DTS HD over Optical Fiber - Newbie ?

[walmat]

Does anyone know why DTS HD sounds better than just DTS when I run it through the PS3 on bitstream to my older amp over an optical fiber cable?
(example Live Free or Die Hard)
When I try the same thing with Dolby HD it sounds identical to standard Dolby. ( example Batman Begins)
Has anyone else experienced this or am I crazy?
Also why do ppl bash Cerwin Vega spkrs? I'm no audio expert but they sound pretty good to me for home theater.

[cartman781]

it should. I believe it plays the DTS core at a bitrate of 1.5 mbps instead of the 640kbps on DVD. Someone correct me if I'm wrong.

[aramis109]

It's just playing the DTS core so there's no reason it should sound any different than a DTS title. Optical can't pull through that kind of bandwidth to my knowledge.

Dolby HD- do you mean TrueHD? It sounds the same because it's probably playing the standard Dolby Digital 5.1. While I don't think TrueHD carries the "core" in the same way that DTS-HD MA does, I think it's still there in some form. You're just getting DD 5.1.

To get the HD audio codecs you need a receiver that can either accept HDMI audio or a receiver and player that both have analog out/inputs.

[walmat]

Originally Posted by aramis109

It's just playing the DTS core so there's no reason it should sound any different than a DTS title. Optical can't pull through that kind of bandwidth to my knowledge.

Dolby HD- do you mean TrueHD? It sounds the same because it's probably playing the standard Dolby Digital 5.1. While I don't think TrueHD carries the "core" in the same way that DTS-HD MA does, I think it's still there in some form. You're just getting DD 5.1.

To get the HD audio codecs you need a receiver that can either accept HDMI audio or a receiver and player that both have analog out/inputs.

This is just an observation I've found but it might be just that the disc itself.

[olds403]

Actually none of the high res audio formats will bitstream due to digital rights management. They will only either decode in the player or can be decoded by the reciever via HDMI only.

You are hearing the standard DTS track if you are bitstreaming over optical cable.

[mx2004]

Originally Posted by cartman781

it should. I believe it plays the DTS core at a bitrate of 1.5 mbps instead of the 640kbps on DVD. Someone correct me if I'm wrong.

Cartman is correct. The DTS core extracted from the Master Audio soundtrack is at 1.5Mbps, and will sound better than DVD - the idea being that non-HDMI users can get some of the benefit while they save up for their new receiver.

Link to DTS website

DTS-HD encoded content contains a DTS surround sound “core”, plus an “extension” that delivers even higher quality. When you play a DTS-HD encoded disc through an older DTS-capable receiver, the DTS-HD extension is simply ignored and only the DTS core is decoded — but not at ordinary quality levels. Your older receiver will play back DTS-HD material with DTS surround audio at twice the data rate of other DVD video surround formats. Meaning? You get immediate compatibility and a boost in quality.

[walmat]

Originally Posted by mx2004

Cartman is correct. The DTS core extracted from the Master Audio soundtrack is at 1.5Mbps, and will sound better than DVD - the idea being that non-HDMI users can get some of the benefit while they save up for their new receiver.

Link to DTS website

So I'm not crazy. Too bad the same thing doesn't apply to Dolby True HD.

[Stephan.klose]

Originally Posted by walmat

So I'm not crazy. Too bad the same thing doesn't apply to Dolby True HD.

Yep, sadly it extracts only the DD 5.1 Track. At 640kbps

[Big Daddy]

Originally Posted by walmat

Does anyone know why DTS HD sounds better than just DTS when I run it through the PS3 on bitstream to my older amp over an optical fiber cable?
(example Live Free or Die Hard)
When I try the same thing with Dolby HD it sounds identical to standard Dolby. ( example Batman Begins)
Has anyone else experienced this or am I crazy?
Also why do ppl bash Cerwin Vega spkrs? I'm no audio expert but they sound pretty good to me for home theater.

Your statement makes no sense at all. You cannot send DTS HD or Dolby TrueHD through an optical cable. When you connect PS3 to an old receiver with an optical cable, you are getting DTS Digital and Dolby Digital. Both codecs can be encoded at different bit rates. To get DTS HD High Resolution, DTS HD Master Audio, Dolby Digital Plus, and Dolby TrueHD, you need an HDMI cable. You also have to set your PS3 to PCM. PS3 cannot sent HD audio in bitstream. Read A Guide to Home Theater Audio CODECs.

