Hi Nuno, First, can I suggest that you take a look at my series on wavetable oscillators? It covers some of the questions you have, and in particular goes into detail about table length.
Well, this is annoying, I think an automated WordPress update killed my site, I need to look into it. But normally, go to earlevel.com and click the right-column topics for oscillators and the series will come up. But you can get the gist of it from my video: https://youtu.be/k81hoZODOP0 <https://www.youtube.com/watch?v=k81hoZODOP0> Note that linear interpolation would help your low frequency oscillator issue, and help your oscillator at high frequencies too. 2048 is a good minimum table length for 20 Hz and up, so you’re in the right ballpark. (Longer if you aren’t using interpolation between samples, and longer to get sharp edges for LFO—for instance, a low frequency sawtooth won’t have a crisp “tick tick tick”, but a more muffled one, at 1 Hz if your table is only 2048.) Nigel > On Sep 11, 2015, at 8:13 AM, Nuno Santos <[email protected]> wrote: > > Hi, > > Curiosity, by sinc do you mean sin function? > > Before anything: I’m a newbie. If I say something stupid don’t throw fire at > me, please! :) > > During this last year I have been developing a synthesizer. My lookup table > hadn’t more than 2048 samples. The sounds coming out from the oscillators was > alright. > > When I got to develop a chorus, I was using the very same table for the lfo > oscillators. The modulation was causing artifacts. It took me a while to > understand that the problem was being caused by the lack of resolution of my > tables. I ended up with a table 441000 length, for a 44100 sample rate. The > artifacts were gone! My conclusion was that the raw steps were causing > audible artifacts and increasing the resolution was the solution. > > I haven’t tried to find the lowest point of resolution that doesn’t cause > artifacts. I was so tired of trying to solve the artifacts that I have only > remember this problem when I saw this question from Victor. > > For the oscillators table I have simply doubled the initial value and now i’m > using 4096. > > What do you guys think of this? > > Thanks, > > Regards, > > Nuno > >> On 10/09/2015, at 20:15, Victor Lazzarini <[email protected]> wrote: >> >> Is there much to gain in going above a 1024 window, when doing sinc >> interpolation (for table lookup applications)? >> >> (simple question; no intention of starting flame wars; not asking about any >> other method, either ;) ) >> >> Victor Lazzarini >> Dean of Arts, Celtic Studies, and Philosophy >> Maynooth University >> Ireland >> _______________________________________________ >> dupswapdrop: music-dsp mailing list >> [email protected] >> https://lists.columbia.edu/mailman/listinfo/music-dsp > > > _______________________________________________ > dupswapdrop: music-dsp mailing list > [email protected] > https://lists.columbia.edu/mailman/listinfo/music-dsp
_______________________________________________ dupswapdrop: music-dsp mailing list [email protected] https://lists.columbia.edu/mailman/listinfo/music-dsp
