Plex Dolby Atmos, TrueHD & DTS-HD MA

Achieving lossless object-based audio passthrough without transcoding or losing spatial metadata.

The Passthrough Problem

You hit play on a pristine 4K reference file with TrueHD 7.1 Atmos. Instead of an immersive soundscape, your AVR shows "PCM", the height channels vanish, or the server begins buffering aggressively. The hardware is capable, but the signal path is compromised.

Media Server Diagnostic
4K Reference

TrueHD 7.1

Reference Cinematic Title

4K HDR10 Dolby Vision TrueHD Atmos 7.1
Video 4K (HEVC Main 10) Audio TrueHD Atmos 7.1 / DTS-HD MA Bitrate 85.4 Mbps
Illustrative Cinema Machina diagram, not a client application screenshot.
Signal Diagnostic: Transcode vs Passthrough
Transcode Risk
Source TrueHD 7.1 Atmos
Output FLAC / PCM
Metadata Spatial Data Removed
Direct Play
Source TrueHD 7.1 Atmos
Output TrueHD 7.1 Atmos
Metadata Object-Based Audio Intact
Illustrative Cinema Machina diagram, not a client application screenshot.

What Cinema Machina Verifies

To experience true lossless audio (Dolby TrueHD Atmos, DTS-HD MA, DTS:X), the client device must send the raw data (bitstream) directly to the AV Receiver without interference. We map the path before making configuration changes.

1. Source Verification

Hardware Capabilities

We verify that your playback client physically supports TrueHD and DTS-HD MA passthrough. Many popular commercial streamers decode internally and cannot be forced into true passthrough mode.

2. Passthrough Checks

Client Configuration

We verify the client path can hand off the raw bitstream. The correct behavior depends on the specific device firmware, receiver model, and display path.

3. Routing Validation

Direct to AVR vs eARC

We map whether the playback device routes directly to the AV Receiver or relies on an eARC return channel from the display. If routing through a display, both the TV and the Receiver must be correctly matched to allow high-bandwidth audio passthrough.

Why is the server transcoding my TrueHD 7.1 Atmos audio?

Transcoding happens if the client device does not support lossless passthrough, or if the TV/AVR chain does not properly negotiate eARC. Most built-in TV apps and certain standalone devices do not support TrueHD passthrough, forcing the audio into FLAC or PCM, which permanently removes the Atmos spatial metadata.

What does a lossless Dolby Atmos path require locally?

To get true lossless Dolby Atmos (TrueHD), you need a playback device that explicitly supports audio passthrough, connected directly to an AVR or soundbar that decodes TrueHD, or routed through a display that reliably handles eARC without internally downmixing the signal.

Why does the player say 'Direct Play' but my receiver says 'PCM'?

If TrueHD is Direct Playing but the receiver shows PCM, the playback device is decoding the audio internally instead of passing the bitstream to the AVR. On an Apple TV, this is by design (it uses MAT 2.0). On other platforms, it indicates that passthrough behavior and content audio resolution are not correctly matched to your display hardware.

Map the Signal Chain

The exact configuration path varies drastically per room. Let Cinema Machina map your audio chain to ensure you're hearing the uncompressed spatial audio you paid for.

Book a Playback Chain Audit