Help with Best Blu-ray Sound from my HTPC?

[Tomodan]

Please let me know if this should be somewhere else!

So, I am looking for some advice from the experts as I am slowly going insane trying to understand the best way of getting the best quality audio from my HTPC.

I have the following kit:

Motherboard : Gigabyte GA-MA78GPM-DS2H
Blu-Ray/HD DVD Drive ; LG (forget the model)
Receiver ; Yamaha RXV 4600
Speakers ; KEF Egg (think they are 3002s)
Blu-Ray software ; PowerDVD9
SAMSUNG LCD TV (forget model but it is 1080p etc)

I use the TV purely for picture and the receiver for sound. I am aware that the receiver will not support HDMI 1.3

I can currently get the following to work:

Audio over HDMI to the receiver
Audio over S/PDIF to receiver
Audio over Analogue outputs to multi input on receiver.
Picture to TV via receiver over HDMI.

What I am struggling with is this:

I cannot get HD Audio (either Dolby True HD or DTS Master HD) out of the motherboards HDMI Socket or SPDIF Socket due to hardware / bandwith restrictions.

As I understand it the next best thing would be LPCM 5.1 via one of these outputs but how do I get this to work? at the moment I am getting dolby digital 5.1 via both optical and HDMI but as I understand it this is no better than DVD audio (I.E not as good as uncompressed LPCM 5.1)?

The only LPCM setting I can find results in only a stereo output.

Is the answer to use the analogue outputs on my motherboard into the multi channel input on the receiver? Would this sound better than DD 5.1 via a digital link?

I am not in a position to upgrade my receiver yet but could possibly stretch to the Asus HDAV 1.3 deluxe sound card and use the analogue outputs for now (until I get a receiver with HDMI 1.3) but only if this will make a big difference

I suppose the question I am asking is what will give me the absolute best sound quality when watching Blu-ray with this setup?

Many thanks in advance!

[jameson_uk]

Originally Posted by Tomodan

Motherboard : Gigabyte GA-MA78GPM-DS2H
...
As I understand it the next best thing would be LPCM 5.1 via one of these outputs but how do I get this to work?

Your motherboard only does SPDIF audio (over both optical and HDMI). You can not get LPCM over HDMI with a 780G board.

Is the answer to use the analogue outputs on my motherboard into the multi channel input on the receiver? Would this sound better than DD 5.1 via a digital link?

This should work (assuming you have software which is capable of decoding the HD audio). As to how much better it will be then it depends. First off you are using the DACs on your motherboard which are might not be great then you are outputting an analogue signal through an electrically noisey area to your amp. That said the cost of three 3.5mm to stereo phono cables is probably worth a go. (you should also be aware that the difference in HD is not anywhere near the same as the difference between SD and HD video, in some cases the difference between the DD and TrueHD tracks on some badly encoded discs is not noticable, at least IMHO)

If you amp does not have HDMI 1.3 inputs then you are limited to either analogue connections or if it will accept it LPCM over HDMI. Both routes are slightly limited in that they are not considered secure so get limited by the playback software to 16 bit 48Khz (which is what most films are encoded at anyway). Whether this actually makes a difference in real use is still debated but having forked out £150 for an Asus Xonar HDAV I am not sure there is much in it.

For LPCM over HDMI the cheapest and easiest route is probably an ATI 4550/4650 dedicated GPU. You can get a passive one of these for around £40 and it will support LPCM output.

Getting a HDAV would not really help you as you need HDMI 1.3 for HD audio bitstreaming and getting it with the analogue output card would still be limited as above (both in terms of actually limiting the output and still having analogue connections; albeit the DACs should be much better)

[MikeK]

at the moment I am getting dolby digital 5.1 via both optical and HDMI but as I understand it this is no better than DVD audio (I.E not as good as uncompressed LPCM 5.1)?

While it isn't as good as uncompressed or lossless audio, it's often better than DVD - DD on DVD was always limited to 448kbps (and often it was 384k), and while there are some Blurays with 448k DD audio, most have 640k tracks, or will output a 640k stream downconverted from the higher quality source track (is EAC3/TrueHD). Similar story with DTS - while it wasn't actually limited to 768kbps by the DVD spec, the vast majority of DVD discs with DTS audio had the lower bitrate version. Nearly all Blurays with DTS audio will have either a core 1536kbps track, or a DTS-HD track with a core of 1536k, and hence will output 1536k DTS over SPDIF.



You also have two other options

You could buy a decent quality 7.1 analogue soundcard for about £50 (or less if you don't mind s/h from ebay) - should give a reasonable quality jump over most motherboard audio (though for many mbd audio is fine)

You could rip your BDs to your hard drive and convert the DTS-HD audio to FLAC (TrueHD/EAC3 can be played as is) - this will give full quality with no downsampling.


BTW - while it does depend on the soundtrack in question, overall I'm with jameson about lossy vs lossless audio - I often find it hard to appreciate that much of a difference between DTS and DTS-HD (or a FLAC thereof) while actually watching a film - if you don't watch and try some critical "eyes closed" listening, you can often tell them apart (though it's not really night and day). There's probably slightly more difference between DD and TrueHD, though again, while actually watching, it's not night and day!
As jameson said, it certainly doesn't bring the same improvements as the upgrade to HD video did - at least for me!
That said, effects placement certainly seems better on the few 7.1 soundtracks I've heard - quite noticably so!