FabFilter User Forum

Phase cancellation in Twin2

Hi,

I am still playing with the Twin2 demo, but I am definitely going to upgrade! One thing though: I made a very simple patch: starting with the 'basic saw' patch, I added Osc 2, Saw wave, same octave, slightly detuned, and Osc 3, Square wave, one octave lower. This gives me a great patch to put some funky accents in my tracks. However, when I check for mono compatibility, I get strong phase cancellation of the patch, and what's more, it seems to create some kind of void in which other instruments in the track are also sucked up. Is this normal behavior? And what would be the best workaround to keep the patch mono compatible without degrading its stereo presence. Any suggestions will be much appreciated.

Cheers,

Jack

JackV

That patch should be completely mono unless you're using panning on the filters or oscillators? Works fine for me.

DQ

You do not get a pure mono sound with the settings I posted. When you select the Basic Saw patch, Stereo is per default set to 100%. I played a bit with the Stereo setting, and at 200% there is almost complete cancellation in mono. For the moment, I find 50% useable in that it still gives satisfactory mono signal and spreads out a bit in stereo.
I have not experienced this phase cancellation effect to such extremes with other soft synths, therefore I am wondering if it could be avoided altogether by implementing the stereo spread differently.

Cheers,

Jack

JackV

Hi Jack,

Stereo effects are introduced by either unison, or the panning settings at various places in the Twin 2.

The stereo spread setting then allows you to adjust the width of the stereo field. But if there is no stereo information to begin with, this won't have any effect and won't introduce any phase problems.

If all oscillator and filter pan settings are at 0.0, and if Unison is turned off (set to 1), you won't get any phase cancellation.

Cheers,

Frederik (FabFilter)

I am so ashamed... Indeed, there was one further modification I made to the basic patch, namely set Unison to 2. My question remains, though: should Unison introduce that serious phase cancellation?

Cheers,

Jack

JackV

Hey there, I've found that using any unison for a square wave form with the default 'fabfilter 1' filter causes what sounds like phase cancellation, but it's actually filter overdrive.

Try switching the filters to another mode, or off for the purposes of testing.

Hades of spades

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