BRUEL & KJAER 4188 - Page 61

Chapter 3 — Prepolarized Free-field
1
/
2
" Microphone Type 4189
Dynamic Range
Falcon™ Range of Microphone Products
Microphone Handbook
Brüel & Kjær
3
−
16
The preamplifier’s effect on the inherent noise of the combined microphone and
preamplifier depends on the sensitivity and capacitance of the microphone (for
1
/
2
"
Microphone Preamplifier Type 2669, see Fig.3.16 and Chapter 8).
Fig.3.16
1
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3
-octave-band inherent noise spectrum. The shaded bar graphs are the broad-band
(20Hz to 20kHz) noise levels and the white bar graphs the A-weighted noise levels of the
microphone (M),
1
/
2
" Microphone Preamplifier Type 2669 (P) and microphone and pream-
plifier combination (C)
– 10
– 5
0
5
10
15
940717e
20
10 1 k 10 k
100
Sound Pressure Level
re 20 µPa (dB)
Frequency (Hz)
MPC
Microphone
and
Preamplifier
Combination
Preamplifier

Microphone

20 k
L
A
L
A
L
A