Just to clear up a mistake on my part: No gen30 does not keep everything below the "cf freq", it does only keep harmonic partials. Sorry for the misinformation. Oeyvind 2008/1/23, Oeyvind Brandtsegg : > I think Gen30 will keep all (also the non-integer) partials up to the > top one. If I understand it correctly, the upper partial can be > thought of as a "filter cutoff frequency" sort of. > > The phase synced interpolation you want can be done with partikkel by > using the 4 available source waveforms and crossfading between them. > There might be a simpler way of doing it too, just using regular > oscillators as you suggest. > If you use partikkel, you can change the source waveforms at k-rate, > so you can dynamically evolve your timbre over more than 4 waveforms. > You can also link several partikkel opcodes phase synced via the > partikkelsync opcode. > With partikkel you could also do fm on the source waveforms, and with > some care you could also do phase modulation. > This will indeed be a complex setup, but it seems your idea requires a > quite complex instrument in any case. > > And, btw, I do have an example of PSGS with partikkel. It does formant > transposition quite nicely. I haven't shared the example yet because I > wanted to see if I could get pitch transposition to work smoothly as > well. It seems the description of PSGS in microsound is not sufficient > to create pitch transposition without audible sidebands but I have > some other ideas to try out. > > Oeyvind > > 2008/1/23, Tim Mortimer : > > > > I'm back! ; ) > > > > So i've been browsing the manual this evening, trying to find out what's the > > best way to go about designing some "crossfading oscillator" synthesis > > instruments with Csound, & to be honest i'm a little uncertain what is the > > best way to proceed (as mostly up until now for me Csound has been about > > sample playback or resynthesis in one form or other). > > > > I touched upon some alaising concerns in an earlier post (about 6 weeks or > > so back..) & yes, "aliasing happens!" Anthony Kozar ; ) ... but, err, i'm > > still not sure how to approach this. > > > > I'm concerned because i am likely to want to use square & impulse & > > generally "pointy" like oscillator shapes, but i also want to be able to > > crossfade the oscillator shape during playback with other "found" & "random" > > type shapes (snipped from samples or created in text file) or other more > > additive GEN routine based ftables even (do i dare add FM to the mix at this > > point?), to create diverse & changing spectra in a single crossfadeable, but > > phase aligned synthesis method. > > > > now the obvious thing to do to start this would be use some sort of oscil > > based table read - but surely (from what i can gather reading the manual..) > > VCO2 & GEN30 (???) are designed to overcome any aliasing issues > > (particularly again with those "squarer/pointy" waveshapes..) by performing > > some sort of analysis on the "spectra" implied by any given oscillator > > shape, & reproduce the signal band-limited to within Nyquist safe regions? > > > > So do i load all my oscillator shapes in a bunch of ftables, analyze them > > all in separate gen30's to bandlimit the spectrum to appropriate levels, & > > then tablemix from these / selected GEN30's to create the desired effect?? > > > > GEN30 manual entry does refer to "harmonic partials" - does that mean it > > creates a sine based reduction of integer value frequency ratios only, & > > doesnt represent the complete spectra in all it complexity? > > > > Alternately, i'm not sure any VCO2 based implementation is going to make the > > job of crossfadeing phase-synced oscillators any easier.... > > > > I know what i'm looking for for the rest of this synth design > > > > > LP/HP/Notchfilters > > > allpass filters > > > envelopes > > > feedback, pitchshifting & modulating delaylines > > > > to mainly create some nice classic ambient pad sounds that can "expand > > upwards" into lots of top end sizzle!, but i wan't to make sure i get the > > cross fadeable phase synced oscillator section right, particularly when i > > can't phase sync gbuzz or the like to get nyquist friendly pulse waves that > > way, so basically I have to look at some sort of table based alternative it > > seems to keep the "pulse oscillator state" in phase alignment with the other > > less harmonically rich oscillator shapes... > > > > There are plenty of Synthesis gurus on this list. Do any of you have any > > useful advice as to how i might best proceed with this? > > > > I also recall the recent crossfadeable Waveshaping discussion, & wonder if > > as part of that there was a method i might borrow to perhaps better align > > tablemix transitions to zero crossings in the wave playback for > > example...??? (as opposed to simply at constant krate - but that hopefully > > would be ok anyways as long as the crossfading wasn't to ambitious in terms > > of speed of execution...) - Anthony, did you achieve this "transition of > > crossfade at 0 crossings only" at all? Was it necessary to achieve the > > effect u were after? > > > > Please share your experiences & insights & suggestions! > > > > & many thanks as usual. > > > > T. > > > > > > > > > > > > > > > > > > > > -- > > View this message in context: http://www.nabble.com/phase-synced-crossfade-synthesis-without-aliasing---how--%28-Gen30--%29-tp15037443p15037443.html > > Sent from the Csound - General mailing list archive at Nabble.com. > > > > > > > > Send bugs reports to this list. > > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound" > > >