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PCM vs Passthrough

PCM vs Passthrough

When we were discussing the PCM vs Bitstream settings in the LG TV, the Passthrough topic came up when we arrived at more complex architecture landscapes such as the ones we have in the home theaters arrangements.

Audio PCM vs Passthrough is an important discussion only if you want to use your TV in a home theater setup and you are playing content with high-quality audio, so it will not matter too much if you are using internal speakers, a headphone, or just gaming.

In the discussion PCM vs Passthrough, we can determine that Passthrough technology is better than PCM regarding sound quality and ease of use and is preferred in home theater landscape arrangements. Nevertheless, PCM technology is better at handling multiple audio channels and converting analog sound to digital.

One of the biggest challenges with Pass-Through audio tech is that you may experience some syncing problems, which you can resolve using PCM.

To know if we have a better experience with PCM or Passthrough, we connect a video source and a receiver to the TV in the Enhanced Audio Return Channel (eARC) or in a regular return channel (ARC) port.

Then, you have to play with the different audio formats desired, such as Dolby Digital of course, and check if the TV device can “passthrough the audio” through the receiver with its functionality and synchronization in perfect shape. We have to check PCM and Passthrough as well.

Audio passthrough is a way for you to connect multiple devices to your TV and pass high-quality audio signals to a receiver, which helps keep your setup clean, and you can use the video features your TV supports like HDMI 2.1 and variable refresh rate (VRR) that your receiver might not.

Passthrough reduces the number of cables necessary for a surround-sound system and gaming, and it makes your audio setup overall cleaner and less complicated.

The ease of using Passthrough devices makes them the best bet for some users, although true audiophiles would probably choose differently since it doesn’t genuinely improve the sound quality.

Pass-Throughs can transmit audio signals from a high HD source to a home theater system using an HDMI cable.

This feature comes in handy when using numerous home entertainment devices such as home theater systems, HD set-top box to gaming devices. However, a PCM may be necessary if you have multiple channels or need to convert analog audio.

Going down this road will bring you down a step down from multiple channels to merely two supported channels. If your device cannot handle multi-channel, use the PCM option to output audio.

PCM is best for DVDs, CDs, 2-channel output systems, and when you want to use your TV speakers as your main speakers. Subs and soundbars also work fine with PCM.

Passthrough

To have the best home theater experience, you won’t only need a TV with great picture quality, but you’ll also need the best sound experience possible. Audio passthrough is an important feature if you want to use your TV in a home theater setup and you’re playing content with high-quality audio. Audio passthrough is a way for you to connect multiple devices to your TV and pass high-quality audio signals to a receiver, which helps keep your setup clean, and you can use video features your TV supports like HDMI 2.1 and variable refresh rate (VRR) that your receiver might not.

PCM

PCM is an uncompressed audio format, which means it will theoretically have the best overall sound quality, as no information will be removed to facilitate transmitting the signal. PCM is sent unencoded by the source, meaning the full, unpacked instructions for what sounds to play are sent directly from the source to the receiver and then on to the speakers.

Unfortunately, this makes for a signal that is more difficult to transmit. For most TVs, sending a PCM signal to or from a TV will downgrade the signal to 2.1 for two speakers and a subwoofer, thus eliminating the extra channels necessary for surround sound.

PCM can work with a receiver that supports the format, so if you want uncompressed sound, you’ll need to forego passing the audio through your TV and instead output the sound directly from the source to the receiver if the source outputs PCM. Only HDMI can transmit a PCM signal as Digital Optical is limited to 2.1 or 2.0 channels.

When to use PCM

For audio, use PCM sound only if you:

  • Output audio directly from each source device to the receiver.
  • Output this audio via HDMI and not optical.
bob ludwig

I am Bob. I work as an audio engineer and audio technician. I work in mastering and arranging bridges in existing songs and the arrangement and orchestration of the chorus. In Planet HiFi I test gear for a couple of days and write a review. I also write about AV topics, amplifiers, speakers, and headphones.