5.1 versus 7.1?

[jmille7351]

Hello everyone,

I’m new here but not all that new to HT systems. Not real high-end stuff but I just upgraded my Receiver and fronts with a new Harmon Kardon 7.1 DPR 1001 receiver and Infinity Alpha 20’s for fronts. The rest of my stuff (Polk sub and rears) I’ve been happy with and decided not to replace them. Currently I’m still using this as an 5.1 system and I’m very happy with the overall sound and effects that I’m getting but I was wondering what I’m missing not using the other 2 rears. The guy I bought the receiver from claimed he didn’t like the 7.1 setup. He said he thought it was a distraction from the language. I’ve really never got to listen to a 7.1 setup and just wondered with new movies recorded in 7.1 how much am I missing. Is it worth putting up the other 2 speakers? Any help would be greatly appreciated. Thanks very much

[midfiguy]

Anyone correct me if i'm wrong, but as far as I know, there is no such thing as a commercially available 7.1 for consumers. I think DTS-ES discrete 6.1 is as high as the processing has gotten yet. There's also THX-EX and Dolby Digital EX which is a "derived" 6.1 from true 5.1. The only true 7.1 I know of is Sony's SDDS, which is only used in theaters.

I think 7.1 is for "derived" channels or ambience channels that are not discrete. But maybe there is something new out there that I don't know about.

[kexodusc]

Hi there,


The guy I bought the receiver from claimed he didn?t like the 7.1 setup. He said he thought it was a distraction from the language.
This guy is a complete goof then...the addition of speakers has nothing to do with the language or dialogue...


I?ve really never got to listen to a 7.1 setup and just wondered with new movies recorded in 7.1 how much am I missing. Is it worth putting up the other 2 speakers? Any help would be greatly appreciated. Thanks very much

A few things first...If your couch/seating area is against a back wall, you can pretty much forget about 7.1 setups.

As of today, there are no 7.1 channel sources on any DVD's (that I'm aware of, certainly not many if there's even 1). What you're hearing in Dolby Digital/DTS ES/EX is a 6 channel surround system, with 2 rear channels getting the rear channel signal.

As for how much you are missing, well, I would make sure you have the 5.1 setup done as well as you can before upgrading to 7.1. Proper placement, etc.
If you have room, and money to spare, then "7.1" will nicely fill in the rear.

I was quite skeptical of the improvements myself. My experiments with 6.1 were terrible. By chance, a deal came along on 2 more identical speakers to my 5.1 system, so I tried 7 channels out. The results were much improved.

In my room, it makes the surround environment feel much wider and deeper becausse of how it allows me to place my other surround speakers. The rear effects are much better and more ambient and engulfing. The side is much more open and doesn't feel confined as much.

I would say, in my opinion, it's as significant a step up from 5.1 as 5.1 was from Pro-Logic. But it doesn't come cheap and depending on your level of satisfaction with your current system, and what you use it for (stereo music/home theater) there may be other areas to upgrade first.

[Woochifer]

What you're missing depends on whether or not your room can accommodate the extra back surround channels. Basically, if your sofa backs up against the backwall, forget about 7.1 or 6.1. Get the best 5.1 speaker positioning you can fit, and be done with it.

If you have space behind the sofa, then it might be worth trying a 7.1 speaker setup. As kex said, results will vary. It's really up to you whether or not the back surround speakers are worth the trouble. Generally, I wouldn't bother if you can't voice match the back surrounds to the L/R surrounds, and/or if you have to resort to a funky placement to get the back surrounds into your room.

And back on my soapbox -- "7.1" is one of the biggest misnomers and abuses of terminology in all of home theater. Just because a receiver has seven channel outputs does not mean that it's actually "7.1." It's a misnomer because we do not refer to Pro Logic as a 5.0 system, since it has five channel outputs. But, because they are not discrete channels, the appropriate referral is 2.0 Dolby Surround.

As kex and mid pointed out, there are no commercially available 7.1 formats for consumers. ONLY DTS ES is a 6.1 format. Officially, DD EX is a 5.1 format because there are only five discrete channels (plus the .1 subwoofer track) -- the back surround channel is a matrixed channel that decodes encoded sound information (this is similar to how Pro Logic decoders extract the center channel in 2.0 Dolby Surround soundtracks). Even though the ES and EX formats have been available to consumers for four years, there are barely 100 movies out there with 6.1 encoding. Everything else out there is 5.1.

