Key takeaways
- ARC's roughly 1 Mbps of bandwidth is enough for every streaming Atmos mix, since those arrive as Dolby Digital Plus rather than a lossless track.
- eARC's roughly 37 Mbps only matters once lossless Dolby TrueHD or DTS-HD Master Audio is involved, which in practice means a 4K Blu-ray disc rather than a streaming app.
- eARC's dedicated data channel does not depend on HDMI-CEC to negotiate the connection, which is why it drops out far less often after a TV or soundbar wakes from standby.
- Both the TV and the soundbar or receiver need to support eARC specifically. A cable alone cannot add the capability to a device that lacks it.
- A household that watches almost everything through streaming apps loses nothing by staying on plain ARC, while a household with a 4K Blu-ray shelf should confirm both ends support eARC.
ARC decodes compressed Dolby and DTS formats over roughly 1 Mbps of bandwidth. eARC adds enough headroom, about 37 Mbps, to carry lossless Dolby TrueHD and DTS-HD Master Audio untouched, and that gap is the entire difference between the two names on the box.
Everything else people notice, dropouts after standby, a missing Atmos badge on a Blu-ray, a soundbar that only ever shows Dolby Digital, traces back to that single number. Four comparisons make the practical difference clear: bandwidth, format support, cable and port needs, and how reliably each one actually holds a connection.
Bandwidth: the number underneath both labels
ARC’s roughly 1 Mbps ceiling was set for a world of compressed 5.1 audio: Dolby Digital, DTS, and later Dolby Digital Plus, which is how Netflix, Disney Plus, and most streaming Atmos actually arrives. That figure comfortably covers a compressed multichannel stream with room to spare.
eARC’s roughly 37 Mbps was set for a different job: carrying uncompressed 7.1 channel PCM at up to 24-bit and 192kHz, or the lossless bitstreams that a 4K Blu-ray disc actually stores. Those figures come from the HDMI Forum’s own eARC documentation, and they explain every other difference in this article.
The extra bandwidth also raises the practical channel ceiling. eARC’s specification allows for up to 32 audio channels of metadata, which matters for object based formats like Atmos where the mix carries individual moving sounds rather than a fixed set of speaker feeds. ARC was never built with that many objects in mind.
| Feature | ARC | eARC |
|---|---|---|
| Approx bandwidth | 1 Mbps | 37 Mbps |
| Typical channel count | Up to 5.1 compressed | Up to 7.1 or more, compressed or uncompressed |
| Depends on HDMI-CEC | Yes | No, separate data channel |
Which audio formats each one actually decodes
ARC carries Dolby Digital, DTS, and Dolby Digital Plus, which covers every mainstream streaming Atmos mix without issue. What it cannot carry is a lossless track: Dolby TrueHD or DTS-HD Master Audio, the formats a 4K Blu-ray disc actually stores its Atmos or DTS:X mix in.
eARC carries everything ARC does, plus those two lossless formats. A Denon AVR-X1800H or a soundbar with an eARC labelled port will show the difference immediately: the same movie streamed shows Dolby Digital Plus, while the same movie played from disc through eARC shows Dolby TrueHD. DTS:X follows the same pattern, streaming in a compressed form and arriving on disc as DTS-HD Master Audio, which only eARC has the bandwidth to carry whole.
For the full technical background on why the object metadata itself depends on this, see HDMI eARC explained from the connection up.
A customer once brought back a soundbar convinced it had failed because a 4K Blu-ray of a recent release showed Dolby Digital rather than Atmos on the display. The soundbar was fine. The TV’s only audio output was ARC, which will never show a lossless format regardless of how the disc itself is encoded.
Cable and port requirements in practice
ARC works over almost any HDMI cable rated to the old High Speed standard, since 1 Mbps of audio is a trivial load. It piggybacks on the same pin used for HDMI-CEC signaling, which is part of why it can be temperamental.
eARC needs both the TV and the soundbar or receiver to explicitly support the standard, a labelled eARC port on each end rather than a plain ARC port. Buying an eARC capable soundbar and plugging it into a TV that only offers ARC gains nothing, since the connection always falls back to the weaker end of the pair.
The cable itself rarely needs replacing for eARC’s audio bandwidth alone, though long runs past about 5 to 10 metres benefit from an Ultra High Speed certified cable regardless. The specific cases where a new cable is worth buying are covered in whether you need a special cable for eARC.
Cable certification labels add to the confusion. A cable printed Premium High Speed, a rating from around 2017, carries eARC audio without trouble even though the name says nothing about eARC at all. The label to look for on a new purchase is the certification badge, not the marketing copy on the packaging.
