Soundbar 4K Passthrough vs eARC: Which Connection Wins

What is 4K passthrough?

4K passthrough describes a soundbar with one or more HDMI inputs and an HDMI output that connects to your TV. You plug a source like a streaming box, game console, or Blu-ray player into the soundbar, and the soundbar forwards the video signal to the TV while also processing the audio for its own speakers. This creates a single point of connection: all your devices plug into the soundbar, and only one HDMI cable goes to the TV.

The main benefit of passthrough is that it reduces the number of HDMI cables running to your TV. If your TV has limited ports, a soundbar with multiple HDMI inputs can act as a hub. However, the soundbar becomes an active part of the video path, which means it must support the video formats your sources output, such as 4K resolution and high dynamic range (HDR). If the soundbar's HDMI ports are older than your TV's, the video signal may be limited.

What is eARC?

eARC (enhanced Audio Return Channel) is a feature of the HDMI specification that sends high-quality audio from your TV back to a soundbar over the same HDMI cable that carries video to the TV. With eARC, you connect your source devices directly to the TV, not the soundbar. The TV selects the video source, and the audio from that source is transmitted to the soundbar through the eARC-enabled HDMI port.

eARC supports object-based audio formats like Dolby Atmos and DTS:X, as well as high-bitrate audio, making it ideal for modern soundbars. Because the soundbar is not in the video path, it cannot degrade or limit the picture quality. Your TV handles all video processing and format support, which is often more capable than the circuitry in a soundbar.

For a deeper dive into how eARC differs from standard ARC, see our article on HDMI ARC vs eARC.

Bandwidth and feature differences

The HDMI specification defines the capabilities of both passthrough and eARC. For video passthrough, the soundbar's HDMI inputs and output must handle the full video bandwidth of your sources. This includes features like 4K resolution, high refresh rates, and HDR metadata. If any part of the chain fails to support a format, the signal may be downgraded or fail to display.

eARC, on the other hand, only needs to carry audio. The video path goes directly from your source to the TV, so the TV's HDMI ports determine video compatibility. The eARC channel operates over an HDMI connection but uses a separate, dedicated audio channel with higher bandwidth than the original ARC. This allows lossless and object-based audio formats.

The HDMI Forum continues to update the specification, with recent versions introducing higher bandwidths to support new video and audio features. Choosing equipment that adopts the latest HDMI standard helps future-proof your setup, but the practical benefit depends on your TV and soundbar supporting the same features.

For more about HDMI features that matter for gaming, see soundbar HDMI 2.1 features and HDMI input passthrough latency.

When should you use 4K passthrough?

Choose passthrough when your TV lacks eARC or when you want a single cable to the TV, simplifying a wall-mounted setup. If your TV only has ARC (not eARC), passthrough may be the only way to get lossless audio formats like Dolby TrueHD or DTS-HD Master Audio from a Blu-ray player. Some soundbars also offer extra HDMI inputs that let you connect more devices than your TV has ports.

Another reason to use passthrough is if you have an older TV with limited HDMI ports and you want to avoid a separate switcher. By connecting your sources to the soundbar, you can reduce clutter and potentially improve cable management. However, you must verify that the soundbar supports all the video formats your sources output, such as 4K HDR at high refresh rates.

For older TVs that lack eARC, passthrough can be essential. Read our guide on soundbars for older TVs for more context.

When should you use eARC?

eARC is the preferred choice when your TV and soundbar both support it, because it keeps the video path entirely in the TV. This ensures that video formats are handled by the TV's HDMI inputs, which are typically newer and more capable than soundbar inputs. You also avoid any potential processing delay or signal degradation caused by passing video through the soundbar.

If you use the TV's built-in apps (Netflix, Disney+), eARC is the only way to get high-quality audio from those apps to your soundbar, since the apps run on the TV. Passthrough cannot carry internal audio back to the soundbar; you would need a separate connection like ARC or eARC. Thus, for streaming apps on your TV, eARC is a must.

eARC also simplifies setup because you plug sources into the TV, which is usually easier to reach and has more ports than a soundbar. The soundbar then just needs one HDMI cable to the TV's eARC port.

To see which soundbars support eARC, check our best HDMI ARC soundbars guide, which lists models with both ARC and eARC capabilities.

How to decide what's best for your setup

The decision largely depends on your TV and the devices you own. If your TV has eARC, use it. It's less likely to introduce compatibility issues, and it supports the same audio formats as passthrough, plus it handles all video switching cleanly. If your TV only has ARC, or if you have a source device that requires full-bandwidth audio like a Blu-ray player, passthrough may be your only option.

Consider the number of HDMI inputs you need. If your TV has plenty of ports and you mostly use streaming apps, eARC is simpler. If you have multiple consoles or set-top boxes and your TV is short on ports, a soundbar with multiple HDMI inputs can serve as a hub, but you must confirm the soundbar's video handling matches your sources.

For projectors, passthrough is often necessary because projectors rarely have eARC or even ARC. See our soundbars for projectors article.

Also consider the audio formats you care about. If you want object-based audio like Dolby Atmos from physical media, both eARC and passthrough can carry it, but only if all devices support the same format. Check our Dolby Atmos vs DTS:X comparison for details.

• If your TV has eARC, connect the soundbar to the eARC port and plug sources into the TV.
• If your TV lacks eARC but has ARC, use ARC for basic audio; for lossless audio, consider passthrough.
• If your TV has no HDMI ARC at all, use passthrough if the soundbar has HDMI inputs; otherwise use optical or analog.

What to pick for your use

Questions

Does 4K passthrough reduce video quality?

Not if the soundbar's HDMI ports support the same video formats as your source and TV. However, if the soundbar is older and lacks features like HDR or high refresh rates, it can limit the signal. eARC avoids this by keeping the video path directly from the source to the TV.

Can I use both eARC and passthrough at the same time?

Usually not; you connect the soundbar either as a passthrough hub (source to soundbar, then to TV) or as an eARC endpoint (source to TV, TV to soundbar). Some soundbars allow you to use both, but that's rare and adds complexity.

Do all soundbars support eARC?

No. eARC is a feature that requires the soundbar to have an HDMI port labeled eARC and the TV to support it as well. Check the specs of each soundbar in our buying guides, such as best HDMI ARC soundbars.

Which connection gives better audio quality: passthrough or eARC?

Both can carry the same high-quality audio formats, including Dolby Atmos and DTS:X. The key is whether each device in the chain supports those formats. eARC often works more reliably because it uses a dedicated audio channel and doesn't depend on the soundbar's video processing.

What if my TV has eARC but my soundbar only has standard ARC?

You can still use the soundbar, but it will operate in ARC mode, which may not support lossless formats. You would need to use passthrough if the soundbar has HDMI inputs and your source can connect through it to get better audio.

Does Bluetooth matter for this comparison?

Bluetooth is a wireless audio technology that can stream from a phone or tablet, but it cannot carry 4K video and has lower bandwidth than HDMI. For video connections, you must use HDMI, either passthrough or eARC. Bluetooth is only a supplement for casual listening.