KLING & FREITAG K&F TOPAS - Manual (Page 61)

User's manual System Amplifier K&F TOPAS
KLING & FREITAG GMBH © 2014 Version 3.1 Page 61 of 65
11.1.4 HighP = High Pass Filter
This example shows different high pass filters which are characterised by varying Q factors.
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Frequency in [Hz]
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FilterType = 'HighP' (Highpass) Freq = 1000Hz
Q = 0.707 Butterworth 1.Ordnung
Q = 0.2
Q = 0.5
Linkwitz-Riley 2.Ordnung
Q = 0.707 (default) Butterworth 2.Ordnung
The resulting filter Q = 0.707 is a 2nd order Butterworth filter and causes attenuation of
3 dB at the cut-off frequency (-3dB @ 1000Hz). Below the cut-off frequency, there is an
attenuation of 12 dB per octave (-12dB/octave).
A Q higher than 1 causes a level increase at the crossover frequency.
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Frequency in [Hz]
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FilterType = 'HighP' (Highpass) Freq = 1000Hz
Q = 0.707 (default) Butterworth 2.Ordnung
Q = 10
You can choose between a high pass filter 1st or 2nd order. The Q of a 1st order high pass
filter is always fixed. At a 2nd order high pass filter Q is adjustable in steps of 0.001 from 0.2
to 20.
The parameter 'Gain' has no effect with the high pass filters.
11.1.5 LowP = Low Pass Filter
This example shows various low pass filters at 1000Hz, which are characterised by different
Q-factors. The resulting filter with Q = 0.707 is a 2nd order Butterworth filter and causes an
attenuation of 3dB at the cut-off frequency (-3dB@1000Hz). Above the cut-off frequency,
there is an attenuation of 12dB per octave (-12dB/octave).
20 50 100 500 1000 5000 10000 20000
-40
-36
-24
-12
-6
-3
0
2
Frequency in [Hz]
P
o
w
e
r
in
[
d
B
]
FilterType = 'LowP' (Lowpass) Freq = 1000Hz
Q = 0.707 Butterworth 1.Ordnung
Q = 0.2
Q = 0.5
Linkwitz-Riley 2.Ordnung
Q = 0.707 (default) Butterworth 2.Ordnung
A Q higher than 1 causes a level increase at the crossover frequency.