Hey. I'm working through Andy Farnell's book, Designing Sounds. A formula in one of the granular synth patches has me stumped - it's using a formula (2^(n/120)-speed) / "chunk size" (which I think is grain size?) to compute grain length. I get that tempo & pitch are related, and grain sizes are inversely proportional to the speed. But I don't understand 1) why his formula for pitch uses 2^(n/120)...I figured it would be cents, but cents is n/1200...maybe he was just setting max variation for the pitch at one semitone? 2) Don't understand why it is "pitch - speed" in the formula. 3) In the patch the chunk-size is scaled by 1/1000th...my guess is to give finer control for grain size, but correct me if I'm wrong. Thanks!

http://www.pdpatchrepo.info/hurleur/psola-2.pd

Hey. I'm working through Andy Farnell's book, Designing Sounds. A formula in one of the granular synth patches has me stumped - it's using a formula (2^(n/120)-speed) / "chunk size" (which I think is grain size?) to compute grain length. I get that tempo & pitch are related, and grain sizes are inversely proportional to the speed. But I don't understand 1) why his formula for pitch uses 2^(n/120)...I figured it would be cents, but cents is n/1200...maybe he was just setting max variation for the pitch at one semitone? 2) Don't understand why it is "pitch - speed" in the formula. 3) In the patch the chunk-size is scaled by 1/1000th...my guess is to give finer control for grain size, but correct me if I'm wrong. Thanks!

http://www.pdpatchrepo.info/hurleur/psola-2.pd

Hey, I'm working through Andy Farnell's Designing sounds...in the chapter on wavetable synthesis, he uses the word "index" a lot...I tried flipping back to earlier chapters, but never really found an explanation...

"...the index is placed centrally around the middle of a table," "we keep the indexing waveform fixed," "the table is filled...and we index it with a phasor" etc.

what does "index" mean in this context?

Hey, I made a patch, tried to use textfile to store my data...but I keep getting a 'write failed' error message and a 'no method for symbol' error. Not sure what I'm doing wrong, any help would be appreciated! Thanks

http://www.pdpatchrepo.info/hurleur/textfile-thing.pd

Hi. I made a midi fader patch, but whenever I try to adjust the volume on my computer speakers, I just get clicks. Nothing comes out of the midi fader. Is there something wrong with my patch?

I did read the help file (before I posted) and still don't get it. And what do you mean by "addressing the index"?

Thanks!

I had two problems: I used the wrong MIDI channel input (modulation instead of volume). Also, I had the patch set up to multiply a cos wave by the scaled midi signal to give final output.....and forgot to include the cos wave.

Not sure exactly what caused the speaker click. But my guess is that I didn't scale my MIDI input right.

Never mind, I got it working!