Reverse damping
Backward attenuation , also backward sensitivity, is a term used for directional microphones . It characterizes the sound level attenuation that is measured from the rear of the microphone , i.e. from the 180 ° direction of sound incidence . The backward attenuation is more or less dependent on the frequency, so the specification usually refers to 1 kHz. A back attenuation of at least 15 dB is common for large-diaphragm microphones with a cardioid directional characteristic . For small diaphragm microphones with the same directional characteristic, the backward attenuation is 25 dB or more. A so-called wide cardioid has a backward attenuation of about 11 dB. A high backward attenuation also ensures good feedback suppression with additional loudspeakers from behind.
The term sideways attenuation for the microphone can also be classified here. That is the sound level attenuation 90 ° to the direction of sound incidence.
In the case of directional antennas, there is also reverse attenuation, which, in addition to the antenna gain, is an important parameter in antenna technology.
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 .
- Communication technology part 1 Basics of radio frequency. 1st edition, Institute for the Development of Modern Teaching Methods e. V., Bremen, 1980
- Norbert Pawera: Microphone Practice . 4th edition, Franzis Verlag GmbH, Munich, 1993, ISBN 3-932275-54-3