Re: [Bluemusic-users] Modal Freqs
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From: Mark V. P. <Mar...@te...> - 2007-10-10 09:12:56
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Steven Yi wrote: > Hi Mark, > > Thanks for sharing your experience! I think I'm finding similar > experiences as you in regards to working with PRAAT. I think though > that with modal synthesis the excitation signal used is going to shape > and mold the sound as well. > Yes, the excitation signal is significant. Logic tells me that a pulse is probably best for instruments like a xylophone and a gong, because these are hit shortly after which the sound slowly fades out. For instruments like a violin this is not the case, there the excitation signal should be something continuous (but I don't know what). I've been thinking about my courses on Laplace transforms (a mathematical theory that is applicable to these things), and it doesn't seem easy to find both the formants (freq., bandwidth and ampl.) and the excitation signal, at least not in a theoretical, clean way, maybe it is possible with numerical methods. So far the theory, software that does it would be nice :-). > For myself, I think to some degree I would like to get close to > imitating the sound of the instruments I'm analyzing, but with some > degree of acceptance that the sound won't be exactly the same, though > just as musically useful and flexible. > In some cases I found an approximate imitation of a real world instrument to be worse than an instrument that doesn't sound like any real world instrument, because you are reminded of the real world instrument but know that it is not correct. But in other cases it sounded intriguing. > I haven't had an opportunity to work through much more than what you > have done yourself; I would say though that the work Harm Visser did > does sound very good to my ears and I think I would find if I could > create similar results that it would be musically very useful. > Yes, the examples on his website sound amazing. > Thanks again for looking into this and sharing your thoughts on it! > steven > > On 10/7/07, Mark Van Peteghem <Mar...@te...> wrote: > >> I downloaded Praat this week and experimented with it. I rendered a >> single note of a xylophone with a soundfont (Campbells_Grand_Xylophone) >> to a wavefile and loaded it in Praat. It looks like this one needs at >> most 8 formants, because when I tried more formants, several formants >> had about the same values. >> >> The textfile produced by Praat contains a frequency and a bandwidth for >> each formant. The mode opcode requires a frequency and a quality, but >> you can convert this easily with the formula quality = frequency / >> bandwidth. I didn't average the values, because the values seem quite >> constant. When I made an instrument with the 8 formants, it sounded like >> a xylophone but still not like the original sample. >> >> idur = p3 >> iamp = ampdb(p4) >> >> aexc mpulse 1, 0 >> >> a1 mode aexc, 1582.29932, 1582.29932/7.89720488 >> a2 mode aexc, 2225.94, 2225.94/10.8666286 >> a3 mode aexc, 2746.1, 2746.1/2.10496593 >> a4 mode aexc, 3595.45, 3595.45/22.9179974 >> a5 mode aexc, 4504.3584 , 4504.3584 /27.6062775 >> a6 mode aexc, 5079.95215 , 5079.95215 / 18.8226795 >> a7 mode aexc, 182.29932, 182.29932/302.28 >> a8 mode aexc, 1606.29932, 1606.29932/391.61 >> >> asig = (a1+a2+a3+a4+a5+a6+a7+a8)*iamp >> ;asig = (a8)*iamp >> >> blueMixerOut asig, asig >> >> a7 and a8 can be removed without affecting the sound. >> >> I tried using the bandwidth value instead of the quality, which >> ironically made it sound a little better, but still not like the >> original (in this case you can remove all of them except a7 and a8 ). >> >> The most likely problem is that Praat doesn't give amplitudes for the >> formants. I therefore used the same amplitude for all of them, but this >> means that a formant may be too strong or too weak. Praat is actually >> meant to *recognize* a sound (what is needed in speech recognition), not >> too *imitate* a sound (which is what we want). >> >> -- >> Mark >> _________________________________________ >> When you get lemons, you make lemonade. >> When you get hardware, you make software. >> >> >> ------------------------------------------------------------------------- >> This SF.net email is sponsored by: Splunk Inc. >> Still grepping through log files to find problems? Stop. >> Now Search log events and configuration files using AJAX and a browser. >> Download your FREE copy of Splunk now >> http://get.splunk.com/ >> _______________________________________________ >> Bluemusic-users mailing list >> Blu...@li... >> https://lists.sourceforge.net/lists/listinfo/bluemusic-users >> >> > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Bluemusic-users mailing list > Blu...@li... > https://lists.sourceforge.net/lists/listinfo/bluemusic-users > > > -- Mark _________________________________________ When you get lemons, you make lemonade. When you get hardware, you make software. |