PCM vs Bitstream: Which One Should You Select?
PCM vs bitstream is a common choice in televisions, disc players, consoles and streaming devices. The labels can make an audio menu look like a sound-quality contest. Usually it is a routing decision: should the source decode the programme and send PCM, or should it send an encoded bitstream for the receiving device to decode?
PCM vs Bitstream: The Bottom Line
Choose the setting that preserves the channels and formats your system supports reliably. PCM is often practical when the source must mix sounds or the receiver does not support the original codec. Bitstream is often practical when a compatible AV receiver or soundbar should perform the decoding. Neither label guarantees higher fidelity on its own.
What changes in the signal path?
When you select PCM
The player, television or console decodes a supported soundtrack before sending audio. The output may be two-channel PCM or multichannel Linear PCM, depending on the source settings and connection. The receiving amplifier, receiver or soundbar then handles any available processing, volume control and conversion to analogue.
When you select bitstream
The source sends an encoded audio stream, such as a supported Dolby or DTS format, without first turning it into output PCM. The receiving device identifies and decodes that stream. After decoding, many products still use PCM internally for processing before digital-to-analogue conversion.
Bitstream is not one codec. It describes a flow of encoded bits. The receiver must support the codec inside that stream. Likewise, “PCM” alone does not reveal channel count, sample rate or bit depth. Read PCM Audio Explained for those fundamentals.
Does PCM or bitstream sound better?
There is no universal winner. If a lossless programme is decoded correctly, moving the decode step from a compatible player to a compatible receiver need not create a meaningful quality difference. Practical differences can arise from format support, channel conversion, level handling, device processing, connection limits or configuration—not from the menu word by itself.
Compare at matched playback levels. A louder output can seem more impressive even when the underlying programme is the same. Also check the receiver’s information display: it may show “PCM” after the source has decoded Dolby or DTS, which does not automatically mean that the soundtrack was reduced in quality.
HDMI and optical are not interchangeable
Our HDMI input audio format guide explains the PCM/bitstream setting in detail. HDMI, HDMI ARC/eARC and optical S/PDIF have different capabilities, and individual products implement different subsets. A format that works over a direct HDMI connection may not pass through a television in the same way. Optical connections commonly support stereo PCM and selected compressed surround bitstreams, but the exact list belongs to the device manual.
Do not infer support from the connector shape alone. Check the source output menu, the TV pass-through settings, the receiving input specification and the programme format. Firmware and app behaviour can also affect which option is available, so consult the current manual for the exact television model.
A concrete Denon Home Amp example
The Denon Home Amp shows why model-specific checking matters. Its official manual lists optical support for two-channel Linear PCM at 32 to 192 kHz and 16, 20 or 24 bits. For optical bitstream, it lists Dolby Digital. That does not mean every bitstream format is supported, and it does not turn its two-channel PCM specification into a general rule for other products.
The same manual tells users to connect a compatible television to the HDMI eARC/ARC terminal and use optical when the television lacks eARC or ARC. HDMI control can link input switching, power and volume on compatible equipment, though Denon notes that some functions may not operate with every TV.
When PCM is a sensible first choice
- The receiving input accepts PCM but not the source codec.
- The source must combine programme audio with interface or game sounds.
- A stereo system needs a compatible two-channel output.
- You are troubleshooting silence and both manuals identify PCM as a supported fallback.
Confirm whether the PCM setting outputs stereo or multichannel audio. A TV may convert incoming surround to two channels, while a player connected directly to an AV receiver may provide multichannel PCM over HDMI. The menu label alone is not enough.
When bitstream is a sensible first choice
- The receiver or soundbar explicitly supports the soundtrack codec.
- You want the receiving device to perform decoding and report the incoming codec.
- The connection cannot carry the required multichannel PCM configuration but supports the encoded stream.
- The product manual recommends pass-through or bitstream for the intended surround format.
Troubleshooting in the right order
- Confirm the physical connection and select the correct input.
- Check the receiving device’s supported formats for that exact input.
- Set the source to a known-supported output, then verify channel count.
- Test a familiar programme without changing several settings at once.
- If the path includes a TV, compare a direct connection with TV pass-through where practical.
If the system works in PCM but not bitstream, the likely issue is compatibility or configuration somewhere in the encoded path—not proof that one method is inherently superior. If both work, choose the route that preserves the required channels, remains stable and makes the system easier to use.
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