HOLOPHONIX Virtual Soundcard

HOLOPHONIX Virtual Soundcard is a free macOS virtual audio driver that routes audio between applications on the same Mac with zero additional latency. Audio sent to its output channels is immediately available on its input channels, so any application can feed any other — a DAW into HOLOPHONIX Native, a media player into a recorder, a game engine into a spatialisation engine.

It is distributed free of charge as part of the HOLOPHONIX ecosystem.

⬇ Download the installer

This project is a modified version of BlackHole, © 2019–2026 Existential Audio Inc., used under the GNU General Public License v3.0. The driver core is Existential Audio's work; HOLOPHONIX Virtual Soundcard changes only the branding, the channel-count variants and the installer. See Relationship to BlackHole for the exact list of changes. "BlackHole" and the BlackHole logo are trademarks of Existential Audio Inc. and are used here only to identify the upstream project. This is not an official BlackHole build and is not supported by Existential Audio.

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Table of Contents

• Features
• Installation
• Uninstallation
• Usage
• Relationship to BlackHole
• Building from Source
• FAQ
• Support
• Licence and Source Availability
• The HOLOPHONIX Ecosystem

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Features

• Four channel-count variants: 16, 32, 64 and 128 channels — install any combination
• Zero additional driver latency — audio is passed through a shared ring buffer
• 32-bit float, matching what macOS Core Audio uses natively at the system level
• Sample rates: 8, 16, 24, 44.1, 48, 88.2, 96, 176.4, 192, 352.8, 384, 705.6 and 768 kHz
• No kernel extension — it is a userspace Core Audio AudioServerPlugIn (HAL plugin), so no changes to system security settings are needed
• Signed and notarised for Gatekeeper
• Single installer that both installs and uninstalls any variant
• macOS 10.10 Yosemite and newer; native on Intel and Apple Silicon

Installation

1. Download the latest installer
2. Quit all running audio applications
3. Open the .pkg and select the channel-count variants you want to install
4. Restart your Mac

Each variant appears in Audio MIDI Setup as a separate device, for example HOLOPHONIX Virtual Soundcard 64ch. The driver bundles are installed to /Library/Audio/Plug-Ins/HAL/.

Installing several variants side by side is supported and is often useful — a 16ch device for general routing and a 128ch device for a full spatialisation session, for instance.

Uninstallation

Option 1 — use the installer

The installer package also contains uninstall options. Open the same .pkg, click Customise, and select the variants you want to remove under Uninstall HOLOPHONIX Virtual Soundcard. Install and uninstall choices for the same variant are mutually exclusive.

Option 2 — manually

1. Delete the driver bundle — mind the quotes, the name contains spaces:

   sudo rm -R "/Library/Audio/Plug-Ins/HAL/HOLOPHONIX Virtual Soundcard 64ch.driver"

   Replace 64 with 16, 32 or 128 as appropriate. Note this is the root /Library, not ~/Library.

2. Restart Core Audio:

   sudo killall -9 coreaudiod

Usage

Route audio between two applications

1. In the sending application, set the output device to HOLOPHONIX Virtual Soundcard
2. Output to any channel
3. In the receiving application, set the input device to HOLOPHONIX Virtual Soundcard
4. Take input from the matching channels

Record or capture system audio

1. Create a Multi-Output Device in Audio MIDI Setup containing both your real output and HOLOPHONIX Virtual Soundcard
2. Right-click the new Multi-Output Device and choose Use This Device For Sound Output
3. In your DAW or recorder, set the input device to HOLOPHONIX Virtual Soundcard

Enable drift correction on every device in a Multi-Output or Aggregate except the clock source, otherwise audio will glitch after a few minutes.

Hear the audio while routing it

Use a Multi-Output Device, as above. A virtual driver alone has no physical output.

Relationship to BlackHole

HOLOPHONIX Virtual Soundcard is a fork of BlackHole by Existential Audio Inc., licensed under GPL-3.0.

The audio driver itself — BlackHole/BlackHole.c, the ring buffer, the Core Audio plugin implementation, all of the DSP and device logic — is Existential Audio's work, unmodified. Credit for how well this driver performs belongs to them.

What this fork changes:

Area	Change
Product name	Devices are named HOLOPHONIX Virtual Soundcard <N>ch (via the kDriver_Name build constant)
Manufacturer	Reported as HOLOPHONIX (via kManufacturer_Name)
Icon	HOLOPHONIX device icon in place of the BlackHole icon
Bundle identifiers	com.amadeus.holophonix.vs<N>ch
Channel variants	16, 32, 64, 128 — upstream ships 2, 16, 64, 128, 256
Plugin factory UUID	Regenerated per build, so this driver can coexist with an existing BlackHole installation
Installer	New build script (Installer/create_holo_installer.zsh) producing a single package that installs or uninstalls any combination of variants

No change is made to the audio path. Consequently:

• Bugs in audio behaviour are almost certainly upstream bugs. Please check the BlackHole issue tracker before reporting, and report driver-core issues there so all users benefit.
• Report packaging, naming, signing and installer problems to HOLOPHONIX support — those are ours, not upstream's.
• Upstream's wiki applies to this driver too, substituting the device name.

