5.1 Vs 7.1

Movieman

I'm setting up a small home theatre. Does anyone know if 7.1 is really any better than 5.1?

concealer404

Movieman wrote: »

I'm setting up a small home theatre. Does anyone know if 7.1 is really any better than 5.1?

Depends on room size and budget....

You said "small," so i'm going to guess "no."

Movieman

Just to provide more detail - the room is 14 feet by 11 feet and I will have 5 or 7 in-wall speakers (plus a sub) depending on if I choose 5.1 or 7.1. The speakers will be in the front and back walls, with the extra two speakers in the ceiling. I'll have a sofa around 11 feet from the front wall and against the back wall I will have a raised platform with 4 movie theatre seats.

concealer404

5.1.

Knucklehead

Yep I agree, not many movies formatted for 7.1 anyway.

thuffman03

Stick with 5.1.

SoundEsc

The new 7.1 format like Dolby PLIIz Height and Audyssey DSX are definitely worth looking into. I wouldn't invest in a new receiver without these two formats.

The two extra front heights or front wides speakers add great effects to any movies or games.

Check out these reviews, and decide:

Dolby PLiiz Height Review

Audyssey DSX Review

wutadumsn23

concealer404 wrote: »

5.1.

Knucklehead wrote: »

Yep I agree, not many movies formatted for 7.1 anyway.

+1 and +1, lol. Stick with 5.1 and you will be fine, no sense cramming in two extra speakers that you won't even notice are there. A well set up 5.1 will outperform a cramped up 7.1 anyday.

-Jeff

cnh

Dolby heigh effects are pretty much 'synthesized' sound or sound that is matrixed from other channels--so I would argue that it is too early in the development of this format to really say that it has been perfected.

When we actually have 9.2 discrete channels of information and a room large enough for all that, then I might consider upgrading to this format. Till then I agree with the others above...that room is a tad small for so many speakers...think of all the reflection and timing problems a 9.2 system would present it with?'

cnh

kuntasensei

Knucklehead wrote: »

Yep I agree, not many movies formatted for 7.1 anyway.

I hate when people say this, because there's a misconception that if it's not a discrete channel, there isn't audio intended to be there. Let's be clear: Pretty much every movie created for the theater today is mixed with rear channel audio matrixed into the left and right surrounds by the very nature of how mixes are done. 7.1 is simply a way to bring the rear channel audio of a theater's speaker array system into a smaller home space using 5.1 soundtracks.

So while you don't see many 7.1 discrete mixes on home video (nor do you need to - they're usually created the same way your AVR processes them anyway, then encoded to discrete channels), there is still a very clear advantage to having a 7.1 system and using DPL-IIx to create the rear soundstage. Alternately, you can use Dolby EX (which is what is typically applied in the theater to steer to the rear speaker array), which is a 6.1 technology, but the purpose of having two rear speakers is to prevent the perceived reversal of sound caused by single point sources of audio directly behind the listener. For a home 7.1 system, Dolby recommends using DPL-IIx instead of Dolby EX, even with DD-EX flagged titles. 7.1 was created solely to address acoustic issues in the home and help recreate the sound you get from speaker arrays in the theater, and is not a format that movies will ever be mixed in for the theater space.

All that said, if your seating is against the back wall, don't bother trying to do in-ceiling rear surrounds. If you can't put them behind you, they won't properly recreate the sound of a theater space as they would in a proper setup. I would go with 5.1 with the surrounds 110 degrees ON THE SIDE WALLS (not the rear wall) to the sides of the listening position as per Dolby's specs found here. You have a better chance of getting phantom imaging across the rear soundstage this way than you would of getting solid well-positioned sound in a poorly placed 7.1 setup. If you're using good in-wall speakers, you can angle the tweeters slightly forward so that your forward rows of seating get good imaging.

As for DSX and DPL-IIz: I don't care for DSX that much for creating height channels, though I haven't tried a configuration with width channels yet because of the placement issues that would cause in my room. I am, however, currently running a 9.1 system with height channels and DPL-IIz and find that it works surprisingly well with existing mixes, even if there's not any content mixed specifically with the height channels in mind as of yet. However, since Dolby's mixing specs dictate that ambient sound be placed out-of-phase in the surrounds to create diffuse sound, and since this is part of how DPL-IIz determines height channel information, the technology does work to shift ambient noise up to those channels with current mixes. It's not a difference that will blow you out of the water, but it is one of those things that you definitely miss when you disengage it. Since you're obviously spending the money to wire up in-walls, I recommend running the extra wire for those channels (including the rear surrounds) now just as a matter of future-proofing your theater and even if you don't intend on going that route just yet.

gp4jesus

I think you answered a queston I've had for a while with my newly acquired Rotel RSP 1068, replacing a Rotel RSP 980/RDA 975
I have wondered for a while if I use the "Center back" channel(s*), do the surrounds become side channels?

