Dolby Atmos Theatre System - Page 3

However, DTS's acquisition of SRS, including their MDA technology, does suggest that DTS intends to be a major player in the theatrical 3D audio mix biz, which translates to influence over industry standards for the format of DAW deliverables . . . and the more intimate DTS's knowledge|control over the format of soundtrack stems, the better DTS will be positioned to deliver a future HT 3D audio technology in competition with "home Atmos".

Hmmm...maybe it will be called "Atmosh", or maybe "HAtmos".



Thank You...I'm here all week!

Mark

Why do you keep repeating that? Breaking up traditional audio channels into streams with spatial metadata allows new (and forgotten) renderers that use less speakers, e.g. Ambisonics with only 4 speakers.

Did you notice what I quoted? "I could see a very convincing image with just 6 surround wall speakers and 4 on the ceiling along with the normal 3.1 up front."

That is promoting 14 speakers by my count.

That's just one possible (very uninspired) renderer. People need to stop thinking in channels or speakers but in (re-)creating a wave field. Did I mention Ambisonic yet

P.S. http://www.audiosignal.co.uk/Gerzon%20archive.html

But the one I responded to. Please make you own point separately.

Unsurprisingly, you have just described a superset of the DTS Neo:X 9.1 Wide and Auro-3D 9.1 speaker configurations . . . which would also accommodate (full) Yamaha CinemaDSP 11.1 and Audyssey DSX 11.1 play back.

[Ok, now that we've settled on the HT speaker|amp requirements, how soon can we expect the first CE decoders and at-home movie content? ]

Indeed, 7.1 plus 4 heights was the 11.1 layout that the inventor of DTS Neo:X (James Johnston) preferred, despite his (former) employer choosing to go 11.1 with 2 heights and 2 wides.

What difference does it make. There's always been someone repeating that when we went from mono to stereo and stereo to surround.

[quote=Originally Posted by markus767
Certainly would be an improvement because it could force bass management into the content creation process. This could result in better translation to different types of rooms.[/QUOTE]


I do not really agree with this. I think the idea of bass management is not well understood.

Current Cinema 5.1 (7.1, etc.) actually does FORCE the creator to do the bass management in the mixing room. The LFE track is completely separate, and that is all that will come out of the subwoofer. There are some smaller speaker systems, and some DSP x-overs and such that can bass manage, but if I am setting one up I usually turn it off unless the main fronts just can't do it. Low frequency sounds are LESS able to be localized, but certainly not impossible. If the screen speakers are just too wimpy to go below 40 Hz, ok we may have to help them out. The screen speakers should be powerful enough in a cinema to do the job. Surrounds are a crap shoot though. The current spec does list 20-20K but in reality, most surrounds do roll off somewhere between 40 and 60 Hz. But when used in an array of 8 though, they do couple together and go lower, so even there, it is rare to bass manage in 5.1 or 7.1

Bass managing the main front speakers is still not what I recomend. The acoustic mix of correlated sounds from 2 screen speakers will result in a 3 db bump in level. But if you electrically add those, you get a full 6 db bump up. This can be compensated for to some degree, but it is never as good as having true full range speakers.

Having a system bass manage on playback is actually taking away a little control from the content creator. If you dump everything below 80 Hz into a common sub, you now have mono below 80 Hz. Can you tell where 60 Hz hum comes from? Maybe the director had a buzzing power line in the room somewhere?? This is an extreme case, but I hope you get where I am coming from. Bass management becomes a necesary evil in some cases.

How would you rank changes in impact?

1 -> 2 speakers
2 -> 5
5 -> 13

I see diminishing returns in cost/benefit in that order. Do not construe that to mean that I think such evolution should not happen. Just that is less necessary. Of course I can see that as an unpopular notion among enthusiasts.

Necessary for what?
My point wasn't about the number of speakers but the motive you assign for inventing newer technologies that can take advantage of more speakers.
At best, you're projecting.

