There's no GUI for it, but I'm willing to help you with it. If you have no asoundrc (i.e. you let ALSA figure it out for you) the example in the README will work. Otherwise you can email me or post on the mailing list and I can get back to you.
Unrelated to this I want to be able easily switch between my Headphones and HDMI output whereas HDMI out needs to be routed through dmix->alsaequal->softvol->HDMI. I gave up after spending two hours tinkering.
pcm.!default {
type asym
playback.pcm "cards.pcm.default"
capture.pcm "rnnoise"
}
As for the second thing, you could do what I do and use pcm_jack, like this: pcm.!default {
type asym
playback.pcm "plug:jack"
capture.pcm "plug:rnnjack"
}
pcm.rnnjack {
type rnnoise
slave.pcm plug:jack
}
Keep in mind this will need more setup, specifically to set JACK up, and is definitely overkill, but may be fun. Also, this config is how my setup works exactly.