Most new TVs now carry the apps, the tuner and the game console inputs, so the sound has to travel back out of the TV to a soundbar or receiver. That return trip is what the HDMI ARC vs eARC question is about. The two features share a port and a cable, but they carry very different audio. This guide explains where each came from, what each can carry, how CEC fits in and how to fault-find a return channel that will not play.
What is the difference between HDMI ARC and eARC?
Both send audio from the TV back to a soundbar or receiver over the HDMI cable already connecting them. ARC, from the HDMI 1.4 generation, carries stereo and compressed 5.1 surround. eARC, added in HDMI 2.1, carries uncompressed 5.1 and 7.1, lossless and object-based formats. Both ends must support eARC to use it.
What ARC does and where it came from
Audio Return Channel lets a TV send sound “upstream” to an audio device over the same HDMI cable that brings video down to it. Before ARC, a TV that played its own apps or tuner needed a separate optical or analog cable back to the receiver. The HDMI Licensing Administrator lists ARC among the features of the HDMI 1.4b specification; the feature first arrived with HDMI 1.4 in 2009.
ARC carries roughly what an optical connection carries: two-channel PCM and compressed 5.1 surround bitstreams of the kind used by broadcast TV and many streaming services. It does not carry uncompressed multichannel audio or the lossless formats used on discs, although some devices pass compressed object-based streams over it. For a TV feeding a modest soundbar, that is often enough.
ARC usually lives on just one of the TV’s HDMI inputs, marked ARC on the panel. The soundbar or receiver must plug into that input, and into the HDMI output marked ARC on the audio device.
What is HDMI eARC?
Enhanced Audio Return Channel is the second generation of the feature. The HDMI Forum, which writes the specification, introduced it as part of HDMI 2.1, announced on November 28, 2017, describing it as a feature that simplifies connectivity and supports the most advanced audio formats. It remains part of the current specification.
The HDMI Licensing Administrator’s Enhanced Audio Return Channel page states that eARC supports high-bitrate audio up to 192 kHz and 24-bit, uncompressed 5.1 and 7.1, and 32-channel uncompressed audio, including lossless and object-based surround formats. The same page says it makes it easier to discover connected components and optimize audio.
One point trips up buyers: eARC is a feature, not a port speed. A TV can list HDMI 2.1 inputs without offering eARC on any of them, so check the specification sheet for the eARC label itself.
HDMI ARC vs eARC: audio formats compared
The table sets ARC and eARC beside optical, the connection both were meant to replace. It describes capability; what plays in practice also depends on the source, the TV’s audio settings and the decoder in the soundbar or receiver.
| Capability | HDMI ARC | HDMI eARC | Optical (S/PDIF) |
|---|---|---|---|
| Introduced with | HDMI 1.4 generation (2009) | HDMI 2.1 (2017) | Predates HDMI |
| Two-channel PCM | Yes | Yes, up to 192 kHz, 24-bit | Yes |
| Compressed 5.1 surround | Yes | Yes | Yes |
| Uncompressed 5.1 and 7.1 | No | Yes | No |
| Lossless surround formats | No | Yes | No |
| Remote control over the link | Through CEC | Through CEC | No |
Most eARC soundbars and receivers fall back to ARC when connected to an ARC-only TV, and the reverse, but the link then runs at ARC capability. Check both manuals before promising a client lossless sound.
CEC: the control half of the connection
Consumer Electronics Control is the HDMI feature that lets one remote run several devices: the TV remote changes the soundbar volume, and switching the TV off powers the audio device down. TV makers give CEC their own menu names, so look for it under external device or HDMI control settings.
ARC depends on CEC. The TV and the audio device use CEC messages to agree that audio should flow back, so with CEC switched off, ARC often will not start at all. eARC adds its own discovery between the two devices, but CEC still handles power and volume in most installs, so leave it on.
CEC can also cause odd behavior: a streaming box that wakes the whole system, or inputs that jump when a device powers on. Turn off CEC on the source that misbehaves rather than on the TV, so the TV and audio device keep their link.
Troubleshooting ARC and eARC
Most return-channel faults are settings, not hardware. Work through the chain in this order before replacing anything:
- Ports: confirm the cable sits in the TV input marked ARC or eARC and the audio device’s ARC output.
- CEC: switch HDMI control on in the TV and the audio device.
- eARC mode: many TVs ship with eARC off or set to auto; enable it in the sound menu.
- Audio output: set the TV’s digital output to bitstream, passthrough or auto. A TV set to PCM converts surround to stereo before it leaves.
- Power sequence: switch everything off, power the audio device first, then the TV, and let them handshake.
- Firmware: update the TV and the audio device, then test again.
- Cable: only now try a known-good, certified cable, connected directly with no switch or coupler.
If sound arrives but runs behind the picture, look for a lip sync or audio delay setting on the audio device. Record the working settings on the job sheet; a TV update can reset them.
Cables and ports for an ARC soundbar connection
For an ARC soundbar connection, any HDMI cable that already passes video between the TV and the bar will usually work. The return path uses the HDMI Ethernet and utility pins, so a cable of the High Speed with Ethernet class or better is the safe choice for eARC, and an Ultra High Speed cable covers every HDMI 2.1 feature. Avoid adapters and couplers in the return path where you can.
Length limits apply to the video the same cable carries; our guide to HDMI cable length limits and long runs covers that. Short patch leads, such as the PHI45-7406-SP 6 foot HDMI cable with Ethernet, are listed in the Bursma audio video cables category.
When to skip the return channel
ARC and eARC exist because the TV has become the switcher. On a system with a receiver, another layout often works better: connect every source to the receiver and send one video output to the display. The receiver then decodes each source’s audio directly, and the return channel only carries the TV’s own apps and tuner.
That layout suits racks where sources live together; see how to choose an AV equipment rack. If the client is still choosing between a bar and a component system, our comparison of soundbar vs AV receiver systems covers the trade-offs. Bars are listed in the sound bars category and receivers in the AV receivers category, all within the Bursma audio video division.
For pricing and ordering, talk to your sales representative through the Bursma contact page. Installers without an account can apply for a Bursma dealer account.
Frequently asked questions
Can I plug an ARC soundbar into an eARC port?
Usually, yes. Most eARC TVs fall back to ARC with an ARC-only soundbar, and the link then carries ARC formats. Check the TV manual to confirm the fallback.
Do I need a new HDMI cable for eARC?
Not always. A good High Speed HDMI cable with Ethernet often works. An Ultra High Speed HDMI cable supports every HDMI 2.1 feature and is the safe choice for new installs or a link that drops out.
Is eARC better than optical?
For surround, yes. Optical carries stereo and compressed 5.1 only, while eARC adds uncompressed multichannel and lossless formats, plus CEC control over the same cable.
Why does my TV send only stereo over ARC?
The TV’s digital audio output is often set to PCM, which mixes surround down to two channels. Set it to bitstream, passthrough or auto, and check that the source itself sends surround.