Square waveform and PWM question (Zebra2)
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- KVRist
- 61 posts since 4 Oct, 2006 from MD, USA
I'm trying to modulate a pulse width of a square wave and I cannot get the timbre I want from Zebra2. If I draw the waveform and use symmetry FX, the wave does not cancel out in either direction. So the only way to get the cancellation (I need to go from no sound to a really hollow one) is to use inverted phase feature with a sawtooth. However the waveform I get in both cases (and the timbre) is different from a square wave. It looks more like square-saw mix. I checked a couple of other softsynths, they all produce waveforms much closer to square than Zebra2. Is there a way to produce a more "square" like sound in Zebra or it is the feature I have to live with?
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- KVRian
- 1100 posts since 4 Aug, 2004 from Copenhagen, Denmark
I know of at least 4 ways to produce a Square waveform. Dunno if it will help you but might help others.
the quick one
On FX panel select Odd for Even and then turn value all the way to the right
another quick one
On PHASE panel turn INV on and set Phase value to 50 i think.
on the wavetable (GeoMorph)
Well here just raise point 3 to MAX and move point 4 to just below the V in Wave 1 and pull point 5 all the way down.
on the wavetable (SpectroBlend)
Add harmonics in a downhill motion, and remove every second harmonic when done.
EDIT: an advanced way to produce another Square could be by using waveshaping a triangle or sine either by distortion or the XMF overdrive.
/Michael
the quick one
On FX panel select Odd for Even and then turn value all the way to the right
another quick one
On PHASE panel turn INV on and set Phase value to 50 i think.
on the wavetable (GeoMorph)
Well here just raise point 3 to MAX and move point 4 to just below the V in Wave 1 and pull point 5 all the way down.
on the wavetable (SpectroBlend)
Add harmonics in a downhill motion, and remove every second harmonic when done.
EDIT: an advanced way to produce another Square could be by using waveshaping a triangle or sine either by distortion or the XMF overdrive.
/Michael
www.xsynth.com - Sound Synthesis with Vintage flavour
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- u-he
- 30213 posts since 8 Aug, 2002 from Berlin
Hey,
actually what you're seeing is a frequency-dependent phase shift, while the pectrum is still that of a square wave.
The most probable reason for the phase shift is the frequency split/eq in the ModFX (Chorus/Phaser). If you turn off all FX in the effects Grid you'll not only hear the square wave, it'll also look like one
Cheers,
Urs
P.S.: I've used Symmetry for PWM in ZebraCM... seemed to work quite good there... but I had to turn "Normalize" in the [more OSC1] pane down to 0... otherwise the short pulses become too loud and jucky...
actually what you're seeing is a frequency-dependent phase shift, while the pectrum is still that of a square wave.
The most probable reason for the phase shift is the frequency split/eq in the ModFX (Chorus/Phaser). If you turn off all FX in the effects Grid you'll not only hear the square wave, it'll also look like one
Cheers,
UrsP.S.: I've used Symmetry for PWM in ZebraCM... seemed to work quite good there... but I had to turn "Normalize" in the [more OSC1] pane down to 0... otherwise the short pulses become too loud and jucky...
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- KVRist
- Topic Starter
- 61 posts since 4 Oct, 2006 from MD, USA
Thanks, Urs!Urs wrote:Hey,
actually what you're seeing is a frequency-dependent phase shift, while the pectrum is still that of a square wave.
The most probable reason for the phase shift is the frequency split/eq in the ModFX (Chorus/Phaser). If you turn off all FX in the effects Grid you'll not only hear the square wave, it'll also look like one
Cheers,
P.S.: I've used Symmetry for PWM in ZebraCM... seemed to work quite good there... but I had to turn "Normalize" in the [more OSC1] pane down to 0... otherwise the short pulses become too loud and jucky...
I didn't realize that I had to disable the default chorus/phaser effect. Now phase inversion works flawlessly. I still couldn't cancel out the wave with the symmetryFX, but I got what I wanted anyway.
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- KVRist
- Topic Starter
- 61 posts since 4 Oct, 2006 from MD, USA
Thanks for this one! Not exactly the square wave, but exactly what Subtractor is capable of in multiplication mode.mkastrup wrote: the quick one
On FX panel select Odd for Even and then turn value all the way to the right
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- KVRist
- 221 posts since 2 Oct, 2006
You can't really tell the waveform by looking at it in an oscilloscope (exactly because of phase -- humans can only hear phase differences of partials to the extent they lead to cancellation; a pure square shape will come only when all partials are exactly in phase with each other). A spectrum analyzer would be the way to check it against other soft synths, as there you are viewing only the partials, not the phase. Of course if the phases are changing that will complicate things even more, as cancellation will lead to different spectra over time.michkhol wrote:However the waveform I get in both cases (and the timbre) is different from a square wave. It looks more like square-saw mix. I checked a couple of other softsynths, they all produce waveforms much closer to square than Zebra2.
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- KVRist
- 130 posts since 17 Dec, 2003 from Germany
maybe I don't get the problem right but why don't you use the wave sets with geo morph like this patch:
PWMUli
PWMUli
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- KVRist
- Topic Starter
- 61 posts since 4 Oct, 2006 from MD, USA
This is also a good option. But my problem was not about using, but understanding how to use it and what options are available. Which was resolved to my total satisfaction. Thanks to all!