optimized for correct acoustic measurements under free-field conditions with 0 degree incidence. The equalization of the static air pressure is by means of a capillary to the preamplifier (rear-vented).
The microphone capsule is suitable for sound level meters of Type 1 acc. IEC 61672.