HDMI ARC vs Optical – which connection is better?

After taking a look at your TV and soundbar, you realized that both devices can support HDMI ARC and optical. The problem is you don’t have either cable, and you’re wondering which one is the best in terms of audio quality.

In this article, we’ll not only be comparing HDMI vs optical but also the audio formats and other features each cable provides.

You also might be looking for a soundbar with specific features, and you’re wondering if you really need an HDMI ARC enabled soundbar. Or is optical enough? Are there any advantages or disadvantages to either cable you should know about? Let’s take a closer look.

Look:

When it comes down to it, both HDMI ARC and optical deliver good quality audio and they can support the same audio formats and channels. HDMI ARC provides a feature called CEC (more on that later) and Lip Sync correction.

Let’s start with HDMI ARC.

HDMI ARC Features:

HDMI is the standard all-in-one technology that can not only transfer video but also high-quality audio. The vast majority of consoles and displays support HDMI.

1 – Consumer Electronics Control (CEC)

HDMI ARC’s most useful feature is a feature called CEC which allows you to use your TV remote to control the volume of a connected audio device. It was introduced in HDMI 1.4 which was released in 2009.

The main advantage to CEC is it reduces the cables required to connect a TV to an audio system. You also don’t need to use separate remotes, you can use one remote to control the volume on an external speaker.

Another point is CEC can be used to turn on your TV and soundbar with the same remote, which makes things a lot more convenient.

2 – Lip Sync Correction

Lip sync correction is a feature introduced with HDMI 1.3 that automatically adjusts audio and video timings to avoid delays and other issues. The issue occurs because a TV can sometimes take longer to process video than it does to process audio.

When using external speakers, sometimes there can be a noticeable delay between the video and audio, and HDMI ARC fixes that. The feature has been around since 2008, and most consumer electronics support it. HDMI ARC supports this feature, and you can toggle it on or off as you please. I recommend leaving it on.

3 – Supports Video Signals

You can use an HDMI cable to connect your TV to a soundbar for audio, and then later use the same cable with a console or DVD-Player for games or movies. It’s a multi-purpose cable.

CEC and Lip-sync correction are HDMI ARC’s most noteworthy features.

Optical Features: Good for Casual Use

Optical, also known as Toslink, has been around for a long time (since 1983), and it’s still in use today because it’s affordable, reliable, and delivers decent audio. Toslink is an audio cable, it can’t carry video signals, and it doesn’t have any special features.

There are two points worth mentioning about optical. For one, it’s much cheaper than HDMI, and secondly, the build design is actually more interference-proof than HDMI.

The reason it’s better at blocking interference is that the technology is based on sending light through fibreglass, which is much more resistant to electromagnetic fields. In other words, the audio stream will be much more stable and less prone to lag or interference.

On the subject of interference, most HDMI cables have a layer of shielding around the copper wire, so the signal is also very well protected. The quality of that protection will vary depending on the manufacturer. If you have a lot of wireless devices, they could be interfering with your HDMI cable.

In short, optical is cheap and stable, but it does not have any special features.

HDMI ARC vs Optical: Supported Audio Formats:

What’s interesting about HDMI ARC vs optical is both support options support the same multi-channel audio formats, such as; stereo, 5.1, and even 7.1 (Dolby Digital).

ARC does have more potential bandwidth but that doesn’t necessarily translate into higher quality audio. For a full list of formats and features, take a look at this table:

If you have a simple audio setup, like a single soundbar, or stereo speakers, either option can deliver about the same quality audio. For 2.1 audio channels, either device will deliver good audio. People with Smart TVs sometimes mention apps like Netflix sound better with HDMI vs optical but it can be hard to notice.

There’s another version of HDMI ARC called HDMI eARC which supports practically every audio function.

HDMI eARC (Best for Home Theaters)

HDMI eARC (Enhanced Audio Return Channel) is an advanced version of ARC that was introduced in HDMI 2.1.

For advanced audio systems, eARC is the absolute best connection method because it supports the most common formats as well as advanced audio formats such as Dolby Atmos, Dolby Digital True HD, and DTS:X.

If you have a home theatre system that is designed for these formats, you will need to use HDMI eARC. The problem is the feature is still relatively new, there aren’t many TVs or devices that support eARC at the moment, although that will likely change in the near future.

 

Function
TOSLINK: GOOD
HDMI ARC: BETTER
HDMI eARC: BEST
Cable Used
Optical S/PDIF
HDMI
HDMI with Ethernet
Stereo Support
Yes
Yes
Yes
Compressed 5.1
Yes
Yes
Yes
Uncompressed 5.1
No
No
Yes
Uncompressed 7.1
No
No
Yes
High Bitrate & object-based up to 192KHz, 24-bit (eg: Dolby Atmos, DTS:X)
No
No
Yes
Maximum Audio Bandwidth
~384 Kbits/second
~1 Mbits/second
37 Mbits/second
Discovery
No
CEC
eARC data channel
eARC Capability (Audio EDID, etc.)
None
CEC
eARC data channel
Lip Sync Correction
No
(Optional)
(Mandatory)
TV Mutes & Controls Volume
No
Yes (CEC)
Yes (CEC)
Powering TV Powers Audio Device
No
Yes (CEC)
Yes (CEC)
ARC Fallback
No
N/A
Yes

 

What About Bluetooth?

Most TVs and soundbars can be paired via Bluetooth. There are a few issues to connecting a TV to a soundbar via Bluetooth that you should know about. For one, Bluetooth’s bandwidth is much lower than even optical, and the codecs compress the audio quite a lot.

Secondly, the lip-sync issue could be more obvious with Bluetooth because Bluetooth audio takes much longer to process. There’s more audio delay, and it can be quite bothersome, especially when watching movies.

Generally, it’s not recommended to pair a TV to a soundbar over Bluetooth, a wired option for audio is much better, preferably HDMI ARC.

The Bottom Line:

So when it comes down to it, HDMI eARC is the best option here. If you already bought a soundbar that has HDMI ARC support, then go ahead and buy an HDMI ARC cable. Otherwise, look for a soundbar that has an ARC port.

You might be thinking why I’m not recommending eARC soundbars. The reason for that is there are only a handful of soundbars that support eARC at the moment. But for the average consumer, an ARC cable provides good enough audio quality for movies, games, and any other kind of entertainment.

Even the optical cable is good enough for most media. Most people agree that the audio from HDMI ARC sounds a little more pronounced than optical, although it’s very difficult to notice these subtle differences.

View also:

About S. Santos

👋 I'm a technology columnist and tech blogger, with a love for video games, gadgets, home entertainment and personal technology. I've been writing about the industry now for over 10 years - first as an editor of various magazines before branching out to work on my own blog. I like to keep up with the ever-evolving world of gadgets, home entertainment, and personal technology. If not fiddling with AV cables at home or in front of the computer, I can be found playing tennis or padel. This blog is my space to explore new topics related to these hobbies; as well as share some thoughts about life in general (sometimes you need a break from electronics!). 😎

Leave a Comment