If you’ve ever fired up Netflix or HBO Max and seen the little “Dolby Atmos” badge, you could be forgiven for thinking that your TV and soundbar will automatically reproduce sound in glorious spatial audio. I thought the same, when in fact, my Atmos-ready soundbar wasn’t delivering Dolby Atmos at all. The problem didn’t lie with my TV, my soundbar, or the apps I was streaming.
The issue was that I wasn’t using the correct HDMI cable.
It wasn’t about quality, as I understand the pitfalls of using substandard connectors, but about bandwidth. In short, Atmos needs more bandwidth than old-school HDMI ARC can handle, and what I needed was an eARC (Enhanced Audio Return Channel) cable. This is the mystery component that unlocks lossless Dolby Atmos and DTS:X on your TV.
What eARC actually does (and why ARC isn’t enough)
How the enhanced audio return channel unlocks full-resolution sound
ARC (Audio Return Channel) has been around for years and acts as a conduit that sends audio to a soundbar or AV receiver via HDMI. This is good enough to deliver Dolby Digital Plus—a compressed format that is around 20 years old—but falls short of the latest high-bandwidth, lossless formats like Dolby Atmos. Streaming platforms can circumvent this by compressing Atmos to squeeze it through ARC, but this will bottleneck the signal, resulting in inferior sound quality.
eARC solves the problem by massively increasing the bandwidth. It’s like widening a congested road to a four-lane highway, allowing more traffic to flow freely, although in this case, it’s transporting uncompressed Dolby TrueHD Atmos or DTS:X to your audio system. The only catch is that you need the right HDMI cable to carry the signal.
The cable I switched to (and the most critical factor)
Choose a certified Ultra High Speed HDMI cable that fully supports eARC
I quickly realized that not all cables are created equal. For eARC to work reliably, you’ll need an Ultra High-Speed HDMI cable that is rated to HDMI 2.1 specifications. Even older cables that handle 4K video just fine can be throttled by the full-bandwidth audio that eARC sends. I found a branded, Certified Ultra High Speed HDMI cable on Amazon for less than $20 (ensuring it carried the official HDMI hologram logo), which supported bandwidths of 48 Gbps. There are fancier options out there with gold connectors and premium cables, but as long as it specifies HDMI 2.1, you’re good to go.
As soon as I swapped cables, the difference was night and day. My TV instantly recognized my soundbar as an eARC device, and the difference in audio was palpable. With Dolby TrueHD Atmos, I experienced real surround sound, enhanced detail in overhead effects, clearer dialogue, and deeper bass. All I had to ensure was that once I switched cables, I accessed my TV’s audio settings and enabled eARC.
Use the HDMI port labeled ARC or eARC on your TV. Using the wrong port will leave you wondering why your Dolby Atmos still sounds flat.
The payoff: why eARC is worth the effort
Experience richer, lossless audio that transforms movies, games, and music
Swapping out an HDMI cable isn’t the most exciting upgrade to your audiovisual setup, but with the right gear, the difference is instantly noticeable. Once eARC was activated, Dolby Atmos immediately sprang into life and sounded just like it’s supposed to—immersive, powerful, and precise. I ultimately gave it the litmus test: Top Gun: Maverick on Apple TV+. Even more than the original 1986 movie, this film features incredible spatial audio mixing with overhead effects that sound as if they’re moving across your ceiling and crisp dialogue that can be heard over the roar of afterburners.
Another benefit is that eARC is future-proof. While HDMI 2.2 was released in June 2025 and can handle twice the bandwidth of HDMI 2.1, the latter will still be able to support whatever next-generation audio formats and bitrates emerge. If you are planning to upgrade your home theater, gaming setup, or even just your living room soundbar, an eARC-compatible cable is a small investment that makes a big difference.
Revolutionize your audiovisual setup for the price of a takeout
As it turned out, spending just $20 on an HDMI cable that could handle ultra-high-speed bandwidths was the final piece of the puzzle. Looking back, it was laughable that I had high-end gear operating well below its potential, all because I insisted on reusing some old cables that looked like they’d do the trick. Now, whenever I see the Dolby logo appear, I can be confident that I am receiving the best quality sound, not a compressed imitation.
Don’t underestimate the power of the HDMI cable. Check whether your soundbar and TV support eARC, grab a certified Ultra High-Speed HDMI cable, activate eARC in your TV’s settings, and let your audiovisual setup shine. Your ears will thank you.
