HDMI and optical cables are two popular choices for transmitting audio from a source, such as a TV or Blu-ray player, to an external A/V system or speaker setup. HDMI can transmit both audio and video, while optical cables only transmit audio. But beyond that keystone specification, there are a few other key differences between the two and a few reasons why you might want to choose one over the other when building your entertainment system(s).
HDMI ARC vs Digital Optical (TosLink) | How to Get the Best Sound?
Both optical and HDMI cables can carry multi-channel, high-quality audio, offering significant advantages over more traditional analog audio connectors. However, HDMI supports newer, higher-resolution audio standards, such as Dolby TrueHD and DTS HD Master Audio. Optical cables do not.
HDMI can also transmit video and, in combination with ARC and eARC technologies, provides a unique cable solution for connecting your video and audio sources to a TV and an external A/V system, while optical cables can only function as audio transmission cables.
Optical cable connections are still found on many modern devices, although HDMI is much more common. Older devices that supported HDMI do not have the same set of audio features as more modern devices. HDMI 1.3 introduced Dolby TrueHD DTS-HD Master audio support, while HDMI 1.3 added the audio return channel (ARC). HDMI 2.1, meanwhile, added support for eARC.