I suspect that the 75%+ of Americans who listen to their TV|video audio though the TV set's built in speakers will continue to do so even when DolbyHomeAtmos appears as an audio track encoded on the next-generation-BD they are watching, they are after all already ignoring the majority of the benefits offered by the DD5.1 and TrueHD soundtracks in OTA|cable TV, DVD, and BD. And few among the remaining 25% (who do find added value in DD5.1 or TrueHD) will likely be willing to add 'several' speaker pairs in order to 'fully appreciate' the extra SQ available from DolbyHomeAtmos. So one strategy to wider exploitation of DolbyHomeAtmos might be rethinking what sound quality enhancement technology can be delivered through speakers built into the TV chassis:

For example, (if I understand correctly) this recent ITU demonstration of NHK's UHDTV system on an 85-inch LCD screen reproduced the 22.2 multichannel sound component of the program through a frontal loudspeaker array frame, integrated with the LCD display, which used 102 loudspeaker units with 'sound projector style' DSP in order to reproduce all the appropriate surround sound.

I just wanted to coment on some of Roger's last post about bass management here. I am sorry this got far longer than intended. I hope you read it as intended. This is not about DOLBY ATMOS, as I feel it applies to any multi channel sound system. All my opinion from 30+ years of tuning rooms, your feelings and experience may differ.

Carefully used Bass Management can certainly work very well. The problems we run into are very inconsistent quality of sub woofers with wildly varying amount of distortion and even frequency range.

The older IMAX film format was actually a 6.0 system with all 6 channels bass summed into a common hue sub woofer with about 10 db on in band gain. So if you fed any of the 6 channels with flat pink noise, you would measure pretty close to X-curve from 16K down to around 100 Hz or so, but from there down, it would ramp up to + 10 below 80 HZ from the common sub. Play correlated noise into 4 channels now and the electrical summing makes the low end go to more than +20 db while the mid range is at just +6. But for IMAX mixes this worked just fine because they were mixing the tracks knowing this was the room they were going into. But if you take a 5.1 mix into an IMAX room, it turns into a pile of monster bass. And here is the problem. Noone is mixing in a room with bass management like that for normal cinema. On that 1812 Overture recording you talked about.. are the canon blasts mic'd with 5 mics, or was it mono mic'd and panned across the 5 channels, or something in between? This will greatly change how the bass summing will mix. Was the mix done on a system using bass managemant also? Was the room where the mix was done, and where it was played both Eq'd to the same curve and cross over point to the common sub-woofer?

All these questions and many more make it difficult to keep the results consistent across hundreds, or thousands of rooms of different sizes and shapes. Of course there are many people who like a bit of extra bass, so having the bass summing create the artificial boost makes it sound "better" than the creators original mix. We have even had some content creators admit that they liked an artifact like that, even though they knew it was not faithful to the original mix. My personal view is that I am in the business of RE-production, not PROduction. Once the content creator signs off on how it sounds on the dub stage, it is my job to make it sound IDENTICAL in the final theatre environment, not richer, crisper, boomier, etc. I have had some excellent results in smaller rooms using bass management when the owner chose to use some smaller main front speakers, but it took extra tuning time and some trade offs that made it sound a little different than the original intent.

When I do have to make a compromise on a system setup, the goal is to make any deviation from perfect playback be on the side of "pleasing to the ear". So in most cases we end up with a bit more bass in a bass managed system, but it is not as accurate to the original mix.

I love huge dynamic range when used well, but there have been some recordings that are just plain silly. I am sure you will know one I am speaking of. It is a 2 trk version of the 1812 Overture with real mic'd canons, but the producer made a choice where the canons are 40 db louder than the orchestra playing the music. To me this sounds like it was recorded to be the point of view of the man standing at the canon to fire it, while the orchestra was a half mile away. I was not the mixer or producer, I try to play it faithful to the creator's vision, but I just can't enjoy this version myself. I know that has little to do with the discussion, but you mentioning a recording of the 1812 Overture made me think of how much that recording bothered me. Just because we can make those canons that loud does not make it a good choice. There is a schene in a film called "Smokin Aces" where a girl fires a 50 cal. In one theatre, I felt it bounce the entire back wall of the auditorium over an inch from the pressure wave. Yet it was far more pleasing than those silly 1812 canon blasts. I screened that film at 4 different locations, and no two sounded alike. It was a very good use of the LFE track, but it also showed how difficult it is to match the lowest octave performance. This was not a case of low end responce, it was more about the attack speed of the pressure wave on the first cycle. Ported cabinets do not have any resonanse help on a shock like that. I never did get to hear it on an infinate baffle or Bag End sealed system, that would probably stop your heart for a second from the pressure pulse. As it was the bank of 18 18 inch woofers felt like getting punched in the chest, even at about 100 feet from the speakers. In a much smaller room, a bank of 6 18's with over 3000 watts behind it just didn't have near the thump on your ribs, even though my analyzer showed nearly identical 1/12th octave measured frequency response to well below 20 Hz. In fact, the thump seemed to have far more energy up at 80 to 100 Hz. In any case, this kind of a sound could never be produced from the main channels due to the 10 db gain difference below 125 hz. This is why I think the idea of 3 sub woofer feeds will work much better. Keep the screen speakers separate, use a dedicated high output LFE subwoofer, and then use smooth no in band gain bass managed sub woofers to augment the smaller surround speakers. The signal and demand placed on the two systems are quite different.