I have the surrounds up high in the corners pointing down into the listening area; my seating is against the back wall.

* I can configure w/one or two CB channels; PU a third matching speaker early last year for the CB. A long time ago some told me I could use my old analogue SSP front center channel to create a rear center. Connect the 5.1 rear chnls ""thru the old SSP LCR channels.

C'VILLE

I would stay with 5.1 in a room that size.

digitalvideo

How do movie theaters get sound out of atleast 12 speakers in the theater like at a Lowe's for example? Can home owners do that too with the right equipment?

Also Lionsgate movie studio has been offering all of their movies lately in 7.1 while most the other studios release their's in 5.1. In order to get 7.1 for a movie soundtrack does Lionsgate have to shoot the movie with certain sound designs/channels while in production/post production to get those channels or do they add that feature later on when converting it onto formats like bluray? Do the studios later on when the movie is being prepared to the home rental market decide to release the dvd/bluray in 5.1 or 7.1 or can they only do that while filming the movie I mean?

It just seems like a universal standard trend in Hollywood to all use the same sound stage creation for a movie, there's no real new radical advances in sound design where one studio does something completely different from the other. Does Dolby and DTS have any effect on how Hollywood studios make sound format?

kuntasensei

digitalvideo wrote: »

How do movie theaters get sound out of atleast 12 speakers in the theater like at a Lowe's for example? Can home owners do that too with the right equipment?

Also Lionsgate movie studio has been offering all of their movies lately in 7.1 while most the other studios release their's in 5.1. In order to get 7.1 for a movie soundtrack does Lionsgate have to shoot the movie with certain sound designs/channels while in production/post production to get those channels or do they add that feature later on when converting it onto formats like bluray? Do the studios later on when the movie is being prepared to the home rental market decide to release the dvd/bluray in 5.1 or 7.1 or can they only do that while filming the movie I mean?

It just seems like a universal standard trend in Hollywood to all use the same sound stage creation for a movie, there's no real new radical advances in sound design where one studio does something completely different from the other. Does Dolby and DTS have any effect on how Hollywood studios make sound format?

If you want to do an array on the sides and have room, you just run the surround signal out from your AVR or Pre-Pro to an amp that can feed all those speakers. You could put as many up on the wall as you want. But the point is that if you set your room up properly, you don't have to. A lot of the reason you see people use dipoles as side surrounds is because they mimic an array by having two sets of drivers firing out of phase so that you're hearing the reflection off the side/rear walls more than the direct sound (due to the cancellation directly to your sides caused by the drivers firing out of phase). For direct radiators in a 5.1 setup, placing them several feet up on the wall does a fairly good job of diffusing the sound without relying on sidewall reflections the way dipoles do. That said, a properly placed 7.1 setup can steer sound very precisely around the room and create a very convincing recreation of a theatrical array in a home space. But if you have the space, some external amps, and are just feeling crazy enough to set up an array in your room, go for it.

Lionsgate's 7.1 mixes, if we're being honest, are just re-purposed from the 5.1 mix and are nothing special. They're not doing any more than a technology like DPL-IIx does - they're just doing that processing before they encode it to the disc, whereas applying DPL-IIx to a 5.1 track does the processing in your AVR. There should be no real difference other than that they get to put a blurb on the box for marketing purposes. If the original mix is done to typical mixing standards, the data for precise placement across the rear soundstage already exists in the 5.1 mix for steering technologies like DPL-IIx to work correctly in a home space.

As far as whether Dolby and DTS have any effect on how mixes are done, I'm sure Dolby probably has more pull since they're the de facto standard... but for the most part, both companies' technologies exist to translate what the mixers are doing based on speaker placement standards dictated by the audio community. The reason you're not seeing any new technology as far as theatrical sound is that it isn't really needed. Technologies such as Audyssey's DSX or Dolby's Pro-Logic IIx are primarily to address audio in the home space, whereas the existing 5.1+EX standards have the theatrical space pretty much covered. The only technology that could potentially make its way into the theater is the use of a height channel, which Dolby first attempted on a very limited run of the movie We Were Soldiers. Mixers have long asked for a height or "voice of God" channel to be implemented, though they currently mimic this by placing out-of-phase information in the surrounds to create a diffuse ambient sound above the listener in the theatrical space. Dolby's DPL-IIz Height in the home works on that same method of extracting the out-of-phase data from the surrounds, though it uses a bit more steering logic by comparing that data to the other surrounds for directional purposes.

