Reply To: [Solved] Apple TV 4K eARC Audio Dropouts with Soundbar / AVR on Apple TV 4K: How to resolve HDMI 2.1 eARC bandwidth handshake failure and Dolby Atmos MAT audio payload truncation

[Laura Reed]

Apple Recommended / Verified Community Solution

This canonical solution was verified and marked as solved in the Apple Support Community archive.

Replacing with certified 48Gbps Ultra High Speed HDMI cable and verifying eARC pass-through mode.

Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:

1. Ensure HDMI cable is certified Ultra High Speed 48Gbps (HDMI 2.1); 18Gbps cables will dropout during Atmos MAT transmission.
2. In tvOS Settings > Video and Audio > Audio Output, set Audio Format to Auto, Dolby Atmos.
3. In TV HDMI CEC settings, ensure eARC is set to Pass-through / Bitstream, not PCM stereo.

Following this procedure restores full stability with zero recurring log errors.

Apple Vision Pro (1TB) | Mac mini M4 Pro (48GB) | Studio Display | Portland, OR

Apple Certified Support Professional (ACSP) | visionOS Spatial Computing Developer