Why Does OBS Need a Virtual Audio Cable on Mac?
macOS separates audio into two categories: input devices (microphones, audio interfaces) and output devices (speakers, headphones). OBS reads from input devices only. When a soundboard app or any other application plays audio, that audio goes to the system output. OBS has no way to intercept it.
A virtual audio cable solves this by creating a new audio device that acts as both an output and an input. Audio sent to the virtual output appears on the virtual input. OBS captures the virtual input like any microphone. The result is system audio, soundboard output, and any desktop sound flowing into OBS without additional hardware.
Windows includes WASAPI loopback capture, which lets OBS grab desktop audio natively. macOS has no equivalent. Every Mac streamer who wants desktop audio in OBS needs a virtual audio cable or a hardware loopback cable.
How Do You Set Up a Virtual Audio Cable for OBS on Mac?
- Download and install LitLink free virtual audio driver for Mac
- Toggle System Audio Passthrough in LitLink routes desktop audio to the virtual cable automatically
- Open OBS and add an Audio Input Capture source Sources panel, click the plus icon
- Select LitLink Audio Bridge (LitLink) as the device system audio now flows into OBS
LitLink creates a "LitLink + Speakers" multi-output device automatically so audio continues playing through your headphones or speakers while simultaneously routing to OBS. Built-in mic passthrough means your voice is also included in the LitLink Audio Bridge signal without adding a second source.
BlackHole is a free, open-source alternative that requires manual setup. After installing BlackHole, you must open Audio MIDI Setup, create a multi-output device combining your headphones and BlackHole, set it as the system output, and then add BlackHole as the OBS input. LitLink automates every one of these steps.
How Do You Add Multiple Audio Sources to OBS with a Virtual Audio Cable?
Microphone audio requires its own Audio Input Capture source in OBS. Select your USB microphone, audio interface, or built-in microphone as the device. This source appears as a separate channel in the OBS Audio Mixer panel with its own volume slider and mute button.
System audio arrives through the virtual audio cable. The LitLink Audio Bridge device captures everything that plays on your Mac: soundboard pads, music players, browser audio, game sounds, and notification chimes. OBS treats it as a second microphone input with independent volume control.
LitLink mic passthrough offers a streamlined alternative. When enabled, your physical microphone signal is mixed with system audio and delivered through the LitLink Audio Bridge device as a single combined source. Streamers who want the simplest possible OBS configuration use this approach. Those who need separate volume control over voice and desktop audio in the OBS mixer add two sources instead.
The OBS Audio Mixer displays all active audio sources with real-time level meters. Each source has independent volume, mute, and filter controls. Adjust the balance between voice and system audio directly in the mixer without leaving OBS.
What Are the Best OBS Audio Settings for Virtual Audio Cables?
Sample rate mismatches cause crackling, pitch shifting, or silence. LitLink operates at 48 kHz by default. Confirm OBS matches by opening Settings, selecting Audio, and verifying the sample rate. If you use BlackHole, check Audio MIDI Setup to confirm both the multi-output device and BlackHole are set to the same rate.
macOS audio ducking reduces system volume when it detects a communication app (FaceTime, Zoom) is active. OBS can trigger this behavior. Disable it in System Settings under Sound to prevent unexpected volume drops during a stream. OBS audio filters such as a compressor, noise gate, or limiter can be applied to the virtual audio cable source to control peaks and maintain consistent levels throughout a broadcast.
Which Virtual Audio Cable Is Best for OBS Streaming?
Most streamers need system-wide audio routing: everything playing on the Mac goes into OBS. LitLink and BlackHole both accomplish this. LitLink removes the manual configuration steps and adds mic passthrough, making it the better choice for streamers using soundboards alongside OBS.
Loopback by Rogue Amoeba provides a visual routing interface that lets you capture audio from individual applications. A streamer could route only the soundboard and game audio to OBS while excluding notification sounds and browser tabs. This level of isolation is useful for professional broadcasts but unnecessary for most streamers.
All three options add negligible latency. Virtual audio cables operate at the kernel level and pass audio buffers directly between applications. The delay is sub-millisecond and imperceptible during live streaming. The LitPads feature overview covers how audio routing integrates with the full soundboard workflow on Mac.
Marcel Iseli is an indie developer, DJ, and music producer with over 20 years behind the decks and in the studio. Rooted in hip hop culture, he collects drum machines, samplers, and vintage audio gear. LitPads grew out of that obsession: decades of triggering samples on hardware led him to build the software equivalent he always wanted.