[music-dsp] Iterative decomposition of an arbitrary frequency response by biquad IIR
Hello music-dsp, I like to decompose an arbitrary frequency response by biquads. So I'm searching for an algorithm or paper on how to run an iterative decomposition. In my imagination it should be possible to a) find a first set of biquad parameters with a best fit frequency response in comparison to the given response b) create a IIR filter with inverse gain c) apply the filter to the given response to get a new one d) repeat a)-d) until some end criteria is reached a) should include the different filter types like peaking filter, lowpass, highpass, lowshelf, highshelf... Is there any good information for such an approach around? Is there a downside for such an approach? Uli -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
Re: [music-dsp] Iterative decomposition of an arbitrary frequency response by biquad IIR
For matching just the magnitude response, MATLAB has a built-in function for it: http://www.mathworks.com/help/signal/ref/yulewalk.html And maybehaps some more parametric modelling techniques will be useful for you http://www.mathworks.com/help/signal/ug/parametric-modeling.html -Stefan On Mon, Mar 3, 2014 at 12:00 PM, Uli Brueggemann uli.brueggem...@gmail.com wrote: Hello music-dsp, I like to decompose an arbitrary frequency response by biquads. So I'm searching for an algorithm or paper on how to run an iterative decomposition. In my imagination it should be possible to a) find a first set of biquad parameters with a best fit frequency response in comparison to the given response b) create a IIR filter with inverse gain c) apply the filter to the given response to get a new one d) repeat a)-d) until some end criteria is reached a) should include the different filter types like peaking filter, lowpass, highpass, lowshelf, highshelf... Is there any good information for such an approach around? Is there a downside for such an approach? Uli -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
[music-dsp] R: Iterative decomposition of an arbitrary frequency response by biquad IIR
Thanks Peter, that sounds interesting, have you ever tried DE on filter estimation? M. -Messaggio originale- Da: music-dsp-boun...@music.columbia.edu [mailto:music-dsp-boun...@music.columbia.edu] Per conto di Peter S Inviato: lunedì 3 marzo 2014 13:04 A: A discussion list for music-related DSP Oggetto: Re: [music-dsp] Iterative decomposition of an arbitrary frequency response by biquad IIR On 03/03/2014, Uli Brueggemann uli.brueggem...@gmail.com wrote: I like to decompose an arbitrary frequency response by biquads. So I'm searching for an algorithm or paper on how to run an iterative decomposition. ... Is there any good information for such an approach around? Is there a downside for such an approach? I guess you can always use a general iterative problem solving approach like differential evolution if you apply that to audio filters: https://www.google.com/search?q=differential+evolution Such genetic algorithms are great to iteratively find a 'best fit' set of parameters. - Peter -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
[music-dsp] R: Iterative decomposition of an arbitrary frequency response by biquad IIR
Stefan/Uli I use Scilab and there is not so much as in MAtlab for filter estimation. My experience with Scilab's invfreqz (which is based on the Levi paper I think) was always deluding for practical analog filter identification, but I bet I was unlucky or I didnt get the point of how to use it effectively. What I dont personally like in these methods is that they also need a weight vector on the data set, which adds a new degree of freedom that you must guess (not only the order). Let me know how is/was your experience then... Marco -Messaggio originale- Da: music-dsp-boun...@music.columbia.edu [mailto:music-dsp-boun...@music.columbia.edu] Per conto di Stefan Sullivan Inviato: lunedì 3 marzo 2014 12:17 A: A discussion list for music-related DSP Oggetto: Re: [music-dsp] Iterative decomposition of an arbitrary frequency response by biquad IIR For matching just the magnitude response, MATLAB has a built-in function for it: http://www.mathworks.com/help/signal/ref/yulewalk.html And maybehaps some more parametric modelling techniques will be useful for you http://www.mathworks.com/help/signal/ug/parametric-modeling.html -Stefan On Mon, Mar 3, 2014 at 12:00 PM, Uli Brueggemann uli.brueggem...@gmail.com wrote: Hello music-dsp, I like to decompose an arbitrary frequency response by biquads. So I'm searching for an algorithm or paper on how to run an iterative decomposition. In my imagination it should be possible to a) find a first set of biquad parameters with a best fit frequency response in comparison to the given response b) create a IIR filter with inverse gain c) apply the filter to the given response to get a new one d) repeat a)-d) until some end criteria is reached a) should include the different filter types like peaking filter, lowpass, highpass, lowshelf, highshelf... Is there any good information for such an approach around? Is there a downside for such an approach? Uli -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
Re: [music-dsp] R: Iterative decomposition of an arbitrary frequency response by biquad IIR
Marco, No, I've never actually had much luck with those kinds of filter design approaches. Matlab is not my favorite tool in the world. I usually find it a bit annoying that matlab seems more interested in matching some sort of brick-wall filter than designing a good-sounding audio filter. Although, this one doesn't seem to have weights, so it may be a little easier to use. That said, for OP's question, I think the paper referenced in that page is at least a step towards a good (better than matlab's?) solution. -Stefan On Mon, Mar 3, 2014 at 4:24 PM, Marco Lo Monaco marco.lomon...@teletu.it wrote: Stefan/Uli I use Scilab and there is not so much as in MAtlab for filter estimation. My experience with Scilab's invfreqz (which is based on the Levi paper I think) was always deluding for practical analog filter identification, but I bet I was unlucky or I didnt get the point of how to use it effectively. What I don't personally like in these methods is that they also need a weight vector on the data set, which adds a new degree of freedom that you must guess (not only the order). Let me know how is/was your experience then... Marco -Messaggio originale- Da: music-dsp-boun...@music.columbia.edu [mailto:music-dsp-boun...@music.columbia.edu] Per conto di Stefan Sullivan Inviato: lunedì 3 marzo 2014 12:17 A: A discussion list for music-related DSP Oggetto: Re: [music-dsp] Iterative decomposition of an arbitrary frequency response by biquad IIR For matching just the magnitude response, MATLAB has a built-in function for it: http://www.mathworks.com/help/signal/ref/yulewalk.html And maybehaps some more parametric modelling techniques will be useful for you http://www.mathworks.com/help/signal/ug/parametric-modeling.html -Stefan On Mon, Mar 3, 2014 at 12:00 PM, Uli Brueggemann uli.brueggem...@gmail.com wrote: Hello music-dsp, I like to decompose an arbitrary frequency response by biquads. So I'm searching for an algorithm or paper on how to run an iterative decomposition. In my imagination it should be possible to a) find a first set of biquad parameters with a best fit frequency response in comparison to the given response b) create a IIR filter with inverse gain c) apply the filter to the given response to get a new one d) repeat a)-d) until some end criteria is reached a) should include the different filter types like peaking filter, lowpass, highpass, lowshelf, highshelf... Is there any good information for such an approach around? Is there a downside for such an approach? Uli -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
