Rogue Amoeba Loopback

Loopback is a Mac-only utility from Rogue Amoeba that creates virtual audio devices, letting you route system sound, app output, and microphone input through any combination you can dream up. For podcast producers, this solves a recurring problem: how do you get a remote guest, a local microphone, a music bed, and an interpreter all into a single multi-track recording with each on its own channel for later editing?

Loopback handles it. You build a virtual device that aggregates whatever sources you want, then point your DAW or recording tool at that device. The interface is straightforward once you understand what you're routing, with a node-style canvas that shows sources flowing into mixers and outputs.

Quality is pristine, with no resampling artefacts or dropouts, and Rogue Amoeba's long track record on Mac audio software means support and reliability are excellent. The downsides are the obvious ones.

It's Mac only, so Windows users need VoiceMeeter or something similar. The price is higher than most utility apps because the engineering is non-trivial, but a perpetual license is reasonable next to ongoing subscription tools.

If you have one mic and use Riverside or Zencastr's local recording, you don't need Loopback. If you're running a complex multi-source live show, it pays for itself the first time you avoid losing a recording.