Most TVs, surround sound receivers, and soundbars have HDMI ports labeled ARC, but few consumers know what ARC is or what it can be used for. ARC stands for audio return channel, and it allows for two way audio communication between devices. This means that if two ARC enabled devices are connected, only one HDMI cable is required to send audio to and from each device. For example, by connecting the ARC HDMI port on a TV to the ARC port on an AV receiver, audio can be sent from the TV back to the AV receiver without using a separate audio out from the TV. This simplifies AV receiver set up and allows for smart TV apps and over the air television to be heard through a high end speaker setup.
ARC also makes soundbar setups cleaner, and more minimal. By using the HDMI ports on the TV to switch between components (Apple TV, cable box, Bluray, etc.), a single HDMI cable can be used to send audio back to the soundbar through ARC. The downside to ARC is that since the surround audio processing is now being done by the TV, results will be mixed. In that event, we suggest using the optical out of the TV to achieve the same goal, albeit with more cables.
HDMI ARC Bottom Line
An HDMI audio return channel can possibly simplify a home theater setup by requiring less cables and connections. It can also make sound bars easier to install and control. It is especially useful for sending audio from a TV's over the air broadcast tuner (major networks like NBC ABC CBS etc.) to a higher end speaker setup. This allows cable and satellite TV users to have an emergency backup of major networks (useful during bad weather, or outages), without sacrificing the sound quality of their high end AV receiver. Remember, for ARC to work properly both sides of the HDMI connection need to be labeled HDMI ARC.