Playing ES or EX Material Out Of A 5.1 Array...

Scott Adam · 07-30-2003, 10:37 AM

Hello Again Friends,

While I continue to take under advisement the suggestions that were made to me regarding my last post about calibrating my Onkyo TX SR600 "properly" with an SPL meter and such (see "Issues With My Onkyo TX SR600..."), I have some more questions for you insightful, most helpful lads -- a question that I never really understood the answer to when someone attempted to provide such an answer under a totally different post...

As everyone in here knows, Onkyo's TX SR600 is a 6-channel unit, but because my system is set up in a studio apartment and the listening area is small, I am only running a 5.1 speaker array; my couch and sweet spot is smack right up against a wall, with the wall unit housing all my surround gear opposite on the facing wall; there's only about nine feet between the sweet spot and the wall unit. And so, I opted not to buy that back surround channel because it would literally have to sit on the wall right behind the listener's head. Now, I have heard all the debates regarding whether or not 6.1 and 7.1 is worth the effort, heck I have started a lot of them---but I had just thought because of my apartment's space, 5.1 would do fine...if anyone has any disagreements on this, please fire away...

But my dilemma is this: I have a handful of DVDs in my collection which have "extended" 6.1 soundtracking -- off the top of my head, I believe this includes Gladiator (DTS-ES), The Exorcist: The Version You've Never Seen Before (DD EX) and Attack Of The Clones (DD EX)...all the rest of the discs in the collection are all standard 5.1 Dolby Digital or standard DTS. Even though I do not have that sixth back surround channel to enjoy DTS-ES or DD EX films, I always choose the DTS ES or DD EX soundtrack from a certain film's menu before beginning the DVD because I actually HEAR a distinct difference between the sources; for instance, when I play back Gladiator, I CHOOSE the DTS-ES soundtrack on the menu---NOT the DD 5.1 soundtrack---because I can swear it sounds SO MUCH better...yet, I have no back surround speaker(s) for this DTS-ES mode...

So, my question is this...what is "happening" when I play back 6.1 processed DVD information WITHOUT that sixth channel in my system? Am I "losing" any information by playing back a soundtrack with six channel sound yet I have no sixth channel? I have heard COUNTLESS theories on this topic; people have told me that because my receiver is set up to acknowledge that there is no back surround speaker, when I play back soundtracks with 6.1 sound, that sixth channel's sound is actually being MATRIXED and fed between the two rear surrounds and what I am hearing is a ghost or phantom center surround effect when sitting directly between the two rear surrounds...should I be playing DTS ES or DD EX soundtracks even though I only have a 5.1 setup? Is anything being "lost" here? And what is happening in my system when you choose for a DVD to play back in one of these modes --- DD EX or DTS ES --- and yet there is no extended sixth channel present? Am I hearing that back surround channel in a "ghosted" matrixed signal between the rear surrounds?

If someone can explain this as plainly as possible, I would greatly appreciate it.

"Someone in this camp aint who appears to be....right now thats one or two of us...by spring it could be all of us...."
-Kurt Russell, "John Carpenter's The Thing"

John Garcia · 07-30-2003, 11:11 AM

This same question, and variations upon, is asked about every other week. Try a search, it has been covered quite extensively.

Scott Adam · 07-30-2003, 11:14 AM

Thank you, John...but can anyone else perhaps lend some insight to the questions I'm having regarding playing 6.1 material through a 5.1 system?

"I dont give a f***ck about your war.....or your president..."
-Kurt Russell, "John Carpenter's Escape From New York"

Michael Reuben · 07-30-2003, 12:57 PM

First of all, your description of the formats needs refinement.

DD Surround EX is a 5.1 format, not a 6.1 format. Even Dolby says so.

DTS-ES Matrix is the same.

The only "6.1" format is DTS-ES Discrete. The only title you've named in that format is Gladiator. Titles encoded in DTS-ES Discrete are also backward compatible with DTS-ES Matrix; all of the sounds in the rear center channel are also matrixed into the rear left and right, and the decoder handles which "version" of those sounds is used, depending on the equipment and configuration.

