Native CoreAudio HAL : Zero Drivers

Play audio through two outputs at the same time.

A native macOS menu bar app that lets you stream audio across two or more output devices simultaneously with one click. Share a movie with two pairs of AirPods, play through speakers and headphones in sync, or stream without third-party audio drivers.

Download DuoSound v1.0 : 2.1 MB : Free

brew install --cask duosound

Interactive Multi-Output Simulator

Test device selection, live waveforms, and audio routing right in your browser

⌥⌘D

CONNECTED AUDIO OUTPUTS (SELECT 2 OR MORE) Multi-Output: Active

MacBook Pro Speakers Built-in

48,000 Hz : 2 Channels 24-bit

85%

AirPods Pro Bluetooth 5.3

48,000 Hz : Active Drift Compensation

92%

Studio Display Audio Thunderbolt

96,000 Hz : 6-Speaker System

70%

Engineering Architecture

Zero Audio Drivers: Built entirely on Apple CoreAudio HAL APIs (AudioHardwareCreateAggregateDevice with kAudioAggregateDeviceIsStackedKey = 1). No kernel extensions, no virtual soundcards, and zero third-party kext security prompts.
Hardware Drift Compensation: Automatically enables CoreAudio hardware drift correction when pairing Bluetooth headsets with wired or built-in speakers, preventing audio desynchronization over long sessions.
Independent Volume Sliders: Controls the gain of each audio device in the multi-output mix independently, letting you balance headphones against loud room speakers seamlessly.
Global Hotkey Toggle: Press ⌥⌘D anywhere in macOS to toggle multi-output mode without opening the menu bar extra.
Instant Disconnect Recovery: If AirPods go into the case or a monitor disconnects, DuoSound instantly restores your previous default audio output and destroys the aggregate device without dropped samples.

Technical Specifications

SYSTEM REQUIREMENTS macOS 13.0 Ventura or later (Sonoma, Sequoia)

ARCHITECTURE Universal Binary (Apple Silicon & Intel)

APP SIZE 2.1 MB DMG (Zero dependencies)

MEMORY FOOTPRINT Under 12 MB RAM, less than 0.1% CPU

LICENSE MIT Free & Open Source

SOURCE CODE github.com/tejastelkar/duosound

Crafted by Tejas Telkar

Software and AI systems engineer from Pune, India. Designing tactile, fast, and private native macOS utilities with Apple platform purity.

← All Open Source Apps GitHub Profile @tejastelkar