Path: utzoo!attcan!uunet!timbuk!cs.umn.edu!msi.umn.edu!src.honeywell.com!sol.ctr.columbia.edu!zaphod.mps.ohio-state.edu!julius.cs.uiuc.edu!psuvax1!rutgers!news-server.csri.toronto.edu!clyde.concordia.ca!ccu.umanitoba.ca!umbirch2 From: umbirch2@ccu.umanitoba.ca (Robert Birch) Newsgroups: comp.music Subject: Re: Additive Synthesis Message-ID: <1990Nov6.034353.6341@ccu.umanitoba.ca> Date: 6 Nov 90 03:43:53 GMT References: <1990Nov5.155309.466@ccu.umanitoba.ca> <8528@pasteur.Berkeley.EDU> Organization: University of Manitoba, Winnipeg, Canada Lines: 32 In article <8528@pasteur.Berkeley.EDU> maverick@fir.Berkeley.EDU (Vance Maverick) writes: > > If I read you right, you're asking "How do I make a bunch of partials >sound like two notes at the same pitch?" Well, there are several cues >we use to fuse partials together into a single tone-percept. > One of these is the harmonic-series property, which will obviously hold >for all the partials if you're doing straight naive additive synthesis. >The chorus effect on the Synclavier (and doubtless other additive >systems) is created by a second set of harmonics, all based on a >fundamental at some ratio to the nominal fundamental of the note you >play. To my ear, this sounds less like a doubling than like a fattening. > There's another cue you can use, which Stephen McAdams calls >"micromodulation": suppose you pick a random bunch of sine tones. They >won't sound like much if they just play steadily, but if you impose on >them all the same faint frequency wobble (multiplicative in frequency), >they will group together much more strongly. So if you have two >identical sets of harmonics, but impose on them two different wobbles, >you can cause them to group into two notes. Check Stephen Handel's book >"Listening" for more of this material, and some advice on frequency and >degree of modulation. > > -- Vance I may not have been as clear on this as I thought. I want to take two completely different waveforms playing different notes and combine them into one waveform playing both notes at there proper pitches with the right sound. For example, have a piano playing a C, and a violin playing a G, and getting both sounds to come out of on channel (or voice). I hope this clears things up. Robert Birch