BRUEL & KJAER 4188 - Page 90

Chapter 4 — Free-field
1
/
2
" Microphone Type 4190
Dynamic Range
Falcon™ Range of Microphone Products
Microphone Handbook
BE1376– 12
4
−
15
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.4.16 and Chapter 8).
Fig.4.16
1
/
3
-octave-band inherent noise spectra. 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 micro-
phone (M),
1
/
2
" Microphone Preamplifier Type 2669 (P) and microphone and preamplifier
combination (C)
– 10
– 5
0
5
10
15
940718e
20
10 1 k 10 k
100
Sound Pressure Level
re 20 µPa (dB)
Frequency (Hz)
MPC
Preamplifier

Microphone

20 k
Microphone
and
Preamplifier
Combination
L
A
L
A
L
A