Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site topaz.RUTGERS.EDU Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!qantel!dual!lll-crg!seismo!columbia!topaz!mohan From: mohan@topaz.RUTGERS.EDU (Sunil Mohan) Newsgroups: net.music.synth Subject: Re: Stupid Question About FM Message-ID: <3646@topaz.RUTGERS.EDU> Date: Fri, 13-Sep-85 12:11:46 EDT Article-I.D.: topaz.3646 Posted: Fri Sep 13 12:11:46 1985 Date-Received: Sun, 15-Sep-85 11:57:13 EDT References: <817@mit-vax.UUCP> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 51 > I can't take it anymore! I can't wait a year to take Bose's accoustics > course to learn this. What, exactly *is* FM sound synthesis and why is > it so great? Somebody out there must know! I expect that I am simply > missing something obvious because I do know: An excellent reference would be John Chowning's article on FM for music. This was republished in the Computer Music Journal (I forget the issue, but pre 1980 I think), and also in the book "Foundations Of Computer Music", both published by MIT press. And you do not need Bose's Accoustics course. I think there are two main reasons why FM is "so great" (I personally am not too impressed, but then the kinds of sounds I need are not that readily, or at least easily reproducible in FM): - Something to do with its being digital allows it to produce nice "clean" and strident sounds, which can easily ride over other instruments, making it good for leads in pop/rock. - The ability to specify time-varying modulation ratios allows the overtones structure (timbre) of a sound to vary over its Volume Envelope, and with note dynamics. This is a prime requirement for duplicating natural accoustic timbres. All FM instruments allow additive synthesis, which is inherently more flexible than subtractive by allowing arbitrary overtone structures. Note that the voluble proponent of additive synthesis, Wendy Carlos, uses individual oscillators for the lower overtones, resorting to FM only at the upper reaches. This brings me to a burning question: Why do all Analog synths I have seen (inc the mighty MATRIX-12) have only one Voltage Controlled Resonance Frequency in their filter sections ? Wouldn't having more than one add flexibility ? Also FM allows a greater variety of overtone structures (as in the shape of the locus of amplitudes of overtones) than traditional subtractive synthesis (see flame above). Has anyone experimented with any of the following: - More than one VCF on a voice ? - Adding VCFs to a DX7 or sthg similar ? - Using a choruser/whatever on a DX7 to try to get "thick analog" sounds ? -- _ Sunil UUCP: ...{harvard, seismo, ut-sally, sri-iu, ihnp4!packard}!topaz!mohan ARPA: Mohan@RUTGERS