eARC vs ARC: what the difference means for your soundbar, and which port to use

ARC (Audio Return Channel) lets a single HDMI cable carry sound back from the TV to a soundbar or AV receiver, so everything you watch on the TV, from its apps, antenna or other inputs, plays through the speakers. eARC is the same idea with much more room.

ARC vs eARC at a glance

The eARC column is what HDMI’s licensing body lists for eARC; the bandwidth figures are TCL’s. ARC’s limit isn’t a fault: it was designed for the compressed 5.1 of broadcast TV.

What it means for Dolby Atmos

Dolby Atmos isn’t a separate stream; it rides inside two carriers, according to Dolby:

• Dolby Digital Plus, the codec streaming services and broadcasters use. It’s compressed and small enough that many TVs pass it over plain ARC, Atmos included. Whether yours does depends on the TV and soundbar, which is why “Atmos over ARC” works on some setups and not others.
• Dolby TrueHD, the lossless codec on Blu-ray and UHD Blu-ray discs. It’s far too big for ARC. If a disc player or console is plugged into the TV and the sound goes on to the soundbar, you need eARC on both to keep TrueHD Atmos; over ARC the TV sends a compressed fallback.

DTS:X and DTS-HD Master Audio work the same way: lossless, so eARC only.

Which HDMI port is eARC on each TV

Every current TV line in our catalogue has eARC on one HDMI input. Where the spec sheet names the port, it’s below:

On TVs with only some fast inputs, the eARC port can be one of the 4K 120 Hz ones, which matters if you also game. On the Hisense U8, the eARC input is HDMI 3 of three, so the soundbar uses one of the fast inputs. Sony’s BRAVIA lines take 4K 120 Hz on HDMI 3 and 4 only; check the back panel for which one carries eARC before choosing where the console goes. If you run out of fast inputs, connect the console to the TV and let the TV pass the sound to the soundbar, not the other way round; see HDMI 2.1 TVs.

Setting it up

1. Connect the soundbar’s HDMI ARC/eARC port to the TV’s eARC port with one HDMI cable. HDMI.org says a Premium High Speed HDMI Cable with Ethernet works for eARC; an Ultra High Speed HDMI Cable is the one that supports every HDMI 2.1 feature.
2. Turn on HDMI-CEC on the TV, under its brand name: Anynet+ (Samsung), SIMPLINK (LG), BRAVIA Sync (Sony), T-Link (TCL), CEC (Hisense). It lets the TV remote control the soundbar’s volume.
3. Turn on eARC in the TV’s sound settings. Some TVs leave it off by default or call it “eARC mode: Auto”.
4. Set digital audio output to “Auto”, “Passthrough” or “Bitstream”, not “PCM”, so the TV sends Dolby and DTS formats to the soundbar instead of decoding them to stereo.
5. Check the soundbar’s display or app while playing an Atmos title: it should say Dolby Atmos or Dolby TrueHD.

If the sound drops out or the bar won’t switch on with the TV, power everything off, unplug the TV and soundbar for a minute and reconnect. Firmware updates on both often fix eARC handshake problems.

What about optical?

An optical (TOSLINK) cable carries about what ARC does, stereo or compressed 5.1, but no Dolby Digital Plus or Atmos and no CEC control. It’s a fallback for older soundbars without HDMI, not a substitute for eARC.

Do you need eARC?

• TV speakers to a basic 2.1 bar: ARC is plenty. LG’s S40T, for example, is ARC only (soundbars for LG TVs).
• Streaming with an Atmos soundbar: eARC is safer, and since every current TV we list has it, buy a bar with eARC too.
• Blu-ray, UHD Blu-ray or a console with lossless audio through the TV: eARC on both ends.

For the soundbar itself, start with the width: what size soundbar for your TV, then the brand-matched features in soundbars for Samsung TVs.