Not sure if my previous post made it through, but for this task the best solution is linear phase BLEPS and BLAMPS, you can overlap them as much as you want without DC error. 16 taps will be loads for excellent results since the BLEP is pre-integrated you get another -6 dB / Octave attenuation over and above the original linear phase low pass filter you integrated to get it. For basic shapes like saw at worst you will need to add 16 taps per sample, as well as a division per sample, which is really not that bad in terms of cpu on modern computers.
I used a similar method for the oscillators in Synth Squad as well as in the LFO in The Drop, basically anywhere you want to have piecewise linear segments or other smooth shapes like sin / exp stitched together. This way the shape can be completely parametric and you can modulate not just the pitch but the shape smoothly. Cheers, Andy On 18 May 2013 09:25, Nigel Redmon <earle...@earlevel.com> wrote: > > Thanks for the detailed explanation, Marco. > > For minBLEPs, I did generate my own tables, though that was lost and I'd have > to recreate that…but at the moment I'm not in search of a "classic synth > waveforms only" solution. (And if I were, I might well go the BLIT route > instead.) > > For periods less than the minBLEP size, I'm pretty sure you need to overlap > multiple minBLEPS, making the solution less attractive at higher frequencies… > > Nigel > > > On May 17, 2013, at 2:29 AM, Marco Lo Monaco <marco.lomon...@teletu.it> wrote: > ... > > > Moreover how to use that minBLEP for periods of less than 32 samples is > > still an open question. Maybe just use different minBLEP tables, but their > > resolution would be always less in terms of Nz, and I don’t understand > > cleary how it would affect the aliasing (Eli is not so clear about it or at > > least I don’t geti it :) ). > > > > My idea is that I will have to use different techniques depending on the > > contest: BLIT is working very well, the sincM formula is so pretty. I am > > also trying to use the SWS method (truncated sinc in an OLA fashion) to see > > if frequency modulation can be reliable in the integration stages. > > If this fail, I will consider wavetables only for pitchbending and LFO > > vibrato, accepting that in those context there could be a bit of alias. An > > issue will be how to transit from the BLIT/sincM to wave tables in a > > glitchless way. > > > > Thank you for time > > If you want I can post a different email to the NG and talk about minBLEP, > > cause I am also really interested in it. > > > > Have a good day > > Marco > > -- 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
