Axis angle
The word axis angle α comes from the X / Y stereophony recording technique ( intensity stereophony ), in which the stereo microphone (which theoretically consists of two directional microphones located at one point) can be set at this angle to each other.
It is always the total angle between the major axes of the two microphone systems with their usually at X / Y same directivity pattern meant. Dickreiter and other audio engineering authors also referred to this angle as "opening angle" or "offset angle", although sometimes it was not the angle between the microphones but the recording angle, i.e. the angle of the recording area, and sometimes half the angle was also meant. This leads to confusion. It is therefore recommended to only use the term “axis angle”. Even the half angle with the name “offset angle”, which only means half the axis angle, does not contribute to the clarity.
This term axis angle can also be applied to microphone systems, as they occur in equivalence stereophony, for example, as an ORTF stereo system , in which the axis angle is α = ± 55 ° = 110 °. With the NOS stereo system and the EBS stereo system, the axis angle is α = ± 45 ° = 90 °.
literature
- Michael Dickreiter , Volker Dittel, Wolfgang Hoeg, Martin Wöhr (eds.): Handbuch der Tonstudiotechnik , 8th, revised and expanded edition, 2 volumes, publisher: Walter de Gruyter, Berlin / Boston, 2014, ISBN 978-3-11- 028978-7 or e- ISBN 978-3-11-031650-6
- Hubert Henle: The recording studio manual. 5th edition, GC Carstensen Verlag, Munich, 2001, ISBN 3-910098-19-3
See also
- Stereophony | Intensity stereophony | Equivalence stereophony | Runtime stereophony
- ORTF stereo system | NOS stereo system
- Audio event direction | Recording area | Expansion area | Microphone base
- List of audio terms
Web links
- Comparison of the axis angles for different equivalent microphone systems , sengpielaudio.com (PDF file; 134 kB)
- Well-known stereo microphone systems and their angles (axis angle and recording area) , sengpielaudio.com (PDF file; 34 kB)
- Visualization: EBS stereo microphone system cardioid / cardioid 90 ° microphone base 25 cm equivalence stereophony , sengpielaudio.com