BRUEL & KJAER 4188 - Page 146

Chapter 6 — Pressure-field
1
/
2
" Microphone Type 4192
Frequency Response
Falcon™ Range of Microphone Products
Microphone Handbook
BE1378– 12
6
−
11
6.3.6 Random-incidence Response
A microphone’s response in a diffuse sound field is equivalent to its random-inci-
dence response. The microphone’s random-incidence correction curves are shown in
Fig.6.6 and Fig.6.8. These corrections are added to the microphone’s actuator re-
sponse obtained using Electrostatic Actuator UA0033 in order to determine the
random-incidence response. The typical random-incidence response with and with-
out the protection grid are shown in Fig.6.10 and Fig.6.11.
The random-incidence corrections are calculated from the free-field corrections
measured in 5° steps according to Draft IEC1183–1993.
Fig.6.9 Typical free-field response (0° incidence) for the microphone without protection grid
Fig.6.10 Typical random-incidence response for the microphone with Protection Grid DB3421
940893/1e
5
15
10
0
– 5
– 10
1 k 10 k 100 k100
Frequency (Hz)
Response (dB)
940942/1e
– 5
5
0
– 10
– 15
– 20
1 k 10 k 100 k100
dB
Frequency (Hz)
Response (dB)