KLING & FREITAG K&F TOPAS - Manual (Page 57)

User's manual System Amplifier K&F TOPAS
KLING & FREITAG GMBH © 2014 Version 3.1 Page 57 of 65
11. Appendix
11.1 Parametric Filters
There are four parametric filters for room equalisation available in every channel
The speakers are equalised in the speaker blocks (see page 33).
You can choose following parameters under 'Filter' by the web interface
• Bypass (no filter)
• Bell (bell filter)
• LShelv (low shelving filter)
• HShelv (high shelving filter)
• HP-1st (high pass first order)
• HP-2nd (high pass second order)
• LP-1st (low pass first order)
• LP-2nd (low pass second order)
• AP-1st (all pass first order)
• AP-2nd (all pass second order)
• Notch (notch filter)
Up to four parametric filters per input channel serve to equalise the system, i.e. to adjust the
speaker frequencies to the room conditions. They can also be used to eliminate the feedback
during monitor uses. The PEQs (parametric equalizers) are saved with the setup.
In the PEQs, the parameters for filter type, gain, frequency, and Q-factor can be adjusted.
If you change to another type of filter, the Q-factor automatically sets itself to a value
of 0.707. The default value of bell filters and notch filters is 1/3 octave (Q = 4.318). This
safeguards against unexpectedly high levels which might be caused by a Q-factor that is
too high. When you have changed the type of filter, always make sure if a Q-factor of 0.707
meets your needs and correct it, if necessary.
Explanation of the filter types of the PEQ:
The parameter "Gain" is adjustable in steps of 0.1, from -96 to +24 dB (independent of the
input and output gains). The parameter ‘Gain’ has no effect on the filter types 'LowP', 'HighP'
and 'AP'.
The parameter "Freq" is adjustable in 1Hz steps, from 10Hz to 20kHz.
11.1.1 Bell = Bell Filter
This filter increases certain frequency ranges (positive gain) or attenuates them (negative
gain). The gain determines the maximum or minimum level increase or attenuation of the
filter (in the graph: increase of +6dB).
20 50 100 500 1000 5000 10000 20000
0
3
+6
Frequency in [Hz]
P
o
w
e
r
in
[
d
B
]
FilterType = 'Bell' (Bell Passband) Gain = +6dB Freq = 1000Hz
Q = 0.2
Q = 0.707
Q = 1.414
Q = 5