We all know that HDMI cable transfers sound from players, game consoles, and set-top boxes to a TV, but some people don’t even realize that you can capture audio from the TV with the same cable. This is possible thanks to ARC technology, and no additional wires are needed. 
How does ARC work?
The ARC data transfer protocol is supported by most modern AV devices. 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 disappear.
How to find out if the TV supports ARC?
The rear panel should have an “HDMI ARC” connector. Most new and even outdated models have such an entrance.
All settings occur in automatic mode: you just need to connect through the correct connector, and the signal will be broadcast to any soundbar. With the release of HDMI version 1.3, there is no longer a synchronization problem even in budget av receivers under 300$: the function of eliminating the discrepancy between video and sound ensures that everything will be transmitted without delay. Besides, this option compensates for any lags that occur during the processing of the audio signal by processors.
What is 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 true possibilities of eARC are revealed when working with HDMI 2.1. The latest version of HDMI (2.1) allows you to easily transfer UHD video with a high refresh rate, including 8K/60 Hz. Blu-ray disc players, game consoles and other devices will now be able to display a picture in 4K at 120 frames per second. As for bandwidth, it is more than enough – 48 Gb/s.
The essence of eARC is high bandwidth and, accordingly, support for advanced high-quality audio formats. Based on this, eARC is ideal for surround sound. It is important for the end-user that eARC will provide support for DTS Master, DTS: X, Dolby TrueHD, and Dolby Atmos. Home theater owners should appreciate the new features.
If we talk about 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.
And if we talk about quality, eARC allows you to broadcast data simultaneously for eight channels at 192 kHz/24 bit (Hi-Res).
