Getting audio from your TV to external speakers can be a head-scratching task for some. Depending on the type of TV and external speakers you have, there could be only one or maybe many kinds of audio connections available to you. Perhaps your TV has both HDMI ARC and digital optical audio, both of which are great options. So which one is better? HDMI ARC or digital optical audio?
HDMI ARC is a better option. It supports Dolby Digital Plus, Dolby Atmos, and up to 7.1 channels of uncompressed audio while Digital Optical only supports Dolby Digital and up to 5.1 channels of uncompressed audio. HDMI ARC also offers features like CEC in which your TV remote can control the volume levels of a connected soundbar or A/V receiver.
Since your television may have both digital optical audio and HDMI ARC, you may be stuck between a rock and a hard place determining which one is best for you. There are many facets to consider like cable length, quality, connections available, and the cables you have on hand. If you would like to find out about audio quality, features, and how digital optical and HDMI ARC compare, you’re in the right place!
How HDMI ARC and Digital Optical Compare
HDMI ARC and digital optical audio connections are sometimes both available on televisions. However, digital optical (sometimes called TOSLINK) audio is the older of the two, with HDMI ARC being first introduced in 2009 along with CEC (consumer electronics control). As you might expect, since HDMI ARC is newer, it does a lot more. It provides a return channel for audio and simplifies connection to multiple devices.
However, an even newer version of HDMI ARC is called HDMI eARC (enhanced Audio Return Channel). HDMI eARC was first introduced with the HDMI 2.1 chipset but has been made available many TVs that don’t have HDMI 2.1
CEC (which HDMI ARC is a sub-feature of), audio is controlled by a single remote control. This audio control means that you can use any of your remote controls (TV, media player, soundbar, A/V receiver, etc.) to adjust the volume level. Additionally, you can use the same remote to turn off and on the TV and any other devices connected via HDMI, all with one click of a button on one remote.
Digital optical audio cables just provide audio from one device to another through a fiber optic cable. Digital optical cables are also made of fiber optics, which are not prone to electromagnetic interference (EMI) like copper wire in HDMI cables. However, EMI is usually not a problem in most home entertainment setups.
What are the Audio Quality Differences Between HDMI ARC, eARC, and Digital Optical?
The table below details the different levels of audio quality that HDMI ARC, HDMI eARC, and Digital Optical can handle:
|Audio Capabilities||Digital Optical (Good)||HDMI ARC (Better)||HDMI eARC (Best)|
|Stereo 2.0||Yes (Lossless)||Yes (Lossless)||Yes (Lossless)|
|5.1 Channels||Yes (Lossy)||Yes (Lossy)||Yes (Lossless)|
|7.1 Channels||No||Yes1 (Lossy)|
Dolby Digital Plus
Dolby TrueHD, DTS:X
|Dolby Digital Plus2|
|DTS Digital Surround|
|DTS-HD Master Audio|
2. Dolby Digital Plus and Dolby TrueHD can both include Dolby Atmos Audio. Dolby Digital Plus can provide lossy or compressed Dolby Atmos, while Dolby TrueHD can provide lossless or uncompressed Dolby Atmos.
Also, I made a really in-depth YouTube video on HDMI ARC and Digital Optical and how these compare in terms of audio codec support like Dolby Atmos and DTS:X.
What Features Are Supported by Digital Optical, HDMI ARC, and HDMI eARC?
The below table breaks down the different features supported by Digital Optical, ARC, and eARC:
|Function||Digital Optical (Good)||HDMI ARC (Better)||HDMI eARC (Best)|
|Cable Type||Optical (S/PDIF)||HDMI||HDMI w/Ethernet|
|Volume Up/Down||No*||Yes (CEC)||Yes (CEC)|
|Mute||No*||Yes (CEC)||Yes (CEC)|
|Power On/Off||No||Yes (CEC)||Yes (CEC)|
|Automatically Change Input||No||Yes (CEC)||Yes (CEC)|
As you can see from this table, HDMI ARC and eARC are far superior when it comes to the features offered because of HDMI CEC.