[kexodusc]

I would just add, to be fair to the marketing initiatives of receiver manufacturers, that the various DSP modes that extract "7.1" from 5.1 sources like ProLogic IIx and DTS Neo 6, do a really good job from what I've heard.
I'd also recommend if you take the plunge, don't bother with just buying a center channel and going the 6.1 route. I find the 2 rear channels does a much better job (probably has something to do with the ear lobe factors Sir Terrence talks about) than just 1 channel. You can often buy 2 bookshelfs for the price of a center channel anyway.

And don't feel "pressured" to have 7 speakers because a bunch of receivers have the capability. I have no doubt we'll be up to 13.1 in a year or two...but sooner or later it just gets rediculous. I've heard more than a few 7.1 setups that sounded horrible. A good 5.1 system does just fine.

[techgeek42]

I found a really good article about this here: http://www.techlore.com/article/10276/

[edtyct]

And when high definition audio from Dolby and DTS officially arrives with the HD formats on DVD, watch out for even greater channel envy. The extra bandwidth will further expand the number of possible channels. Too bad greater bandwidth doesn't also make houses and rooms bigger.

Ed

[Sir Terrence the Terrible]

And when high definition audio from Dolby and DTS officially arrives with the HD formats on DVD, watch out for even greater channel envy. The extra bandwidth will further expand the number of possible channels. Too bad greater bandwidth doesn't also make houses and rooms bigger.

Ed

Right now there is little worry about this. I think what you will see before more channels, are channels with a higher bit rate, and sample rate before you will see anything more than what is already present. There are few dubbing stages that can even mix a EX and discrete ES signal let alone 7.1 or higher. The only 7.1 configuration that can be currently be configured for the home is SDDS, and at this point there is no SDDS codecs for the home. Also there is little consensus for 5 channels up front in most current hometheaters because the closeness of the front speakers would kill imaging anyway.

Why would anyone create a 7.1 or higher mix if only a few theaters in the home, and in the professional environment could reproduce it. Ceiling channels are a possibility, but few homes have ceiling heights over 8ft, so that implies delay, and more processing that would complicate processors.

It is relatively easy to up the bit rate, or the sample rate, because the pipeline for the new upcoming formats is much larger than the 9.8kbps the current DVD standard's maximum allowance. Dts++ has a bit for bit loseless codec that is approved as an option for the new HD-DVD and Blue Ray standards.

I just cannot see more channels as benefitting most of the current hometheaters in the field.

[edtyct]

Terence, I found this next bit of news astonishing. A recent article by Lorr Kramer at DTS in WSR states that, in light of the new disk media about to emerge, "digital cinema is driving plans for additional channels for motion pictures." As you say, the current demand, and technical capacity, to deliver more channels to the home is limited (some industry people maintain that 7.1 is an unnecessary escalation). Nonetheless, some of the new numbers in circulation will undoubtedly make jaws drop, even if they are destined to remain abstractions to anyone without a white lab coat. Kramer reports that channels can be organized in as many as 32 sets of 64, a staggering total of 2048, which would, theoretically, be available for cinema. In fact, however, these expanded channels will have value only for audio archiving--another significant application of DTS HD--since the two new high-definition DVD formats mandate no more than 8 channels, which will certainly become the norm (even if my livingroom can't accommodate them). But who knows what's in store? If the next wave of media, and home theater, can add to the channel count, as well as its method of delivery, many more people could find ourselves removed from the state of the art. It would not be the first time that technology outstripped the culture's ability to keep up with it.

Ed

[shokhead]

You mean those of us with a basic living room and wife are sol with more then a 5.1 setup. I know they can add more channels all they want but i'm stuck with not getting anymore speakers. I'm not sure i want anymore then a 5.1 setup anyway.

[edtyct]

I'm sure that new developments will be backward compatible, with at least a "reasonable" lag time, as they are in the computing industry now. All of DTS' upgrade plans regarding audio for home theater, for example, accommodate the current standards as well.

Ed

[Kaiser Sosze]

Well, my couch is against the back wall, and have recently installed 7.1 speaker setup. Which surround channel is more important and gets more use, especially in instances of 5.1 formats. I have a good set of surrounds on the sides and the lesser quality on the rear above the couch.
Is it actually hurting the sound quality compared to the 5.1 because of the layout of the room?
I hope I don't have to move :(

[Sir Terrence the Terrible]

Terence, I found this next bit of news astonishing. A recent article by Lorr Kramer at DTS in WSR states that, in light of the new disk media about to emerge, "digital cinema is driving plans for additional channels for motion pictures." As you say, the current demand, and technical capacity, to deliver more channels to the home is limited (some industry people maintain that 7.1 is an unnecessary escalation). Nonetheless, some of the new numbers in circulation will undoubtedly make jaws drop, even if they are destined to remain abstractions to anyone without a white lab coat. Kramer reports that channels can be organized in as many as 32 sets of 64, a staggering total of 2048, which would, theoretically, be available for cinema. In fact, however, these expanded channels will have value only for audio archiving--another significant application of DTS HD--since the two new high-definition DVD formats mandate no more than 8 channels, which will certainly become the norm (even if my livingroom can't accommodate them). But who knows what's in store? If the next wave of media, and home theater, can add to the channel count, as well as its method of delivery, many more people could find ourselves removed from the state of the art. It would not be the first time that technology outstripped the culture's ability to keep up with it.

