HDMI ARC: How the HDMI Audio Return Channel works
The term ARC in the HDMI universe has got nothing to do with famous french triumphal structures. Instead it is an acronym standing for HDMI Audio Return Channel. An HDTV screen or display equipped with an HDMI port featuring the Audio Return Channel (ARC) can - together with the right HDMI ARC cable - both receive and send audio signals over this dedicated HDMI port.
The advantage: You’ll save one cable! Namely the digital sound cable (e.g. S/PDIF) which would otherwise be needed to output sound signals from your TV to your speaker system or external A/V receiver.
For example: With HDMI ARC you could…
- … send HD audio signals from your integrated DVB receiver to your external sound system.
- … connect a game console like Playstation or XBOX to your TV using HDMI and send the audio back to an external A/V-Receiver
- … watch a BluRay disc using your sound system without plugging in an extra sound cable.
Two sketches will make it even more clear:
Old: Without HDMI ARC
In this configuration a BluRay-Player is connected via HDMI to an external digital A/V HDMI receiver. This receiver outputs the video signal to the HDTV and plays sound over the external speakers connected to the A/V receiver.
Let’s say the HDTV now has a built-in HD receiver which lets you receive HD-TV channels with HD-sound using an integrated tuner or TV cable (e.g. DVB). In order to play the sound of the TV program over your external A/V-Receiver you will need to connect the A/V receiver to your TV with an extra digital audio cable (e.g. S/PDIF). Both the TV and the receiver are connected with two cables - the HDMI and the digital sound cable.
This is where HDMI ARC comes into play…
New: With HDMI ARC
The configuration is the same like above. A BluRay-Player connected with HDMI to an A/V-Receiver which is again connected to a TV using HDMI. The TV will receive HD TV channels over an integrated tuner or DVB antenna cable. The sound of the TV programme should be played over the external A/V receiver. Thanks to HDMI Audio Return Channel (ARC) the sound of the TV can now be outputted right through the HDMI cable to the connected A/V receiver. The second sound (S/PDIF) cable becomes redundant.
HDMI ARC is a practical thing and can be used for many other cases as well. Whenever it is necessary to transmit audio signals from your TV back to any other HDMI device (in most cases this would be your external A/V receiver) you could use HDMI ARC. In simple words: HDMI ARC will replace the audio-out port of your TV screen in some cases.
Some restrictions apply. The most important one: All of the connected devices have to support HDMI ARC explicitly.
How to make sure that HDMI ARC works for you
- Pay attention that both devices - the TV and the audio receiver - actually support HDMI ARC (read the products’ technical specifications)
- All HDMI cables following the 1.4 HDMI specs will support the Audio Return Channel. However, we recommend to use a dedicated High Speed HDMI Cable to avoid compatibility issues.
- Connect your devices through the dedicated ARC HDMI ports. HDTV screens have several HDMI ports but only some (or even only one) will support the Audio Return feature. Most TV manufacturers would mark the relevant HDMI port by printing ARC next to it. You might want to check your TV’s manual to find out which HDMI port support the ARC feature.
HDMI ARC Cable
Every HDMI cable following the HDMI 1.4 specifications will support ARC - practically any HDMI cable on the market today. However, to avoid compatibility issues we recommend to use a dedicated "High Speed HDMI" cable. For example this one:
- High Speed HDMI Cable with Audio Return (ARC) support
ca. 5$, Amazon.com