Roku Sound Settings for a Soundbar: Auto, PCM, Dolby Digital, or Dolby Digital Plus?

If your Roku picture looks fine but your soundbar is quiet, silent, or limited to stereo, start with the Roku audio setting. The right choice depends on what the TV and soundbar can decode. In most modern setups, Auto is the best first choice because Roku reads the capability it receives from the TV or soundbar and sends a compatible format.

Start with the connection path

A Roku connected directly to the TV sends audio back to the soundbar through HDMI ARC or eARC. A Roku connected to an HDMI input on the soundbar sends video onward to the TV. Both can work, but the soundbar must be selected as the active TV audio output. For an ARC or eARC connection, use the port labelled ARC/eARC on the TV and the matching HDMI output on the soundbar.

Before changing formats, confirm the soundbar plays ordinary Roku menu sounds or a streaming program. If it does not, work through our soundbar eARC troubleshooting guide.

Use Auto first

On Roku, open Settings > Audio and look for the HDMI or digital audio format setting. Choose Auto first. It is the sensible default because it asks the connected equipment which formats it accepts, rather than forcing a format the TV or soundbar may reject.

Auto is usually right for a current soundbar that supports Dolby Digital Plus, and it is the setting most likely to preserve surround sound from supported streaming apps. Do not expect every program to be surround or Atmos: the title, app, subscription tier, and the rest of the signal chain must support it too.

When PCM is useful

PCM sends uncompressed stereo in many Roku-to-TV setups. It is useful as a troubleshooting setting when Dolby audio produces silence, dropouts, or harsh digital noise. If PCM restores reliable sound, the physical connection is probably working and the remaining issue is format compatibility or a TV audio setting.

PCM is not the best choice when your goal is Dolby Digital, Dolby Digital Plus, or Atmos. It can reduce a multichannel soundtrack to stereo before the soundbar receives it. Use PCM to diagnose a problem, then return to Auto after correcting the TV or soundbar setting.

Dolby Digital versus Dolby Digital Plus

Dolby Digital is broadly compatible and is a good fallback for older optical connections or older TVs. Dolby Digital Plus can carry better-quality multichannel audio and is commonly used by streaming services. It generally needs HDMI rather than optical, and the TV must be able to pass it through to the soundbar.

If Auto does not produce the expected surround sound, try Dolby Digital. If that works but Dolby Digital Plus does not, the limitation may be the TV’s ARC passthrough, its digital-output setting, or the soundbar—not the Roku itself.

Check the TV settings too

Set the TV’s audio output to Bitstream, Auto, Pass Through, Dolby Audio, or a similarly named option. Avoid forcing PCM when you want the Roku to send a Dolby track. Turn on CEC if you want the Roku, TV, and soundbar to cooperate over HDMI control; the name differs by TV brand.

For more help deciding which part should handle sound, see Should You Connect Devices to the TV or the Soundbar?.

Quick troubleshooting order

1. Set Roku audio to Auto.
2. Confirm the TV output is Bitstream, Auto, or Pass Through.
3. Play a known surround title in a supported app.
4. Try Dolby Digital as a compatibility test.
5. Use PCM only to test whether the connection is fundamentally working.
6. Restart the Roku, TV, and soundbar after changing HDMI settings.

Make one change at a time

After each audio-format change, play the same short scene and look at the soundbar display or information screen. That keeps you from mistaking a change in the program for a change in the setup. If the soundbar says PCM, the TV or Roku is still converting the signal. If it says Dolby Audio or Dolby Digital, the handoff is working even if the content is not Atmos.

Also avoid changing several settings before restarting. HDMI devices remember their handshake. Power the Roku, TV, and soundbar off, disconnect power for about a minute, then start the TV first, followed by the soundbar and Roku.

Frequently asked questions

Should I leave Roku audio on Auto?

Yes. Auto is normally the best everyday setting because it selects a supported format without you having to guess.

Why does PCM work when Dolby does not?

PCM is a simpler stereo output. It can work when a TV, soundbar, cable, or setting cannot correctly pass the Dolby format.

Can Roku send Dolby Atmos to a soundbar?

It can when the Roku model, app, title, subscription, TV connection path, and soundbar all support Atmos. For the full checklist, read our Dolby Atmos setup guide.

For compatible HDMI cables or streaming-device accessories, browse high-speed HDMI cable options or Roku streaming-device options.

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