EMUSIC-L Digest Volume 38, Issue 07 This issue's topics: filter project:3 (?) (2 messages) Pitch bend and digital synthesis Your EMUSIC-L Digest moderator is Joe McMahon . You may subscribe to EMUSIC-L by sending mail to listserv@american.edu with the line "SUB EMUSIC-L your name" as the text. The EMUSIC-L archive is a service of SunSite (sunsite.unc.edu) at the University of North Carolina. ------------------------------------------------------------------------ Date: Wed, 11 Mar 1992 14:33:25 EST From: ronin Subject: Re: filter project:3 (?) on nick's resonant waldorf filter... i believe that is a characteristic of lopass in general. it's not something one normally pays attention to, because the increased amplitude at the resonant peak 'masks' the loss of the low frequencies. this loss would be due to the cancellation that occurs as a result of the 'resonance' function, which is, after all, feedback. the only reason i can think for it to be more noticable in the digital domain is that the digital implementation of the lopass might not have the same phase characteristics as the analog. in analog, the frequency-dependent phase shift might reduce the actual degree of feedback-induced cancellation, while in digital such phase characteristics could conceivably be designed out. -----------< Cognitive Dissonance is a 20th Century Art Form >----------- Eric Harnden (Ronin) or The American University Physics Dept. 4400 Mass. Ave. NW, Washington, DC, 20016-8058 (202) 885-2748 ---------------------< Join the Cognitive Dissidents >------------------- ------------------------------ Date: Thu, 12 Mar 1992 17:10:58 +0000 From: Nick Rothwell Subject: Re: filter project:3 (?) >on nick's resonant waldorf filter... >i believe that is a characteristic of lopass in general. it's not something >one normally pays attention to, because the increased amplitude at the >resonant peak 'masks' the loss of the low frequencies. Sure; it's possible I only noticed it because I often use the Waldorf's filter resonance above the audible range for the effect it has on the rest of the spectrum. Other analogue synths I've come across don't seem to have this effect; perhaps it's a quality of the Waldorf's filters, or perhaps it's because of the rich harmonic structure of the source waveforms. >the only reason i can think >for it to be more noticable in the digital domain is that the digital >implementation of the lopass might not have the same phase characteristics >as the analog. Well, the Waldorf's filters are analogue... Nick. ------------------------------ Date: Mon, 16 Mar 1992 13:45:36 EST From: borst@SERVER.CS.JHU.EDU Subject: Pitch bend and digital synthesis Hello! I have a question which has been bothering me for quite a long time. Can anyone suggest an algorithm to change the pitch, but not the duration, of a given sound? I'm currently working on a simple DSP program, and I'd love to do this. Thus far, I've got code for mixing bits of sound and generating simple waveforms, but pitch bend is a problem that I haven't been able to puzzle out yet. Thanks for any help, Scott Borst borst@cs.jhu.edu ------------------------------ End of the EMUSIC-L Digest ******************************