PCM Audio for a Soundbar: Output Settings and Compatibility

Should you set PCM for a soundbar?

Choose PCM when your soundbar cannot decode the format the TV or player sends, or when you get silence, dropouts or clicks with other settings. PCM is the most broadly compatible digital audio format, so almost any soundbar with a digital input can play it. The trade-off is that over most connections the TV converts surround soundtracks to stereo before sending them. If your soundbar supports Dolby Digital, DTS or Dolby Atmos and you want its surround processing, choose Bitstream, Auto or Passthrough instead. If you are unsure, try Auto first and fall back to PCM if problems appear.

How PCM output works

PCM (pulse-code modulation) is uncompressed digital audio. When the TV, console or computer is set to PCM, it decodes the soundtrack itself and sends ready-to-play audio samples. The soundbar only converts them to sound. With bitstream or passthrough, the source sends the original encoded stream, such as Dolby Digital, and the soundbar does the decoding.

Because PCM decoding happens in the source, the soundbar usually shows PCM or no format at all on its display or indicator lights. That is normal and does not mean something is broken. It does mean the soundbar's own Dolby or DTS indicator will not appear, and some format-specific processing may not activate.

How the connection limits PCM

The cable and port matter as much as the menu setting. These are the general limits; exact support depends on the specific TV and soundbar, so check both devices' specifications.

• Optical (TOSLINK/S/PDIF): carries two-channel PCM. Surround over optical requires a compressed bitstream such as Dolby Digital, not multichannel PCM.
• HDMI ARC: commonly carries two-channel PCM plus compressed surround formats. Whether multichannel PCM works depends on the devices.
• HDMI eARC: designed to carry multichannel PCM and lossless formats, when both the TV and soundbar support eARC and it is enabled.
• USB or HDMI from a computer: the computer usually sends PCM, and the channel count and sample rate depend on the operating system's settings and what the soundbar reports it can accept.

Sample rate is part of the PCM signal. TV audio is commonly 48 kHz, but sources can send other rates. If a soundbar does not accept a given sample rate, the result may be silence or intermittent sound, which is version- and model-dependent.

Choosing the right setting in practice

Look for the digital audio output or audio format option in your TV, streaming box or console settings. Names vary by manufacturer and firmware, so search the settings for terms like digital audio out, audio format, PCM, Bitstream, Auto or Passthrough rather than relying on a fixed menu path.

• Soundbar is a basic stereo model without Dolby or DTS decoding: choose PCM.
• Sound cuts out, crackles or goes silent on some channels or apps: switch to PCM and test the same content again.
• Soundbar supports Dolby or DTS and you want surround or virtual surround: choose Auto or Bitstream, then check the soundbar's format indicator.
• You use eARC and the soundbar supports multichannel PCM: PCM can deliver surround, but confirm in the soundbar's manual that it accepts it.
• Computer connected to the soundbar: in the system sound settings, select the soundbar as the output device and pick a sample rate and channel layout the soundbar supports.

After any change, play a source you know well and compare. Switching between PCM and bitstream can change the perceived volume, so adjust the level before judging quality.

Limits and related questions

PCM does not improve sound quality on its own. For a stereo source, PCM and bitstream can sound effectively the same. For a surround source over optical or many ARC setups, PCM loses the extra channels because the TV downmixes them to stereo.

Lip-sync delay can change when you switch formats, because decoding moves between the source and the soundbar. If dialogue drifts out of sync, check for an audio delay or lip-sync option on the TV or soundbar.

Hiss, hum or background noise is usually not caused by the PCM setting. A digital connection either delivers the signal or fails. Steady noise more often points to an analog connection, a ground issue or the soundbar's own processing. Note that soundbar output settings are separate from microphone input devices and input level settings used for video calls. Changing PCM output does not affect how your microphone is captured.

Exact options, supported formats and default behavior differ between models and change with firmware updates. Treat the device manuals and current specifications as the authority for your specific TV and soundbar.