He said this is the one that fixes the single biggest complaint people have about their TV: "The sound is terrible."
Most people either use their TV's built-in speakers which are thin, flat, and positioned facing the wall behind the screen or they connect a soundbar to whatever HDMI port happens to be easiest to reach.
The problem with the second approach: not all HDMI ports support the same audio format. A standard ARC port sends compressed audio basic Dolby Digital 5.1 at best. If your soundbar supports Dolby Atmos or DTS:X, you're not getting it. You're getting a downgraded version of the audio because the port can't pass the full signal.
The eARC port usually labeled "HDMI eARC" or "HDMI 2" on most TVs supports lossless, uncompressed surround sound. It passes full Dolby Atmos and DTS:X at their highest quality, the way they were mixed in the studio.
"A guy had a $700 Atmos soundbar connected to HDMI 1. I moved the cable to the eARC port and played the same scene. He heard sounds above him for the first time. He'd owned the soundbar for two years and never heard what it actually does."
He said if you're still using an optical cable to connect your soundbar, you're limited to basic stereo or compressed 5.1. Optical was the standard 20 years ago. eARC replaces it entirely more bandwidth, better audio, one cable.
"Your soundbar isn't bad. Your port is wrong."