Atmos that cuts in and out — a half-second of silence, the sound dropping mid-scene, audio re-syncing every time a new show starts — is genuinely maddening, but it's almost never your soundbar dying. It's an HDMI handshake that keeps re-negotiating, usually because of a marginal cable or an audio-format switch. Once you know what's triggering it, it's fixable.
What's happening
Every time the audio format changes — say a show goes from a Dolby Digital ad to an Atmos scene, or you jump between apps — the Apple TV, TV, and soundbar re-do the eARC handshake, and you hear a brief drop while they re-sync. If the cable or the link is even slightly marginal, those re-syncs turn into constant dropouts. So the goal is a rock-solid link and fewer format switches.
The quick fix (most cases)
- Reseat and swap the cable. The eARC link is bandwidth-hungry, and a cable that's "fine" can drop Atmos intermittently. Reseat both ends, and try a short certified Ultra High Speed cable on the TV's eARC port. This resolves the majority of dropouts.
- Confirm you're on the eARC port (not plain ARC or a second HDMI input), and that eARC is enabled in the TV's audio settings.
- Power-cycle the chain in order. Unplug the Apple TV, TV, and soundbar for at least 30 seconds; power the TV first, then the soundbar, then the Apple TV. A clean handshake from cold fixes a lot of "it started doing this randomly."
Why it happens (and how to reduce the triggers)
The format-switching is the deeper cause, so you can cut the dropouts by reducing how often the chain re-handshakes:
- Turn off "Reduce Loud Sounds" (Settings > Video and Audio) — it processes audio in a way that can cause drops on some setups.
- Leave "Match Content" on for video but test it for audio. If dropouts are constant, try setting a fixed audio format in the source app instead of letting it switch per-title.
- Update everything. An Apple TV, TV, or soundbar firmware update often includes eARC handshake fixes — this is a common official cause of intermittent Atmos.
When it's the soundbar or receiver
If the cable's good and it still drops, the audio device's eARC implementation may be the weak link — especially on bars from the first eARC generation. A firmware update on the bar/receiver is the fix; if there isn't one, routing the source so the bar receives Atmos directly (source → soundbar HDMI-in → TV) avoids the TV's eARC entirely. For bar-side eARC faults, see Apple TV soundbar eARC problems.
FAQ
Why does the sound drop for a second when a show starts? The chain re-runs the eARC handshake whenever the audio format changes. A solid cable and current firmware shrink those drops to nothing.
It only started recently — what changed? Often a software update on one device, or a cable that's aged into marginal. Reseat/swap the cable and update all three devices.
Is my soundbar broken? Usually not. Atmos dropouts are almost always the cable or the handshake. Rule those out before blaming the bar.
Does the cable really matter for audio? Yes — eARC Atmos needs real bandwidth, and a weak cable drops it intermittently even when video looks fine. Use a certified Ultra High Speed cable on the eARC port.