All of these formats are designed and geared toward 5.1 playback, which is the still the common denominator. All of the sounds for the rear back channel are present for 5.1 playback. One could describe the effect, in a properly configured 5.1 system, as a "phantom" back center channel, but the description really isn't meaningful. It makes sense to talk about a phantom front center, because the front center is almost constantly active -- it's where the main audio "action" of the film occurs. A rear center channel, by contrast, will generally be limited to incidental effects and won't have enough of a continuous presence to constitute a "phantom" extra channel.

The rear center channel was originally conceived to facilitate sound pans, such as fly-overs and fly-bys. It was conceived for the theatrical venues, where there was often a "gap" in the surround field because of the typical arrangement of speakers in an auditorium. The same problem doesn't present itself in the typical home theater, where two properly placed rear speakers may be more than enough to create a coherent soundfield. IMO, the preoccupation with "6.1" and "7.1" setups has more to do with the desire of hardware manufacturers to sell more gear than it does with any significant enhancement to the home viewing experience.

M.

P.S. John Garcia is right. This has been covered numerous times. And now once more.

Scott Adam · 07-30-2003, 01:10 PM

"First of all, your description of the formats needs refinement.

DD Surround EX is a 5.1 format, not a 6.1 format. Even Dolby says so.

DTS-ES Matrix is the same.

The only "6.1" format is DTS-ES Discrete. The only title you've named in that format is Gladiator. Titles encoded in DTS-ES Discrete are also backward compatible with DTS-ES Matrix; all of the sounds in the rear center channel are also matrixed into the rear left and right, and the decoder handles which "version" of those sounds is used, depending on the equipment and configuration.

All of these formats are designed and geared toward 5.1 playback, which is the still the common denominator. All of the sounds for the rear back channel are present for 5.1 playback. One could describe the effect, in a properly configured 5.1 system, as a "phantom" back center channel, but the description really isn't meaningful. It makes sense to talk about a phantom front center, because the front center is almost constantly active -- it's where the main audio "action" of the film occurs. A rear center channel, by contrast, will generally be limited to incidental effects and won't have enough of a continuous presence to constitute a "phantom" extra channel.

The rear center channel was originally conceived to facilitate sound pans, such as fly-overs and fly-bys. It was conceived for the theatrical venues, where there was often a "gap" in the surround field because of the typical arrangement of speakers in an auditorium. The same problem doesn't present itself in the typical home theater, where two properly placed rear speakers may be more than enough to create a coherent soundfield. IMO, the preoccupation with "6.1" and "7.1" setups has more to do with the desire of hardware manufacturers to sell more gear than it does with any significant enhancement to the home viewing experience.

M.

P.S. John Garcia is right. This has been covered numerous times. And now once more."

First of all, let me say thank you Mike for responding to this. I understand John is right that this has been covered numerous times---I even acknowledged the fact as such in my last post. But last time, it was extremely unclear to me, as it still is, because you are explaining this phenomenon in methods not easily understood by the Home Theater noobie.

So, now, that said, I must turn my attention toward some other references you make, most notably, the fact that Dolby Digital EX is 5.1 soundtrack---if this is so, can you please explain what the "EX" badging is referring to? I thought EX referred to an "extended" channel or signal of some kind beyond 5.1...this is incorrect? And the what of the Attack of the Clones DVD---same 5.1 DD EX soundtrack?

I know Gladiator is a true, discrete DTS ES 6.1 soundtrack---it clearly states on the box that it pumps out 6.1 channels of audio. But Im lost on the Dolby Digital EX thing; what is the DIFFERENCE between DD and DD EX then if they are both 5.1? Just some added ambience effects in the rears?

So then, if mostly marketing hoopla, can I play back DVDs such as Gladiator in their DTS ES DISCRETE six channel mode even though I only have 5.1 speakers? And then WHERE is that back surround channel's info going since I have no sixth back surround speaker?

