Would it be possible to add a “invert” output to the filter device? I guess the inverted output of a lowpass would be different from just turning it into a highpass filter. Besides new effects and sounds this would surely be usefull to do things like very accurate mutli-band compression for example.
Furthermore I’d really like to have a 12dB and 6dB filter (back) in the current filter device.
This is something that I’ve experimented with a bit in the past, by mixing a phase inverted signal back into a filtered version of itself, so that it partially cancels out and essentially achieves what you’re describing: http://illformed.org/temp/invert-filter-example.xrns
I started a thread a while ago that you might find interesting: