HDMI ARC, eARC and CEC

In short: ARC and eARC send sound from the TV back over the same HDMI cable to a soundbar or receiver. CEC lets devices control each other.

In more detail: Without ARC you would need a second (optical) cable for the sound of TV apps. With ARC one cable between TV and soundbar is enough.

In Depth

• ARC (audio return channel): Return channel for sound, limited to compressed formats such as Dolby Digital or DTS and 2-channel PCM.
• eARC (enhanced): More bandwidth: uncompressed multichannel sound, Dolby TrueHD, DTS-HD, Dolby Atmos in full quality. This needs HDMI 2.1 ports marked eARC and preferably certified Ultra High Speed cables.
• CEC (“consumer electronics control”): One device switches others on, the TV remote controls soundbar volume. Brand names: Anynet+, Bravia Sync, Simplink.
• Typical problems: Wrong HDMI port (only one carries ARC/eARC), sound dropouts, CEC switching on unwanted. Solution: check the port, set the TV’s sound output to “passthrough”, turn off CEC individually.
• Related: Optical (Toslink) as an emergency solution, compressed only.

See also: HDMI