Loopback Release Notes

Issues where sample rate conversions could cause distorted audio have been rectified.

When a device is missing from the system, its volume sliders in the “Sources” and “Monitors” column will now be dimmed.

Source meters will now correctly activate, even when a source is not hooked up to any output.

When missing audio devices are reconnected, they will now immediately receive audio.

When a Loopback virtual audio device is set as the default system output, user interface sounds or other short audio clips will no longer be slightly cut off.

Monitoring startup has been improved to prevent small bursts of unmuted audio from unexpectedly popping through.

A bug where Loopback could mute all channels of a multi-channel device while running has been squashed.

Cross-compatibility with SoundSource has been improved, particularly with regard to SoundSource’s ability to redirect audio to a Loopback virtual audio device.

Loopback virtual audio devices now work better with Audio Hijack, behaving like standard audio hardware in all known ways.

Loopback now properly updates when changes are made to the channel or sub-device configuration of an aggregate device being used as an input source or an output monitor.

In some cases, meters could fail to work properly immediately after an update to the ARK plugin. No longer!

Meters in Loopback have been improved to feel more responsive and update faster.

The “Finder” special source will no longer incorrectly receive audio when previewing inside another app’s “Open” dialog.

A rare crash when using devices with mismatched sample rates has been fixed.

VoiceOver will now correctly identify volume sliders as sliders.

Multiple drawing bugs have been fixed, including problems where wires might display incorrectly after adjusting window size, as well as unchecked checkboxes on disabled sources drawing incorrectly.

The license unlock sound now plays via the “systemsoundserverd” process, which correctly respects the system’s alert volume and device preference.

Improvements to Special Sources
The “Siri” special source now correctly includes sound effects on MacOS 14 (Sonoma), and the “VoiceOver” special source has been optimized to capture only necessary processes.

The “Pass-Thru” source has been optimized to improve overall performance.

The level meter seen in the app’s “Devices” sidebar is now more accurate.

An incompatibility with Boinx Software’s “mimoLive” has been fixed.

Loopback now uses improved heuristics to confirm the ARK plugin is loaded correctly, avoiding a rare “Repair needed” warning. This also improves reliability between Loopback and Audio Hijack, when an Audio Hijack session is set to automatically run on login.

Audio capture has been improved in certain situations, to avoid instances where it might silently fail.

Possible Issues With Distorted Audio Have Been Corrected
A problem where audio captured by Loopback could get choppy or distorted has been corrected. This fixes a regression introduced in version 2.4.0, as part of the overhauled audio capture backend.

Loopback Again Correctly Captures From All Applications
Audio is now correctly captured from applications that are playing to audio devices other than the default system audio output. This fixes a regression introduced in version 2.4.0, as part of the overhauled audio capture backend.

CPU Usage Optimizations
Loopback’s CPU usage has been optimized both when adjusting volumes and when the app is idle. This fixes regressions introduced in version 2.4.0, as part of the overhauled audio capture backend.

An issue where pass-thru (output) volume could fail to be applied has been corrected. This fixes a regression introduced in version 2.4.0, as part of the overhauled audio capture backend.

Previously, audio meters could go missing for some channels in configurations with virtual device sources. They have been found, and convinced to appear correctly at all times.

Loopback will no longer unexpectedly impact VoiceOver audio when installing or updating Loopback. As well, an issue with poor VoiceOver responsiveness within Loopback has also been fixed.

An issue where monitor volume controls were not properly highlighted has been corrected.

A minor display issue with Monitor Channels 1 & 2, where the “(R)” could be cut off, has been corrected.

MacOS 15 (Sequoia) is not yet supported, but Loopback now behaves better on it. Updates with support for Sequoia are still in the works, and will arrive later this summer.

The “Siri” special source has been updated to work as expected on all releases of MacOS 14 (Sonoma).

The “Sources” menu has been updated to alphabetize using the on-disk name, which ensures apps like “Ableton Live” appear where you’d expect.

A minor display issue with Output Channels 1 & 2, where the “(R)” could be cut off, has been corrected.

VoiceOver now uses correct names for all special sources in Loopback.

Loopback will now launch and run as expected on MacOS 14.1.

Several small quirks have been fixed to make using Loopback with VoiceOver better than ever.

A rare crash which could occur when metering audio while the system’s `coreaudiod` process was restarted has been fixed.

An issue where focus rings could flash undesirably has been fixed.

The celebratory sound effect heard when unlocking Loopback will now correctly play through the Mac’s configured “Sound Effects” device. After all, sound effects play through a separately configured output in MacOS.

It’s now possible to control-click in the “Name” and “Code” fields of the “License” window, making it possible to copy and paste in data.

Several small interface issues have been corrected.

A rare crash which could occur when an audio device’s configuration changed has been fixed.

Several improvements have been made to the naming of Loopback devices, to prevent issues such as devices having blank names.

Changing the displays connected to the Mac no longer incorrectly triggers a spike in CPU usage.

A drawing bug where wires might display incorrectly after toggling the visibility of Monitors has been corrected.

An issue which could cause Loopback to crash after its Uninstall process is run has been fixed.

Meters will no longer report invalid levels when their target device’s sample rate is changed.

A rare channel mapping issue with certain devices which could result in instability for the `coreaudiod` process has been corrected.

A logic issue has been fixed to prevent clock desynchronization when a device clock resets.