Why eARC’s handshake tends to be more reliable
ARC’s audio return signal shares a data line with HDMI-CEC, the same system that lets one remote control multiple devices. When a games console, a streaming stick, and a TV are all fighting for that CEC line at once, ARC’s audio connection is what tends to break first, often silently after standby.
eARC uses its own dedicated data channel, separate from CEC entirely. That is the real reason eARC setups drop out less often, not some vague improvement in build quality between generations of TV.
A living room I rewired last year had Atmos vanish every single morning until the TV had been power cycled, purely because three CEC devices were negotiating the same ARC line overnight. Moving the soundbar to the TV’s eARC port solved it permanently, with nothing else in the chain changed.
CEC itself goes by a different marketing name on every brand, Anynet Plus on Samsung, SimpLink on LG, Bravia Sync on Sony, which is part of why the shared cause behind ARC dropouts rarely gets diagnosed correctly. The underlying signaling is the same regardless of what the settings menu calls it.
Turning CEC off entirely stops the congestion but also disables the one remote convenience most people bought a soundbar expecting. The better fix, where the hardware allows it, is moving to eARC rather than switching CEC off and losing that convenience along with the fault.
Matching the port to your actual TV and soundbar
A TV from around 2016 to 2019 paired with a soundbar of similar age, watching mostly Netflix, Disney Plus, and cable television, loses nothing by staying on ARC. There is no lossless disc content in that routine for the extra bandwidth to carry.
A household with a 4K Blu-ray player and a soundbar or receiver bought since roughly 2020, like a Sonos Arc Ultra or a Denon AVR-X1800H, should confirm both the TV and the bar list eARC support specifically, not just ARC, since that is where a disc’s full lossless track actually lives.
If Atmos or surround sound keeps dropping after the TV sleeps overnight on an older ARC connection, and both devices support eARC, switching to that port usually clears it, since eARC does not share the same CEC signaling that caused the problem in the first place. Where ARC and eARC symptoms overlap with a broader handshake fault, clearing an HDMI handshake problem covers the wider set of fixes.
Buying a new soundbar for eARC alone rarely makes sense if the household’s actual viewing is streaming heavy. Save that upgrade for the point where a 4K Blu-ray collection, not a spec sheet, is asking for it.
- Mostly streaming apps, older TV and soundbar: ARC is enough
- Own a 4K Blu-ray player, newer soundbar or receiver: confirm eARC on both ends
- Atmos drops out after standby on ARC: try the eARC port if both devices support it
- Buying new gear specifically for eARC: check the household’s actual disc collection first
Not every source in the room touches this HDMI conversation at all. A turntable feeding a soundbar through its aux or phono input skips ARC and eARC entirely, since the signal never passes through the TV in the first place, a wiring path covered in connecting a turntable straight into a soundbar.
A dedicated home theater room built around a 4K Blu-ray shelf and a receiver like the Denon AVR-X1800H is exactly where eARC earns its keep. A spare bedroom TV running Apple TV and Spotify most evenings has nothing to gain from it at all.
Questions readers ask about this
Not for streaming. Dolby Digital Plus, the format behind streaming Atmos on Netflix and similar apps, fits well within ARC's roughly 1 Mbps of bandwidth. The gap only shows up with a 4K Blu-ray disc's lossless Dolby TrueHD or DTS-HD Master Audio track, which ARC cannot carry at all.
No. eARC needs a dedicated data channel built into the HDMI hardware itself, not just different firmware. A TV without that physical support will never gain eARC no matter how many software updates it receives, so the only fix is a newer TV.
Often the same physical port, but not always. Many TVs share one port for both, labelled ARC or eARC in the settings menu rather than on the case itself. Check the specification sheet or settings menu directly rather than assuming from the port's position.
This is a common ARC symptom. ARC's audio signal shares a data line with HDMI-CEC, and when several CEC devices renegotiate control after standby, the ARC audio link is often the first thing to drop. Moving to an eARC connection, which does not depend on CEC, usually stops it recurring.
Mostly, yes. eARC's extra bandwidth exists for lossless Dolby TrueHD and DTS-HD Master Audio, formats used almost exclusively on physical 4K Blu-ray discs. A household watching only streaming services gains little from eARC beyond the more reliable handshake it happens to provide.
About the author
Rahul Gupta
Rahul Gupta has spent nearly a decade quietly wiring living rooms, testing soundbars in every awkward apartment layout imaginable, and untangling the kind of HDMI handshake problems that make people give up on Atmos altogether. He writes here about what actually works when you get the boxes home—not what the spec sheet promises. If a piece of gear on this site earns a recommendation, it earned it in a real room with real furniture, not a lab.
