AKG K-180

The K-180 is the AKG headphone where you could move the transducers inside the earcups. Knobs on the outside of each cup backed them away from your ears or brought them up close. AKG called this a "presence control." High Fidelity (June 1971, p.30) described the effect with the transducers close to the ears: the perspective approximated a front-row center orchestra seat. Move them outward, the report said, and the image grew larger and more diffuse, like listening from farther back in the auditorium.

Beyond that, the record is thin. The K-180 was distributed in the US by Norelco and delivered with a coiled cord. A later tabulation in Audio (October 1974, p.120) lists it as a dynamic headphone covering 16-20,000 Hz, 600 ohms impedance, at a price of $69.00. That same listing repeats the "presence control" note and confirms it changed the transducer-to-ear distance.

Known specs:

Type: dynamic stereo headset
Transducers adjustable within earcups (presence control)
Frequency response: 16–20,000 Hz (per Audio's 1974 listing)
Impedance: 600 ohms
Coiled cord supplied
List price: $69.00 (1974)

Little else is documented about the K-180 beyond its period listings and that one news item. There is no service literature, no later reviews and no production figures.