HDMI passthrough in macOS Sequoia sends the original Dolby Atmos audio signal to a connected AV receiver or soundbar for multi-channel processing.
The Apple TV and Music apps on macOS Sequoia have gained a new HDMI passthrough feature to bypass Apple’s spatial audio processing, making it easy to enjoy the ultimate surround sound on your AV equipment.
Instead of having your Mac use audio filters and effects to simulate surround sound on your AirPods or device speakers, a Dolby audio feed is passed unaltered to the connected Hi-Fi receiver or AV soundbar via the HDMI interface.
macOS Sequoia gains HDMI passthrough for Dolby Amos
To be clear, you need specialized hardware like a dedicated AV receiver, soundbar or television capable of processing and rendering multi-channel Dolby Atmos audio. This feature does not require an Apple Music subscription or any other subscription.
The Apple TV 4K already supports Dolby Atmos, so why do people want passthrough support? One reason is that the Apple TV 4K decodes Atmos (and all other audio) on-device and outputs it over HDMI as Dolby MAT 2.0, which is LPCM plus metadata for Atmos, i.e., a high-bandwidth signal supported only by some devices and only via a TV if the TV supports HDMI eARC.
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Another reason is that users want to play their Blu-ray and UHD Blu-ray rips with lossless sound such as Dolby TrueHD and DTS-HD MA. This does not require audio passthrough (and Apple TV 4K already supports TrueHD and DTS-HD MA if you buy the license in an app such as Infuse), but the hope is that audio passthrough will make it more universally supported in apps and that it will unlock support for Dolby Atmos in TrueHD and DTS:X, which are the two audio formats not supported by Apple TV 4K in any form.
There you have it.
macOS Sequoia: How to toggle HDMI passthrough
The new option is available in the Apple TV and Apple Music apps on macOS Sequoia. Open the TV or Music app, choose Settings from the menu, select the Playback tab and click the HDMI Passthrough menu, then choose Off to stop using the feature or Prefer HDMI Passthrough to turn it on.
“Play supported audio in Dolby Atmos and other Dolby Audio formats using HDMI Passthrough when connected to a supported device,” reads the description.
This feature will come to your Mac with the release of macOS Sequoia this fall. tvOS 18 doesn’t support HDMI passthrough though Apple TV owners have been asking for it for years. iOS 18 and iPadOS 18 also don’t yet support HDMI passthrough.
Automatic subtitles on the iPhone, iPad, Mac and Apple TV
As reported yesterday, iOS 18, iPadOS 18, tvOS 18 and macOS Sequoia tweak the behavior of the Mute button. Pressing Mute on the Siri Remote or another paired remote not only mutes the video but also engages automatic subtitles.
Subtitles are also automatically turned on when you turn the volume down. The option is enabled by default on all devices. To toggle it on your Mac, open the TV app and choose Settings from the menus, then select the Playback tab and enable Show When Muted next to Automatic Subtitles.
The current betas of iOS 18, iPadOS 18 and tvOS 18 lack this switch but Apple may add it in later betas. Despite the lack of an outward-facing toggle, automatic subtitles also work on the iPhone, iPad and Mac.