On 20-Jul-18 18:13, Mehdi Touzani wrote:
So... how do you do a resonance in a lowpass circuit? :-) not the math, not the code, just the architecture.
There are many different ways to create resonance in a lowpass circuit (esp. if the order is larger than 2). The higher is the order of the filter, the more different answers there are. Making a feedback loop around a lowpass chain is one way, but AFAIK it works perfectly (or close to that) only for the 4th order filter (the so called Moog ladder). I'm not aware of any standard generic structure (or even a transfer function to begin with) which could be referred to as a generic Nth order resonating filter. Recently I tried to propose one way of generalizing the 2nd order resonance to an arbitrary order by what I called "Butterworth filters of the 2nd kind", but this involves just the transfer function, whereas you still have lots of freedom in the implementation structure. You could look into the latest revision of my book for more details (where I also explain the problems with the lowpass feedback). Regards, Vadim -- Vadim Zavalishin Reaktor Application Architect Native Instruments GmbH +49-30-611035-0 www.native-instruments.com _______________________________________________ dupswapdrop: music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
