What Is a Virtual Audio Cable? A Plain English Explanation

You’ve probably seen this term thrown around if you’ve ever tried to share audio on a call or record what’s playing on your computer. You search for how to do it, and suddenly every forum post and tutorial is telling you to install a “virtual audio cable.” But what does that actually mean?

Let’s break it down in plain terms.

Think of it like a real cable

Imagine you have a speaker playing music. Now imagine you want to feed that music into a microphone input on another device. In the physical world, you’d grab an audio cable, plug one end into the headphone jack and the other end into the mic input. Done. The audio flows from point A to point B.

A virtual audio cable does the same thing, but entirely in software. There’s no physical cable involved. Instead, a piece of software creates virtual audio devices on your computer that act like invisible wires connecting one app’s audio output to another app’s audio input. The operating system treats these virtual devices just like real hardware, so any app that can use a microphone or speaker can use them.

That’s it. That’s the core idea.

Why would you need one?

Most operating systems don’t give you a built-in way to route audio between apps. On macOS, for example, your system audio goes to your speakers or headphones. Your microphone feeds into apps that listen for mic input. But there’s no native option to take what’s playing on your system and pipe it into a Zoom call, a screen recording, or a podcast.

Here are the most common reasons people reach for a virtual audio cable:

Sharing audio on calls. You want the other people on your Zoom, Google Meet, or Teams call to hear a video, a song, or a presentation playing on your Mac. Without a virtual audio cable, they’d only hear your microphone picking up your room (and your speakers, poorly).

Recording system audio. You’re making a tutorial, demo, or screen recording and you need to capture the actual audio output from your computer, not a microphone recording of your speakers.

Streaming. If you’re streaming on Twitch or YouTube, you often need to mix game audio, music, and your voice into separate channels. Virtual audio cables let you route each source independently.

Podcasting and music production. Some podcasters route audio from a browser or music app into their DAW (digital audio workstation) for live mixing. Virtual cables make that possible without extra hardware.

How virtual audio cables work on macOS

On macOS, audio devices are managed by something called the Core Audio HAL (Hardware Abstraction Layer). It’s the system that sits between your apps and your audio hardware. Every microphone, speaker, and headphone that shows up in your Sound preferences is registered through the HAL.

A virtual audio cable installs what’s called a HAL plugin, a small audio driver that registers new virtual devices with the system. These devices don’t correspond to any physical hardware. They exist purely in software. But because they’re registered through the same system as real devices, every app on your Mac can see and use them.

When you select one of these virtual devices as your audio output, the sound that would normally go to your speakers gets sent to the virtual device instead. On the other end, another app can select that same virtual device as its audio input (like a microphone). The audio flows from the output side to the input side, just like a cable connecting two jacks.

Some virtual audio cables create a pair of devices (one output, one input). Others create a single device that acts as both. The details vary, but the principle is the same.

Older solutions on macOS

If you’ve done any research on this topic, you’ve probably come across a few names.

Soundflower was one of the first free virtual audio cables for macOS. It worked well for years, but development stopped and it became unreliable on newer versions of macOS. Many users ran into kernel extension issues as Apple tightened its security requirements.

BlackHole picked up where Soundflower left off. It’s an open source virtual audio driver that avoids the deprecated kernel extension approach. It’s functional, but it still requires some manual setup. You need to create multi-output devices in Audio MIDI Setup, configure routing yourself, and troubleshoot when things don’t stick between restarts.

Both of these tools give you the raw building blocks, but they leave the setup and configuration to you.

A simpler approach with Soundshine

Soundshine is a modern virtual audio cable built specifically for macOS. It installs a lightweight audio driver and gives you a virtual microphone that carries your system audio. Instead of asking you to configure multi-output devices and dig through Audio MIDI Setup, it handles the routing for you from a simple menu bar app.

You install it, and a new mic called “Soundshine” shows up in any app that accepts microphone input. Select it in Zoom, Google Meet, OBS, QuickTime, or whatever you’re using, and the other side hears your system audio. That’s the whole workflow.

Under the hood, Soundshine uses the same Core Audio HAL plugin approach described above. It registers a virtual audio device with the system, captures your system audio output, and makes it available as a microphone input. The difference is that all the wiring is handled automatically.

Do you actually need one?

If you’ve ever been on a call and someone asked “can you hear my screen?” while you heard nothing, or if you’ve tried to record a tutorial and realized the recording captured silence instead of the app audio you were demonstrating, then yes. A virtual audio cable solves that problem.

It’s one of those tools that feels invisible when it’s working. You set it up once, and audio just flows where it needs to go. No physical cables, no extra hardware, no complicated signal chains.

For most people on macOS, the simplest path is to grab a tool that handles the setup automatically rather than piecing it together yourself. That’s exactly the kind of problem Soundshine was built to solve.