The short answer
tvOS has no bitstream output for Dolby TrueHD or any DTS format, and Apple’s Apple TV 4K specifications list Dolby Digital, Dolby Digital Plus and Dolby Atmos only. Every app that plays a TrueHD or DTS track decodes it on the Apple TV and sends something the Apple TV can output: multichannel PCM, or Dolby Digital Plus.
Dolby Atmos is supported directly when it arrives in Dolby Digital Plus, which is how Apple TV+, Netflix and Disney+ deliver it. Atmos in a TrueHD track, and DTS:X, are the cases that need the app to do more.
What an Apple TV can send
- Stereo PCM and multichannel PCM, up to 7.1.
- Dolby Digital 5.1, which the Apple TV can also encode on the fly.
- Dolby Digital Plus, up to 7.1, with or without Atmos.
- Dolby Atmos from the system’s own spatial audio, which an app can feed with audio it has rendered itself.
No TrueHD, no DTS, no DTS-HD Master Audio and no DTS:X leave the box in their original form.
Format by format
DTS and DTS-HD Master Audio
Decoded on the Apple TV by the app. What the receiver sees depends on what the app sends next: PCM or Dolby Digital Plus on its display, never DTS.
DTS:X
Decoded like DTS-HD Master Audio. Unless the app renders the objects itself, the track plays from its 7.1 or 5.1 bed with no height channels.
Dolby TrueHD
Decoded on the Apple TV, then sent as PCM or Dolby Digital Plus.
TrueHD Atmos
The Atmos part rides inside the TrueHD stream, so it needs the same treatment as DTS:X: the app renders the objects or plays the track without its height channels.
Dolby Digital Plus Atmos
Supported directly, and sent to an Atmos receiver as Atmos with nothing re-encoded.
Two ways a player handles it
Object audio: Spectati
Dolby Atmos in Dolby Digital Plus reaches the receiver untouched, TrueHD and DTS play as 5.1 Dolby Digital Plus, and TrueHD Atmos and DTS:X keep their height channels on AirPods, HomePods and Atmos receivers.
Spectati renders the objects in a TrueHD Atmos or DTS:X track into speaker channels and plays them as Apple Spatial Audio. By default it does this on every Mac and wherever the output reports Spatial Audio or Dolby Atmos: AirPods, HomePods, and Atmos receivers and soundbars, which Apple TV sends it to as Dolby Atmos. To render for a room you know, set Speakers in Settings to 5.1.2, 5.1.4, 7.1.2, 7.1.4 or 9.1.6. It works on films and shows from every source, comes with a subscription, and replaces the lossless track with a high-bitrate lossy encode.
Decode to PCM: Infuse
Infuse decodes TrueHD and DTS to multichannel PCM, up to 7.1 channels at 24-bit, with higher sample rates converted to 48 kHz. A 7.1 track keeps all eight channels. Infuse’s own documentation says it supports Atmos from Dolby Digital Plus tracks and lists TrueHD Atmos and DTS:X as unsupported, so those play from their bed channels.
Spectati is the one of the two that plays TrueHD Atmos and DTS:X with their height channels, so an Atmos remux sounds like Atmos. Infuse’s PCM route keeps a 7.1 track without heights at its full channel count. The free tier direct-plays your 4K remuxes with no transcoding, in SDR. HDR and surround sound are what a subscription adds.
When the server converts the audio
If an app tells Plex or Jellyfin it cannot play a track, the server converts the audio before sending it, usually to a lossy format, and the receiver sees that instead. This is what is happening when a server’s dashboard shows an audio transcode while the video plays direct. An app that decodes TrueHD and DTS itself leaves the server to send the file as it is.
Settings to check
- On the Apple TV, open Settings, Video and Audio, and leave Audio Format on automatic, or choose Dolby Atmos if your receiver supports it.
- Connect the Apple TV to the receiver’s HDMI input, or use eARC from the TV. Plain ARC usually carries Dolby Digital Plus but not multichannel PCM.
- In Spectati, the speakers setting is under Dolby Atmos and DTS:X in Settings, Playback. Automatic is the default and suits most rooms.
The Dolby Vision and Atmos guide covers the picture side of the same settings.
If your receiver must decode it
If your receiver must see the TrueHD or DTS bitstream itself, for instance to apply its own DTS:X processing, the Apple TV cannot do it with any app. Android TV boxes such as the NVIDIA Shield, dedicated media players and UHD Blu-ray players can.
