Dolby Digital 5.1 vs Dolby Digital 5.1 EX??

[inglourious basterd]

The Seven: Platinum Series, Cast Away, and Episode One feature this sound system and they all have extraordinary sounds. My question is that is there a difference between 5.1 and 5.1EX? Does it require a different amplifier/setup? If so, how do you do so? Anyone? STEEEEEEEEFAN!!? lol...if I could get any opinions, it would be much appreciated.

[stefanb]

Geeze... how come when the problem requires a technophile wire geek, people suddenly know me by name? That's starting to concern me. http://www.joblo.com/ubb/biggrin.gif

-S

Here's the FULL scoop:

http://www.timefordvd.com/tutorial/SurroundSound.shtml

But here's the part you're after:

THX Surround EX™ & DTS Extended Surround™ (DTS-ES™)

Just when you thought 5.1-channel Dolby Digital and DTS surround sound were enough, at the leading edge today are two new "Extended Surround" formats, namely THX Surround EX™ and DTS Extended Surround™ (or DTS-ES™ for short).

The THX Surround EX format is jointly developed by Lucasfilm THX and Dolby Laboratories, and is the home theater version of "Dolby Digital Surround EX™", an Extended Surround sound format used by state-of-the-art movie theaters. Lucasfilm THX licenses the THX Surround EX format for use in receivers and preamplifiers. And as of November 2001, Dolby Laboratories has begun to license what is THX Surround EX under its own name, Dolby Digital EX™, for consumer home theater equipment. (Since THX Surround EX and Dolby Digital EX are equivalent, we will refer to THX Surround EX and Dolby Digital EX interchangeably, with preference for the former since that name has been around longer.)

THX Surround EX is the Extended Surround version of Dolby Digital 5.1, while DTS-ES is that of DTS 5.1. The difference between the new Extended Surround formats and their 5.1-channel surround sound counterparts is the addition of a surround back channel, whose corresponding speaker is placed behind the audience. This allows certain soundtrack effects to be presented behind the audience, thereby achieving more enveloping and complete 360° surround sound. (Remember that in the 5.1-channel surround sound formats, the surround speakers are placed one on each side of the audience - not behind them.) Additionally, while the Extended Surround sound format calls for one surround back channel, two surround back speakers are generally recommended for better envelopment. Acknowledging this widely accepted industry position, some high-end receiver manufacturers have introduced "7.1-channel" capable receivers, with decoding and sometimes amplification for the two extra surround back channels.

Both THX Surround EX and DTS-ES Matrix surround sound encode the surround back channel information into the surround left and surround right channels (similar to the way the center channel is encoded for Dolby Surround Pro-Logic). This cross-channel encoding is referred to as matrix encoding, since the surround back channel is encoded and later decoded (or derived) from those of the surround left and surround right channels. Because of this matrix encoding scheme, the surround back channel is not a true discrete channel and is technically considered a 5.1- channel format. And for this reason, they are sometimes referred to as "Dolby Digital 5.1 EX" or "DTS 5.1 ES". To refer to these matrix encoded Extended Surround formats as 6.1-channel would be wrong. (When we use quotes, as in the "7.1-channel" reference above, we are recognizing that it may not be a true discrete 7.1-channel system.)

[Tyler Dyrden]

Dolby Digital 5.1, Dolby Digital 5.1 EX what's the difference, they're are the same. just kidding, but i dont really understand all that shit so i guess im not any help.

[inglourious basterd]

Well...i dont consider you a geek (although that might be the best word for your vast knowledge http://www.joblo.com/ubb/smile.gif ). The thing is that all the schmoes are appreciative of it. Thanks for the help. http://www.joblo.com/ubb/smile.gif

[stefanb]

<font face="Verdana, Arial" size="2">Originally posted by Tyler Dyrden:
Dolby Digital 5.1, Dolby Digital 5.1 EX what's the difference, they're are the same. just kidding, but i dont really understand all that shit so i guess im not any help.</font>

He he he... That's ok man... would a picture help any? I just sat down for 2 seconds with Microsoft paint... you'll have to forgive my shitty art skills. The red circles are speakers. the picture on the left is DD5.1, while the picture on the right is DD5.1EX

http://www.lfchosting.com/regflycl/x/51ex.jpg

[This message has been edited by stefanb (edited 12-10-2001).]

[[SD] Bob Plisskin]

so why aint it just DD7.1?

&lt;OB&gt;

[stefanb]

Good question... it's not called 7.1 for the exact same reason that Dolby Stereo (2 channel) isn't called 5.1 simply because you hit the "surround sound" button on your stereo.

VHS tapes are recoded in 2 channel Stereo (only left and right "discrete" signals), but when you play them in surround sound, you get sound out of all 5.1** speakers. How does that work? Basically, the other channels are encoded into the channels that already exist, and those channels are later "pulled out" and played separatly. However, just because your stereo can turn 2 channels into 5.1**, doesn't make it 5.1** -- it's still 2 channel, just playing on surround sound.

This 5.1EX concept works the same way. The two "extra" rear channels are encoded into the two existing rear "discrete" surround channels. They're not a distinct channel, or it would be 7.1 -- The rear channels are played in the exact same way that the center channel is played when you play a VHS tape on surround sound (consider this: your VHS tape doesn't have a center channel... How did you think it made the center channel play sounds when you watch a tape on 'surround sound'?). This is also the reason that really old 2-channel movies sound like shit in a surround sound system. They were never encoded with the intention of being played in a full surround sound system, hence, it sounds like shit.

Hope that answers it for ya.