Ed

Ed,
One thing I have learned in mixing film soundtracks is that just because the capacity is there, does not mean they will fill it. It is all driven by purchasing power, not by technical capacity. If you cannot get theater owners and hometheater consumers to purchase more processors, speakers, and amps, then all the capacity in the world will do you no good.

The next big hurdle would be where would you mix it? The only studio I could think that would have the guts to do this kind of installation would be Lucasfilm.

Who would design and build a digital mixing desk to mix this many channels. To do the typical big budget movie it takes a desk with 96 channels to do a 5.1 mix. Can you imagine what size desk it would take to do a 15.2, or 20.4 mix?

Aside from the ceiling(which has been used already for a special mix of The Patriot) where would all of these channels go?

I think the only need for that many channels(or even more channels at home) would be to control the movement of seating, give que's to live effects like smell-a-vision, or extra audio to headsets like the PSE's they use in some IMAX theaters.

I am sure somewhere down the road there will be 7.1 mixes done. The problem is how would these channels be cofigured, SDDS style with five in the front of the room, or split rear center surrounds? Eh...who knows!!

[Woochifer]

Well, my couch is against the back wall, and have recently installed 7.1 speaker setup. Which surround channel is more important and gets more use, especially in instances of 5.1 formats. I have a good set of surrounds on the sides and the lesser quality on the rear above the couch.
Is it actually hurting the sound quality compared to the 5.1 because of the layout of the room?
I hope I don't have to move :(

Pretty easy, the "side" surrounds are the ones that are most important. In a 5.1 mix, those are the speakers that playback the surround content. Even with a 6.1 DTS ES mix or 5.1 mixes encoded in DD EX, it's really up to the sound engineer as to how much content they want to mix into the back surround channel.

Keep in mind that the vast majority of soundtracks are 5.1, very few of them have any kind of back surround encoding mixed in. By keeping the ES/EX decoder on with normal 5.1 soundtracks, there's no guarantee as to how well the decoder will fill in the back surround channel given that the channel was not deliberately matrixed into the mix like it would have been on a DD EX soundtrack.

If you're using unmatched speakers and angling them down for the back surrounds, then chances are good that it hurts more than it helps. Ideally, you want all four surround speakers to be identical and arranged in an arc at the same height. Using mismatched speakers with two of them angled from above (close to both the ceiling and the backwall) is not a good way of creating a consistent soundfield in the back. The way to check for yourself as to whether or not you should keep this arrangement is to turn off the back surround speakers and hear the difference.

No need to move. Just get the 5.1 alignment right and that will give you the best enjoyment out of 99.9% of the DVDs on the market. Just because you CAN play a 7.1 speaker setup, does not mean that you SHOULD use all channels and squeeze the back surround speakers into your room no matter how impractical that arrangement is.

[edtyct]

Terrence, you may have put your finger on what could happen. Lucas will recruit and train a highly efficient and dedicated task force of well-armed A/V enthusiasts to gain control of the movie studios and sound companies, preferably by peaceful financial means but by "force" if the "dark side" is too strong. Headquarters will be centered in San Francisco at the old Presidio, allowing for expansion into the surrounding community as the soundstage grows. THX will become a mandatory program. Failure to comply will incur serious punishment. Taking semantic liberties, if not political ones, the THX juggernaut will resuscitate the lapsed "Star Wars" defense scheme to deliver high-quality digital entertainment throughout the world from outer space (with a side benefit of protecting democratic ideals). THX theaters will be equipped with state-of-the-art digital projection and as much sound capability as they can physically hold--to be determined by the proper authorities--or they will not show movies at all. In order to carry THX certification, and thus remain in business, electronics companies will have to keep their footing on the slippery slope of digital technology. Social Darwinism will be replaced by electronics Darwinism; obsolecence will not be planned so much as perpetual. THX will dictate that anyone with pretentions of home theater will, by defintion, have to own a home and designate at least one room as the theater. Inspectors will periodically spot-check to ensure compliance with minimum requirements. Apartment dwellers need not apply, thank you.

The future is right around the corner.

Ed