12dB lowcut?
-
I would like to build a 12dB/octave lowcut, as neutral as possible.
The 1 Pole HP looks neutral, but it is only 6dB/octave and stacking 2 of these filters will not exactly be the same as 1x 12dB/octave filter.
I read here on the forum that the SVF filter is 12dB/octave (is it?), but I'm afraid it will alter the sound (will it?). What Q setting would be as neutral as possible? From the curve in the GUI I would say 0.8? EDIT: ChatGPT says resonance is "neutral" at 0.707.
And what about the lowcut in the parametric EQ? How steep is it?
Any other ideas? -
Stacking two 1-pole (6 dB/oct) high-pass filters is definitely an option, but it doesn’t behave exactly like a single 12 dB/oct design. The slope doubles, but the overall response (phase and the cutoff alignment) will be slightly different.
The SVF can do a true 12 dB/oct response that's mathematically “neutral”.
If you need more control over the resonance, a Sallen–Key filter is another solid choice for a 2-pole high-pass filter.
-
So, I took two SVF with 12dB/oct each and put them behind each other.
I've set the resonance of both to 0.707 as I read this would be a neutral position
and that's what it also looks like in HISE GUI.When I check the VST it gives me -22.x dB/oct, so that's ok.
But at the cutoff frequency where I would expect 2x -3dB = -6dB, I have around +1dB!
As if there was a resonance boost.So I made a version with resonance set to 0.3 - the lowest setting possible and I still
get +0.4dB instead of -6.Any idea what's going on?
Or is it wrong to expect -3dB at the cutoff frequency of a SVF?
