[LAD] Wavetable synthesis : Creating fat wavetables

[harryhaaren at gmail.com]

My intention is indeed to do "waldorf style" cascaded wavetables which are  
interpolated between. I have a program that I can use to test the  
wavetables, but the issue of tuning remains a problem for me.

Example:
I record a C3 note, 10 seconds of it. Then I want to create a wavetable.  
Search for a zero crossing after 1 second, chop. Looped playback = C3.
Now I want to have a C#3, so 1/12 of the double of the frequency, playing  
back at that rate will NOT always provide a C#3.

Why? The sample is the wrong length. The "fundamental" of the note is not  
perfectly looped, not even all the harmonics are. Hence you "feel" a wrong  
pitch. Its a bit of a wierd problem.

I've read this page, and figured I should probably check my algorithm that  
does the rate and frequency calculations.
http://en.wikibooks.org/wiki/Sound_Synthesis_Theory/Oscillators_and_Wavetables

Has anybody got some experience in this domain? I'm new to creating my own  
wavetables, so experiences / noob-advice welcome :)
-Harry



On , Julien Claassen <julien at mail.upb.de> wrote:
> Hello Harry!

> It's an interesting topic, which I had been investigating. I do have a  
> wavetable based hardware synth, but I was thinking about emulating it in  
> software. Waldorf didn't say a lot about creating one's own wavetables.  
> You might just as well try csound - or one of its accompanying programs -  
> to create your wavetables. My synth works in such a way, that it has  
> wavetables, made up from 128 samples. So you should be able to load such  
> a wavetable into a sampler (is Specimin still state of the art?) and then  
> use its envelope generators and filters and whatever else. I suppose the  
> modular synthesizers like AMS, Om and co. might also do your bidding, if  
> they allow to read samples or oscillator shapes. Perhaps even better then  
> a sampler, since they might allow for modulating and otherwise mangling  
> your wavetables. The question is, how many samples per waveform/wavetable  
> they might expect.

> If you are thinking about wavetables completely the Waldorf way, that  
> would include having a number of related waveforms stored in one table,  
> so you can morf between them. I don't have the slightest clue, how to be  
> realise that. There I would suggest PD or similar. I'm sorry,if that  
> hasn't been much help.

> Warm regards

> Julien



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