HDMI vs. Optical: What Cable Should You Use?
To transfer sound from your TV to your soundbar or receiver you need either an HDMI cable or an optical cable. Both can work, but for some types of audio you’ll need an HDMI cable. Fortunately, both types of cables are inexpensive and easy to connect. For most people, we recommend simply getting a cheap and high quality HDMI cable. They will work with just about anything, including the best televisions.
However, if you have an optical cable collecting dust in the box of spare cables we all have, they will work fine. Technically HDMI is better, but on most systems the difference will be minimal. There are a few caveats to this, which I will discuss. Here are the advantages and disadvantages of each type of connection.
The basics of both
HDMI and optical ports transmit digital audio from one device to another. Both are better than analog (the old fashioned red and white cables). Both can transmit multichannel audio, such as Dolby Digital. Both cables are quite inexpensive.
The biggest difference is that HDMI can transmit higher resolution audio, including formats found on streaming services such as Dolby Atmos. These formats cannot be transmitted using an optical cable.
In terms of simplicity, HDMI also transmits video signals. So if you just want a single cable between two devices, HDMI (using ARC) is the best choice.
The optics are “good”
Depending on your equipment, you may not have the HDMI option. Maybe you have an older receiver. Maybe everything is connected to your TV and you just want to stream audio to a sound bar (and the only option is optical). In this case, the optics are suitable. Don’t worry about not being able to connect via HDMI. For most configurations, the sound will be as good over optical as over HDMI.
One complication is if you have a soundbar that can benefit from a surround sound signal. Some TVs do not transmit digital surround sound from their optical outputs. If your soundbar doesn’t have HDMI or you can’t use HDMI, it’s worth seeing if you can connect the bar directly to your source, like a Roku or Apple TV box, cable box, etc.
When HDMI is best
The only way to transmit Dolby Atmos from your TV to a soundbar or receiver is via HDMI. Depending on the complexity of your audio system, Atmos may not do much compared to Dolby Digital sent via optical. On a good home theater systemwith quality speakersyou might get better surround sound, but the difference in the audio quality itself will be less obvious.
If you’re setting up your system for the first time, it’s worth spending a few extra dollars and getting some. HDMI cables. They’re pretty cheap, even at long distances, so there’s no reason to use optics if you can avoid it.
Conclusion
Use HDMI when you can. They are cheapand having a single cable for audio and video simplifies setup. If you can’t, the optics are fine. If your equipment is not equipped with HDMI, it cannot benefit from Dolby Atmos anyway. On the other hand, Dolby Digital is surprisingly good, and unless you have decent Atmos-capable equipment, you probably won’t hear much (if any) improvement with Dolby Atmos.
Note: This guide was first published in 2014 but has been updated with new links and information.
In addition to covering audio and display technology, Geoff takes photo tours of museums and cool locations around the world, including nuclear submarines, aircraft carriers, medieval castles, epic 10,000-mile road trips and much more.
Also see Budget travel for dummieshis book and his best-selling science fiction novel on city-sized submarines. You can follow him on Instagram and YouTube.
