Topic: Interaction between the sustain and sostenuto pedals
I've seen info on this topic posted a few places here, and I wanted to "stir the pot" again...
On an acoustic piano, the sostenuto pedal catches all the dampers in the raised position if the damper pedal is down when the sostenuto pedal is engaged. This is actually a real pain and makes the sostenuto pedal much less effective than it should be. I'm convinced that this interaction between the pedals is basically a design flaw, and that the sostenuto pedal should work independently of the damper pedal, i.e., it should only catch the notes that are currently pressed, regardless of the damper pedal's position. I've gone into more detail on the advantages of an independent sostenuto pedal, and how it can be "hacked" on an acoustic instrument here and here.
Most electric pianos that have a sostenuto pedal have it work independently of the damper pedal. The Pianoteq sostenuto pedal used to work independently, but now it's been "fixed" to imitate the flawed acoustic mechanism. In my opinion, a shame! I've tried the "Super Sostenuto" pedal as well, but that doesn't work correctly either. The super sostenuto pedal holds the notes on an imaginary second instrument, which gives a completely different effect if I retake any of the notes I'm holding on the sostenuto pedal.
What's the best way to get a sostenuto pedal in Pianoteq that works independently of the damper pedal? For now, I'm using Pure Data to filter out certain midi note off events while the sostenuto is pressed, and then to send those events once the pedal is released. I'm hoping there's a internal way to get the same result.