PCM Audio on TCL TV: Configure the Output

Setting PCM output on a TCL TV

To get PCM from a TCL TV, open the TV's sound or audio output settings and change the digital audio output format to PCM. The TV then decodes the audio from the app, tuner or HDMI source and sends plain uncompressed audio to the soundbar, receiver or amplifier connected by optical cable or HDMI ARC. Choose PCM when the connected output device does not recognize Dolby or DTS bitstreams, or when sound is missing, cuts out or crackles in Auto or bitstream mode.

Menu labels depend on the TCL model and its operating system. Google TV, Android TV and Roku TV versions name and place these options differently, and firmware updates can move them. Look for a setting named something like digital audio output, digital audio format or S/PDIF, usually grouped with the sound or speaker settings. If you cannot find PCM, check the user manual for your exact model number rather than relying on a generic menu path.

• Connect the soundbar or receiver with an optical cable, or to the TV's HDMI port labelled ARC or eARC.
• On the soundbar or receiver, select the matching input, such as optical, TV or ARC.
• On the TV, set audio output to the external device instead of the built-in speakers, if your model offers that choice.
• Change the digital audio format to PCM.
• Play something and confirm the sound comes from the external device.

What PCM means on a TV audio output

PCM (pulse-code modulation) is uncompressed digital audio: a stream of samples taken at a fixed sample rate and bit depth. Nearly every digital audio device can play it, which is why PCM is the compatibility setting on TVs, soundbars, receivers and audio interfaces.

A TV's digital output generally works in one of these ways. In PCM mode, the TV decodes the audio itself and sends PCM. In Auto, bitstream or passthrough mode, the TV forwards compressed formats such as Dolby Digital or DTS unchanged, and the external device decodes them. Some models also have a fixed Dolby option that re-encodes the audio. Which of these modes your TCL TV offers, and what they are called, varies by model and software version.

The connection type limits what PCM can carry. Optical (S/PDIF) carries only two-channel PCM, so surround sound over optical needs a compressed format. Standard HDMI ARC is generally limited to two-channel PCM as well. eARC can carry multichannel PCM, but only when both the TV and the receiver support it. In practice, selecting PCM on an optical or ARC connection usually means stereo output, even if the source is 5.1.

The TV and the source together set the sample rate of the PCM stream. Many receivers and some soundbars show the incoming format and sample rate on their display or in their app, which is the most reliable way to confirm what is actually arriving.

When to choose PCM and when to avoid it

• The soundbar plays TV channels but goes silent in some streaming apps: try PCM, because the app may be sending a format the soundbar cannot decode.
• Older soundbars, stereo amplifiers with optical inputs, and DACs or headphone amplifiers: use PCM, since many of these cannot decode Dolby or DTS.
• Recording TV audio through an optical input on a capture device or audio interface: PCM gives a plain stereo stream that the input device is more likely to accept, provided the hardware supports optical PCM.
• A surround receiver with Dolby and DTS decoding on optical or ARC: keep Auto or bitstream so it receives surround; PCM would leave you with stereo.
• An eARC receiver that supports multichannel PCM: PCM may carry surround, but confirm support in both manuals.

To compare modes, play the same scene in each one and watch the receiver or soundbar's format indicator and channel count. If the device reports PCM with two channels while you expected surround, the connection or the format setting is the limit.

Loudness can change after switching to PCM because the TV now handles decoding. On some models the TV's volume and sound processing affect the digital output; on others the output stays fixed and you control volume with the external device. If the input level on the soundbar or receiver seems too low or too high, check your model's manual for how its digital output volume behaves.

Limits and related questions

Does PCM lower quality? For stereo content, there is no inherent loss, because PCM is an uncompressed decode of the source. The trade-off is channel count: over optical or ARC, surround and immersive formats generally need passthrough or eARC to keep their extra channels.

Pops, clicks or bursts of static are usually not ordinary background noise. They often mean the external device is receiving a bitstream it cannot decode, and switching to PCM is the usual fix. A steady hiss or hum more likely comes from analog connections or the speakers, and changing the digital format will not remove it.

PCM and bitstream modes can involve different processing, so lip sync may shift after you switch. If dialogue drifts out of sync, look for an audio delay or offset setting on the TV or on the soundbar.

The digital audio format setting usually applies only to optical and HDMI ARC or eARC outputs. Bluetooth headphones and speakers use a separate audio path, so changing this setting will typically not affect them.

If PCM is missing, greyed out or keeps reverting, check for a TV software update, make sure the cable is in the correct ARC or optical port, and confirm that the TV's audio output is set to the external device. If none of that helps, the manual for your model or the manufacturer's support is the authoritative source for what that model supports.