Sonos Soundbar Lip Sync Off or TV Audio Cutting Out? Fix It in Order

Which of the three symptoms do you have?

Constant offset — the sound is consistently early or late by a fixed amount. That is a delay-compensation issue and your TV usually has a setting for it. Gradual drift — it lines up at first and gets worse the longer you watch. That is a clock sync issue, usually tied to the audio format or the streaming source. Intermittent dropouts — audio vanishes for a second or two and returns. That is an HDMI handshake or cable issue. The three have completely different fixes, so naming yours first saves real time.

① The eARC handshake: confirm it is actually on eARC

The soundbar has to be on the HDMI port labelled eARC or ARC — not just any port. Many TVs support it on exactly one port, and the label is small. The classic symptom of the wrong port is "there is sound but only stereo" or "it works intermittently". Once it is on the right port, confirm in the TV settings that HDMI-CEC is enabled (vendors call it Anynet+, Bravia Sync, SIMPLINK or Viera Link) and that eARC is set to Auto rather than Off.

When the handshake is unstable, a reliable reset order is: turn the TV off, unplug the soundbar's HDMI cable, unplug the TV from power for 30 seconds, power it back on, then reconnect HDMI. The order matters, because CEC state is negotiated during the power-on handshake.

② Which audio format should the TV send?

The TV sends whatever format it believes the soundbar supports. When that negotiation goes wrong you get stuttering, popping, or no sound at all. In the TV's audio output settings, force the format twice: try PCM first (the most compatible — if it stabilises, the problem was format negotiation), then try Dolby Digital / Auto. Dolby Atmos only holds up over eARC with a cable that can carry it.

One point that gets missed: the streaming app's track format counts too. If Atmos tracks on Netflix stutter on the same TV where ordinary programmes are fine, that is not the TV — it is that Atmos stream exceeding what the current link can carry.

③ Should I turn off the TV's own audio processing?

The TV's sound enhancement, virtual surround, auto volume levelling and night mode all add latency, and the amount varies with content — which is a common source of gradual drift. Since you already have a soundbar, none of that processing earns its place; switch it all off. Also set the TV speakers to off or external-only, so two outputs do not stack into an echo-like misalignment.

Only after the processing is off should you use the TV's own audio delay or lip-sync slider for the final trim. The order matters: switch off processing first, otherwise you are calibrating against a moving target.

④ Cable and port

eARC needs more bandwidth than ordinary HDMI audio. Use the cable that shipped with the soundbar — it was specified for the job. If it has gone missing or you swapped in a longer run, confirm the replacement is rated High Speed with Ethernet or better; a poor long cable on eARC shows up precisely as intermittent dropouts. Avoid HDMI splitters and switchers too, as their eARC support is widely incomplete.

Swapping the cable is the only genuinely falsifying test in this step: borrow a known-good short cable and connect directly. If the dropouts stop, you have your answer.

⑤ Why does grouping add more delay?

Once the soundbar is grouped with other rooms, the system reserves buffer for multi-room sync and TV audio latency rises noticeably. That is a design trade-off, not a fault. Ungroup the soundbar while watching and lip-sync returns immediately. If you genuinely want the whole house on TV audio, that delay is the price.

No sound at all — is that the same problem?

If there is no sound at all, set the delay material aside. Go in this order: confirm the TV's audio output is set to the external system rather than its built-in speakers; confirm the soundbar shows the TV input in the Sonos app rather than playing music; and confirm it is neither muted nor pulled into another group. Those three cover the large majority of "no sound at all" cases.

If the soundbar does not appear in the Sonos app at all, that is a network problem rather than a TV problem — start with the speakers-not-showing-up guide instead.

The order to work through

1. Confirm it is on the port labelled eARC/ARC and that HDMI-CEC is enabled.
2. Turn off every audio processing option on the TV and set the TV speakers to off.
3. Force the audio format to PCM for one round, then try Dolby Digital.
4. Run the power-order reset: TV off, unplug HDMI, unplug the TV for 30 seconds, power on, reconnect HDMI.
5. Swap in a known-good HDMI cable connected directly, with no splitter in between.
6. Only then use the TV's lip-sync slider for the final trim.

After each step, watch a real programme before judging rather than a few seconds of test material — format negotiation and processing latency both take tens of seconds to settle.

Official references

• TV audio stops or skips
• TV audio and video are out of sync
• Error when connecting a home theatre product to TV
• Unsupported audio on your home theatre speaker