OK, this is getting technical, but where do the nonlinear effects come from? As I understand it, nonlinearity happens when the response is amplitude dependent. Reflections from hard surfaces, even complicated reflections, will be linear. Reflections from softer surfaces, say human bodies, may be nonlinear. Do the nonlinearities come from the bodies of the players?
Beats, the wah-wah from different frequency sources come from the nonlinearity of the human ear. Multiphonics come from the nonlinearities of the player. Herb Foster ________________________________ From: "[email protected]" <[email protected]> To: [email protected] Sent: Wed, February 17, 2010 7:02:57 PM Subject: [Hornlist] Empirical horn transfer function Professor Baker - this is an interesting idea and I say bravo for thinking along such lines in response to a common, practical problem. I think such mucking around in the frequency domain is commonly done in generating/editing audio for certain effects, and in many recording and production circumstances. The problem is with this idea applied to recording is that the acoustic environment around a horn (the room) and its interaction with the horn and the microphones is fundamentally NOT a linear system. There are all kinds of nonlinear coupling and effects in such a complex acoustic system. Probably to a weak first-order approximation this transfer-function could be made, but I believe your suggestion relies on clean, linear-superposition of the behind and front acoustic signals, which would not be very accurate in a real situation. Check out the literature on acoustic source-separation and you'll find this problem ubiquitous in similar tasks. just my .02 cents. this would not be hard to mock-up in MATLAB sometime and try it out. any other thoughts anyone? david - physics and horn performance student _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
