AFTER MORE THAN 70 YEARS IN PRODUCTION, Shure’s Unidyne 55 series easily takes the prize for the longest running, most successful product in audio history. The story begins in 1937 with Shure engineer Benjamin Bauer looking for a single-capsule approach to creating a unidirectional microphone.

He experimented with capsules having front and rear openings that allowed sound waves to reach the diaphragm. Partially blocking the rear openings created a short phase delay that effectively cancelled the sounds from the rear. Varying the rear port resistance created various directional patterns—cardioid, hypercardioid and supercardioid—and the Unidyne was born. In 1939, Shure announced its model Unidyne 55. more