If you are not a HOLOPHONIX user

You almost certainly want BlackHole itself — it is the original, it is actively maintained, and it offers 2ch and 256ch builds that this fork does not. Consider sponsoring Existential Audio; this fork exists only because their work is good.

Commercial licensing of the driver core

BlackHole is GPL-3.0. To use the driver core in a project that is not GPL-3.0, a licence must be obtained from Existential Audio — contact them at devinroth@existential.audio. That arrangement is between you and Existential Audio; Amadeus cannot grant it, and nothing in this repository does.

Building from Source

Requires Xcode and a macOS host. Building the driver alone:

xcodebuild -project BlackHole.xcodeproj -configuration Release -target BlackHole

To install a driver you built yourself:

1. Copy the built .driver bundle to /Library/Audio/Plug-Ins/HAL
2. sudo chown -R root:wheel "/Library/Audio/Plug-Ins/HAL/<your driver>.driver"
3. sudo killall -9 coreaudiod

Building the release installer

Installer/create_holo_installer.zsh builds all four channel variants, signs them, and produces the combined install/uninstall package. Run it from the repository root:

./Installer/create_holo_installer.zsh

Before running it, set devTeamID and notarizeProfile at the top of the script to your own Apple Developer team ID and notarytool keychain profile, or set notarize=false to skip notarisation. Signing and notarisation credentials are not included in this repository.

Upstream's own Installer/create_installer.sh is retained for reference and is not used for HOLOPHONIX builds.

FAQ

Why doesn't it appear in the Applications folder? It is an audio driver, not an application. It appears in Audio MIDI Setup, in Sound settings, and in the device lists of audio applications.

Which variant should I install? The smallest that covers your channel count. Installing several is fine.

Nothing is playing through it.

• Check System Settings → Privacy & Security → Microphone and confirm your application has microphone access.
• Check that input and output volume are up in Audio MIDI Setup.
• In a Multi-Output Device, macOS requires the Built-in Output to be enabled and listed first.

Audio glitches after a few minutes in a Multi-Output or Aggregate device. Enable drift correction on every device except the clock source.

What bit depth is used, and can I change it? 32-bit float, because that is what Core Audio uses natively system-wide. It is lossless for up to 24-bit integer material, and there is nothing to configure at the driver level.

Can I change the volume of a Multi-Output Device? macOS does not support this. Set the volume of the individual devices in Audio MIDI Setup instead.

The installer fails. Some macOS versions fail to run installer packages from certain folders. Move the .pkg to the Desktop (or to Downloads if it is already on the Desktop) and try again.

Can I use it alongside BlackHole? Yes. The bundle identifiers, device names, device UIDs and plugin factory UUIDs are all distinct.

Which applications is it known to work with? Any Core Audio application. Reported working with Ableton Live, Cubase, Digital Performer, IanniX, Logic Pro, Max, Nuendo, Pro Tools, Pure Data, Pyramix, QLab, Reaktor, REAPER, Reason and Traktor, among others.

Support

Issue tracking is not enabled on this repository. Please use these channels instead:

• Packaging, installation, naming or signing problems — HOLOPHONIX Help Center
• General help and setup — HOLOPHONIX documentation
• Audio behaviour (dropouts, sample rates, Multi-Output devices) — these belong upstream, see Relationship to BlackHole

Please do not contact Existential Audio for support on this build.

Licence and Source Availability

HOLOPHONIX Virtual Soundcard is a modified version of BlackHole and is distributed under the GNU General Public License, version 3 — see LICENSE. The complete corresponding source for every released binary is in this repository:

https://github.com/HOLOPHONIX/HOLOPHONIX-Virtual-Soundcard

You are free to use, study, modify and redistribute it under the terms of the GPL.

• BlackHole is © 2019–2026 Existential Audio Inc. — https://github.com/ExistentialAudio/BlackHole
• Modifications for HOLOPHONIX Virtual Soundcard are © Amadeus.
• Signed and notarised under Amadeus's Apple Developer identity.
• "BlackHole" and the BlackHole logo are trademarks of Existential Audio Inc. and are not licensed by the GPL. They appear in this repository, and in the upstream file and target names it retains, solely to identify the project this work derives from.
• "HOLOPHONIX" and "Amadeus" are trademarks of Amadeus.

The HOLOPHONIX Ecosystem

HOLOPHONIX is a spatial audio platform developed in coordination with IRCAM, combining several spatialisation techniques — Wave Field Synthesis, High-Order Ambisonics, Distance-Based Amplitude Panning and others — for theatre, concert, museum and immersive installation work.

HOLOPHONIX Native	macOS spatialisation application, up to 128 inputs. The most common companion to this driver — route a DAW into Native on the same Mac
HOLOPHONIX Ultra	Flagship hardware spatialisation processor
HOLOSCORE	Free plugin for automating spatialisation from a DAW timeline
HOLOPHONIX Designer	Free offline editor with binaural preview, for macOS and Windows
All software · All hardware

Company and contact: https://holophonix.xyz/en/contact

Upstream project this driver derives from: BlackHole by Existential Audio Inc.