The system worked best when the stereo sound had been recorded via two bidirectional microphones on the same spot.

This coincident technique employs a bidirectional microphone facing sideways and another microphone at an angle of 90 , facing the sound source.

He records almost exclusively using the Blumlein binaural or Stereosonic method invented by Alan Blumlein, which involves the usage of two bidirectional microphones in a 'coincident', 'crossed pair' configuration.

This coincident technique employs a bidirectional microphone (with a Figure of 8 polar pattern) facing sideways and a cardioid (generally a variety of cardioid, although Alan Blumlein described the usage of an omnidirectional transducer in his original patent) at an angle of 90 facing the sound source.