KVR Audio

ZioKiller · Post by **ZioKiller** » Mon Aug 02, 2004 11:47 am

Hi all
I wish to produce this waveform:

I've tried with sines, tangents.. and combinations of them,
waveshaping methods.. none of my attempts gave me satisfying results.

any advice?

t.i.a.
Guido.

tobybear · Post by **tobybear** » Mon Aug 02, 2004 12:07 pm

Something similar can be achieved by additive synthesis of an sawtooth (amplitude of the nth harmonic is 1/n times that of the fundamental, truncate after some iterations).

Cheers

Toby

www.tobybear.de

texture · Post by **texture** » Mon Aug 02, 2004 12:09 pm

looks a bit like a lowpass filtered sawtooth.

Big Tick · Post by **Big Tick** » Mon Aug 02, 2004 12:12 pm

additive synthesis will do it nicely. Just FFT this waveform and take the first 3 or 4 harmonics...

You can probably get it too using FM and a little waveshaping, although it'll be harder to antialias.

'Tick

texture · Post by **texture** » Mon Aug 02, 2004 12:14 pm

Alternatively, a generic way of doing this would be to write a genetic algorithm to come up with the equation for you - enter in the waveform as a series of points and give the program a time variable, a few mathematical functions to choose from, and a selection of persistant variables that it may use. Then leave it to run until it gets a good approximation.

tobybear · Post by **tobybear** » Mon Aug 02, 2004 12:15 pm

Just checked: as I said, you can easily get this waveform by summing the first 4 or 5 harmonics (scaled by 1/n) with phase set to 0. Just add up the sines or (as Big Tick suggested) use inverse FFT.

Cheers

Toby

www.tobybear.de

Kim Lajoie · Post by **Kim Lajoie** » Mon Aug 02, 2004 12:28 pm

Wavetable!

Just kidding.

Forever,

Kim.

no_signal · Post by **no_signal** » Mon Aug 02, 2004 12:51 pm

http://www.phy.ntnu.edu.tw/java/sound/sound.html
http://www.phy.ntnu.edu.tw/java/OTHERS/ ... index.html

valley · Post by **valley** » Mon Aug 02, 2004 2:18 pm

check out bazzoid[1]. The system for waveshaping in Bazzoid is very simple, and easy to understand, and you can see the waveform that results from your settings.

I think you may find some useful clues there.

(that and it is a great Bass VSTi).

[1] Cheers, Jens.

ZioKiller · Post by **ZioKiller** » Mon Aug 02, 2004 2:48 pm

Thank you all guys!
Your help has been really precious for me!

Borogove · Post by **Borogove** » Mon Aug 02, 2004 7:03 pm

Also, Audiomulch has the "10Harmonics" tone generator, which lets you set the relative contribution of the first 10 harmonics of a wave, and graphs the wave in real time as you mess with the harmonics levels -- you could find an approximation to that wave in a couple minutes of twiddling, I imagine.

Borogove · Post by **Borogove** » Mon Aug 02, 2004 7:04 pm

Oscillator: from visual waveform to math formula. How?