Audio routers are patching writ large.
Audio routers are “virtual cables” that route audio out of limited parochial software into differently limited parochial software, giving you flexibility at the cost of confusion and labour. Using audio effects software to apply effects audio synthesis software doesn’t sound like rocket science, but turns out to be tedious.
There are many that I am aware of, with different reliability, licensing, and platform support.
BlackHole“is a modern MacOS virtual audio driver that allows applications to pass audio to other applications with zero additional latency.”
jack(open source, Windows, macOS, Linux, powerful but unfriendly)
- loopback (commercial, macOS)
- soundflower (free, macOS, flakey)
- VB Audio Cables (donationware windows)
- Audiobus, the iOS router, which I have no use for at present.
Breaking it down by platform:
Jack on macOS has its only working version hidden deep in the github bug reports as opposed to the normal download page, indicating that development on this project stutters. But it seems to be the most felxible. BlackHole is new and I have not tried it yet.
Soundflower is inflexible and periodically unmaintained despite intermittent commercial backing. Fragility hell in these free options is avoided somewhat by [L]oopback](https://rogueamoeba.com/loopback/), a rather expensive commercial competitor which is maintained, but AFAICT doesn’t have the flexibility of Soundflower as far as routing audio from an app back to the app as with external apps, and seems to only do stereo. Maybe owners Rogue Amoeba will use that funding to keep maintaining their product, having ruined soundflower on their own watch? But should I reward that behaviour by buying a license?
Apparently I did.
See Linux audio hell. In principle Jack shoudl work well there, realtively speaking.
Jack seems to work on Windows. But there is also… VB Audio Cables seems to be a viable workalike for Windows.