LMMS
Calf Filter Plugin Sweeps Automatically
If you add a Calf Filter to an instrument or channel while the engine is running, or on it's first play after it's added, or on export, the cut off seems to sweep briefly. I have one project where it didn't do this (I think), but in all my subsequent tests it does it.
Could be that the control value is simply interpolated and it is initially at a cutoff value defined by the calf people and when you open it fresh it will then do a bit of a trip to whatever value is defined by the lmms ladspa settings?
If I read this correctly the cutoff value would start it's life here with a knob value of '0'. Then it would get set to it's proper value here and the value is interpolated here but I don't know if that interpolation could answer for a sweep that long. Maybe. I'm not concerned by that sweep as you don't usually record sound live when adding/removing pluggins. What I'm a bit worried about however is initializing the model to '0' as that assumes the pluggin isn't doing something silly as actually using a frequency of '0', which actually has been the case if I remember correctly. Some HP filter was trying to EQ '0' Hz resulting in something glitchy. This was pre 1.0 .
This is also on the LV2 version of calf filter. The behavior is the same when I add a module in Ardour @JohannesLorenz You hack calf. This is an upstream issue right? Close-ish?