I also do understand that 60 cycle buzz will have higher harmonics, but you have to agree, even the 60 Hz sine wave can be located by human ears. True, it is not as easy to localize, but I know many people who can walk right to the source of a clean 60 Hz hum. I wanted to show an obvious example where bass summing would detract from a directors vision.

I am not saying to never use bass management, I agree it can be helpful, but I also feel it is over used and set up poorly far too often. I would rather have independant screen channels with a smooth roll off around 30 Hz rather than bass manage them below even 40 and go down to 20 Hz. Of course that is my personal preference. In the end, I will install what the customer wants and tune it as accurately as possible to re-create the original intent of the content producer. And in more than a few cases, the system owner then went in and cranked up the surrounds and low frequency levels to their taste. Oh Well, might as well pay for the ISF display calibration then crank up the blue to make the sky and water prettier too.

Hi GXMnow,

Curious to know what your field of work is? Commercial audio system installer/calibrator? It's always fascinating to get insider viewpoints on the industry workings. In fact, in another thread, I had been musing about the whole bass management bit as I was mentioning how a fair number of BD movie soundtracks actually had more Low Frequency content in the Main channels than in the dedicated LFE .1 channel.


Max

I fully agree that the tie had to be cut but Atmos does it only halfway. There are still beds which is the old channel paradigm. Beds are pre-rendered content so to speak. I'm afraid they will be used a lot by content creators because it fits common production techniques.

The full potential of objects-based audio can only be released with a complete separation of audio data, spatial data (not only positional data but also virtual room data) and renderer.
Maybe it's only another 80 years or so from now until it will finally happen. Nevertheless, kudos to Dolby for moving in the right direction with a real product.

I fully agree with everything Roger has said but would like to add some comments.

Bass management makes all those uncertainties in mixing and reproducing go away. The only drawback might be deliberate directionality at low frequencies in larger rooms like cinemas vs. unachieveable LF directionality in small rooms like living rooms and home theaters. In my mind a small price to pay.
By the way, using a 1/12 RTA for tuning bass frequencies might be the wrong tool to get really great results.

I know a studio that does remixing for DVD/Blu-ray without any bass management. There's a lot of LF content in the mains that never gets heard by the mixing engineer but will ultimately make it onto the disc. Not a desirable situation in my mind. The simple solution is bass management.

The described 60Hz hum problem is probably more relevant to an installer. But this should be easy to track down.
If there's hum in the mix then simply solo files/tracks. That's everyday business for a mixing engineer anyway.

Projecting for what?

Gary,

you make it look like Atmos was "invented" for the sole purpose of selling more speakers. This simply isn't true. Although I agree that it can be (mis)used to do so, dumping the old channel based systems for object based audio is of much greater importance. Just because the invention of the electric light bulb helped sell even more "candles", it obviously had a much larger impact.

Don't blame them even if true. As I said there is not much left to sell after surround, Room EQ and lossless. Neither did I say it is a bad thing. It is a niche thing. I don't see many HTs (let alone households) with 14 speakers any time soon. Yes the object based strategy sounds good but a what cost? It's not exactly just another chip on your AVRs processor board. It sounds good for commercial theaters though.

The implications of moving from channel based reproduction to audio objects is more profound than moving from mono to xx.x surround. It's more of a revolution than an evolution, especially for home reproduction.
I don't believe the movie theater business model will gain much from object based audio (unless they can keep it exclusive to theaters) nor do I think it will survive in the long run. But it's a very good thing that it's still strong enough to drive innovation like object based audio.

I have met GXM.

I can assure anyone reading this that he most definitely has reliable information regarding Atmos.

From what I see this thread has drawn the interest of pretty much just the high end 1 per centers. We shall see.

Pardon my slightly OT follow-up, but you don't think movie theaters will survive?

Jeff