Some Filters / FilterTool

Some scientific filters and a visualization of the Gain / Phase behaviour

(23 Votes)
2.0 (Updated 10 years ago)
August 14, 2010
Reaktor 5 or lower


Basic scientific filters with included transferfunction calculation (removable)

version 2: complete rebuild

filtertypes: Butterworth, Bessel, Chebyshev Type I

2,4,6,8,12 pole (doubled to 4,8,12,16,24 in bandpass/ bandstop form). calcs all parameters except for the Besselform (included zerotable up to order 12).

performs "true" transformations from lowpass to highpass/bandpass/bandstop now

transferfunction-visualization: gain, phase, dewrapped phase, phasedelay and groupdelay. linked to the ezfft-analyzer

original vs. filtered scope


Massimiliano Bucci
8 years ago
Modulation of a sound wave, easy to use but to create a good effect you have to work a bit on.
michael o'hagan
9 years ago
Hello, these are amazing, Thank you very much. I only have 1 issue. I am adding these into a multi filter macro with a vowell filter and a few others. these other filters measure between 20 and 140 (Reaktor multifilter standard macro) with the pitch/freq knob. your filters create a lot of noise and then shut of when a message below 30 is sent in, or a message above 130. is there a way to fix this? I did the math so that the knob gets scaled coming in but when I use an LFO it becomes a problem as I cannot scale the LFO message without messing up its ratio with the rest of the filters.
Jan Brähler
9 years ago
Hi. Sorry for this late reply. (Didn't get an email-notification.) You can transform the F_begin and F_end to center-pitch and bandwidth via F_beg = F(pitch-bw/2) F_end = F(pitch+bw/2), where F(P) is Expon.(Frequency) and P_beg = P(F_beg), P_end = P(F_end), P_center = (P_beg+P_end)/2, bandwidth= (P_end-P_beg)/2. Those chebychev-filters have a heavy allpass-effect, so they are not neutral.
El Saw
9 years ago
Hi, Jan Brähler! Found Some Filters / FilterTool v2.0 very usefull for crossover (5 band xover) setup. Have you any modification (or point where I can find) of filter (chebyshev bandpass 12/24) where I can set input band width with two params F_beg and F_end. And how can I calculate F_beg-F_end from Fcutoff and Bandwidth param?
Simon D Klapper
10 years ago
COOL! Thanks. They sound very intersting, especially when increasing ripple on the chebyschev.
S Millward
11 years ago
These would not load in Reaktor 5. What version of Reaktor 5 is required?
11 years ago
Thank you for these filters.