HDMI (High-Definition Multimedia Interface) and digital optical are two of the most common types of cable connections that we use for audio. Both are easy to use, and an average person won’t really experience any noticeable difference when using either of them.
HDMI Vs. Optical for Audio – Which Gives Better Sound Quality?
When comparing HDMI vs. optical audio cables for sound quality, HDMI is better than optical. Moreover, with optical cables, the usage is limited to speakers up to 5.1, while HDMI takes advantage of Dolby TrueHD and DTS HD Master Audio.
If you’re still in the planning phase for your next home theater system, you might want to stick around. There’s a lot that you have to learn regarding these two connections. So let’s discuss both in great detail to find out which of these two is better for your sound system.
Also read: 9 Cables Required For Home Theater Installations
Optical Digital Connection
An optical digital connection uses optical fibers and light to transmit audio signals from your TV or a transmitter to your speakers. These fibers can be plastic, glass, or silica, but what makes it an excellent audio transmitter is because noise can’t pass through an optical cable.
Game consoles, set-top boxes, television sets, and home theater systems use optical connection because of its ability to transmit uncompressed Dolby Digital and DTS surround sound. Due to the massive adaptation of various manufacturers, digital optical may be the only connection that you can use when setting up sound systems.
High-Definition Multimedia Interface (HDMI)
HDMI uses copper as its main component, which is cheaper. Plus, it boasts various advantages, such as being a one-size-fits-all audio and video connection, a much higher bandwidth capability than optical, and a perpetually evolving technology.
It allows playback for newer devices that use audio formats such as Dolby TrueHD and DTS HD Master Audio. The newer HDMI versions can even take advantage of Dolby Atmos and DTS:X soundtracks. Blu-ray players and soundbars use HDMI because of its straightforward setup and higher audio bandwidth.
A user only needs one cable for video and audio, which works exceptionally well in transmitting both signals. That’s why more and more manufacturers are trying to incorporate this technology with their devices.
Differences Between HDMI and Optical Cables for Audio
It can be challenging to figure out which one is better without putting them side by side. However, an optical cable will always come at a disadvantage—it can only transmit audio signals. So for us to have a comparison that would even make sense, let’s keep video transmission out of the picture, okay?
Here is a quick comparison table which will be elaborated upon in this article.
|HDMI (for Audio)||Optical|
|Effect of Length||Retains audio quality upto 5 meters only||Retains audio quality upto 10 meters|
|Audio Support||Stereo, Dolby Digital, DTS, Dolby TrueHD, DTS HD MA, Dolby Atmos, DTS:X||Stereo, Dolby Digital, DTS|
|Availability||Easily available||Availability reducing|
|Price||Slightly less||Slightly less|
Optical fiber vs. copper, there’s really not much of a competition here. Copper is a cheaper material but is more susceptible to interference. On the other hand, optical fibers are more expensive, but they use light to transmit signals, making them less likely to suffer from interference.
However, since optical fibers use brittle materials, bending the cable too much can cause sound degradation. HDMI doesn’t have this issue, because it uses copper and electricity to transmit signals. Even when heavily bent, copper will still be an excellent conductor.
The length of cable wouldn’t be a problem for many people, but for those who require an extended connection, the transmission of signals might be an issue.
Optical cables retain sound quality even at 10 meters. There are even some who are using it at 30 meters with no problem! But if you’re going to use HDMI for your sound system, it would be best to keep it under 5 meters to maintain sound quality and low latency. Read my article on how long HDMI cables can be.
Most audio devices support both connections, especially those for home use, and you’ll most likely get excellent audio quality from both.
However, digital optical audio can only support channels up to 5.1 surround sound. There’s nothing wrong with it, though, because most 5.1 speakers are still capable of delivering high-resolution sound output.
On the other hand, HDMI can support Dolby TrueHD and DTS HD Master Audio. The difference in quality may still be unnoticeable at the moment, but it’s an evolving technology. So HDMI is more likely to adapt to the newer audio technologies that manufacturers will incorporate in their devices.
Almost all videos, movies, and programs that we watch today only use surround sound technology. So, there’s not much of a difference with the audio quality that both connections can produce. The only real advantage that you’ll get from HDMI is when you start using Blu-ray discs, which use more audio channels.
