KU 80

Common name: Neumann KU 80

Production Status: Discontinued / Vintage

The KU 80 is the first “Dummy Head” stereo microphone system launched by Georg Neumann GmbH in 1973 and manufactured until 1981, when it was replaced by the KU 81 dummy head. Neumann’s dummy heads are developed in cooperation with IRT (Institute fur Rundfunktechnik – Munich). The system consists in a reproduction of a human head with two special version KM 83 pressure condenser microphones installed inside. Tunable Helmotz resonators and further coupling allows the 5 mm ear canal reproduction to reach the 21 mm microphone capsule (for details refer to Dr. S. Peus’s writings and other specific pieces). The target in developing the KU 80 microphone system was to create the illusion for the listener of being in the actual recording room. The dummy head polar pattern is quite different compared to that of standard microphones. The KU 80 design and development was referenced to free field use, in particular trying to simulate the human ear free field response at a particular point in the ear canal. The dummy head was equalized for a linear free field frequency response for sound coming from the front, just like it is usually done for standard microphones, presuming that this solution would provide a good compatibility with loudspeakers reproduction. When the KU 80 was tested in different recording situations, it was clear that the sound quality was good for headphone listening, but quite unrealistic in loudspeakers playback. The complicated shape of the outer ear, only allowed free field equalization for one sound source direction. The IRT’s researchers started working with Neumann’s engineers to to develop a new dummy with diffuse field equalization. This is how the KU 81 was born. The KU 80 also had other limits such as maximum SPL (the sound pressure at the capsule diaphragm were considerably higher than outside) and difficult microphone system placement. The existing KU 80’s were up-gradable to KU 81 specifications.