[Jesse Chappell] >Tim Goetze wrote on Wed, 24-Mar-2004: > > > the algorithm 'accumulates' energy from the pvoc frame bins into a > > 'static' pvoc frame, thus the basic effect sounds a bit like an echo > > or reverberation. (in fact i think it could be made to produce a > > real nice reverb tail, with a _lot_ of tweaking though.) > > > > of course this is combined with a decay mechanism so the stored energy > > doesn't stay around forever. also, for some sound effects of the > > stranger kind, Accumulate can also move the stored frequency > > coefficients around, resulting in constant glissando of the 'sound > > tail'. > >This is pretty much what FreqTweak's Delay module does, although >I could not reproduce the exact Accumulate effect sound in FT upon >some basic tweaking. Of course, FT has absurdly more control :)
it does indeed :) >I've been waiting for someone to post a preset for FT that they >hand built to produce a good reverb tail, but it appears no one's >up to the challenge..... i don't know how you feel about this, but my personal impression is that the classic all-pass/comb reverbs are capable of producing very fine sounding tails (especially with a slowly modulated delay line), it's more the early and distinct reflections that i see as a weak point. so, seeing the dramatic difference in CPU usage between the two techniques, using FT/pvoc to produce a reverb tail would seem a rather academic exercise to me. though, of course, "you won't know if you don't go", maybe it's a particularly enlightening experience. >The pitch scaling algorithm sounds quite similar to the one in >FT (which is basically the Sprengler algo from SWH's pitch scaler), >but Tim's sounds better, so I'm going to go code diving. it would be more accurate to call it Richard's than mine -- i only re-packaged the code from Richard Dobson's pvplugs in LADSPA shape. (actually, the whole pvoc package is just a by-product; i needed the phase vocoder for something completely different but found the plugins good fun, and the stretch utility worth writing.) to tell the truth, i haven't even spent much time deciphering the Transpose algorithm. it did sound kind of OK with the guitar so it got green light for shipping. :) tim
