HDMI ARC and optical are both sound solutions for your TV. HDMI ARC is a type of audio/video interface that supports uncompressed digital video signals, digital audio signals, and control data. This provides the highest quality video signal but requires an HDMI input on the TV or receiver. Optical cables transmit sound using light pulses and are a popular option because they offer high-quality audio at a lower price than HDMI cables.
Both HDMI ARC and optical cables can deliver high-quality audio, but which is better?
HDMI ARC is a better option than using optical cables. HDMI ARC has a higher bandwidth (1 Mbps) and supports uncompressed 5.1 channel surround sound, whereas optical has a lower bandwidth (384 Kbps) and therefore has to compress 5.1 surround sound audio.
On top of that, HDMI ARC allows for video and audio usage, making them a better option when used in conjunction with your television, Blu-ray player, game consoles, or any system that requires video.
HDMI is the newer standard, and it continues to improve. If you can, HDMI with ARC (or even eARC) offers a better all-around experience. The HDMI ARC vs. Optical debate was won long ago.
However, there is one exception where optical is better than HDMI. Optical is better for long cable runs.
What’s the difference between HDMI ARC and Optical?
| Optical | HDMI ARC | HDMI eARC | |
| Bandwidth | 384 Kbps | 1 Mbps | 37 Mbps |
| 5.1 Surround Sound | Yes (Compressed) | Yes (Uncompressed) | Yes (Uncompressed) |
| 7.1 Surround Sound | No | No | Yes |
| Dolby Atmos, TrueHD, DTS HD, and Dolby Digital Plus | No | No | Yes |
HDMI cables and optical cables transmit a multi-channel digital audio signal. Optical connections are limited to just the digital audio aspect by design, but HDMI is designed as both a video and audio transmission cable. Having a single cable makes it easy to connect devices and looks cleaner.
Both HDMI and optical cables can transmit 5.1 surround sound, yet HDMI is a more up-to-date technology that is still improving. HDMI support for newer audio technology such as Dolby Atmos, TrueHD, DTS HD, and Dolby Digital Plus is included in these updates. Having the latest tech can make a big difference in how good your favorite movies and TV shows sound.
For the absolute best audio experience, HDMI 2.1 cables can support 7.1 surround sound, making it the only choice for the most high-end audio systems.
HDMI also supports a feature called audio return channel, or ARC, a feature not available with optical connections. HDMI ARC enables audio from the TV to be transmitted back down the same HDMI cable to a soundbar, receiver, or another audio device. HDMI ARC is a feature that allows two-way communication along the HDMI cable, which helps to reduce the number of cables required.
Optical cables can’t do this. A comparable setup would see the media source connected to the TV via HDMI, and a second optical connection between the TV and sound system. In other words, audio and video are sent to the TV over the HDMI cable, and a second cable is needed to send the audio portion from the TV to your sound system.
HDMI and optical cables are built differently, too. Optical cables use fiber optic technology to transmit the signal. These cables are typically made with plastic but can also use glass or silica.
That leads to a high-quality connection with high signal integrity over the length of the cable. HDMI cables require shielding in order to be protected from outside interference.
Cables length is only really a problem at greater lengths and when using lower-quality cables that don’t have adequate shielding. HDMI and optical cables both have a max of around 10 meters.
If you want more information about cable design and length, check out these Wikipedia articles: Optical and HDMI.
HDMI vs. Optical For Sound Bars
There are soundbars that have HDMI ports, there are soundbars that have optical audio inputs, and then there are soundbars that have both HDMI and optical.
Which one is right for you? Let’s take a look at the difference between the types of soundbars.
HDMI Sound Bars
You must use the TV’s HDMI ARC input when connecting an HDMI cable from a TV to a soundbar. HDMI ARC sends the audio signal from the TV to the soundbar. An HDMI ARC port can be used as a regular HDMI input but also doubles as an audio output.
I realize that can be a little confusing. Using an HDMI input as an audio output doesn’t sound right at first take. You’re probably wondering how the TV gets an input signal then. To understand that, we have to take a look at the soundbar.
When a soundbar has HDMI ports, it will often have two HDMI ports, one for input and one for output. The output should be labeled as an HDMI ARC port. The HDMI input gets connected to your media source, and the soundbar passes the video through to the HDMI output, which gets connected to the TV. The soundbar acts as a pass-through for the video.
If you are using apps on the TV, the HDMI cable connected to your TV will send the audio to the soundbar via the HDMI ARC connection. If this is the only way you are viewing media, you don’t need anything connected to the HDMI input on the soundbar.
Optical Sound Bars
An optical cable, also referred to as a Toslink cable, relays audio from your TV to the soundbar. Optical cables only transfer audio and are not capable of sending video signals. You’ll need an additional cable to connect your devices to transfer video and images.
Comparing Optical and HDMI Sound Bars
You must consider personal factors and preferences when selecting which Soundbar is ideal for you. Primarily, you need to consider what input and output options are available on your TV.
In general, if HDMI is an option, you should go with HDMI.
You must think about the sort ports, both input and output, that your equipment has, including your source media device and your soundbar. Older devices may not have an HDMI port. Others, usually newer, may only allow for HDMI cables.
If your device does not support HDMI connections, ensure you have the correct video cables for relaying footage between your television and other equipment.
You’d be amazed at how many people make a purchase thinking they’re buying something with a particular port only to discover their device doesn’t actually allow for that connection when they take it out of the box.
Conclusion
Given a choice, go with HDMI. It is the industry standard, and optical connections are becoming obsolete. It is hard to even find media streaming devices, such as the Apple TV, that even includes an optical connection anymore.
I use Apple TV as an example because the older generation used to have an optical connection but has since dropped that port.
You should aim for using an HDMI cable unless you have a pair of old speakers and a receiver that only works with optical connections and no HDMI.
It’s just easier to get an HDMI cable. Plus, the sound quality will be better. You’ll also have one less cable to worry about because it also transmits video signals.
HDMI is more future-proof, while optical connections will be increasingly difficult to obtain. Get an HDMI cable.