Degree of bundling
The degree of bundling (formerly also called sound power bundling ; Directivity Factor DRF or Q , not to be confused with the directional factor ) indicates the bundling ability of the sound in loudspeakers , microphones and individual sound sources in the diffuse sound field .
details
The degree of concentration is a pure ratio that indicates how much the degree of concentration is greater than that of an ideal sphere . The greater this difference, the greater the degree of concentration and thus the "fading out of the room", i. H. the suppression of diffuse sound. The degree of bundling makes z. B. a statement about the noise suppression in the direct field ( free field ) with directional microphones . The sound picked up by a directional microphone is compared with the sound that an ideal microphone with omnidirectional characteristics would pick up with the same transmission factor.
The degree of bundling depends on the frequency : it usually rises to high frequencies.
Derived quantities
- The bundling factor ( distance factor ) results from the root of the bundling degree:
- The directivity index (engl. Directivity index of the directivity factor in) is dB expressed:
- When Random Energy Efficiency is the reciprocal of the directivity factor shall apply:
Some values
Microphone bundling ability | ||||
Microphone characteristics | Degree of bundling γ | Bundling factor | Bundling dimension | REE = 1 / γ |
Sphere ( reference ) | 1,000 | 1,000 | 0 dB | 1,000 |
Wide cardioid (-9.5) | 2.077 | 1.441 | 3.17 dB | 0.481 |
eight | 3,000 | 1.732 | 4.77 dB | 0.333 |
kidney | 3,000 | 1.732 | 4.77 dB | 0.333 |
Supercardioid | 3.732 | 1,932 | 5.72 dB | 0.268 |
Hypercardioid | 4,000 | 2,000 | 6.02 dB | 0.250 |
See also
literature
- Michael Dickreiter, Volker Dittel, Wolfgang Hoeg, Martin Wöhr: Manual of the recording studio technology. 2 volumes. Published by the ARD.ZDF media academy. 7th, completely revised and expanded edition. Saur, Munich 2008, ISBN 978-3-598-11765-7 .
- Thomas Görne: Sound engineering. Fachbuchverlag Leipzig in Carl Hanser Verlag, Munich et al. 2006, ISBN 3-446-40198-9 .
- Norbert Pawera: Microphone Practice . Tips and tricks for stage and studio. Technology, acoustics and recording practice for instruments and vocals. 4th, completely revised and expanded edition. PPV-Medien, Bergkirchen 2003, ISBN 3-932275-54-3 .
- Siegfried Wirsum: Practical sound reinforcement technology. Device concepts, installation, optimization. Franzis-Verlag GmbH, Munich 1991, ISBN 3-7723-5862-4 .
Web links
- Degree of bundling of the microphones (PDF file; 100 kB)
- Theoretical microphone data on the directional characteristics (PDF file; 37 kB)
- Explanation of theoretical microphone data (PDF file; 33 kB)
- Difference between hypercardioid and supercardioid (PDF file; 118 kB)
- Degree of bundling as DEGA recommendation 101 (PDF file; 1016 kB)