First of all I'm a newbie regarding AV receivers and all its terminology so apologies if I'm wrong. I have also searched for similar questions here but none fully explains answers my questions.
Recently I got the Yamaha HTR-2067 AV receiver, plus some speakers, to connect the blu-ray, PC, BT box and Switch onto it and get good quality sound. After reading many forums and trying different configurations I think, pretty much, am starting to understand how things function and slowly tuning each component to my liking but still have few doubts/issues I would like to share for the more technically savvy.
All the connections are made via HDMI, the receiver isn't capable of DolbyTrueHD or DTS-HD if I recall correctly either. I think the Nvidia 970 it's capable of decoding this formats though so it shouldn't be a problem as it's connected via its HDMI output.
My OS is Debian 9 unstable and kernel 4.12 in case that matters. So first sceneario would be like this. Turn on my PC, 5.1 surround speakers selected in the audio settings, and start playing a game, for example. If given game has surround sound, i.e The Witcher 3, the signal would be sent to the receiver normally and I would get the dialogue from the front speaker and music and ambient on the other ones. With films including a 5.1 audio track the results are pretty similar -at elast with the film I've tried, the despecialised version of Star Wars- In this case the AV receiver shows the signal as PCM.
So here comes my first question; Does that PCM mean the signal audio is being decoded on the PC and then sent to the AV hence the PCM shown?
If, however, I use this configuration for playing older games, music or an episode from Netflix or Crunchyroll -all things I've tried so far- the results are a bit less satisfactory. Yesterday tried with the remastered version of Grim Fandango and all the sound comes from all the speakers. Like if it was a single audio track. Same with music, etc. Also, playing with presets here sometimes gives a funny metalic sound, specifically in dialogue.
Does this happen because the original audio signal it's only stereo? Shouldn't the audio card/video card decode this onto surround sound via Dolby Pro Logic or any other format?
When I change this config in the settings and select that only 2 speakers are available on the system, things change again. With this setup, older games, crunchyroll and so on send a stereo signal to the AV receiver -that now would show Dolby Prologic II if selected as decoder- and it would be transformed into a surround sound. Dialogue would come from the front speaker, presets would work normally and overall "location" of the different sounds seems better. On the down side of this, I believe the signal could be slightly poorer and overall volume lower too.
Why can this be? Shouldn't the audio/video card decode as well and send the signal to the AV? Am I not losing sound quality by downmixing to stereo and the decoding back to 5.1 on the AV? Would a SPDIF cable solve all the issues though to a lower quality signal?
About the other devices, I couldn't check so much as with the PC, so not so sure about the outcome but I have this questions in case someone isn't bored of me yet xD
With the Blu-Ray things seem a bit simpler. If I select bitstream the sound it's sent to the AV and this one decodes it. The player does have DTS-HD and Dolby True HD though so if playing a Blu-Ray disk and I select PCM and send the signal to the AV this options is preferable due to a better overall quality instead of bitstream it and let the AV decode onto a lower quality format, right?
And with the Nintendo Switch, will it be better to select stereo and let the AV do the job or select surround (which is a PCM signal as well) and send the signal directly?
Sorry for the huge post, I hope isn't the wrong forum either, and thanks a lot for reading and replying!
