HPF bug

[biggnome]

OS (if applicable): OSX 10.11.6 Version (or "dev" if compiling from source): 0.4.0

The highpass output of the standard VCF module does not give a typical highpass response--instead it seems to slightly attenuate the stopband kind of like a shelf EQ, but does not filter it out per se. This becomes even more aberrant with resonance turned up.

[jamshark70]

Same behavior here in Linux, Rack 1.1.6.

I can understand if this is emulating Eurorack behavior, but technically speaking it isn't really "highpass" so it should be called something else, and a true highpass filter provided somewhere.

(Use case where it makes a difference: I had wanted to use Rack to demonstrate some sound design techniques for producing user interface effects by filtering white noise. This works only if the stopband really is stopped, not just "somewhat attenuated." So, in the lecture, I will have to pipe Rack's output through SuperCollider and apply a HPF there.)