: HD Audio True or False?


martinwoolwich
2007-12-10, 07:26 PM
I have just been told that the only way to get proper HD audio is through HDMI and that the sound from an HD disc via optical or coax connector will not reproduce full HD audio.

Is this true?

If so what happens to people like me who send HDMI picture only to a projector and audio via Optical through to the processor. My processor doesn't have any HDMI switching. Does this mean I have to upgrade?


Please god NO!

darrylr
2007-12-10, 07:36 PM
Yes it is true to get the full data from the HD Audio streams (Dolby True HD, DTS HD, PCM on Blu-rays) you need to use a receiver than can process (and maybe decode) audio from an HDMI connection. There is debate to how much better sounding the HD audio formats are over the standard Dolby Digital 5.1 and DTS but as far as the HD audio codecs go then yes you need to use HDMI.

Blu-ray and HD-DVD discs also have the standard audio streams (DD 5.1 and/or DTS) on them so you will still be able to hear them (and they generally sound very good) but most of the hi-def discs also have at least form of the HD audio streams on them as well.

rod farva
2007-12-10, 07:40 PM
I have just been told that the only way to get proper HD audio is through HDMI it is not true. 5.1 analog outputs are also available on select players.

Luis_A51
2007-12-10, 07:40 PM
It is true that optical/coax cannot handle HD audio. Its not entirely true that only HDMI can.

HD audio (PCM, Dolby TrueHD, DTS-HD Master Audio) can all be set via HDMI. However they can also be sent (decoded) via analogue inputs I believe.

HDMI is the "cleaner" method though, since 1 cable can send everything.

darrylr
2007-12-10, 07:41 PM
Oh yeah sorry - forgot about those. :(

Alan Bealby
2007-12-10, 07:45 PM
It depends on what you mean by "HD audio". Do you mean any audio that comes with HDTV or the new High Definition Audio which comes with some, but not all, HD-DVD or BD discs?

HDTV that comes with HDTV Over-the-Air, cable or satellite currently only comes with audio up to Dolby Digital 5.1 or DTS 5.1. These should be accessible through digital coax or optical audio connections. The same holds true for HD-DVD or BD discs that only have Dolby Digital 5.1 or DTS 5.1 sound tracks.

The potential problem occurs with the new HD audio formats that may be available with HD-DVD or BD discs. These formats cannot be passed through the digital audio coax or digital audio optical connectors but can only be passed through a HDMI connection to a the destination device being able to properly decode that signal. However, I believe that the players should down convert the HD audio signals and pass them through the coax and optical audio outputs so you would still get sound, just not the full high audio.

How many HD-DVD or BD discs have audio tracks with the higher definition audio on them at present?

In any case this is just another in a long line of new capability that is not backward compatible with old equipment. Nothing new there.

peterhefer1
2007-12-10, 07:59 PM
Regardless your going to need a new reciever for these new HD audio formats i.e TrueHD, DTS-HD. but like it was mentioned above all hd players come with the ability to use dd5.1 threw the optical so don't worry to much about upgrading unless you want to take advatage of the uncompressed audio that these disc's offer.

darrylr
2007-12-10, 08:03 PM
About 60% of Blu-ray discs currently have lossless audio on them (True HD, DTS HD, or PCM). About 20% of HD-DVD discs currently have lossless audio on them. This puts the number of discs with the HD audio formats on them at over 300 titles.

james99
2007-12-10, 08:22 PM
I have just been told that the only way to get proper HD audio is through HDMI and that the sound from an HD disc via optical or coax connector will not reproduce full HD audio.

Is this true?


See http://www.digitalhome.ca/forum/showthread.php?t=71867

rfielder
2007-12-10, 10:55 PM
The potential problem occurs with the new HD audio formats that may be available with HD-DVD or BD discs. These formats cannot be passed through the digital audio coax or digital audio optical connectors but can only be passed through a HDMI connection to a the destination device being able to properly decode that signal.
Wow! Being new to the hi-def world, this came as a surprise. I just spent the time and $$$ to set up my new Samsung 40" 1080p TV, Rogers HD digital box, and HTPC with S/PDIF feeds to the sound system. Two use optical, and one coax.

Now I find out that these connections can not support the new audio formats. Ouch!

However, I am confused about something.

By the sound of it, you require an HDMI connection to carry the new audio formats. OK, I get that.

The HDMI cable also carries video. In my case, two devices (HTPC and cable box) are connected to the TV with HDMI, for video only in this case. OK so far.

There have been other discussions about having a TV receive an audio signal and pass it on to a sound system. The description of current technology indicates that this won't happen. The TV's on sale today will not pass through an audio signal.

My confusion is - how do you get the audio to a sound system? You have to use an HDMI cable for both audio and video, which must be plugged into the TV, but the TV won't pass the audio signal on.

?????

james99
2007-12-10, 11:01 PM
You pass the Audio/Video from the HD source to the AVR using a HDMI cable. Now you have HD audio. You than pass the Video from the AVR to the HDTV. Now you have HD Video.

57
2007-12-11, 01:06 AM
Be aware that by doing that (going through an AVR and one connection to the HDTV) it makes it more difficult to calibrate individual inputs on the TV if the sending devices require different video settings.

http://www.digitalhome.ca/forum/showthread.php?t=71112 HDMI

http://www.digitalhome.ca/forum/showthread.php?t=17713 TV Setup

http://www.digitalhome.ca/forum/showthread.php?t=57741 General Info.

Paulo
2007-12-11, 11:54 AM
Here is another write-up on the whole lossless vs uncompressed audio issue.

http://hddvd.highdefdigest.com/news/show/Joshua_Zyber/High-Def_FAQ:_Uncompressed_vs._Lossless_Audio/1233


Paul

Arthur Dent
2007-12-11, 12:31 PM
Here is another write-up on the whole lossless vs uncompressed audio issue.

http://hddvd.highdefdigest.com/news/show/Joshua_Zyber/High-Def_FAQ:_Uncompressed_vs._Lossless_Audio/1233


Paul

I couldn't open the link, but I guess you meant to say "lossy vs uncompressed". I often say lossy instead of lossless, although they are not the same, and the differences are severely debated. There is no difference in quality between lossless and uncompressed and there can't be any discussion on the subject.
I personally think that the analog route is the better solution for now. I recently took advantage and purchased an old flagship receiver that doesn't have HDMI, but is top of the line in pretty much everything else. Reasons - the quality of the music is most important to me, and it delivers big time. Music titles on formats that require HDMI are non-existent and there won't be anything audio only, like SACD or DVD-Audio on Blu-ray or HD DVD discs (ever). The only thing you can find so far are a few concert releases which don't really deserve hi-resolution audio. And the future looks even more unfriendly. As for the movie soundtracks, the minimal improvement to the sound that the new codecs deliver over standard DD/DTS in no way deserves a new receiver that will compromise sound quality just to impress the mass market with handling the latest abbreviations like "True HD". Multichannel analog from a player that decodes these new gimmicks is more than enough. 90% of the soundtracks on hi-def discs I've listened to so far don't deserve anything better than standard DTS.

57
2007-12-11, 12:56 PM
The same links were already provided in post 9. There seems to be a temporary problem with that website.

Dog Byte
2007-12-11, 12:57 PM
The link works for me and apparently audiophiles do argue over lossless vs uncompressed. Good article too.

james99
2007-12-11, 02:07 PM
That website was having problems off and on over the past day or two.