Soundbars with Digital Optical Audio and HDMI ARC
If your TV has both HDMI ARC and digital optical audio, you might still be trying to figure which connection is best for you. Despite the practical advantages and features of HDMI ARC, you might still be wondering if it makes sense to use digital optical audio.
In short, if you have HDMI ARC on both your TV and soundbar, then use HDMI ARC. If you don’t have HDMI ARC, then use digital optical. Most soundbars support less than 5.1 channels of audio, so in terms of audio quality, there isn’t really a difference.
But if your soundbar supports more than 5.1 channels of audio, Dolby Atmos and/or DTS:X, then a digital optical cable will severely limit the audio quality of the system.
There are plenty of soundbars and A/V receivers available with both HDMI ARC and digital optical audio inputs. In fact, most soundbar and audio systems that have HDMI ARC still keep legacy connections like auxiliary audio and digital optical audio to simplify connections.
However, suppose your television only has digital optical audio and not HDMI. In that case, it may make sense to opt for a soundbar with just a digital optical audio input. Soundbars without HDMI ARC input are generally lower cost than ones with HDMI ARC compatibility.
When is Digital Optical a Better Option than HDMI ARC
There are certain cases where digital optical audio could be a better choice. For instance, if your existing setup, i.e., TV, sound system, etc., works on digital optical audio and does not have HDMI ARC, then digital optical is clearly better.
Furthermore, digital optical can be a more reliable connection. It’s been around since 1983. It’s lasted so long because it is not only affordable, but it delivers excellent audio quality too. It is much cheaper than HDMI and is not susceptible to EMI like copper-based HDMI cords are.
And digital optical doesn’t induce audio delay nearly as much as HDMI ARC does. On certain TVs and soundbars, HDMI ARC isn’t always in sync and can cause the audio to lag behind a bit, resulting in out-of-sync audio and video. This can be very frustrating, and you’ll usually need to power cycle both the TV and soundbar to fix the issue.
Digital optical cables also have a longer maximum length than HDMI cables before signal degradation (in other words, before the audio quality gets noticeably worse). Digital optical cable can have a maximum length of about 100 feet, while HDMI cables typically top out at around 50 feet without an active extender.
HDMI has a shorter maximum run length not only due to the EMI issues mentioned earlier but because the voltage used on HDMI cables is very low – only 5 volts. In simple terms, longer cords have higher resistance which slows down voltage and prevents the audio from traversing the entire length. In summary, digital optical audio cables will be able to send an audio stream that is stable and not lagging in cases where standard HDMI would fare poorly.
When is HDMI ARC a Better Option than Digital Optical
In most cases, HDMI ARC is the better option when compared to digital optical audio. HDMI ARC is capable of providing better sound quality. It also has CEC (consumer electronics control). If you recall from earlier in this article, it allows control of volume and power of both the TV and the external speaker system with one remote controller.
HDMI ARC also provides the outstanding feature of using multiple devices as the audio source. For example, the TV only has to be plugged into one soundbar with one HDMI cord. In this example, the TV has 4 HDMI inputs with a Playstation 5, Blu-ray player, and an Apple TV. All three devices do not have to be plugged into the soundbar; they just need to be plugged into the TV, then the TV passes the audio to the soundbar via HDMI ARC!
The only negative in this situation is that HDMI ARC takes away one of the HDMI Inputs on the TV. So if your TV only has 3 HDMI inputs, one of which is the HDMI ARC port, then you actually only have 2 HDMI inputs.
In summary, HDMI ARC provides the best audio quality when compared to digital optical audio. It’s the new kid on the block that also has cool features like CEC for simultaneous TV and speaker volume and power control. Additionally, it supports newer audio formats and reduces cables and the clutter of extra devices like receivers.