Filter envelope modulating own peak and sustain level (Ableton preset)


To get some insight on how sounds are created, I sometime analyze or remake synth plugin presets in Ableton.

Today I was checking the Wavetable (stock plugin) Slider Deep Bass preset.

In the modulation matrix I noticed that the filter envelope (Env2) is modulating its own peak and sustain level. When turning this modulation off, I can not hear any difference. What makes it even odder to me, is that the sustain level is at 100%.

Is this a common practice and why would it be done?

Note: I also see the amplitude envelope is modulating its own attack time. This makes sense to me, if you want to make a linear attack concave.


automodulating gives exponential curves (should) it’s a technique used in the Xpander Oberheim (to have the ramp exponential) or in the DUSG serge for the same reason



I found this video explaining the concept on the DUSG Serge.


Since it was not completely clear to me yet. I made small patch doing the following.

The envelope has an inverse relationship with the filter frequency. The patch looks like this and does not produce any sound, because the filter is closed. The filter envelope is visible on the scope.

The envelope inversely automodulates its own peak value. The inverse envelope is send to the attenuator. This gives a smoother curve on the scope, but unfortunately still no sound.

Any suggestions?

It’s the CV1 knob too low, so that the envelope has too little effect on the cutoff frequency?

It works when I turn the CV1 knob past 12 o’clock, but that means there is something wrong with my logic. (Because in Wavetable the relation is inverse).