Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!mcsun!sunic!draken!d88-jwa From: d88-jwa@nada.kth.se (Jon W{tte) Newsgroups: comp.dsp Subject: Re: Pitch shift / offset and FFT Message-ID: <1792@draken.nada.kth.se> Date: 27 Sep 89 11:04:23 GMT References: <89264.171306P85025@BARILVM.BITNET> <9520001@hpsad.HP.COM> <1787@draken.nada.kth.se> <4384@internal.Apple.COM> Reply-To: d88-jwa@nada.kth.se (Jon W{tte) Organization: Royal Institute of Technology, Stockholm, Sweden Lines: 23 In article <4384@internal.Apple.COM> wass@Apple.COM (Steve Wasserman) writes: >If you have a 1000 Hz sine wave and an 1100 Hz sine wave, and you ADD >them, you will not get a 100 Hz harmonic, but rather the two >frequencies will BEAT together at 100 Hz. The perceived effect (in >sound, at least) is a 1050 Hz signal that rapidly gets changes volume. Okay, I think I messed up. You're right and I confused things a bit... Isn't it ring modulation that gives you the sums/differences between the frequencies ? >certainly be able to hear the two beating. Accurate tuning of musical >instruments is possible by listening for this beating against a >properly-tuned standard.) Anyway, if you looked at 1000 Hz PLUS 1100 Yeah, I do that all the time... And you hear the beating, although it gets weaker with increased frequency. Thanx. I love this group :') h+@nada.kth.se -- History does not repeat itself, historians merely repeat each other.