HDfury Diva

Audio

eARC

Enhanced Audio Return Channel

In short

Enhanced Audio Return Channel: the link that sends sound backwards along an HDMI cable from a television to an amplifier, with room for lossless formats.

Apps now live in the television, so the sound has to travel back up the cable it came down. eARC is the fast version of that trick, and the Diva can catch it at TX0.

eARC stands for Enhanced Audio Return Channel, the 2017 successor to ARC. Both solve the same problem: a television has become a source in its own right, with tuners and streaming apps inside it, and that sound needs to reach an amplifier sitting upstream of the display. ARC managed it by borrowing a spare pin and running something close to an optical link over it, which limits it to Dolby Digital, DTS and Dolby Digital Plus, with Atmos only in the compressed form that rides inside DD+.

eARC replaces that with a dedicated high speed data channel on the cable, with roughly enough capacity for uncompressed multichannel PCM and for the lossless bitstreams, Dolby TrueHD with Atmos and DTS-HD Master Audio with DTS:X. The second change is less discussed and just as useful: ARC depends on CEC for discovery, and CEC between two brands is famously unreliable. eARC carries its own capability exchange on its own channel, so it does not need CEC to be enabled at either end.

eARC on the HDfury Diva

TX0 is the output that does this. Connect a television with an eARC capable input to TX0 and the Diva extracts up to Dolby Atmos HBR over TrueHD from it, then sends that out of the dedicated HDMI audio output, a self generated 720p or 1080p stream built to feed any amplifier input. That is how the soundtrack of an app running inside the television reaches an amplifier that has no eARC of its own.

Nothing needs configuring for it. The manual is explicit that eARC does not rely on CEC, that you do not need to select any CEC option, and that extraction happens automatically and is forwarded to the HDMI audio output on its own. That is the practical difference from ARC on the same unit, which does need ENABLE CEC ticked and the CEC device type set to Audio Processor in the CEC and RS232 section, plus Enable DD+/ATMOS ARC, set archbr on, before Atmos over DD+ will come back.

Laying the room out around TX0

  • The television you want audio from goes on TX0, whichever display you consider primary, because CEC, ARC and eARC master is always TX0.
  • The amplifier goes on the dedicated HDMI audio output, decoding whatever it is handed.
  • TX1 stays free for a second or older display, which it feeds in 1080p SDR.
  • If you do not want the television speaking as well, MUTE TX0 AUDIO, set mutetx0audio on, silences that output without touching the extraction.

Related terms

ARCThe HDMI feature that sends sound backwards along the cable, from a television to an amplifier or a soundbar.CDSThe block of audio capability data an eARC device sends over the eARC link, in place of having an EDID read from it.Dolby AtmosObject based surround sound, where the mix carries positioned audio objects that the decoder renders to whatever speakers are present.HBR audioHigh Bit Rate audio: the HDMI packet type for compressed streams too large for a single S/PDIF rate link, such as TrueHD and DTS-HD Master Audio.Audio extractionTaking the audio out of an HDMI stream and delivering it on a separate output, so a receiver can hear it without having to handle the video.

In the manual

The pages of the HDfury Diva manual where this comes up.

All glossary terms