Mon40CSMM10

Pretty much every movie created for the theater today is mixed with rear channel audio matrixed into the left and right surrounds by the very nature of how mixes are done. 7.1 is simply a way to bring the rear channel audio of a theater's speaker array system into a smaller home space using 5.1 soundtracks.

So if one still doesn't use a full 7.1 arrangement, and the receiver only supports 5.1--without upgrading the receiver currently in use, is it worth it to enable the Virtual Surround Back on a receiver that supports it?

kuntasensei

Mon40CSMM10 wrote: »

So if one still doesn't use a full 7.1 arrangement, and the receiver only supports 5.1--without upgrading the receiver currently in use, is it worth it to enable the Virtual Surround Back on a receiver that supports it?

If you have your speakers properly placed per Dolby's specs, you shouldn't need a "virtual surround back" feature. The sound should phantom image behind you just by nature of being in phase between the two side surround speakers. Surround placement in 5.1 is different than 7.1. In 5.1, you want the surrounds to be slightly behind you (Dolby says 100-110 degrees) if possible. In 7.1, you want the side surrounds directly to the sides (90-100 degrees) with the rear surrounds at 135-150 degrees, toed in so they point toward the main listening position.

digitalvideo

Other than Polk which other speaker companies make side dipole speakers? Does Definitive Technology and Atlantic Technology? I have the Polk FXI A6 speakers on my side walls in dipole.

I'm wondering if my 7.1 surround setup in my main tv room is cprrect;y setup so that I'm getting the most out of it when it comes to speaker placement and settings.

My setup:

Polk RTI A9 front L/R
Polk CSI A6 center
Polk FXI A6 sides dipole
Polk RTI A3 rears bipole L/R
SVS sub

The front two tower speakers are on eachside of the tv about a foot from the wall angled just slightly inward towards the seating position. The center speaker is around knee height directly in front of me becase of the entertainment system shelf height. The sides are about a foot from the walls slightly above my head as are the rears. The rears are about 6 feet apart aimed straight forward. Any thoughts and suggestions?

digitalvideo

Also, which is superior for HT for rears between the RTI A3 or the FXI A6?

kuntasensei

http://www.dolby.com/consumer/setup/speaker-setup-guide/index.html
As long as your speakers are placed per that, you should be good.

Lots of companies make dipole/bipole speakers. Def Tech makes bipoles but not dipoles (they fire in phase and you can't switch them), but Atlantic Technology makes switchable dipole/bipoles like Polk does.

Since you say your center is at knee level, you might want to angle it up a bit so it aims toward ear level at the seats. A lot of people use cheap rubber doorstops that you can get from any hardware store.

Your other questions are matters of preference. Personally, I don't like dipoles in a 7.1 setup (though I think they work well for 5.1), so I would put the FXiA6s as rears in bipole mode (since they'd be at the right angle to aim toward the listening position) and put the RTiA3s on the sides (assuming you're following the correct angles per Dolby's setup guide). That's just me though. You might try it and see what you think.

gp4jesus

to Digital video:
You should be able to use the unique shape of your center to accomplish tweeter angling, or at least come close.

to kuntasensei: I don't have the luxury of DV's rear space.
I've a semi-circular couch against the back wall, vaulted ceiling.
A similar front speaker array: A5s LR about ear level; a CSI A6 above a 35" pointed down* into listening area, all about 12-13 from "hot seat."
A1s as LCR rears, all about 7'** from the "hot seat" up high, pointed down into listening area.
* upon completion of new rack, center spkr tweeter height will, w/in 2", be about the same as the A5s
** diagonal

kuntasensei

gp4jesus wrote: »

to Digital video:
You should be able to use the unique shape of your center to accomplish tweeter angling, or at least come close.

to kuntasensei: I don't have the luxury of DV's rear space.
I've a semi-circular couch against the back wall, vaulted ceiling.
A similar front speaker array: A5s LR about ear level; a CSI A6 above a 35" pointed down* into listening area, all about 12-13 from "hot seat."
A1s as LCR rears, all about 7'** from the "hot seat" up high, pointed down into listening area.
* upon completion of new rack, center spkr tweeter height will, w/in 2", be about the same as the A5s
** diagonal

Good call on DV using the shape of his center. I always forget the newer Polk centers have that angle to them. My CSi40 doesn't, but fortunately mine isn't placed too far below ear level.