Attempting to change volumes by selecting a volume knob then manually typing in a new value no longer causes an internal error. Further enhancements to all volume sliders in Loopback are planned for the future.

Due to changes made by Apple, the “Text to Speech” special source is no longer available on MacOS 13 (Ventura). On Ventura, this audio can now be captured on a per-application basis by targeting the application where the text is being spoken.

An issue where upsampling of certain low sample rates could sometimes produce audio artifacts has been resolved.

Assorted improvements have been made to better handle misbehaving Universal Audio devices.

As a result of changes to MacOS, the Shortcuts app erroneously showed non-functional Shortcuts for Loopback. This has been corrected, and those invalid Shortcuts will no longer appear. We hope to add proper Shortcuts support to Loopback in the future.

Monitors now correctly disable volume controls when a device doesn't support them.

The performance of devices with many channels has been improved.

VoiceOver Improvement: The “Delete” and “Hide Monitors” have been re-grouped, for ease of use.

The pressed state for the “New Virtual Device” and “Delete” buttons has been restored.

VoiceOver Improvement: When navigating to sources and monitors, they now announce their status (“Enabled” or “Disabled”).

Loopback now works better with applications like MuseDash which have non-traditional bundle structures.

Assorted drawing issues where items would fail to properly highlight on MacOS 11 (Big Sur) have been corrected.

Loopback's windows will now interact with full screen mode on MacOS 11 (Big Sur) as expected. This also corrects a previous incompatibility with window managers such as Magnet.

Loopback devices will now work correctly when used as the system's “Sound effects” device.

USB device references for certain low-quality devices have been improved, to work better with some third party drivers.

The Quick Tour now properly supports the new “Speak items under the pointer” setting in MacOS 11 (Big Sur).

Improvements have been made for the Installer and Quick Tour, to present better on small resolutions, using scrollbars to make all content accessible.

Loopback now works around issues with aggregate devices, by handling drift correction in more cases.

Loopback’s notifications for missing devices now better handle devices which frequently disconnect.

Additional Audio Fixes in ACE 11.2.2
The Audio Capture Engine (ACE) has been updated to 11.2.2, fixing several issues. Playback to Bluetooth devices has been improved, non-standard audio formats will again play as expected, and several regressions have been fixed.

Critical Fixes in ACE 11.2.1
The Audio Capture Engine (ACE) has been updated to 11.2.1, fixing a regression which would cause captured input audio to be improperly muted, as well as a crash which could occur with multi-output devices.

Full Support for Catalyst Apps
Loopback now works as expected with Catalyst apps such as Voice Memos, Podcasts, and more.

Using a Loopback pass-thru device for system sound effects will now work as expected.

Loopback no longer incorrectly disables devices when ACE is updated.

A rare crash which could occur when using too many monitors for Loopback's main window to fit visually has been fixed.

Multiple issues related to aggregate devices have been fixed, including corrections for missing audio and issues with sample rate mismatches. Issues with capture of FaceTime, Podcasts.app, and more, should now be resolved.

A problem where short glitches could occur when starting to send audio to Bluetooth devices has been corrected.

An extremely rare crash, which could be seen when devices have massive buffer sizes, has been fixed.

Previously, audio devices which failed to properly report their “physical transport” setting might not be captured or heard. This issue has now been resolved.

Improvements have been made to all level meters, to reduce the amount of CPU used and improve performance in multiple situations.

Improvements to Bluetooth Device Reliability
Loopback now does additional work to avoid issues caused by Apple's Bluetooth device handling, so Bluetooth devices will work more reliably when included as part of a Loopback virtual audio device.

An issue where an incorrect sample rate assignment could prevent devices from being enabled has now been resolved.

Several changes have been made to improve performance and robustness, and to better handle changes to configurations while running.

An issue where Loopback devices could fail to be fully removed when the application is uninstalled has been corrected.

Important Crash Fix
A crash which could occur on launch has been fixed. This crash was rare, occurring only when an Application Source's icon could not be found, but it's now entirely corrected.

Improvements have been made for devices imported from Loopback 1, correcting a minor issue where muting modes would sometimes be set incorrectly.

The launch behavior when another copy of Loopback is open has been improved.

The volume indicator icons now use 1/3 of the slider for each wave.

An issue where devices could potentially reappear after uninstalling Loopback has been fixed.

Sources are no longer incorrectly added to a device if the user cancels the “Select Application…” dialog.

A rare bug where very complex virtual audio devices could cause the `coreaudiod` process to crash has been fixed.

An issue where Loopback's virtual devices could be incorrectly deactivated upon updating has now been fixed. Please check that your desired devices are enabled in Loopback's device list.

The monitoring menu now correctly shows multiple audio devices with identical names.

An incompatibility with TouchBar Macs, seen when VoiceOver was on, has been corrected. In addition, the “Add Source” popup menu now properly accepts VoiceOver presses.

Loopback now correctly routes audio on all channels when using nested devices and manual channel mapping.

An issue where rapid starting and stopping of a device could cause monitoring to fail has been fixed.

A very rare issue where the installer could fail to update over very old versions has been corrected.

Notifications that inform the user about mis-configurations and other issues have been fixed to appear correctly at all times.

Device monitoring now works even with pass-thru devices, avoiding a rare configuration issue where audio could appear to be lost.

An obscure issue where deleting an audio source could lead to a crash has been corrected.

Monitoring now automatically restarts when an output device is removed and then returns.

Loopback now uses https whenever relevant.