Smooth filter cutoff via modwheel
I'm trying to set up Unify to let me play expressively with this amazing technique: https://www.youtube.com/watch?v=kyQlcDAtu6k (Huge respect to Nick Semrad for sharing how this works). He's using a Sequential Prophet Rev2 in the video... a top-of-the-range synth, but it seems to me that Unify is definitely capable of the same kind of wizardry.
So far I've experimented with a nice sawtooth patch from the Unify Standard Library called Maxwell 4x. I've assigned filter cutoff to the mod wheel using linked parameter macros, and adjusted the pitch bend wheel to -24 and +2 (a great feature). It works well as a proof of concept, but when I open and close the filter with the mod wheel it doesn't sound as smooth as I would like. Perhaps there is some filter stepping in Guru Sampler.
I'm pretty new to the vst synth world so I thought I'd ask if anyone has thoughts or recommendations on how to accomplish this? Thanks 🙂
Stepping is pretty common when controlling parameters with MIDI, because MIDI only provides 7-bit resolution for MIDI CC messages. Filtering must be added to the code separately for every parameter, so not all of them have it.
The SYNTH - RAW Power: MaxWell 4x patch includes an instance of the built-in FlexEQ filter effect after Guru Sampler. Are you linking the mod wheel to the sampler's filter, or to the FlexEQ filter?
I really appreciate your reply. I'm linking the mod wheel to the sampler's filter (in Guru Sampler's Mod Wheel section - in linked parameters it's called mwCutoffDepth).
Thanks for clarifying about MIDI resolution and stepping. If filtering can be added to the code to compensate for my low resolution MIDI input that would be amazing... If I've misunderstood and that's not possible I'm still very happy to find a VST that has this feature, because I'm totally sold on Unify as a plugin host / audio playground. 👍
If you want your Mod Wheel (aka MIDI CC#1) to open the Guru Sampler filter cutoff, the parameter you want is called filterCutoff. mwCutoffDepth is equivalent to the knob labeled Cutoff in the Mod Wheel section of the Guru Sampler GUI.
This can be achieved without using a Macro knob at all, by just using that Mod Wheel / Cutoff knob to make the Guru Sampler filter respond to MIDI CC#1 directly.
I'm curious that you notice so much stepping at all. Guru Sampler does have quite a bit of smoothing built-in. Could you possibly post the problem patch here as an attached file (Zip it first)?
Absolutely, thanks Shane. I've attached the modified patch. In John's original patch the mod wheel lowers filter cutoff rather than raising it, and after some tinkering I managed to reverse this behaviour. I notice stepping in my version of the patch mostly when I move the mod wheel gradually between 0-50%. It's subtle, but noticeable to me when I'm focusing in on the mod wheel so much. I was thinking it could even be clipping caused by my laptop not keeping up with buffering.
I'm away from my MIDI keyboard at the moment but I'll have a go at the methods you describe as soon as I can. Thanks again!
Thanks for sending the patch. You have added two linked parameters to Macro Knob 1, which (based on your earlier posting) you're probably controlling with MIDI CC#1. The first link is to Guru Sampler's mwCutoffDepth. You should simply take this out entirely, because it means you're using the mod wheel to adjust sensitively Guru Sampler's filter cutoff responds to the mod wheel. Some of the stepping you're hearing could be as a result of Guru Sampler's own mod-wheel response fighting with changes to its mwCutoffDepth parameter.
The second link is to Guru Sampler's masterLevel parameter. That parameter is not smoothed at the moment, so that's probably where most of your audible stepping is coming from. I'll look into adding some smoothing.