What is Audio Return Channel (ARC)?
With the rise of smart TVs and streaming platforms, more users want to watch content from Youku, iQiyi, Bilibili, and other services directly on their TVs, while sending the audio to an AV receiver or external sound system for a better audio-visual experience.
ARC (Audio Return Channel) and eARC (Enhanced Audio Return Channel) were developed to meet this need. The principle is simple: through the HDMI port on the TV, the audio that the TV receives or plays is sent back to the AV receiver or sound system, without needing additional optical or coaxial audio cables. This way, a single HDMI cable can transmit video while also returning audio, simplifying setup and keeping your home theater neat and efficient.
The application of ARC and eARC varies slightly depending on the use case:
TV connected to set-top box → HDMI output to TV → audio returned via ARC to AV receiver → receiver powers the speakers. This setup is common for everyday cable or set-top box viewing, easily delivering multi-channel surround sound.
TV directly streaming online content → audio transmitted via eARC to home theater → receiver powers the speakers in lossless surround sound. When watching high-quality streaming from Youku, iQiyi, or Bilibili, eARC ensures lossless audio transmission, providing a cinema-level immersive experience.
In short, the audio return feature acts like an "invisible channel" between your TV and sound system, simplifying connections while enhancing audio quality, making it a vital technology for modern home theaters.
What’s the difference between HDMI ARC and eARC?
While ARC solves the basic audio return issue, with the rise of Dolby Atmos, DTS:X, and other high-end audio formats, traditional ARC has become limited. HDMI 2.1 introduced the Enhanced Audio Return Channel—eARC.
Bandwidth & Audio Quality
ARC: Maximum bandwidth around 1Mbps, supporting only compressed audio formats like Dolby Digital and DTS 5.1. Lossless audio is not supported.
eARC: Maximum bandwidth up to 37Mbps, capable of transmitting lossless audio (Dolby TrueHD, DTS-HD Master Audio) and supporting immersive formats like Dolby Atmos and DTS:X.
HDMI Version
ARC: Based on HDMI 1.4, supported by most TVs.
eARC: Based on HDMI 2.1, requires support from the TV, receiver/sound system, and HDMI cable.
Compatibility & Latency
ARC: May have compatibility issues across brands, potentially causing audio delay.
eARC: Adds automatic sync, lower latency, and stronger compatibility.
Use Cases
ARC: Suitable for regular users, connecting to a Soundbar or small speaker system.
eARC: Ideal for audiophiles seeking high-quality home theater sound, especially Dolby Atmos setups.
ARC vs eARC Comparison Table
| Feature | ARC | eARC |
| HDMI Version | HDMI 1.4+ | HDMI 2.1 |
| Max Bandwidth | ~1Mbps (compressed audio only) | Up to 37Mbps (supports lossless audio) |
| Supported Audio Formats | Stereo PCM, Dolby Digital, DTS (compressed 5.1 channels) | Dolby TrueHD, DTS-HD, Dolby Atmos, DTS:X (lossless surround/immersive audio) |
| Supports Lossless Audio? | ❌ No | ✅ Yes |
| Supports Immersive Audio (Atmos / DTS:X)? | ❌ Only compressed versions (requires re-encoding to DD+, limited support on some devices) | ✅ Pass-through in original lossless format (e.g., TrueHD with Atmos) |
| Audio Quality | Basic surround, suitable for regular TV shows | High-fidelity, cinema-level audio, ideal for Blu-ray or high-quality streaming |
| Required HDMI Cable | Standard HDMI cable | HDMI 2.1 cable |
| Device Compatibility | Any HDMI port supporting ARC | Both TV and audio device must explicitly support eARC |
| Use Case | Regular TV + Soundbar | High-end receiver + 7.1 / Dolby Atmos home theater |
ARC and eARC Use Cases
Regular Users: TV + Soundbar
Equipment Setup:
A smart TV supporting ARC
An HDMI cable supporting ARC
A soundbar with ARC input
Connection:
Connect the TV's HDMI (ARC) port to the soundbar's HDMI (ARC) port
Enable the “Audio Return (ARC)” function in TV settings
Experience:
When playing content from Netflix, Disney+, or a set-top box, the audio is sent directly to the soundbar, providing clearer, more immersive 5.1-channel sound. For most households, this is sufficient.
Audiophiles: TV + Receiver + Multi-Channel Speakers (Home Theater)
Equipment Setup:
A 4K/8K smart TV supporting eARC (HDMI 2.1)
An AV receiver supporting eARC (home theater hub)
A 5.1.2 / 7.1.4 surround speaker system (Dolby Atmos or DTS:X)
An Ultra High-Speed HDMI 2.1 certified cable
Connection:
TV HDMI (eARC) → Receiver HDMI (eARC)
Receiver HDMI Out → speakers/subwoofer channels
Select “Bitstream Passthrough” in TV audio settings
Experience:
When watching Blu-ray or AppleTV+ content supporting lossless audio, the sound is returned in Dolby TrueHD or DTS-HD Master Audio, ensuring lossless transmission. Combined with Dolby Atmos, audio can immerse you from above, delivering a theater-like experience.
Special Case: TV Without Optical Port + External Audio
Typical Issue:
Some new TVs no longer include optical outputs, relying solely on HDMI ARC/eARC. If the sound system doesn’t support eARC, audio quality may drop or output may fail.
Solution:
Use an HDMI Audio Extractor:
Connect TV HDMI (ARC/eARC) to the extractor
Extractor outputs HDMI to the receiver and optical/coaxial audio to older speakers
Experience:
Even older audio devices can still be used without affecting viewing quality. The extractor also facilitates multiple device switching, handling complex home setups.
High-End Users: Game Console + TV + Receiver
Equipment Setup:
A TV supporting HDMI 2.1 (120Hz/VRR)
Next-gen gaming console (PlayStation 5 / Xbox Series X)
An eARC-compatible receiver and surround system
Connection:
Console HDMI → TV HDMI 2.1 input
TV HDMI (eARC) → Receiver HDMI (eARC)
Experience:
Gamers enjoy smooth 4K 120Hz visuals while eARC returns Dolby Atmos game audio, creating an immersive sound field that enhances gameplay.
Audio Return Channel (ARC/eARC) makes connecting TVs and audio devices simpler and more efficient. ARC meets everyday viewing needs, while eARC—with higher bandwidth and lossless support—is key for high-quality home theaters. For regular users, ARC delivers clear surround sound; for enthusiasts seeking ultimate experiences, eARC is essential. Understanding and properly using both features allows you to unlock your devices’ full potential and enjoy a truly immersive home theater experience.