The biggest difference is that HDMI can pass higher-resolution audio, including the formats found on Blu-ray: Dolby TrueHD and DTS HD Master Audio. These formats cant get transmitted across optical. In terms of simplicity, HDMI also passes video signals.
How good is optical audio?
On the other hand, optical cables still offer decent sound quality. Not only that, but theyre immune to interference, and theyre suitable for very long runs. At the end of the day, which type of cable you need will depend on what youre looking for.
Do optical cables make a difference?
So if youre getting a Dolby Digital signal, and its not cutting out, your optical cable is fine. If youre transmitting PCM, the audiophile answer is that different optical cables can cause different amounts of jitter. The reality is, the digital-to-analog converter in your gear has vastly more effect on the sound.
Does soundbar use HDMI?
There are 2 ways to connect your soundbar with HDMI: you can connect a device to your soundbar (like a Blu-ray player) and then connect the soundbar to the TV, or you can use ARC (Audio Return Channel). ARC is the way to go if you want great sound from streaming apps on your TV and a soundbar.