[prerich]

Originally Posted by olds403

Actually none of the high res audio formats will bitstream due to digital rights management. They will only either decode in the player or can be decoded by the reciever via HDMI only.

You are hearing the standard DTS track if you are bitstreaming over optical cable.

FYI when it's decoded by the receiver via HDMI...that's called bitstreaming The PS3 can't do that, but many standalones can. HDMI provides a PAP (protected audio path) from the player(standalone) to the receiver. HTPC will also be able to bitstream with the new generation audio cards.

[mx2004]

Originally Posted by Big Daddy

You cannot send DTS HD or Dolby TrueHD through an optical cable.

True, you can't send the full HD over optical. When a DTS-HD soundtrack is selected and the audio connection is coaxial or optical digital, the 1.5Mbps DTS Core is output, as stated on the DTS website linked in my post above. It is quite natural that this will sound better than DVD though, as this is much higher than the maximum bitrate of DTS on DVD of 640kbps (Thanks cartman for the figure.) Therefore, walmat's post makes perfect sense.

Originally Posted by Big Daddy

To get DTS HD High Resolution, DTS HD Master Audio, Dolby Digital Plus, and Dolby TrueHD, you need an HDMI cable.

Also true - or you need an appropriately equipped player with 5.1 or 7.1 Analogue outputs to pass the fully decoded HD audio to your receiver (where no HDMI is available).

[brett_day]

Originally Posted by walmat

Does anyone know why DTS HD sounds better than just DTS when I run it through the PS3 on bitstream to my older amp over an optical fiber cable?
(example Live Free or Die Hard)
When I try the same thing with Dolby HD it sounds identical to standard Dolby. ( example Batman Begins)
Has anyone else experienced this or am I crazy?
Also why do ppl bash Cerwin Vega spkrs? I'm no audio expert but they sound pretty good to me for home theater.

er....optical cannot handle the bandwidth required for dts hd! so you are not hearing DTS HD, just regular DTS. Only HDMI can handle the bandwidth for DTS HD

[mx2004]

Originally Posted by KingLeerUK

The above said, there may still be some issues with bass management as not all players on the market offer the best bass management implementations for their analogue audio outputs (or at all for some players). This is one area where the HDMI transported audio path (either PCM or compressed bitstream) and an HDMI equipped receiver come into their own.

Excellent point! And it's something that has concerned me in the past with SACD, too. In my strange 5.0 system (am I the only one who's not too keen on subwoofers?), my traditional concern is the option to switch the sub off and fold the LFE into the main left/right channels - but I was surprised that the Panasonic BD50 (which is the blu-ray I have set my sights on) only offers 100Hz as the crossover point (as well as subwoofer off, for me).

There does seem to be some confusion on these codecs, and I would hope for standardisation of terminology something like this:-

bitstreaming
transmission of the raw HD audio over HDMI for decoding at the receiver

unpacking (suggestions for a better term?)
the player reconstructs the LPCM and passes it via HDMI to the receiver (if the player does this properly the sound should be identical to bitstreaming)

decoding
the player decodes HD audio onboard, to pass to the analogue multichannel outputs

Then we can produce a audio compatability table for each player:-

_____________DD Plus / Dolby True HD / DTS-HD HighRes / DTS-HD MA
Bitstreaming___y______y______________y____________ __y
Unpacking_____y______y______________y_____________ _y
Decoding______y______y______________y_____________ _y

Thoughts?

[Big Daddy]

I don't understand why people are talking about analog transmission. The OP mentioned PS3. As you all are aware, PS3 does not do analog.

DTS Digital at a higher bit rate is not HD. DTS HD HR or DTS HD MA cannot be transmitted through optical. It is not a mystery that DTS Digital at 1.5Mbps sounds better than DTS Digital at a lower bit rate.

You can actually encode DTS Digital at 1.5Mbps on a DVD, provided you are doing music only or you don't have a lot of high quality video.

[mx2004]

Originally Posted by Big Daddy

I don't understand why people are talking about analog transmission. The OP mentioned PS3. As you all are aware, PS3 does not do analog.

As these things do, I think we may have drifted a little from the letter of the original post, and started to discuss more generally some of the codec issues - I mentioned analog (as the alternative way to access HD audio if no HDMI is available) and ran off on a little train of thought of my own, I think! Of course, the PS3 does not do analog - I think the discussion was just taking on a life of its own.

[Canada]

Unfortunatly optical does not have the bandwidth to support the advanced codecs, your s.o.l