HDMI ARC vs eARC: What's the difference?
One HDMI cable can carry the TV's sound back to a soundbar, so you do not need a separate optical cable and one remote handles the volume. That is HDMI ARC. eARC is the newer, faster version of the same idea. The difference only matters for high-end sound, and here is exactly when.
What HDMI ARC does
ARC stands for Audio Return Channel. Normally an HDMI cable sends picture and sound one way, from a device into the TV. ARC adds a return path, so the same cable can also send the TV's own audio back out to a soundbar or receiver. That covers the sound from the TV's built-in apps, the aerial, or anything plugged into another input. Before ARC you needed a separate optical cable for this; with ARC, a single HDMI cable does both directions, and the TV remote can control the soundbar's volume. It has been on televisions for years, so almost any recent TV and soundbar have it.
What eARC adds
eARC, the enhanced Audio Return Channel, arrived with HDMI 2.1 and does one thing that matters: It carries far more data. Plain ARC has limited bandwidth, so it is held to compressed surround formats such as Dolby Digital and DTS, and from some apps it passes only stereo. eARC has the headroom for the full, high quality formats: Uncompressed multichannel audio, and the object-based formats Dolby Atmos and DTS:X in their best form. If you care about Dolby Atmos from a proper soundbar or an AV receiver, eARC is what delivers it intact rather than squeezed down.
The port and the cable
Two practical points decide whether it works. First, the socket: On both the TV and the sound device, only the HDMI port labelled ARC or eARC carries audio back, so the cable has to sit in that specific port at each end, not just any HDMI socket. Second, the cable: Plain ARC is happy with an ordinary High Speed HDMI cable, but eARC moves much more data, so use a High Speed cable with Ethernet, or an Ultra High Speed HDMI cable to be safe. Our guide on what HDMI cable you need covers which is which.
The handshake that turns it on
ARC and eARC lean on HDMI-CEC, the feature that lets the TV and the soundbar talk to each other, so the TV remote can raise the volume and the soundbar can wake with the TV. CEC has to be switched on at both ends, and every brand renames it: Anynet+ on Samsung, Simplink on LG, Bravia Sync on Sony, and so on down the list. When ARC sound cuts out, this handshake is the usual cause, and our no sound on your TV guide walks through resetting it.
Do you actually need eARC?
Only if the rest of your setup can use it. eARC earns its place when you have a soundbar or receiver that decodes Dolby Atmos or DTS:X, and content in those formats to feed it. If your soundbar is a stereo or basic model, or you mostly watch ordinary broadcast and stereo apps, plain ARC already carries everything you will hear, and eARC buys you nothing. Do not pick a TV on the eARC badge alone: Choose it when the sound system in front of it is good enough to notice the difference.
Questions people ask
Is eARC better than ARC?
For high-end sound, yes, because eARC has far more bandwidth. It can carry uncompressed multichannel audio and full Dolby Atmos and DTS:X, while plain ARC is held to compressed formats and sometimes only stereo. For a stereo or basic soundbar the two sound the same, and ARC is enough.
Can I use eARC with an old HDMI cable?
Plain ARC works with an ordinary High Speed HDMI cable. eARC moves much more data, so use a High Speed cable with Ethernet or an Ultra High Speed HDMI cable, plugged into the port marked eARC at both ends.
Why has my ARC sound stopped working?
Almost always the HDMI-CEC handshake. Make sure CEC is switched on in the TV menu, which brands call Anynet+, Simplink or Bravia Sync, and that the cable is in the ARC or eARC port. Power both units off, unplug for a minute, then switch the TV on first and the soundbar second.
If you are weighing up a soundbar or an AV receiver, the sound format is half the decision: Our guide to Dolby Atmos explains what the height formats need to actually work. And to check that sound is reaching both channels of your soundbar, run the TV Speaker Test.