There’s no doubt that both cables are highly capable of transmitting audio signals, but you’re most likely to find HDMI cables in electronics stores. It’s capable of transmitting AV signals with only one cable, so more and more manufacturers use this technology in their devices.
Digital optical cables are still readily available, and you don’t have to look too hard to find one. However, as audio technology improves, the difference in sound quality that HDMI and optical can produce becomes more significant. So it may not be too long before optical cables start to lose ground in the audio market.
The price will always be a massive deciding factor when choosing between HDMI and optical. At a glance, the difference in price isn’t that much, but optical cables are usually slightly more expensive, and that’s just for audio connection!
If you include a video connection, things get a little bit different. When using optical, you’ll need a separate cable for video connection. Optical fiber also degrades faster than copper. On the other hand, HDMI only needs one cable, which also lasts longer, so it’s almost always a cheaper option.
The Better Choice for You
Both HDMI and optical cables are excellent in transmitting digital audio from one device to another, and there’s no difference in the quality of sound that they can produce when using multi-channel audio like Dolby digital. But when it comes to higher resolution audio, HDMI is, clearly, a better option.
However, HDMI isn’t always the best choice for everyone, and the devices that you want to connect will play a significant role in choosing between these two audio connections. Maybe you have an older device that doesn’t support HDMI, or, perhaps, you’re just trying to create a connection between the transmitter and your speakers. In cases like these, using optical cables may be the only option that you have.
It can be confusing at first, so let’s simplify things to help you better understand which of these cables is better for you. Here are some of the reasons why you’d want a digital optical connection:
- Your sound system only has 5.1 surround sound. Don’t sweat at not having HDMI if you’re only going to use 5.1 surround sound because an optical cable can also support it. You’ll get the same audio output with both connections, so an optical cable is a better option since it’s less susceptible to interference.
- Your sound system is well within the average. Even if you’re using devices that use high-resolution audio, the difference in sound quality may not be as pronounced as what you might expect. You won’t even notice the difference between Dolby TrueHD and 5.1 surround sound if you’re like most people who use mainstream speakers.
- You only want to connect your TV to a sound system. Sometimes, people only want better sounds for their TV, especially those who are using newer models that suffer from poor speakers. If you’re not planning to watch Blu-ray or other hi-res videos, then it would make sense for you to take advantage of an optical connection. Using HDMI for a TV to speaker connection doesn’t have a lot to offer, but an optical cable can help you avoid interference.
- You’re only trying to set up an audio zone. HDMI works for audio and video, which is excellent! But if you’re only planning to build a sound room, then that’s another reason to go for an optical connection. Since most of the speakers we have today don’t make full use of hi-res audio, you’re apt to get more from optical cables. It also gives you better flexibility when setting up because of the longer connections that you can create.
- You have a decent but old device. This one is actually a no-brainer; older devices don’t support HDMI—there’s nothing that you can about it. So don’t sweat about not having one because they’ll most likely sound the same even if you can use HDMI to connect your device to a speaker. Remember, you can only take advantage of all the features that HDMI has to offer if your device uses the latest audio technology.
- You need to create a long connection. An optical cable is a better option for you if you’re planning to build a connection longer than 5 meters. Sound quality degrades faster with HDMI, but a digital optical can go as far as 30 meters without losing audio quality. Larger media rooms can get more out of optical cables, and with less susceptibility to interference, it’ll be easier to configure heart-pounding audio.
Sure, the difference in sound quality may not be as much, and, sometimes, you’re better off with optical cables. However, there are times when it’s more advantageous for you to use HDMI that an optical cable simply can’t compete, such as the following:
- Your device supports high-resolution audio. Dolby TrueHD and DTS HD Master Audio, you have to hear it to believe it. These hi-res audio are more open and smoother sounding than what we’re used to hearing. If you’ve invested a lot in your sound system, it makes sense for you to use HDMI cables. It’ll let you take advantage of better audio quality without the installation and configuration complexities you’ll encounter when using a digital optical cable.
- You have a high-end sound system. If you’ve invested a lot in your sound system, then you should consider using HDMI. Currently, the only option you have to make use of the higher audio bandwidth is through the versatile connectivity options that only HDMI can offer.
