Demystifying DTS-HD and Dolby TrueHD...

[desray]

Okay guys...understand that there's alot of confusion for everyone. Myself included at the initial phase of the introduction of new High Definition Sound Formats from the 2 reigning powerhouse, Dolby and DTS.

 

I guess everyone have google the net before and get many many answers here and there...but never quite get a complete picture of what it is and how to relate to it. One thing I can tell you is that...at present you will not see a AVR or Amp's VFD read Dolby TrueHD or DTS-HS MSTR etc...But that does not mean that you're not *hearing* the TrueHD and DTS-HD soundtrack as advertised on the Blu-ray discs and/or HD DVDs. Its happening right before you all this while - its just that we're so used to the fact that VFD should read 'Dolby TrueHD' and 'DTS-HD MSTR' in order to *feel and hear* right :P

 

You can blame it on the sound engineers who come up with this confusing and often times head-scratching ordeal that every consumers face now!  :-X >:( Enough ranting on that...back to the main topic here.  :P

 

All you need to be aware of at present moment is that there are (at present) 2 types of Hi-Def Audio formats existing on most of our HD DVD or Blu-ray titles. There are DTS-HD and Dolby TrueHD. Both of them actually pretty much having the same specs although the former has the capability to reach as high as 24.5mbps bitrate as opposed to the max of 18mbps for the latter. But frankly, all these are at best theoritical values if you ask me (now) - reason is simple, I dun see any HD DVD or Blu-ray titles rolling out the maximum bitrate for their present titles as yet! There has been reports that the upcoming Blu-ray Matrix Trilogy package may have some 'revolutionary' features will be added in just for Blu-ray supporters! BD-J perhaps...???

 

A garden of variety

 

Let's talk about DTS-HD first...we have a few different classes of it - but always remember that the 'baseline' is you will get to enjoy AT LEAST 1.5mbps bitrate as opposed to the 768kbps maximum bitrate achievable at any one point in time from a normal SD DVD! That's what you need to know for DTS-HD sound format.

 

There are a few varieties of DTS-HD formats namely, DTS-HD High Resolution (HR), DTS-HD Master Audio (MA), DTS-HD Encore* (Note this is actually not a sound format but rather a standard set forth for DTS-HD which is in fact the DTS-CORE of 1.5mbps bitrate)

 

More breakdown for you on the DTS-HD...

 

1) DTS-HD HR - capable of getting 96/24bit for a maximum of 7.1 channels. The maximum bitrate attainable is about 6.0mbps on Blu-ray discs and 3.0mpbs on HD-DVDs. Decoding DTS-HD HR requires at least HDMI 1.1 or higher capable AVR/Amp, unless it is decoded by the player and output via the analog outputs.

 

 

2) DTS-HD MA - the best there is - so-called but at present there's no hardwares capable to do the decoding as yet. If you're using a normal DTS-capable AVR/Amp to play Fox Century released Blu-ray titles such as AVP for instance, you can always assured of at least 1.5mbps bitrate - meaning still sound awesome as opposed to a normal SD DVD bitrate. Like DTS-HD HR, its capable of performing 96/24bit processing and can go even higher to 192/24bit if the studio which engineer the Blu-ray titles choose to...but I seriously doubt it lar. DTS-HD Master Audio requires an HDMI 1.3 or higher connection to a DTS-HD Master Audio decoder. HDMI 1.1 or 1.2 may also be used, but that requires that the audio data be sent to the AV receiver in Linear PCM form instead of raw DTS-HD Master Audio. A possible third option is that the audio is decoded by the player and output via 6-8 analog outputs.

 

 

Now let's talk about Dolby TrueHD and Digital Plus (DD+)...

 

Dolby TrueHD, like I mentioned earlier is akin to DTS-HD MA except that the maximum bitrate attainable is about 18mbps on HD DVD as well as Blu-ray titles. But that doesn't mean it will sound inferior when compared to DTS-HD MA...remember the figure are at best theoritical values and does not necessarily translates to higher bitrate will mean better sound reproduction for a movie.

 

Breakdown for you on Dolby TrueHD, Digital Plus

 

1) Dolby Digital Plus (DD+) - provides a somewhat similar sound quality to that achievable by DTS-HD HR Audio format. It can supports bitrates as high as 6.0mbps or at least 3.0mbps on HD DVDs and up to 1.8mbps on Blu-ray discs. Capable of supporting more than 8 channels of 96/24bit. You need at least an HDMI AVR/Amp wth DTS decoding function. A normal HDMI AVR/Amp will process it at a bitrate of 640kbps in LPCM format as opposed to a normal 384kbps bitrate used by normal SD DVD titles. If you are using Toshiba range of HD DVD Players (e.g. E1, XA2 etc)...you should let the Player do the decoding in order to pass the LPCM to your HDMI AVR/Amp to take advantage of ahigher bitrate processing.

 

2) Dolby TrueHD - provides up to 18mbps bitrates for 7.1 channels. Also uses 96/24bit processing mode here. This is supposed to sound better than DD+ but my experience tell me otherwise... :P

 

Hope that after you read through...you will have a better idea now. Question time? ;D

 

[Guest tonytakitani]

 

2) Dolby TrueHD - provides up to 18mbps bitrates for 7.1 channels. Also uses 96/24bit processing mode here. This is supposed to sound better than DD+ but my experience tell me otherwise... :P

 

 

Just to add, the Blu-ray "version" of Dolby TrueHD has a mandatory secondary DD 5.1 640kb track embedded onto the main audio stream, to provide backward compatibility with BD players that cannot decode TrueHD. Its the same function as the "core" DTS track in DTS HD-MA.

 

The HD DVD version of TrueHD doesn't have the DD track, for obvious reasons.

[dannyhgt]

 

2) Dolby TrueHD - provides up to 18mbps bitrates for 7.1 channels. Also uses 96/24bit processing mode here. This is supposed to sound better than DD+ but my experience tell me otherwise... :P

 

 

I can't agree more with my experience with Phantom of the Opera HD DVD which I just acquired.  Dobly TrueHD really sound inferior in this disc.  The whole soundstage practically collapsed.  Another musical HD DVD disc which I have, The Swan Lake, sounded even much better even though it is recorded in DTS only!  I wonder if  my settings are correct?  ???

[Quest88]

My question is.. if there is no hardware supporting DTS-HD MA, then why the big hooha about HDMI 1.3? I had assumed 1.3 was more coveted simply because it had the bandwidth to support higher res sound format and color.

 

Or are HDMI 1.3 AVRs able to be upgraded (firmware) next time to support?

So is it better  to hold out? Or is it relatively safe to get a HDMI 1.3 AVR?

Of course, your 3rd option for analog outputs remains valid but that's a separate thing.

[FookLai]

Two upcoming Denon Bluray player 3800 and 2500 are both able to send the DD TrueHD and DTS HD MA bitstream to receiver which capable to decode them like the Onkyo.

 

Fook Lai