QUOTE(nickywan123 @ Aug 20 2018, 06:21 PM)
What is ARC in plain english? My knowledge on these is not good.
It stands for Audio Return Channel.
A picture to illustrate what it does:
Most people would buy a display and a soundbar. Unfortunately, a soundbar usually only have 1 or 2 HDMI inputs (some has more but they are rare). The idea is that you can connect all your sources to your TV and then use ONE HDMI cable to connect to your soundbar for audio, in theory this makes it clean and simple.
The problem? ARC is a bitch because it will have PMS more than once a month (like everyday if you aren't lucky) and the audio portion doesn't work or the video gets cut out because the HDCP handshake fails to initialize or something else entirely obscure.
This is why many people would use a separate optical cable to connect to their soundbar. One extra cable, no biggie right? Well... it is if you care about lossless audio formats like DTS-HD, Dolby TrueHD, the latest Atmos fad where soundbars are pushing like its gospel or something. Optical only has bandwidth to carry lossless PCM 2.0 or lossy Dolby Digital 5.1 and DTS. So you lose out on sound quality (another topic whether you can even hear the difference with soundbars).
If you buy like those fancy Atmos soundbar - you're basically screwed if ARC decides to have a PMS today or you don't have enough HDMI ports (and you have to keep switching them out which greatly increases the risk of damaging a HDMI port because they are very flimsy).