Re: [music-dsp] What is resonance?
Hi all, I follow the llist for a while, but I am not a DSP programmer, I do DSP audio apps for about 20 years now, for sonic core plateform "Scope" and Xite". I begin with other things like juce or flowstone, but so far, scope is still far superior in terms of sound results. Too bad there is no scripting tool for it (well there is but it is not available to me). My question is probably weird for you - like super noob - , because i am NOT looking for math or codes, but hints about a general design/architecture. So... how do you do a resonance in a lowpass circuit? :-) not the math, not the code, just the architecture. Personnally, i came to the conslusion that some kind of very short delay with feedback, mixed in parallel with the non resonance low pass sound, could do the trick. . The more feedback, the more resonance, and with feedback over -6dB, it would begin to self resonate. But it is having the resonance in parralel to a dry sound that bothers me; but may be that's the only way to do ? I have read about hardware filters and ok, there is math, but there is also the effect of the hardware components. Some articles even suggest that a bandpass in parralel could do the trick : or more exactly, a bandpass fonction is created after the resonance, to remove frequencies that would overlap with the cutoff. So, any hints that could help me improve the process etc would be very welcome. Thanks Mehdi ___ dupswapdrop: music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
Re: [music-dsp] What is resonance?
Hello ! Thanks a lot everyone. Thanks for the book info Vadim. I was not notified that this thread was going on, so I forgot it. I managed to make something work, but sonically speaking, it was far from a moog filter :-) The appearance/disappearnce of the resonance effect was pretty brutal, and with a kind of veil on the higher frequencies. I should have taken a screen shot of the "circuit" (the interconnected modules, mix, feedback, and may be gain). But I think I was too ashamed of my first attempt :) I had to do something else (much much easier = a 4*32 step sequencer with many modulators and triggers) that controls eurorack, using a scope dsp card, and a exprt sleepers converters, no sound magic involved . :-) I've also been educated to dsp cards with development kits, for pretty cheap prices (compared to when I last checked 10 years ago). but right now i will try native tools to try to translate what i've build recently. To be continued Mehdi (for examples of what i've been "building" or putting together) https://spacef-devices.com Le lun. 23 juil. 2018 à 11:42, Vadim Zavalishin < vadim.zavalis...@native-instruments.de> a écrit : > 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 > > ___ dupswapdrop: music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
