Designe new filters.

snaper's icon

Hy guys...

I was just wondering that is it possible to design new filter responses somehow like this :

- "Draw" the response with filtergraph or zplane
- get the coeffs.
- put the into another filtergraph
- the manipulate them with regular filter controls (Curoff/Res/Gain)

Is it possible somehow?

Roman Thilenius's icon

somehow not possible. there is no way to get coefficients for biquad from a custom response curve.

snaper's icon

You can get the coeffs. from the filtergraph object. If you connecz a zplane to the filtergraph you can esig very extrem curves, and you can get the coeffs.

The only problem is that you can use those coeffs for changing it with regular filer controls. Am I right?

snaper's icon

Here is a patch about what I think, maybe I wasn't enough clear.

idea.maxpat
Max Patch
Roman Thilenius's icon

what you are doing there will require 3 biquads. if that was your aim, this way it will of course work to design a filter.
yet you are still ending up with a series of filters of the known standard types. :)

how to use a linear knob or fader to control poles and zeros? no idea.

i think to find musically interesting settings you can stick to using multiple filtergraphs ... the zplane isnt really giving you access to something useful.

snaper's icon

I see...
I finished the original wish, just was wondering, that maybe I can improve with a more "technical" way :D