"Captain Yates tells me you have a problem understanding what these men are in here for...maybe thats because as long as you can kid yourself into thinking theyre just men and not inmates, you can also kid yourself into thinking that you're not a guard....I SAID TURN AROUND!!!"
-Cedric Forrest, "Against The Wall"

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Michael Mohrmann · 07-30-2003, 01:48 PM

Scott,

Information about Dolby Digital EX can be found at:

http://www.dolby.com/ht/co_br_0110_L...rsGuideEX.html

Here's a quote from that page:

"The additional back surround information is encoded onto the regular left and right surround channels of otherwise conventional Dolby Digital 5.1 soundtracks. In cinemas equipped with Dolby Digital Surround EX decoding, the added information is reproduced as a third surround channel. In cinemas without Surround EX decoding, the extra information is played through the regular left and right surround channels, so no information is lost."

Quote:

So then, if mostly marketing hoopla, can I play back DVDs such as Gladiator in their DTS ES DISCRETE six channel mode even though I only have 5.1 speakers?

Yes.

Quote:

And then WHERE is that back surround channel's info going since I have no sixth back surround speaker?

Try the following link:

http://www.dtsonline.com/home&car/ov...?ID=1026399626

Here's a quote from that page:

"Any DTS-ES track is fully compatible with 5.1 decoders because the center surround channel information is matrixed into the LS and RS channels and will thus be heard in and between the LS and RS speakers."

I hope that helps explain how the modes work for a 5.1 setup.

Michael

Michael Reuben · 07-30-2003, 02:00 PM

Quote:

So then, if mostly marketing hoopla, can I play back DVDs such as Gladiator in their DTS ES DISCRETE six channel mode even though I only have 5.1 speakers?

A small refinement on the other Michael's "yes".

Yes, if the decoder/receiver has been properly set up so that it knows not to send any sound to a rear center speaker that isn't there.

Quote:

if this is so, can you please explain what the "EX" badging is referring to?

It refers to the fact that a separate rear center channel was prepared and then matrixed into the left and right for extraction by a matrix decoder. Because the rear center is delivered in a matrix format, it is not an additional discrete channel, and that is why it is not a "6.1" format.

Long before anyone had hear of 5.1, soundtracks were created with four channels (left, right, center, rear) matrixed into stereo. However, those formats are correctly characterized as 2.0, although that notation was not in vogue at the time.

M.

Scott Adam · 07-30-2003, 02:02 PM

Michael,

Thanks a million for the info and links...but let me ask you this now...the Michael from NYC who posted before you says that Dolby Digital EX IS NOT a six channel format; Dolby's website you pointed me toward claims DD EX ADDS to a DD 5.1 soundtrack with an EXTENDED channel...would this not mean SIX point one surround? Why is it still known as 5.1 if there is an EXTENDED algorithym going on here?

And if these 6.1 soundtracks are backward/compatible with 5.1 systems like mine, and you dont need a back surround channel to play them as you are all telling me....then why do people BUY six channel receivers and a back surround speaker? If the 5.1 setup will allow you to hear these 6.1 DVDs, why purchase the extra gear or channel(s)? Seems like everything is compatible with everything, or am I missing something?

Scott Adam · 07-30-2003, 02:09 PM

So, are you all telling me that when I sit down to watch, say...The Exorcist DVD, which boasts a DD EX soundtrack only, and Im running a 5.1 system, that "extended" signal in the soundtrack is being heard between my rear surrounds? I am actually getting the EX effect between them?

BUT when I view DISCRETE six channel DVDs like Gladiator, and run it in DTS ES mode, am I hearing a "ghosted" center surround image through my 5.1 system if I am sitting right between the surround left and right? What kind of info am I "missing" by playing a DISCRETE 6.1 channel DVD through my 5.1 setup? What is happening then?

Thank you all for your continued assistance....