Wave Table prime and Band Limiting

[Father]

Hi
I was curious how does the wave table prime band limit and calculate all the harmonics for a given wave form?
Is it one of those band limiting algorithms out there like Bleps or Nyquist–Shannon? Creating those harmonic steps from any waveform is really nice.
Can any of the experts create an example on the green or ruby so we can study and learn the method?

[BobF]

How father, I second your request.

Thanks, BobF.....

[Spogg]

I really like that demo example.
Plus, I never gave this much thought before...

Cheers

Spogg

[martinvicanek]

You take the Fourier transform of your waveform. Then you chop off the harmonics that would alias at a given playback rate and transform back. Do the last step 256 or so times, removing one more harmonic each time until there is only the fundamental tone left. You end up with 256 wave tables, the rest is organizing them in a way so you can easily pick the right one for a given note.

Nigel Redmon has a nice writeup on that topic here:
http://www.earlevel.com/main/2012/05/03 ... oscillator—introduction/

[rocknrollkat]

You take the Fourier transform of your waveform. Then you chop off the harmonics that would alias at a given playback rate and transform back. Do the last step 256 or so times, removing one more harmonic each time until there is only the fundamental tone left. You end up with 256 wave tables, the rest is organizing them in a way so you can easily pick the right one for a given note.

Nigel Redmon has a nice writeup on that topic here:
http://www.earlevel.com/main/2012/05/03 ... oscillator—introduction/

Hi Martin,
What a great article, I coped and pasted it for myself, I'll finish reading it later today.
Thanks for the post !

ROXY

[martinvicanek]

@Father
I added a demo to your schematic that illustrates what I was trying to describe above.

[Father]

@Father
I added a demo to your schematic that illustrates what I was trying to describe above.

Awesome. I get it now.
That was very nice of you. Thanks.