BRUEL & KJAER 1053 Instruction Manual page 75

Distortion curves are shown in Fig. 6.1 and Fig. 6.2 to help the user optimize the choice
of compressor speed for the particular application. For low to medium a-values, a
"Rate" of "1 dBs-
1
/Hz and a "Max. Speed" of "1 000 dB/s" should result in a suitable
compressor speed.
0
dB
0 'dB
=
1
1
v
R
1
Ms (20
~B cJmpre~sion)
10
20 10%
30
1000 dB/sec
c
0
40
:;::;
£
(J)
i5
50
u
·c:
0
E 60
iii
:I:
"0
70 c
0
u
Q)
CJ)
80
90
1-1%
"'
"'
~
100 dB/sec
300 dB/sec
"
f-0,1%
""""
r--.....
['...
-~
i'-.
~
' " '
~
30 dB/sec
~
""
"'
"'~
f-0,01%
r--
1---
""
--~--
1--
..............
"'
"-. ~
r--.
i'.....
~
10, 3 and 1 dB/sec
--r--
!"'--- ['-.....
~
~
r--r-_
100 t- 0,001%
110
I
0,1 Hz 0,2 0,5
2 5 10 20 50 100 200 500 1kHz 2 5 10
Frequency
860944
Fig. 6. 1. Typical second harmonic distortion curves
0
dB
I I I I I I .
0 dB
=
1 V RMS (20 dB Compression)
10
20
30
c
~ 40
0
iii
i5
50
u
·c:
0
60
E
iii
:I:
"E
70
:c
f-
80
90
100
I I
1000 dB/sec
"'
Comp. Rate
I
1 :
3 dB/sec per Hz
300 dB/sec
r--..,.
10%
100 dB/sec"' ,
II:
1 dB/sec per Hz -
30dB/sec~
"'
""'
Ill:
0,3 dB/sec per Hz
10 dB/sec
i'..._
' IV: 0,1 dB/sec per Hz
3
d~/sec f-~
I
~
~ 0 ~~
'
K
K
r--...
~
f-1%
1
'
~-
~
r-~ ' ~ '
1 dB/sec
,-
f'..
~
~
"-.
"
"'
~
~
~
~
~
""'
"
- - --
-
"'
i\
1-0,1%
r--.......
"'
IV'
~
~
............
f'.~
.......
"'
~ ~
r---
- - - - -
~
"'
t-....
~
..........
~
"
~ ~~
~'-....
!' - ....
~
t- 0,01%
..............
~ !':
~
~
.....
~
'
r-::::
~
"'
0,001%
~
110
0,1 Hz 0,2 0,5 2
5 10 20 50 100 200 500 1 kHz 2
5
10
Frequency
860945
Fig. 6.2. Typical third harmonic distortion curves
67