**5.1 - To answer the next question someone might have (who knows)... why is it called "5.1" and not just "6"?

5 = 5 FULL FREQUENCY channels.
.1 = 1 PARTIAL FREQUENCY channel.

Your subwoffer doesn't count as a channel because it's only encoded to handle very low frequency sounds. Since it can't physically play high frequency sounds, it's not considered a "channel"... only "part" of a "channel" Hence 5.1 - 5 full, 1 partial channels. You may often see it written as "3/2.1" which is the EXACT same as "5.1", just written to show: "3 front, 2 rear, 1 sub-freq channels"

If you see "3/1.1", that means "3 front, 1 rear, 1 sub-freq channels". In this case the two surround sound speakers play the exact same sounds as each other.

"3/0.1" = no surround sound speaker sound... just left/right/center/sub.

"2/2.1" = Left/Right/Left Rear/Right Rear/Sub

"2/0.0" = Left/Right only.

"1/0.0" = Center channel only (the A Clockwork Orange DVD is the only one I've seen like this)

you get the idea...

-S

[This message has been edited by stefanb (edited 12-12-2001).]

[inglourious basterd]

stefan...does your line of work coincide in any way with audio/video/computer information? Thanks for the pretty clear explanation...it was clearer than the audiophile sites Ive seen on the net. Thanks again http://www.joblo.com/ubb/smile.gif

[stefanb]

<font face="Verdana, Arial" size="2">Originally posted by psudoazn:
stefan...does your line of work coincide in any way with audio/video/computer information?</font>

Work... Nothing stereo related actually. I do computer work, but any stereo skill/knowledge is simply because that's what I do to keep myself entertained. I'm mildly obsessive with it at times. Check out the picture below... That's a surround sound speaker in my living room. There's one hanging from the ceiling like that in each (rear) corner of the livingroom. There's a few things worth noting about it. First, The surround speakers that come with your basic stereo SUCK! They're tiny, shitty, and sound terrible. If you want a good surround sound speaker, go buy a 3-way, 6x9 speaker that's actually made for high-power car stereos, and box 'em up. They work soooo awesome like this. I thought the gold colored chains were a nice touch for hanging them. Secondly, you'll notice the wire runs straight into the wall. Why's that? Well, I actually re-drywalled, and re-painted my entire livingroom just to run the wires inside the walls. http://www.joblo.com/ubb/biggrin.gif Obsessive? Me? Well, maybe a little. http://www.joblo.com/ubb/wink.gif So it's just a hobby... albeit I do go rather over-board at times. One of my more famous moments (at least for those who were there) was when I had to stop the movie U-571 half-way through because of the base during the underwater attack scenes. It was making the baseboards around the livingroom vibrate and that made a terribly annoying noise, so I had to add a layer of paper-towel underneath them and then screw them down about 10 times more then any normal baseboard in the world has ever been attached. I've managed to get the entire room rattle-proof over the last year (not an easy task). That's why those surround speakers are hung like that... there's NO WAY that can rattle agaist a floor/wall/stand/ceiling/etc. Unfortunally, the door-knobs (of all things) on the bedroom doors down the hall still rattle during loud scenes, but there's noting I can do about that. C'est la vie... http://www.joblo.com/ubb/biggrin.gif

So you kinda get an idea of how I watch movies. I just finished Jurassic Park III earlier tonight. despite being a so-so flick, it'll certainly keep you awake at full volume. http://www.joblo.com/ubb/biggrin.gif

http://www.lfchosting.com/regflycl/x/spk.jpg

[This message has been edited by stefanb (edited 12-12-2001).]

[stefanb]

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[This message has been edited by stefanb (edited 12-12-2001).]

[inglourious basterd]

Crap stefan...

We have a Bose Acoustimass 15 System (the one with the powered subwoofer) and its been working pretty great for us. In your system, wouldn't there be more base than the average home theater setup? How does that work for you?

[stefanb]

It's only during certain scenes in certain movies where it hits just the right frequency and shit starts vibrating. I have a paradigm sub, but here's the thing with ANY half-ass decent sub. The sound is about 90% placement, and only about 10% power. Just find the right place in the room for your sub, and it'll shake your world. Move it all over until it sounds best. Typically, I've found that aiming the back end of it into a solid corner of the room works best. Sit it 2 feet from the corner on a 45-degree angle pointing towards the center of the room. It's freaky the difference it makes just sitting it in the right place. You'll notice that in most stereo stores... the subs that you get to hear on display are always being fired into a corner because it's the only way they can make a lot of base in a really big store (and that's the only way to make people buy it). Luckily, your livingroom is smaller then a stereo store, so it's quite a bit easier to make a lotta boom. You get WAY more base out of it that way, then just sitting it 'somewhere' in the room at random. The cool thing with the subs is that, when done right, you have no idea where it's coming from, so it doesn't matter where you sit it.... it's not like you're going to hear a bunch of base coming from "that corner over there". Try it.

<font face="Verdana, Arial" size="2">Originally posted by psudoazn:
In your system, wouldn't there be more base than the average home theater setup?</font>

In my system, there's a lot more everything than the average home theatre setup. http://www.joblo.com/ubb/biggrin.gif So yea, there's a lot of bass, but thers's a lot of every other speaker to go with it (so it's not just over-powering bass sounds). You don't really talk during movies at my house... during any sort of loud scene, you can't hear each other anyway... that's why I bought a phone that "lights up"... because you can't hear it ringing. http://www.joblo.com/ubb/smile.gif heh he he... There are times when even I think I'm completely nuts. The first time the thought crossed my mind is when the stereo store sent me a christmas card last year (dead serious about that).

[This message has been edited by stefanb (edited 12-12-2001).]