If you do not use a reverse audio channel (Audio Return Channel or ARC), then we can assume that you are not using the capabilities of your AV-system to 100%. We all know that HDMI cable transfers sound from players, game consoles and TV boxes to a TV, but some people don’t even realize that the cable can be used to capture audio from the TV itself. This is possible thanks to ARC technology, and no additional wires are needed. This feature is found in more expensive receiver models that are aimed at creating surround sound configurations. A striking example of the use of this function can be one of the best AV receiver under 1000 from those reviewed on website.
How ARC works
First of all, you need to understand the essence of the work of ARC: this technology allows you to send sound from the TV to the connected soundbar, set-top box or receiver. Thus, ARC creates a two-way communication channel between the TV and another device. This is convenient, since the need to use optical and other cables in the system, which many get on their nerves, disappears. In other words, ARC is the killer of wires.
What is the difference between ARC and eARC
The eARC protocol is an extended version of the standard reverse audio channel. The essence of eARC is high bandwidth and, accordingly, support for advanced high-quality audio formats. In short, eARC is ideal for surround sound. The eARC will provide support for DTS Master, DTS: X, Dolby TrueHD, and Dolby Atmos. And if we talk about quality, then eARC will transmit data simultaneously for eight channels at 192 kHz / 24 bit (Hi-Res). If you look at the issue from the point of view of transmission speed, everything is very cool here: current HDMI cables send and receive audio at a speed of 1 Mbit/s, and eARC will increase this figure to 38 Mbit/s.
Solving the 5.1 sound problem
No matter how good the ARC is, there is one big problem: 5.1. Technically, TVs cannot transmit 5.1 audio through HDMI. In other words, if you watch a movie on a Blu-ray player with 5.1 Dolby Digital or DTS, and it is connected directly to your TV (option 1 above), then the receiver can only receive 2.0 sound. And eARC solves this problem, thanks to the ability to transmit uncompressed audio.