To answer your earlier question, that ought to be an okay configuration for a 6.1 setup. However, I strongly recommend using DPL-IIx Music Mode full time to generate the rear channel, even for DD-EX encoded tracks. DPL-IIx Music leaves some of the rear surround audio in the side surrounds, minimizing the chance of perceived reversal due to having a single point source directly behind you. That's part of the issue with the way people used to cheat a rear surround by running the L/R surrounds through a separate DPL decoder - it would collapse sound to the rear surround. DPL-IIx was created to address this, as any sounds meant to be in the rear surround in a 6.1 configuration will also be placed slightly in the left and right surrounds at lower levels. In 7.1, you use DPL-IIx Movie Mode instead, which doesn't have to leave the rear surround audio in the side surrounds, since you have two rear channels that can produce the rear audio in equal amounts to prevent perceived reversal. In 7.1 DPL-IIx Movie, sounds that aren't hard right surround or hard left surround are always produced by more than one speaker in the array in varying levels for that reason.

You'll see a lot of people say not to bother with rear surrounds if you're that close to the rear wall, but if you can pull the couch about a foot into the room, you can do a pretty good job with careful speaker placement, especially with 7.1. If you saw how non-standard my setup was, you wouldn't think that 7.1 would work well for me, but I fixed the issue of being a foot from the rear wall by pulling the side surrounds slightly forward of the listening position and splitting the difference between Dolby's rear surround placement and THX's. The result is that I get great sidewall imaging, cohesive pans across the rear soundstage, and still get very precise placement of sound in the 4 surrounds.

With 6.1, I'd say that leaving the side surrounds in the typical spot dictated for 5.1 setups is okay, though you may find that sidewall imaging (particularly pans from the left main to left surround or right main to right surround) won't be as good as if you had the left and right surrounds directly to your sides. The rear surround's job is to draw sound behind you when it's supposed to but leave it to your sides when it's not... which is why many people claim they don't notice an immediate difference going 6.1/7.1.

Polk addict

Unless you have eyes on the back of your head, what's the point of having a speaker directly behind you anyway?

If you have your speakers set up correctly, you should only need 5.1 ...

Just my two cents...

wutadumsn23

Polk addict wrote: »

Unless you have eyes on the back of your head, what's the point of having a speaker directly behind you anyway?

If you have your speakers set up correctly, you should only need 5.1 ...

Just my two cents...

What would your eyes have to do with having a speaker behind you? You can hear with your eyes, lol. Some people use a 6.1 to fill the "gap" between your surrounds. I've never tried it, but have heard of some people who have and enjoy it. I'm a 5.1 man myself, but someday (space willing) I will have a 7.1.

-Jeff

cnh

+1,

6.1 might be a good option for you in such a small room. I understand what K-sensei is saying above...but I've run 7.1 in my room and did not personally notice a wondrous 'difference'. And most movie theaters...especially multiplexes don't often have their arrays properly balanced!

cnh

kuntasensei

Anyone who's happy with 5.1, more power to 'em. That's really what it's all about - whether you're happy with your system.

Besides, don't look at me for your "less speakers" paradigm... I'm rockin' 9.1 with height channels right now.

cnh

Somewhere I have a post that pushes the X.y surround to absurd limits...we're not there yet but we're working on it. The real problem is that most of us are married and 11.4 ain''t gonna cut it...and after that we may as well be living in a studio.

But I'm not here to bash anyone's desires to keep their gear at the cutting edge. It's just 'impractical for the average Joe and Jane.

It's cool.

cnh

wutadumsn23

+1, I would love to have speakers all over and not have any idea where the sound is coming from because it is everywhere, lol. I am happy with my 5.1...for now, lol, but someday I will go back to 7.1 when I have the room for it.

-Jeff

Knucklehead

Someone correct me if Im wrong, but wouldnt you get imaging problems with a 7.1 system regardless of room size if your not using the HD audio formats? I thought thats what 7.1 and above was designed for.

David

wutadumsn23

Knucklehead wrote: »

Someone correct me if Im wrong, but wouldnt you get imaging problems with a 7.1 system regardless of room size if your not using the HD audio formats? I thought thats what 7.1 and above was designed for.

David

I don't know, I ran a 7.1 setup before the days of the new HD formats and it worked pretty well for me.


-Jeff

Knucklehead

Ive been wanting to, I just didnt want to buy the speakers and then find out it sounds like crap. Maybe Ill give it a try. Thanks.

wutadumsn23

Room size/layout will be your biggest obstacles IMHO. Good luck.


-Jeff