Double MS

The principle of the double MS technique is a front- and a backwards-pointing MS set, sharing the same Side microphone. Therefore, just three microphones are needed, but quite a lot of processing/mixing is necessary. As always with MS set-ups, two different transducer technologies are used for the cardioid Mid mic and the bi-directional Side mic and there is a risk of different frequency and phase responses of sound reproduction from the sides or the front.

The double MS technique can be attained by using four identical - even matched - DPA cardioid microphones angled 90° to each other.