Hello Bill, I take your question as a chance to introduce myself. When you sweep the input parameter you are introducing discontinuities in the output signal, and that sounds awful. The simplest case to figure that out in your code is imagining that you have the input variable set at 0 (pan = 0), and then abruptly you change the input parameter to a value that will make the value of the pan variable jump to 1. Both of the channels will generate a square wave, that will sound badly because of the aliasing. One solution is to control the slew rate of your parameter lowpass filtering your parameter. A simple moving average filter should do the job correctly.
I have been reading this newsletter for a couple of years now, and I think that it's the best place to learn about the practical applications of musical dsp. I have been working in the digital audio field since 3 years now, even though I have been interested in computer music since my first years at the university. Now I am freelancing in this field, and I also get to play music more often. This is really stimulating my imagination, and I hope that in the next months I will have the time to implement some new effect or instruments. Thank you for all the nice things that I have learnt here, Alessandro On Feb 22, 2012, at 10:16 PM, Bill Moorier wrote: > Hello, just thought I would introduce myself to the list since I've > been lurking for a little while but haven't posted anything yet. > > I'm been programming computers since I was 9 years old, so 27 years > now. I got started on a zx81 - it had a whole 1kB of user memory! > > I've never really done too much music-related software though, until > now. In my spare time, I've started working on an engine for doing > realtime audio DSP in javascript. It works surprisingly well! Not > ready to release anything yet, but it's good fun :) > > The biggest thing holding me back right now is my lack of a background > in audio. Often it means I have no idea how to track down problems, > like today's for example. I built a dead-simple autopanner: > http://abstractnonsense.com/22-feb-2012-js.html > > It works nicely when you keep the input parameter (from 0.0 to 1.0) > fixed, but it sounds *awful* when you change the parameter, no matter > how smoothly you do it. Here's a sample output: > http://abstractnonsense.com/22-feb-2012-swept.mp3 > > Any pointers for figuring out things like this? I seem to be able to > make a lot of "dead-simple" versions of effects, but it all goes wrong > when I try to beef them up! > > Anyway, thanks for having me on the list, I'm already learning a lot :) > > Cheers, > Bill. > -- > Bill Moorier abstractnonsense.com | @billmoorier > -- > dupswapdrop -- the music-dsp mailing list and website: > subscription info, FAQ, source code archive, list archive, book reviews, dsp > links > http://music.columbia.edu/cmc/music-dsp > http://music.columbia.edu/mailman/listinfo/music-dsp -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
