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

When you’re hooking up your soundbar or audio system together, you usually have to choose between a High-Definition Multimedia Interface (HDMI) and digital optical audio cables. You can also get analog/RCA, but those are obsolete by now and everyone is going digital. There’s also digital coaxial, which offers the same quality of audio as optical but optical is more common.

Essentially, it’s Optical vs HDMI debate for the most part because the two are the most ubiquitous and most affordable. With that in mind, which digital audio connection cable format should you opt for? Read on to find out, starting with the comparison chart below.

Comparison Chart

Audio Cable TypesOptical HDMI
Sound QualityOffers better quality than analog/RCA. It’s difficult to distinguish from digital coaxial since their audio quality is about the same.


Allows for digital audio at a higher bitrate than coaxial or optical. Better than RCA by default because it’s digital.


The only format capable of transmitting high-resolution audio like DTS HD Master Audio and Dolby TrueHD.


DescriptionTransmits digital multi-channel audio as pulses of light as opposed to digital coaxial, which delivers an audio signal instead.


The only format better than it is HDMI while it’s roughly the same quality as digital coaxial.

Transmits digital HD video and multi-channel audio in a single cable versus RCA, which requires multiple cables to achieve surround sound.


Offers the best quality possible compared to optical as well as digital coaxial and analog/RCA.


TipsAvoid getting bends or kinks along the length of the cable because this can lead to audio quality degradation.


To get the best performance out of your HDMI cables, get only HDMI-certified cables.



The Basics of HDMI vs. Optical

As you can see from the chart above, HDMI is the best type of audio cable format available compared to optical, digital coaxial, and RCA cables. This is why between HDMI and optical, the simplest advice is to go HDMI as much as possible. If you can’t, optical is decent enough for your audio or sound needs.

  • Optical: A digital optical audio cable produces a reliably consistent sound quality that outperforms analog/RCA and equals that of digital coaxial. This is the cable type that makes use of pulsing light waves in order to send sound through your audio system of speakers, bass, and subwoofers. These are the type of cables that should work well enough for every home sound system requiring digital sound fidelity.
  • HDMI: While coaxial and optical cables can only transmit audio data, HDMI can support both audio and video, making it a contender for A/V formats like VGA, DVI, and DP as well. HDMI cables are quite ubiquitous, with the ability to work with various electronic systems including computer monitors, televisions, and sound systems. This cable type is popular because it functions as a cable for both video and audio at the same time instead of splitting them into two.

A More Comprehensive Look

HDMI is the most abundant audio cables around followed by optical cables, digital coaxial cables, and finally RCA cables (which is an outdated format at this point in time from a previous generation). You’ll find a good deal of HDMI cables from secondhand stores and businesses as well as electronics stores. They’re quite undervalued but have an impressive lifespan.

  • Similarities: Both optical and HDMI cable formats pass digital audio from one device to another, from a media player to a speaker. Both are superior to analog or RCA cables, which make use of red and white cables. Both are capable of passing multi-channel audio, such as Dolby Digital. They’re also similarly cheap and readily available.
  • Differences: The biggest difference between HDMI and optical is that HDMI can pass higher-resolution audio, which includes formats found on Blu-Ray players and discs. You have your DTS HD Master Audio and Dolby TrueHD that can’t get transmitted across an optical cable or even its similar brother-in-arms, digital coaxial. This is an exclusively HDMI trait.

The HDMI Difference Explained

Both optical and HDMI cables communicate audio between devices excellently and fall under the same price range. Your Dolby Surround Sound System for your audio setup will work with either type of cable. However, in terms of differences, HDMI is on a whole other level. Sure, its ability to provide a video feed on top of a sound feed might be irrelevant for audiophiles who just want to listen to music, but even in terms of audio HDMI blows all other formats out of the water

  • The Home Theater Experience: You might want to invest in HDMI instead if you’re upgrading to higher definition devices like Blu-Ray players with True HD sound or the latest generation of game consoles. With it, you won’t need separate VGA and optical cables to run a state-of-the-art video player or an HDMI adapter to use a DVI cable with sound. DVDs run crisper and at higher frame rates with HDMI.
  • The Only Option for Blu-Ray: The HDMI cable, especially when running on HDMI 2.0, is the perfect format for Blu-Ray players when it comes to unleashing their full audio (and video) potential. It really brings out high-fidelity master audio that will make you feel like you’re there in the recording booth listening to the song, music video, or movie for the first time. It’s the highest quality sound (plus video) put together for one A/V format.
  • One-Dimensional: Digital optical audio cables are one-dimensional compared to HDMI. It’s almost an unfair comparison, like comparing other formats such as DP or DVI with it because of the video component. However, HDMI has even the audio department covered by also transmitting DTS HD Master Audio and Dolby TrueHD. Ultimately though, if the sound system is set for audio and music only, either cable will do.


Bottom Line

Digital optical and HDMI audio cables are both the most readily available options in the market to date as far as cables connecting audio between devices are concerned. The two types of cable fall under a similar price range and both are easy to find in any hardware or electronics.

Many users can justify choosing one or the other without noticeable audio differences, but usually, HDMI can do more or present you with more sound options in one cable. However, if you don’t need HD video and high bitrates for your exclusively audio-based sound system without DTS HD Master Audio and Dolby TrueHD, either cable will perform the same sound function.

AmazonBasics CL3 Rated Optical Audio Digital Toslink Cable: Here
AmazonBasics CL3 Rated High-Speed 4K HDMI Cable – 15 Feet: Here


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