What is the best connection system for audio? Let’s find out together in this guide to Toslink and HDMI ARC or eARC connectors
When we connect a new soundbar or home theater system to the TV we must choose a connection cable that maintains the audio quality of the original source , especially if we really love watching movies via Blu-ray, DVD or via streaming apps such as Netflix or Amazon Prime Video. Although the choice may seem obvious, the technology has advanced so far over the past few years that it has made one of the most famous digital connection methods such as the optical cable (also called S / PDIF or Toslink) obsolete, in favor of the new HDMI. ARC (and its most recent evolution, namely HDMI eARC).
In this guide we will show you what are the differences between Toslink, HDMI ARC and eARC and what is the best technology for digital audio , so you can benefit from multimedia content at a much higher quality than the average compared to analog connections (now totally obsolete for multimedia content available to fans of cinema and TV series).
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Which cable to use for digital audio output
The technologies that we will examine in the following chapters are present on practically any soundbar, Hi-Fi stereo system or home theater amplifier, we just need to get the right cable and make the connection as indicated. For each technology we will show you strengths and weaknesses, complete with a link to buy a high quality cable to make the chosen audio connection.
Toslink or S / PDIF connection
The oldest and most compatible digital audio connection is the optical audio output , present behind the televisions also with the inscriptions Toslink OUT , Optical DIGITAL OUT , Audio Digital OUT or S / PDIF OUT .
This technology uses optical fiber and a red light beam, capable of carrying the audio signal digitally through a succession of light pulses. The digital optical output allows you to obtain excellent audio quality in all scenarios and is compatible with stereo audio and compressed digital audio (Dolby Digital 5.1), but has very obvious limitations: it is not possible to control the final playback device (soundbar or system) with the TV remote control, forcing us to use the device’s dedicated remote control to be able to raise or lower the volume and turn it on or off; with the optical audio output we cannot even take advantage of modern technologies such as automatic sound synchronization with the video being played (Lip Sync) or Dolby Atmos / DTS: X.
However, it remains the most compatible technology even on old TVs or Hi-Fi systems with a few years on their shoulders. To make the connection just insert the Toslink cable in the appropriate optical ports: on TV we must use the Digital OUT port or similar, while on the playback system we must find Digital IN or Optical IN ; after the connection, let’s go to the TV settings, open the audio menu and set the optical audio output for listening. If we want to use this technology we advise you to focus on a quality cable such as the iVANKY Optical Audio Digital Toslink Cable 1.8 m , available on Amazon for less than 10 €.
HDMI ARC connection
The modern technology for making digital audio connections is HDMI ARC , found on virtually all televisions manufactured after 2009.
With this technology we use a dedicated HDMI port to send the audio “backward” compared to the standard HDMI stream (which we remember only goes towards the TV), exactly as the name of the technology suggests (ARC stands for Audio Return Channel or Audio Return Channel). Taking advantage of HDMI we will get a high audio quality, we maintain the support for Dolby Digital 5.1 and we will remedy all the limitations of the optical output : thanks to the CEC (another technology integrated in HDMI) we can control the output volume with the TV remote controland turn on / off the soundbar or the system together with the TV, greatly facilitating the usability of the contents. Optionally HDMI ARC also supports Lip Sync, but only if it is provided for by the settings of the TV and the chosen system. The only limitation of this technology is the perennial occupation of an HDMI port , which will reduce the number of HDMI devices that we can connect to the TV.
It is currently the go-to method for connecting soundbars and home theater systems , as it is simple to set up and provides full control with a single remote. To make this connection, we identify the HDMI ARC port on the back of the TV (not all HDMI ports on the same TV are compatible with ARC) then use a standard HDMI cable to connect this specific port to the HDMI ARC IN port of the soundbar or the plant in use. If we want to use a quality cable to make this connection, we recommend purchasing the Amazon Basics Cable – Ultra HD HDMI 2.0 High Speed Cable with Audio Return Channel, 1.8 m , available on Amazon for less than 10 €.
READ ALSO: HDMI 2.1 ARC: what it is and how to best use it
HDMI eARC connection
The most advanced technology for connecting audio devices is HDMI eARC , which as the name suggests is the evolution of the previous HDMI ARC technology and is present on Smart TVs on the market in recent years.
This technology allows the audio at the highest quality possible , thanks to the audio Dolby Digital 5.1 and 7.1 multichannel audio support uncompressed and support of the most powerful audio codecs like Dolby Atmos and DTS: X . To the incomparable sound quality it also adds the mandatory support for Lip Sync , so as to always have the audio synchronized with the video.
HDMI eARC retains the benefits of ARC in single remote control and is backward compatible with HDMI ARC ports on older devices. Obviously it also maintains the disadvantage of traditional ARC, which is to always keep an HDMI port occupied for audio. Making the connection is simple: we identify the HDMI eARC port behind the TV and use a high speed HDMI cable to connect to the HDMI eARC IN port on the soundbar or home theater system.
For this technology we cannot use a traditional HDMI cable , but we must use a latest generation HDMI 2.1 cable , the only one able to guarantee support for all the features described; if you use a simple HDMI cable we will only be able to take advantage of the traditional HDMI ARC, failing to support the new features. The best cable we can use for eARC HDMI is the Snowkids 48Gbps High Speed Braided 8K @ 60Hz HDMI Cable , available on Amazon for less than € 20.
For fans of cinema and TV series at home and fans of new audio technologies it is time to update: the optical cable can be permanently retired, replaced with great results by the HDMI cable with the return audio channel, which allows you to achieve extremely high quality levels and providing the most requested feature by all fans, namely universal control via a single remote control (that of the TV.
If we are about to buy a new TV, make sure it supports HDMI ARC or better yet HDMI eARC, so that we are ready to connect a soundbar or home theater system in the future. To learn more, we can also read our guides How to choose and buy the best Smart TV and How to choose the right HDMI cable .