Larson Davis Spartan 821, Reference Manual

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Spartan 821/721 Manual Instrument Hardware Specifications A-7
A.1.4 Microphone Model 377B02 Filter Response and Corrections
Frequency response correction filters are available for each sound field/microphone type and for environmental
protection accessories. Note: “RI” indicates “Random Incidence” and “FF” indicates “Free Field.” The default
setting for this instrument is “FF:FF,” which provides the most accurate free-field response for this instrument with
or without the WS001 windscreen.
Figure A-3 allows for comparison of provided filter correction values. See the table footnotes for application
instructions. Figure A-4 through Figure A-10 describe each filter in detail.
FIGURE A-3 Filter Responses in Comparison
TABLE A.2
Correction Filter Shapes
Frequency FF:FF FF:RI 2116 FF:RI 2116 FF:FF 2116 FF:90
250 0.15 0.02 0.04 -0.31 0.13
315 0.14 0.01 0.03 -0.32 0.12
400 0.14 0.01 0.04 -0.35 0.12
500 0.12 0.01 0.03 -0.37 0.1
630 0.09 0.01 0.02 -0.43 0.08
800 0.06 0.01 0.01 -0.49 0.05
25
0
31
5
40
0
50
0
63
0
80
0
10
00
12
50
16
00
20
00
25
00
31
50
40
00
50
00
63
00
80
00
10
00
0
12
50
0
16
00
0
20
00
0
‐2
‐1
0
1
2
3
4
5
6
7
dB
r
e
to
L
e
ve
l a
t
1
000
H
z
Frequency (Hz)
Correction Filter Shapes
FF:FF FF:RI 2116 FF:RI 2116 FF:FF 2116 FF:90