You’ve just bought a new soundbar or AV receiver, and you’re faced with a perplexing choice in the audio settings: Bitstream or PCM. The manual isn’t much help, and a wrong selection can mean the difference between a cinematic, room-shaking experience and a flat, uninspiring one. This fundamental audio setting dictates how your devices handle the complex digital data that makes up your movies and music, and getting it right is key to unlocking the best possible sound from your home theater setup. The central question of Bitstream vs PCM: What Are They and Which Is Better? [Upd. 2025] is more relevant than ever as audio formats continue to evolve.
At its heart, the choice between Bitstream and PCM is about who does the heavy lifting of audio decoding. It’s a decision that involves your source device (like a Blu-ray player or game console), your playback device (like a soundbar or AV receiver), and the specific audio formats you’re trying to enjoy. While one option offers a “set it and forget it” simplicity, the other provides maximum control and compatibility. Let’s break down these two digital audio formats to help you make the perfect choice for your system.
Let’s Start with the Basics: PCM Audio
PCM, or Pulse Code Modulation, is the fundamental language of digital audio. Think of it as the raw, unprocessed ingredient. When sound is converted from an analog wave into digital data, it’s typically turned into a PCM signal. This format is uncompressed and represents the audio waveform directly through a series of samples. Because it’s a direct representation, it’s a universal standard; virtually every piece of digital audio equipment on the planet can understand and play a PCM signal.
When you set your device to output PCM, you’re telling the source (like your Blu-ray player) to do all the audio decoding work. It will read the complex Dolby Digital or DTS soundtrack on a disc, decode it into the multi-channel PCM format, and then send that already-processed signal to your soundbar or receiver. Your receiver then simply amplifies the signal and sends it to your speakers. It’s a straightforward process that ensures broad compatibility, especially with older equipment.
So, What Exactly is Bitstream?
Bitstream, on the other hand, is like handing off a sealed, coded message. When you select Bitstream output (sometimes called “Direct” or “Raw” on some devices), your source player does not decode the audio. Instead, it reads the digital audio track directly from the disc or streaming file and passes it on, completely untouched, to your AV receiver or soundbar. It is then the job of your receiver to decode that Dolby Atmos, DTS:X, or TrueHD signal itself.
This “pass-the-buck” approach has one major visual benefit: it allows your receiver to light up with the specific format logo, like “Dolby Atmos” or “DTS-HD Master Audio.” More importantly, it entrusts the final, critical decoding stage to the device that is specifically designed for high-quality audio processing—your AV receiver or high-end soundbar.
Bitstream vs PCM: What Are They and Which Is Better? [Upd. 2025]
So, which one should you choose? The answer, as is often the case in audio, is “it depends.” There isn’t a single “better” option in all scenarios; the best choice is determined by your specific equipment and what you’re watching or listening to.
In terms of pure audio quality, for standard high-definition formats like Dolby TrueHD and DTS-HD Master Audio, there should be no audible difference between Bitstream and PCM. Both are lossless formats, meaning the final decoded audio sent to your speakers is identical. The difference lies solely in which device performs the decoding.
However, the landscape changes with modern object-based formats like Dolby Atmos and DTS:X. These formats contain extra metadata that tells the processor where sounds should be placed in a three-dimensional space. To get a true Dolby Atmos or DTS:X experience, this metadata must be preserved and interpreted by a compatible receiver. This is where Bitstream becomes essential.
When to Choose Bitstream
- You have a modern AV receiver or high-end soundbar: If your audio equipment supports the latest formats like Dolby Atmos and DTS:X, you should use Bitstream. This ensures the specialized metadata for height channels and object positioning is passed through for your receiver to decode, giving you the full, immersive experience.
- You want to see the format logos light up on your receiver: It’s a small thing, but it confirms your system is working as intended.
- You trust your receiver’s processing more than your source player’s: High-end receivers often have superior digital-to-analog converters (DACs) and processing chips.
When to Choose PCM
- You’re connecting via an older connection like Optical (Toslink): Optical cables cannot carry high-bandwidth Bitstream formats like Dolby TrueHD. Setting your device to PCM can often send a high-quality multi-channel mix over this limited connection.
- Your receiver is older and doesn’t support new codecs: Letting your modern Blu-ray player decode the audio to PCM ensures you still get high-quality sound, even if your receiver can’t understand the latest Bitstream formats.
- You’re gaming on a console: Many gamers prefer PCM for its lower audio latency, which can be critical for competitive play.
- You’re listening to music from a CD or high-res audio file: PCM is the native format for these sources, so it’s often the most direct and pure path.
Making the Right Choice for Your Setup
Your best approach is to experiment. Start by setting your primary source (like a 4K Blu-ray player or game console) to Bitstream. Play a movie with a known Dolby Atmos or DTS:X track. If your receiver displays the correct logo and you hear sound from all your speakers, including height channels if you have them, you’re golden. If you get no sound or an error, switch the setting to PCM. The system will still work, and you’ll likely get a high-quality multi-channel mix, even if you miss out on the object-based effects.
For streaming devices like Apple TV or NVIDIA Shield, the lines can be blurrier. Many of these devices are designed to internally decode audio to a very high-quality PCM format, often with excellent results. Check your specific device’s recommendations, as the “Auto” setting sometimes handles these complexities best.
Ultimately, the debate between Bitstream and PCM is about control and capability. Bitstream passes the audio baton to your receiver to handle advanced formats, while PCM offers a reliable, universally compatible solution. By understanding the role each one plays, you can confidently configure your system to deliver the rich, detailed sound your entertainment deserves.