Audio Routing on Mac

macOS does not include built-in app-to-app audio routing. This guide covers every method for sending audio from one application to another on Mac.

Why Does macOS Not Include Built-In Audio Routing?

macOS audio architecture (Core Audio) sends application audio to physical output devices (speakers, headphones) but does not provide a native mechanism for routing audio between applications. Third-party virtual audio drivers fill this gap by creating virtual devices that act as intermediaries between apps.
BlackHole
Free, open-source virtual driver
Loopback
$99, commercial routing app
Audio MIDI Setup
Built into macOS

This architectural choice affects every custom soundboard app on Mac. Soundboard developers cannot bundle audio routing without shipping a kernel extension or system extension, which introduces security complications and App Store review challenges. The standard approach uses a separate virtual audio driver.

Three methods exist for routing audio between Mac applications: BlackHole (free, open-source virtual driver), Loopback by Rogue Amoeba ($99, commercial routing app), and Audio MIDI Setup aggregate/multi-output devices (built into macOS, requires a virtual driver for app-to-app routing).

How Does Audio Routing Work with BlackHole?

BlackHole creates a virtual audio device on macOS. The sending application (like LitPads) outputs to a multi-output device that includes both headphones and BlackHole. The receiving application (like OBS or Discord) reads from BlackHole as if it were a microphone. Audio flows from the soundboard to the streaming or voice chat application.

The step-by-step BlackHole setup guide covers installation, multi-output device creation, and configuration for OBS, Discord, and Zoom. The complete process takes about five minutes.

BlackHole is free, open-source, and adds sub-millisecond latency. The driver operates at the kernel level and passes audio buffers directly between applications without processing or compression. Audio quality is bit-perfect.

How Does Audio Routing Work with Loopback?

Loopback by Rogue Amoeba ($99) provides a visual interface for creating custom virtual audio devices that combine specific application outputs. Loopback can capture audio from individual applications rather than the entire system, which provides finer control over what audio reaches the receiving application.

Loopback creates named virtual devices that appear as standard audio inputs in any application. A Loopback device configured to capture only LitPads audio sends soundboard sounds to OBS without also sending system notification sounds, music from other apps, or browser audio.

The trade-off is price. Loopback costs $99. BlackHole combined with a virtual audio cable for Mac achieves the same basic routing for free. Loopback's advantage is convenience and per-application isolation, not capability.

What Is the Best Audio Routing Method for Streamers?

BlackHole combined with a macOS multi-output device is the best audio routing method for most streamers. The setup is free, reliable, and adds negligible latency. Loopback is only worth the $99 cost for streamers who need to isolate specific application audio or manage complex multi-source routing scenarios.

Most streamers need exactly one routing path: soundboard audio into OBS. BlackHole handles this perfectly. The soundboard software for Mac compares how different soundboard apps handle the routing requirement and which approaches work best for different streaming setups.

What Are Common Audio Routing Problems on Mac?

The most common problems are sample rate mismatches between devices in a multi-output group (causing clicks and pops), missing drift correction on BlackHole (causing gradual desync), Discord noise suppression filtering out soundboard audio, and the virtual device not appearing after installation (requires restart).
  • Match sample rates on all devices 44,100 Hz or 48,000 Hz in Audio MIDI Setup
  • Enable drift correction on BlackHole prevents gradual audio desync
  • Disable Discord noise suppression Krisp removes non-voice sounds including effects
  • Allow audio driver permissions Privacy & Security on macOS Ventura and later

macOS Ventura and later require explicit permission for audio drivers. If BlackHole does not appear after installation, check System Settings under Privacy & Security.

Sample rate mismatches are the most frequent cause of audio artifacts. Open Audio MIDI Setup, select each device in the multi-output group, and verify they all use the same sample rate. Common rates are 44,100 Hz (CD quality) and 48,000 Hz (video/streaming standard). Mixing rates causes audible degradation.

Discord's Krisp noise suppression is designed to remove non-voice sounds, which includes soundboard effects. Disable noise suppression in Discord Voice & Video settings when using a soundboard. The same applies to Zoom's noise cancellation features.

macOS Ventura and later require explicit permission for audio drivers. BlackHole's installer handles this automatically, but users who block the permission at install time need to re-enable it in System Settings under Privacy & Security.

Marcel Iseli DJing
Marcel Iseli

Indie Developer · DJ · Producer

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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.