If you want a ducking effect, you can’t use velocity. Most of the time ducking is used on longer notes, which have their volume temporarely reduced but recover it shortly after, which produces that swooshy sound.
To be generic the Midi FX should have control over the following parameters:
- Ducking Amount ( % )
- Output CC
- Input Track
The ducking amount would work exactly like the LFO, in the sense that, unless you have a CC anchor value set or other FX manipulating that CC value, the input will be assumed to be 64, since you have no idea what the current volume is. so with 100% ducking it would go to 0, 50% would reduce the incoming data by 50%, etc.
The output CC should be whatever controls volume, but controlling a filter also gives interesting results, or anything if you want to use Midi side-chaining creatively.
The input track parameter controls where the sidechain data is coming from. any note-on would trigger the attack, stay at the ducking value until the note-off, and release afterwards.
you can experiment with an LFO, but you’ll probably want to automate it on and off to match your kick, so you emulate a single cycle LFO rather than a fully periodic one. its actually pretty cool, but tedious. so a dedicated FX would be really fun…