HDMI ARC vs eARC
ARC carries compressed 5.1 at about 1 Mbps; eARC carries roughly 37 Mbps, enough for uncompressed 7.1 and lossless Atmos.
Both send sound from your television back down the HDMI cable to a soundbar or receiver, so you need one cable instead of two. The difference is how much sound they can carry. ARC handles ordinary 5.1 surround, compressed. eARC carries around thirty times more data, which is enough for uncompressed 7.1 and the full lossless versions of Dolby Atmos and DTS:X. If you have a soundbar that advertises Atmos, eARC is what lets it do its best work.
- Verdict:
- eARC if you want lossless Atmos, ARC is fine for everything else
Side by side
| Specification | ARC | eARC |
|---|---|---|
| Bandwidth | About 1 Mbps | About 37 Mbps |
| Dolby Digital / DTS | Yes | Yes |
| Dolby TrueHD / DTS-HD | No | Yes |
| Dolby Atmos | Compressed only | Lossless |
| Uncompressed channels | 2.0 | Up to 7.1 |
| Lip-sync correction | Optional | Required |
| Needs | Any HDMI cable | High Speed with Ethernet or better |
Both ends have to support it
eARC works only when the television and the soundbar or receiver both have it, on the specific ports marked for it. One eARC device paired with one ARC device falls back to ARC, usually without telling you.
Atmos over ARC is not the same Atmos
ARC can pass Atmos inside a compressed Dolby Digital Plus stream, so a soundbar may legitimately say it is receiving Atmos. eARC passes the lossless TrueHD version. Both are Atmos; only one is what the disc or the stream actually holds.
Check the port, not the TV
Televisions rarely put ARC or eARC on every HDMI socket. It is normally one, labelled in small print on the back panel. Plugging the soundbar into the wrong one is the most common reason this feature appears not to work.
Check before you swap. Batteries with similar dimensions are not always interchangeable. Always verify voltage, chemistry and the requirements printed in your device manual before fitting a replacement.