7.1 vs 5.1

[Bam!]

Hey duders!

Let's have it....I want to know how you feel and what changes in sound you have heard from these two formats.

Tell about how you find it with PLIIx....

...with a DTS ES format or DD EX

....which movie made you decide which format.....

Do you think 7.1 is the future ?

[Aussie Geoff]

Comments on ProLogic IIx and 7.1

Bam,

Firstly 7.1 was good even before IIx, but IIx made it something really speacial...

...with a DTS ES format or DD EX

DD EX played without IIx duplicated the matrixed centre channel in the two rears - nice for fill in sound - gives good centre placement but not accurate for pans, sweepts accross the room etc. The same track with IIx gives discrete rear channels where the sound moves accross them based on placement, so for example a panning accross the rear of the room moves smoothly from speaker to speaker. Something like the openning scenes of Arni appearing in Terminator 3 are just so much better - the lightnig etc is exactly where it should be behind you.

DTS ES Matrix - same deal as for DD EX

DTS ES Discrete - Sounds great in 7.1 - can't seem to apply IIx to it on my RSP-1098 though...

....which movie made you decide which format.....

Lord of the Rings - The Fellowshhip of the Ring...

Do you think 7.1 is the future ?

Absolutely - it is backward compatable for 5.1 sysems but it is what the rear effects of "blockbusters" are mixed for. Plus it makes things sound great...

Geoff

[George Bellefontaine]

7.1... love it, love it, love it. Those two back speakers are even helping surround things out when there is no 6 o 7.1 decoding on the dvd. Nothing in particular made me switch to a 7.1 setup, just the fact I wanted a receiver that could do it and the Denon 3801 does it.

[Azeke]

7.1 is simply beautiful, via DoPro IIx, due to the stereo mixing of the center backs. Before, that I tried 7.1 and since it merely provide mono output to the rear, I just stuck with 5.1/6.1. Also, I saved money with 5.1/6.1 configuration.

Now, with 7.1 and DoPro IIx, I ended upgrading the Center Backs for acoustical symmetry with my current system. Now, man it's indescribable, I wouldn't go back, of course you must have the room and the speakers for it.

Also, now I have all these extra speakers laying around, that I probably should sell, oh well.

Hope this helps,

Azeke

[brucek]

I don't know guys. My feeling is that 7.1 will remain a niche product simply because of the inability for most people to fit that many speakers into their listening area. WAF also enters the fray.

I don't question its efficacy, just its acceptance. Are there really enough dedicated home theaters to make 7.1 fly. Not likely.

5.1 will remain the standard in my humble opinion - you may feel free to disagree.

brucek

[Bent]

Brucek,
you are absolutely correct, I'm fortunate in that my listeng room (I wish I could call it a theater, but I'm just not comfortable doing so) is about 28 feet deep, so I have my primary seating area in approx. the center. This affords me the room to have direct radiating rear surrounds placed about 13 feet behind me and a pair of di-poles to either side. Most rooms have the "couch" against the back wall....

[Chris D]

I love my 7.1 setup. My Parasound Halo processor doesn't have DPLIIx, but it always automatically recognizes DD EX and DTS ES when present, so I use those. On non-7.1 material, I'll use the THX Ultra 2 processing for a 7.1 experience.

[Aussie Geoff]

Hi,

Most rooms have the "couch" against the back wall....

I have a large wide room (8.5 metres wide and 5.5 metres deep) but my couch is still against the back wall looking across the 5.5 metres (about 18 feet)

Anyhow, after lots of research (including advice from Dolby Labs) I put in two high quality ceiling speakers above the back wall about 2 1/2 foot out and spaced so that they were equal distances with the side surrounds (full range bookshelves). These speakers allow the high frequency to be directed - I have them a little against the back wall. Bottom - line for HT it is magnificent - most effects are things like rain, and things flying overhead (billets, plains, dinosaur tails etc) and the position these perfectly... Probably the only area where there is a noticeable compromise is some multi-channel music where they have an instrument playing behind you (e.g. Cello) which is now overhead! - However I go months without having this happen as most things are mixed for high speakers.... (and I get a better experience than a friend who has rears at normal listening hight where they are just too close to the listener)

I'm not saying this is perfect - with a much larger room I would have the speakers behind - but it is surprisingly good - and (IMO) makes 7.1 accessible for many more people.

Geoff

[Chris D]

For me, my theater has two rows of seating. The back row is about 2 feet from the back wall to allow for reclining, which works okay, but even better is the front row of seating with is about 6-8 feet from the back wall.

[purplepeople]

Really, there is media that has 7.1 discrete channels of encoded audio? I know that at an AES meeting a couple years ago, Holman showed off a 10.2 channel mix (or something like that), but I didn't think that kind of stuff would show up in the discs so soon. The studios would have to install first, then media availability and only then would playback systems be needed.

As for whether it will be worthwhile having, I say yes.

But in most cases, I don't think the general population will even note the difference. It would certainly be more difficult to tell without physical space between your ears and the speakers and also between the speakers themselves. Without the real estate, there would be a lot of "dead" areas where sounds are supposed to localized, but can only be done with phantom placement. IOW, 7.1 would be mostly unnecessary with seats against the wall and/or a small room.

