Besides making history as the first true multipattern microphone with remote polar control, AKG’s C12 sounded great (and is still highly prized today) and laid the foundation for more than a half-century of future AKG mic designs. Developed by AKG engineer Konrad Wolf, the C12 included an external box for selecting any of nine polar patterns, and its slender tubular housing was more compact than Neumann’s U Series and featured internal shock-mounting, so no external elastic suspension was required.
The heart of the sound of the C12 is its capsule, which uses a dual-backplate design invented by two Siemens engineers and results in consistent on-axis sensitivity when the polar pattern is changed. The C12’s CK-12 capsule paired the dual-backplate approach with two 10-micron diaphragms. (Two years later, the CK-12 capsule was upgraded to 6-micron Mylar capsules.) To expand AKG’s postwar distribution, the mic was also re-branded by Telefunken as the M251 and as Siemens’ SM 204. In the 1960s, as tube mics were losing popularity to the “convenience” of solid-state FET designs, the C12 was discontinued, later to resurface in slightly different forms. In 1983, “The Tube” used a C-414 capsule with the original C12 tube electronics but in a smaller body. The C12 finally reappeared in a more accurate re-creation in 1994, as the C-12VR (vintage reissue), which paired the C12 electronics with a re-tuned CK-12 capsule that simulated the acoustic signature of the orignal C12.
A stereo version of the C12, the C24, was created in 1959 by stacking two identical capsules that could be rotated to vary the stereo perspective. As with the C12, the polar patterns of both C24 capsules can be changed—again, nine choices are offered—so the mic is capable of X/Y, Mid-Side or Blumlein (crossed figure-8) stereo-miking.