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directivity factor (DRF)

The directivity factor (DRF) is a dimensionless characteristic value of loudspeakers and microphones that is specified in gamma. It is a measure for the ratio of a certain radiation characteristic to a spherical sound radiation.

The same applies to the sound pickup of microphones. Here, the sound pickup of a microphone with a certain directional characteristic is put in relation to the sound pickup of a microphone with an omnidirectional characteristic.

The result is that the directivity is a dimensionless value and must always be >1, since all radiation patterns and directional patterns have a more



sound radiation or sound pickup than an omnidirectional one. The directivity is calculated from the reciprocal of the REE (Random Energy Efficiency) value and, depending on the polar pattern, is 1 for omnidirectional, 1.7 for cardioid, 1.9 for supercardioid, 2 for wide cardioid and 3 for hypercardioid.

The degree of bundling is decisive for the sound pickup of ambient noise. The higher it is, the less sensitive the audio pickup is to ambient room sound.

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Englisch: directivity factor - DRF
Updated at: 16.02.2019
#Words: 258
Translations: DE