Audio dropouts on Sonos soundbars connected via HDMI ARC/eARC are typically caused by TV audio format conflicts or HDMI-CEC interference from other devices. The most common culprit is leaving your TV's audio output on "Auto" mode, which causes the TV to constantly switch audio codecs and confuse the handshake with your Sonos.
Quick answer
• Set TV audio to Pass-Through mode — Samsung: Settings → Sound → Expert Settings → Digital Output Audio Format → Pass-Through; LG: Sound → Advanced Settings → Digital Sound Output → Pass Through • Test for HDMI-CEC conflicts — Unplug all HDMI devices except Sonos, watch streaming apps for 1 hour to see if dropouts stop • Use ethernet for bonded systems — If you have surrounds or a Sub, hardwire the main Sonos unit to reduce Wi-Fi interference • Check HDMI cable quality — eARC requires high-speed cables with ethernet pins
Symptoms
• Brief audio cuts lasting 1-2 seconds every 10-20 minutes during playback • Delayed audio start when turning on TV — 30+ seconds of silence before sound begins • Audible popping sound just before audio cuts out • Sonos app status changes showing "TV Audio" dropping in and out repeatedly • Specific to certain apps while others work fine
Quick checks
• Verify the connection — Confirm Sonos is plugged into the TV's ARC/eARC HDMI port (usually HDMI 1) • Test with TV apps only — Try Netflix or built-in TV apps before testing external devices • Check Sonos app status — Look for "TV Audio" vs "No Audio" messages in the app during dropouts • Try different content — Test both regular stereo and Dolby Atmos content to see if format-specific
Step-by-step fix
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Set TV audio output to Pass-Through mode: • Samsung TVs: Settings → Sound → Expert Settings → Digital Output Audio Format → Pass-Through (enable eARC Mode first if this option is greyed out) • LG TVs: Sound → Advanced Settings → Digital Sound Output → Pass Through • Sony TVs: Settings → Display & Sound → Audio Output → Pass through mode → Auto
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Test for HDMI-CEC device conflicts: • Unplug all HDMI devices from your TV except the Sonos soundbar • Watch streaming apps (Netflix, Prime Video) for at least 1 hour • If dropouts stop: Plug devices back one by one until dropouts return — that device is the culprit • For problematic devices: Purchase a "CEC-less" HDMI adapter to block CEC signals
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Address network interference for bonded systems: • If you have Sonos surrounds or Sub: The main soundbar creates a 5GHz private network that can conflict with your router • Connect the main Sonos unit to ethernet to make it the SonosNet root and manage channels better • Keep the 5GHz Wi-Fi band on your router set to a different channel than the Sonos private network
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Verify HDMI cable compatibility: • For eARC connections: Ensure you're using a high-speed HDMI cable with ethernet support • Test with the included cable from Sonos first before trying third-party cables • Consider optical fallback if HDMI issues persist (included adapter) — you'll lose Atmos but gain stability
If it still isn't working
• Try PCM/Stereo mode temporarily — This eliminates surround sound processing as a variable and usually provides rock-solid audio • Test the optical connection — Use the included optical adapter as a diagnostic tool; if optical works perfectly, the issue is HDMI-related • Check for app-specific problems — If dropouts only happen in certain streaming apps (like Hulu on Samsung or HBO Max on LG), consider an external streaming device like Apple TV or Roku • Factory reset the Sonos while keeping TV settings — Sometimes the handshake protocol gets corrupted in the soundbar's memory
FAQ
Why does Pass-Through mode work better than Auto? Auto mode makes your TV constantly re-encode and process audio formats, creating lag and handshake issues. Pass-Through sends the raw audio directly to Sonos, which is designed to handle multiple formats seamlessly.
Will I lose Dolby Atmos if I switch to optical? Yes, optical connections only support stereo PCM or basic Dolby Digital 5.1. You'll need HDMI ARC/eARC for Dolby Atmos and DTS formats. Use optical as a temporary diagnostic tool or permanent fallback if HDMI proves unreliable.
Do I need eARC enabled for streaming apps? Not necessarily. Regular ARC handles most streaming app audio fine, including Dolby Digital Plus. Only enable eARC if you're using external devices that output full Dolby TrueHD or uncompressed audio formats.
Why does ethernet help with wireless surrounds? When the main Sonos unit is on Wi-Fi, it creates a chain: Router → Soundbar → Surrounds. This doubles latency and creates interference. Ethernet makes the soundbar a dedicated wireless hub for just the Sonos system.