- You need your sound system to watch Blu-rays. Optical cables still work with Blu-rays, but it can’t compete with the immersive audio experience that HDMI can produce. If you’re planning to use your sound system for Blu-rays, then, by all means, go all out on HDMI. It’s the only option you have to enjoy the high-resolution audio that you’ll get from Blu-rays.
- You’re trying to set up a home theater system. Since HDMI can support both audio and video using only one cable, it’ll be easier to use it when setting up a home theater system. It’s cheaper, and you can save even more if you’re trying to build a network of speakers and devices with multiple connecting cables. Plus, it saves you from having several wires snaking on your ground.
- You don’t want complicated installations. You can bend copper, and it’ll still be a good conductor. That’s why if you’re using HDMI for audio connection, you don’t have to worry about bending limitations, complicated installation procedures, and proper placement of cables.
- Your media room has several devices that you need to connect. With more manufacturers opting for the HDMI connection, it makes more sense for you to have one HDMI cable for all of your devices. It’ll save you from the hassle of setting up different connections and simply work with one cable that can connect to every device to provide you with both audio and video output!
Recommended Audio Cables
Now that you know which of the two is better for your sound system, it’s time to start setting them up. If you’re planning to get these cables from a brick and mortar shop, what you’ll find are bundle deals that include the surround sound, sound features, and cables. It’s easy to pick the fancier ones with these bundle deals, but it would be best to stick with what you need and then negotiate the price.
We prefer buying audio cables online because it’s easier to find cheaper ones. Plus, you can get them at steep discounts at the peak of the shopping season. Of course, we know that you can’t wait for that to save up on your cables, so here are some of the best deals for HDMI and optical cables:
- Capshi HDMI 2.0 Cable is perfect for most entertainment systems because of its backward compatibility with older versions. It will still work well with HDMI 1.2, 1.3, and 1.4, making it possible for you to only work with one cable. It also uses a durable 24K gold-plated connector that can withstand up to 10,000 bends. They’re even throwing in a lifetime warranty to cover all costs of repairing it!
- iVANKY HDMI 2.0 Cable has the most robust design we’ve seen in HDMI cables. It features a nylon braided outer layer to maintain flexibility and aluminum connector shell that can withstand heavy use without degrading its transmission capability. It’s also backward compatible, which works fine with devices that have HDMI 1.2, 1.3, and 1.4.
- BlueRigger HDMI Cable is Amazon’s choice for HDMI cables and with good reason. It has 100% copper conductors, triple cable shielding, and corrosion-resistant 24K gold-plated metal jacket connectors. This HDMI cable is one of the few that has a certified bandwidth of 18Gbps, capable of 4K resolution at 60 FPS.
- KabelDirekt Pro Series Optical Cable works with multiple channels for surround sound systems. It’s capable of delivering compressed 5.1 surround sound and uncompressed PCM audio. The fully-flexible PVC jacket and corrosion-resistant 24K gold-plated connectors make it one of the most durable cables that you can use for sound systems.
- FosPower Optical Cable uses metal connections and features a durable nylon mesh jacket to make it more durable than most digital optical cables. It works with almost every transmitter, and if you’re still not convinced, they’re offering a limited lifetime warranty to cover the costs of the repair process!
- BlueRigger Optical Cable is CL3 rated for wall installations, making it the perfect choice for easy and safe installation. It features precision-polished optical connectors that work seamlessly with every digital optical-compatible device, making it possible to have maximum signal transfer accuracy. You can use this cable for all devices that use SPDIF, ADAT’s, Dolby Digital, & DTS.
The better choice between HDMI and optical for audio connection is clear. If your device is compatible with both options, you’ll be a happy camper with HDMI. A digital optical connection isn’t really much of a competition with HDMI’s capability to work with more channels and easier installation and configuration.
However, it’s not always the case for many people, since the difference between the sound quality of 5.1 and true high definition audio isn’t as pronounced. Sometimes, optical can provide you with more advantages, especially if you’re only looking for a way to connect your TV to a speaker.
Jason is a home theater expert with over 10 years of experience in setting up home cinema rooms and systems. What started out as a hobby soon transformed him into an authority in the audio-visual field. He is passionate about providing readers with accurate and up-to-date information on the latest audiovisual technologies and their applications for home theaters. Read more about Jason.