Now with a large enough room, the speakers would have a chance to stretch their legs (so to speak). In the same way that LS and RS channels were created to get the surround channel out of the "dead" area directly behind my skull, I was under the impression that 7.1 helps to get the 6th channel out of that same muted zone.

To be honest I was surprised (and disappointed) that they even came out with 6.1 since both Dolby Labs and DTS should have applied the original lesson of doubling the rear channels during the upgrade from Hafler matrix to ProLogic.

ensen.

[Bam!]

Bam,

Firstly 7.1 was good even before IIx, but IIx made it something really speacial...


DD EX played without IIx duplicated the matrixed centre channel in the two rears - nice for fill in sound - gives good centre placement but not accurate for pans, sweepts accross the room etc. The same track with IIx gives discrete rear channels where the sound moves accross them based on placement, so for example a panning accross the rear of the room moves smoothly from speaker to speaker. Something like the openning scenes of Arni appearing in Terminator 3 are just so much better - the lightnig etc is exactly where it should be behind you.

DTS ES Matrix - same deal as for DD EX

DTS ES Discrete - Sounds great in 7.1 - can't seem to apply IIx to it on my RSP-1098 though...



Lord of the Rings - The Fellowshhip of the Ring...



Absolutely - it is backward compatable for 5.1 sysems but it is what the rear effects of "blockbusters" are mixed for. Plus it makes things sound great...

Geoff

Geoff...always a pleasure to read your responses....

I have a question though....PLIIx is to create a feeling of 7 channels from a 5 channel or 2 channel source...right ? Then if so....DTS ES discrete is what a 6 channel ...then how can PLIIx work ?.....

Thanks again!

[Aussie Geoff]

Great Question

Bam,

In a 5.1 set-up there are two discrete rear channels, left and right. Sound mixers wanting to position a sound in the middle rear would mix these equally in the left and right channels. A bit louder in the left channel than the right makes the ear think the sound is a bit to the left, louder in the right then the sound is to the right.

Dolby Digital EX takes this concept and applies it further by using the same matrix decoding for the front centre channel in Dolby Pro Logic to look for the common signal (in phase signal) for the rear left and right channel, remove it from the rear left and right channels, and play it in the centre one or two rear channels. A Dolby Digital EX encoder (used by the DVD lab) will take a discrete rear centre channel and mix it into the two left and right rear channels using matrix encoding. The same sound was played in both centre rear speakers (i.e. DD EX 7.1 had dual mono rear centres... Hence the THX EX recommendation for the two rear centres to be close to each other...)

Now (just like for Dolby Pro Logic) the Matrix process for the rear centre can be applied even to non EX encoded titles to extract a pretty good rear centre channel (basically sounds that are the same in both speakers). So many Reciever and HT processors have a 6.1 Matrix option (or similar name) or let you apply DD EX processing to any 5.1 encoded source...

Following this so far....

Now for Dolby IIx they went one further and said - if you have 2 centre rear speakers, then let’s use the difference in sound volume between the left and the right to vary how much sound is in the rear centre left and rear centre right speaker. IE if the sound was stronger in the left rear channel than the right more to the left then it was put in the left rear centre, etc. In this way smooth sound movements between the rear left and rear right through the two rear centres are possible based purely on the varying volume of common sounds between the left and right rear speakers.

For example a sound that was 75% volume in the rear left and 25% in the rear right would be mostly put in the left centre, while one that was equal volumes for rear left and right would be put in the left and right centres, with one that is 25% in the left rear and 75% in the right rear would be mostly put in the right centre rear. By varing the relative common sounds from 100% left to to 100% right the sound can be moved smoothly accross all 4 speakers.

Once again this is all backward compatible with 5.1 since the processor can look for what the sound volumes were between common sounds in the rear left and right channels. Equally it is backward compatible with 6.1 since that encoded the centre rear channel as a matrix signal in both the rear left and rear right channels anyway...

DTS uses a similar system for DTS ES Matrix. There is a slight complication for DTS ES Discrete, since that actually had a separate 6th rear centre channel - making any IIx processing a little more complex (probably why my RSP-1098 can't do IIx processing on it!)

For more on all this and other formats Here is a link for Dolby as to how their Cinema Sound works DOLBY

and one from Secrets of Home Theatre SECRETS

And - to see how the source Cimena Sound Formats work HOW IT WORKS

I hope this helps!

Geoff

[Harl]

Goeff,
I have a 1098 as well. Boiling all this down, if you are playing an EX encoded disc, ie; star wars, etc, terminator, etc., is it best to use PLIIx or DD EX? I do understand on all other DD 5.1 or lower stuff that IIx is the best, but what about EX discs?

[Aussie Geoff]

Harl,

Dolby Digital EX will pay way better (stereo rears) with IIx in 7.1, about the same in 6.1 and no real difference in 5.1.

Having tried all sorts of options I leave my 1098 in IIx Cinema for movies (DD and DTS). Its better. Dolby Labs recommend this too.

Geoff

[Harl]

Geoff,
Thanks! I have been using IIx for all since it was available on my last upgrade and think it sounds great (i run 7.1). I just started wondering about the EX thing with the release of the new star wars discs. And thanks for all the great info you give on HT and Rotel issues to all on this site!

[Bam!]

Geoff......very nicely put....thanks!