HydrogenAudio

Hydrogenaudio Forum => General Audio => Topic started by: cresco on 2021-09-11 09:58:22

Title: Playing 96kHz 24 bit 6 Channel FLAC files through my AVR
Post by: cresco on 2021-09-11 09:58:22
Some months ago I bought a music download 96/24 6Ch FLAC so I could listen in surround sound. This plays fine through my AVR and 5.0 speaker setup. The music player is a raspberry pi 4 running LibreELEC (which is a version of KODI media centre) with a connected hifiberry digi+ card which is in turn connected to my AVR via S/PDIF coaxial cable. (My AVR does not have HDMI connections)

Now I was expecting the AVR to display "PCM" (as it does for stereo FLAC), but it shows on the AVR display panel as Dolby Digital. I associate Dolby Digital as a lossy format. So can anyone explain what is happening to the hi-res source FLAC as the signal passes from the music player through to the AVR?

For Info' - I had to set some settings in my music player to allow signal "passthrough". I had to confirm that my AVR could decode AC3 (Dolby Digital) and DTS signals.  The settings menu also recommended that I allow the signal to be transcoded if the connection was via S/PDIF

Title: Re: Playing 96kHz 24 bit 6 Channel FLAC files through my AVR
Post by: Roseval on 2021-09-11 10:11:01
To the best of my knowledge, SPDIF is limited to 2 channel PCM.
Hence I expect the media player to mix down to DTS
Title: Re: Playing 96kHz 24 bit 6 Channel FLAC files through my AVR
Post by: ktf on 2021-09-12 13:37:02
As Roseval mentioned, it is not possible to send more than 2 channels over S/PDIF. As far as I know the only digital interface that can transmit multichannel audio as PCM (not counting professional standards such as ADAT Lightpipe, as we are presumably talking about a home theatre environment) is HDMI, so it seems you're out of luck.
Title: Re: Playing 96kHz 24 bit 6 Channel FLAC files through my AVR
Post by: cresco on 2021-09-12 14:48:00
Thanks for the replies. I only have a small number of multi-channel music files, so I am not too concerned that I am not getting the full quality of the audio, with my current set up.  As my AVR is 17 years old, I will probably update it at some point it for a HDMI enabled one.