I don't know jack about JACK on a Mac either 😉
A similar tool on the Mac is "Soundflower" - basically a software audio interface/mixer. It's no longer supported, but still available.
The Rogue Amoeba software folks make some very useful tools that let me capture audio from applications, route it wherever, add plugins, record, etc.
I regularly use Audio Hijack to listen to PLAP YouTube live while applying the very tools to the audio. Great learning experience. Handy for comparing audio streams and the like.
According to their "comparative" software for PC's
you may want to look at the VB-Audio software at
might do the trick?