Note regarding acoustic center of mmc2011 capsule

The MMC2011 Twin Diaphragm Cardioid Microphone Capsule benefits from the unique DPA Microphones Twin-Diaphragm capsule and Interference Tube technologies. This combines the advantages of small capsules (fast impulse response and large frequency bandwidth) with lower inherent noise achieved from a larger diaphragm area.

The use and control of interference tubes has become a DPA area of perfection and for the MMC2011, the Interference Tube assists in controlling both directivity and low frequency response.

The MMC2011 is included in the 2011A and 2011C. Furthermore, and even more relevant, it is included in the selected stereo pairs ST2011A and ST2011C.

Since the interference tube is positioned in front of the capsule to operate correctly, the acoustic center of the microphone is 36 mm (1.4 in) under the tip of the grid, in the middle of the capsule. This should be kept in mind when placing the microphones for stereo recordings like XY, ORTF, NOS and DIN. See the below examples for a XY 90° configuration.