HDMI vs. Optical: Which Digital Audio Connection You Should Use

HDMI offers more bandwidth and heaps of modern features

HDMI and Optical cables 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 transmits audio only. But beyond that keystone spec, there are some other important differences between the two, and a few reasons why you might want to pick one over the other when putting together your entertainment system(s).

Overall Findings

  • Supports multi-channel audio.

  • Transmits high quality audio.

  • Only transmits audio.

  • Supported by many legacy devices.

  • Supports multi-channel audio.

  • Supports Dolby TrueHD, DTS HD Master Audio.

  • Transmits video too.

  • Supports ARC and eARC.

  • More widely available in modern devices.

Both optical cables and HDMI cables are capable of transmitting multi-channel, high quality audio, with major advantages over more traditional analog audio connectors. However, HDMI supports newer, higher resolution audio standards, like Dolby TrueHD, and DTS HD Master Audio. Optical cables do not.

HDMI is also able to transmit video too, and when combined with ARC and eARC technologies, is able to be a singular cable solution for connecting your video and audio sources to a TV and external A/V system, where optical cables can function only as audio transmission cables.

Optical cable connections are still found on many modern devices, though HDMI is far more common. Older devices with HDMI support don't have the same set of audio features as more modern ones. HDMI 1.3 introduced Dolby TrueHD DTS-HD Master audio support, while HDMI 1.3 added the audio return channel (ARC). HDMI 2.1 added support for eARC, in turn.

Compatibility: HDMI Is Newer and More Common

  • More common on legacy devices.

  • Stil available on some modern devices.

  • Converters and adapters can improve optical compatibility.

  • Common on every TV and audio system in the past 15 years.

  • Video and audio capability make it more likely to be in use already with spare cables handy.

  • Available on recent generation graphics cards and consoles.

HDMI cables have become the most common and popular audio and video transmission cable for consumer technologies over the past two decades. It enjoys compatibility with almost every TV, monitor, graphics card, PC, console, A/V system, and DVD and Blu-ray player of the past 15 years. Optical cables, by contrast, are much less common today. They were a more popular feature once, and still appear on some devices, but it's far less common than HDMI. Where most TVs will feature four or more HDMI connectors, they may only have a single optical port and most desktop PCs, laptops and consoles don't offer it.

Often too, devices that do feature optical cables also have an HDMI connection.

Audio Quality: Similar, But HDMI has Improved Features

  • Transmits high quality audio.

  • Supports Dolby Digital.

  • Supports high-quality audio.

  • Supports Dolby Digital.

  • Supports Dolby TrueHD, DTS HD Master Audio.

  • Supports 5.1 and 7.1 multi-channel PCM.

  • Supports Dolby Atmos.

Although some audiophiles may prefer the audio quality of an optical cable-driven A/V system, that's not a common opinion. For most, especially if connected to a capable A/V system and speakers or headphones, there won't be a major discernible difference between the two.

However, there's no argument that HDMI supports the newer, higher-resolution audio options found on modern Blu-rays and games consoles. Optical cables do not support Dolby Atmos, or Dolby TrueHD, nor DTS HD Master Audio. If you're building a modern entertainment center, you'll be able to take better advantage of these if you use an HDMI connection.

Versatility: HDMI Does Video, Too

  • Is audio only.

  • Can be useful for forcing an audio-only connection.

  • Can transmit video anywhere up to 4K 120Hz, as well.

  • Can use ARC and eARC to transmit audio and video back and forth between source, TV, and A/V system for reduced cabling.

If you're looking to transmit audio and video to or from a TV or A/V system, HDMI is the only cable of these two that can do the job. Optical cables are limited to audio only. More recent-generation HDMI connections (namely 1.4 or newer and 2.1) can use ARC and eARC technologies to transfer audio information back and forth along the same cable, making it easy to connect your entire system using a limited string of HDMI connectors, rather than multiple cables of different types.

Optical cables can be useful if you want to output sound to an older device without HDMI support, or from a TV without ARC support. It can also force an audio connection, rather than complicating it with video too, reducing configuration complexity.

Final Verdict: HDMI Is Easier, Better, and Newer

Although optical cables were a useful cable type in the past for handling audio, their prominence has waned. HDMI offers support for newer audio technologies, better compatibility with modern devices, and a simpler cabling system for connecting up larger A/V systems and surround sound speakers. Optical cables can still be useful with legacy devices, especially older A/V systems or TVs, but where you can, HDMI is cheaper and easier to use.

  • What is fiber optic cable?

    Fiber optic cables use strands of glass fibers to transmit data. Compared to wired cables, fiber optic cables offer higher bandwidth, and they can transmit data over longer distances.

  • What's the difference between coaxial vs. optical digital audio cables?

    Coaxial cables are sturdier and provide higher bandwidth, but they are more prone to radio frequency and electromagnetic interference. Coaxial cables offer slightly higher resolution audio, but the difference is only noticeable on high-end sound systems.

  • How do I connect a soundbar to a TV with an optical cable?

    To set up your soundbar, connect one end of an optical cable to the audio-out optical port on the TV, then connect the other end to the audio-in optical port on the soundbar. You may need to change the speaker output settings on your TV.

  • How do I connect a soundbar to a TV without an optical cable?

    Other options for connecting a soundbar to your TV include HDMI and RCA connectors. You can even use a coaxial cable with the help of an adapter. Some soundbars can also connect wirelessly via Bluetooth.

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