Is my A2 giving me 'Free DTS'?

Frank@N · 09-01-2007, 05:45 PM

My A2 is connected to my HDTV by HDMI and my A2 HDMI audio option is set to PCM (not PCM Downmix).

My sound system connected by RCA cables from the TV and is much, much older (circia 1994).

I haven't ditched the sound system yet because it's an intergraded system and still sounds pretty good (Sony SA-VA3).

It's a Pro-Logic system (left, right, center, mono surround). Bass is skimmed off the other channels.

Since the A2 can decode DTS, I've been play around with some Superbit DVDs recently.

Everything sounds good and things get very loud very fast, but I find myself manually adjusting the volume up and down more than with Dolby Digital.

All channels appear to be very active, is my A2 giving me 'Free DTS'?

Frank@N · 09-02-2007, 02:25 AM

Maybe I should have put this in "High Definition Player - HD DVD Owners".

TonyD · 09-02-2007, 12:32 PM

i dont understand your post.
what do you mean "free dts"

i have an xa1 and it displays all sound as dts unless i listen to a truehd track through the aux.

Jason Roer · 09-02-2007, 01:04 PM

If you do not have DTS on your receiver, you are not getting DTS. What happens with the TrueHD/PCM tracks is they are converted automatically to DTS if you have a DTS decoder onboard your receiver (and you don't have a receiver that handles TrueHD). Based on your initial post, I suspect what is happening to you is the signal is being output as Prologic decoding by your receiver. It will still sound fantastic, but when you eventually upgrade, it will be worlds of difference for you! A nice bonus for the future!

Cheers,

Jason

TonyD · 09-02-2007, 01:12 PM

yes, thats what happens with my xa1 and denon 3803

**HTF Ads**

Frank@N · 09-02-2007, 11:02 PM

Well, for the sake of argument, let's just talk about DTS DVDs...

I put in a DVD and select the DTS soundtrack, the A2 decodes DTS and outputs...'something'.

Again, my A2 HDMI is set to PCM (whatever that means).

That 'something' is then recieved by my Pro-Logic sound system and then...(?)

What's coming out sounds good, but I like'd to understand more of what's going on.

Prior to the A2, I was never able to even access a DTS soundtrack because I didn't have a receiver that could decode it.

Rolando · 09-03-2007, 12:16 AM

Well there are 2 answers to your question. Anyone please correct me if I am wrong.

First of all yes you are listening to the DTS track. But don't get excited yet. you are not listening to it as it was intended. As you mentioned your receiver cannot decode DTS. Now even though the player can decode the signal it has no way of sending the 6 digital tracks that it has decoded to your receiver. Instead what it can send is a 2 channel PCM track/signal that your receiver in turn seems to be processing as Dolby Surround.

So to try to put in simple terms

your HD-DVD player can read the DTS track on your DVDs and is conterting it to a stereo (2-channel) PCM track and is sending that either to your TV through the HDMI or to your receiver (or bother) either through coaxial or composite (red and white audio wires) I assume. Your receiver is coverting it to a surround track using dolby surroung decoding.

make sense? Point is you are not listening to DTS 5.1 all of a sudden.

Frank@N · 09-03-2007, 11:15 PM

Thanks for the info, but what's odd is that the DTS track maintains the kind of dimensionality that you never get from just a stereo track.

For example, there's a DTS 'trailer' that plays before the movie on some Superbit discs (you don't see it if you start the movie with Dolby Digital).

It's a short trailer, but the sound builds in the front channels before rushing over head to the rear speakers.

I've also watched entire movies using the DTS soundtrack and the results appear to be very much on a par with the hundreds of 5.1 movies I've watched at home since 1994 on this sound system.

Keep in mind, I am using the A2's 'PCM' option and not the 'PCM Downmix' option.

Also, my reciever/sound system only has RCA input plugs, so I know it can recieve multi-channel soundtracks over two physical channels.

Perhaps there are similarities between the data streams of various decoded 5.1 formats (?) and the Pro-Logic hardware is able to more-or-less handoff the various streams to various channels?

Although I have noticed a slight loss of volume on dialog and bass, which leads me to think that something is not quite 100% right.

But there is a garbage-in/garbage-out angle to be considered, in that most Dolby 5.1 tracks are older than DTS tracks and have less actual sound data.

Even a partially understood DTS track could sound better than a 90's, bit-poor Dolby track.

Jack Gilvey · 09-04-2007, 06:37 AM

Yeah, sounds like you're hearing a stereo track processed with Pro-logic. As you noted, better quality source will sound better since the receiver has more to work with, although it doesn't approach the quality of actual discrete 5.1 DTS.