A virtual audio driver is software that creates an audio device inside macOS that doesn't correspond to any physical hardware. It shows up in an app's input and output list next to your real speakers and microphone, but instead of playing sound out loud or recording from a room, it passes audio data straight from one application into another. Chorus is not this. It works only with the physical devices you already own.
The phrase gets thrown around loosely, often as a catch-all for "anything that moves audio around on a Mac." That looseness is exactly why it's worth being precise about. A virtual audio driver does one specific, useful thing, and Chorus does a different, equally specific thing. Confusing the two is how people end up installing a driver they didn't need, or expecting Chorus to do a job it was never built for.
What a virtual audio driver actually does
Every Mac already has a way to list audio devices: Sound settings, Audio MIDI Setup, and the device pickers inside apps like Zoom or QuickTime. Normally, that list is built from hardware. Your MacBook's speakers, a pair of AirPods, a USB microphone, a monitor with a built-in speaker. Each entry corresponds to something you could point at.
A virtual audio driver adds an entry to that same list that doesn't correspond to anything physical. macOS treats it exactly like a real device: apps can select it as an output or an input, set its sample rate, and send or receive audio through it. But nothing plays out loud and nothing is recorded from the room. Instead, whatever gets sent to the virtual device's input side comes straight back out its output side, or gets read by whichever app is listening. It's a pipe with a device icon on each end, not a speaker or a microphone.
Why installing one is different from installing a normal app
Most Mac apps just run. A virtual audio driver has to do something a regular app can't: add a new device to macOS's own audio system, one the operating system didn't know existed until the driver told it to. That requires deeper access than a background app normally gets, which is why virtual audio drivers typically install a kernel extension or, on newer macOS versions, a signed system extension, and sometimes ask for a reboot before the new device appears in Sound settings.
What people actually build with one
The most common case is streaming and podcasting. A streamer wants their game's audio and their microphone to arrive in OBS as separate, controllable tracks, but OBS only understands audio devices, not individual apps. A virtual audio driver bridges that gap: the game is set to output to the virtual device, OBS is set to capture from it, and the game's sound now behaves like it came from a piece of hardware OBS can pick up. The same pattern shows up in podcasting rigs, voice-changer chains, and anything else that needs one app's sound to land inside another as if a microphone had recorded it.
BlackHole is the free, open-source example most people run into first: a bare virtual audio cable with no interface, wired up in Audio MIDI Setup or another app. Loopback, from Rogue Amoeba, does the same underlying job with a full interface on top, letting you combine several apps and a microphone into one virtual device by dragging and dropping. It's a narrow, technical job, and both are built specifically for it.
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Download for MacWhy Chorus is not a virtual audio driver
Chorus works only with the outputs and inputs your Mac already has: real speakers, real headphones, a real built-in or USB microphone. It groups several outputs so they play as one, with a working volume and per-device balance, and it sends individual apps to whichever output makes sense, so a call can stay on headphones while everything else plays through the room. None of that requires a new device to exist. It's a routing and grouping job across hardware macOS can already see.
That's also why the install is nothing like a virtual driver's. Chorus adds no kernel extension and no system extension, needs no reboot, and doesn't ask macOS to accept a new kind of device. It uses the same output-grouping mechanism macOS ships with by default, the one behind Audio MIDI Setup's Multi-Output Device, with an interface, a working volume and per-app control built on top. Dragging it to the Trash leaves your Mac exactly as it was.
The clearest way to put it: a virtual audio driver moves audio between apps. Chorus moves audio between your speakers and mics. If the job is getting one app's sound into another app, that's a virtual audio driver's job, and Chorus doesn't attempt it. If the job is getting your Mac's own sound out to the right physical device, that's what Chorus is built for.
| Virtual audio driver | Chorus | |
|---|---|---|
| Works with | A device it creates itself | Real speakers and mics you already own |
| Typical job | Send one app's audio into another app | Group and route audio between physical outputs |
| Install requires | Kernel or system extension, often a reboot | Nothing beyond installing the app |
| Creates a new device | Yes | No |
| Typical user | Streamers, podcasters, developers | Anyone with more than one speaker or mic |
If you're not sure which side of that line you're on, ask where the audio needs to end up. Into another piece of software, as if it came from a microphone, means you want a virtual audio driver like BlackHole or Loopback. Out to the right speakers in the room, with one volume and no plumbing, means you want Chorus.
For the full technical detail on the framework, see Apple's own Core Audio developer documentation.
Frequently asked questions
What is a virtual audio driver?
A virtual audio driver is software that creates an audio device inside macOS that doesn't correspond to any physical hardware. Apps see it in their input and output lists just like a real speaker or microphone, but instead of playing sound out loud or recording from a real mic, it passes audio data from one app to another.
Why do virtual audio drivers need a special install, unlike a normal app?
macOS only knows about the physical devices it can detect, so a virtual audio driver has to register a brand new kind of device with the system itself, not just run as a background app. That typically means installing a kernel extension or a signed system extension, and often a reboot, before the device shows up in Sound settings.
Is Chorus a virtual audio driver?
No. Chorus works entirely with the physical outputs and inputs you already have, speakers, headphones, displays and microphones, and groups or routes between them. It doesn't create a new device, doesn't need a driver or a reboot, and doesn't capture one app's audio as another app's input.
What is a virtual audio driver actually used for?
The main use is app-to-app audio capture: taking one application's output and feeding it into another app as if it were a microphone. That's how streamers route game audio and voice chat into OBS as separate tracks, and how tools like BlackHole and Loopback work.
Should I use a virtual audio driver or Chorus?
It depends on the direction the audio needs to travel. If one app's sound needs to go into another app, you need a virtual audio driver such as BlackHole or Loopback. If several real speakers need to play as one, or a call needs to stay on your headphones while music plays elsewhere, Chorus does that without installing anything into the system.
