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Will Dolby's New Atmos 62.2 Format Redefine Surround Sound?
CIStud writes "Anyone who goes to see Pixar's new animated Brave film might come home with their ears ringing. Why? because Brave is the debut of Dolby Lab's new 62.2 surround sound format called Atmos, which adds new developments such as pan-through array and overhead speakers. With 62 speakers and 2 subwoofers, only a handful of theaters nationwide will be able to show the film at its full throttle. Dolby has produced a new highly informative video that talks about how movie sound has progressed from mono to stereo to LCR (left/center/right) to 5.1 and 7.1 surround sound and now Atmos. The big question is will the 62.2 format system be adapted for home theaters intent on emulating the immersive movie experience?" I've seen some busy input/output panels on home stereo equipment, but 62 channels is too many for my interconnect budget. Still, overhead sound seems like a good idea for some kinds of movie.
That's not how this system works, it supports "up to" 62 channels in the encoded signal; these are panned with metadata in the channel bitstream, and then the decoder in the theater (or home) does the math of placing the sound in the space, using prior knowledge of how many speakers you have, and their position in the room. "62.2" doesn't mean 64 speakers, it means that the format supports "up to" that many, and the theater might not have that many actual channels wired, or it might have significantly more if it's a large room, or significantly less -- they can add more speakers to get more directional resolution.
62.2 also doesn't imply that the guy who mixed the thing was using more than 5 or 6. I'm a sound designer in Los Angeles -- just finished Men in Black 3, starting Zero Dark Thirty in a few weeks, and this is the first time I've heard of any of this. This sort of system will require software support from workstation and console vendors, and I'm dubious people will be using it for some time, even though it promises great backwards-compatiblity.
This system appears to be an attempt to get ambisonic-like flexibility without the costs of ambisonics, principally, ambisonic encoding's inability to cope with pan divergence, the problem of "how do I send the same sound to the left and right side of the rooms simultaneously, without it going anywhere else?" It's impossible to do this in ambisonics without adding tons of second-order channels and playing with signal phase. This system might also suffer from one of ambisonic's other problems, namely, it may rely on extremely accurate speaker placement and speaker placement information.
This system also appears to be a shot across the bow of IOSONO, which is a very different process that achieves high horizontal fidelity through a completely different technique of dubious creative utility.
Note- IMAX has overhead sound as well, or at least a "screen-top" channel, but lacks a subwoofer channel and only has point-source surround speakers.
Don't blame me, I voted for Baltar.
www.drafthouse.com
No babies allowed, except on baby nights.
Also you can order a pitcher of beer and a pizza from your seat.
And their no talking psa's are awesome and enforced.
http://collider.com/michael-madsen-alamo-drafthouse-psa/165640/
http://en.wikipedia.org/wiki/List_of_Itchy_%26_Scratchy_cartoons#To_Kill_a_Talking_Bird
Don't know something? Look it up. Still don't know? Then ask.
As a teen I worked concessions at large theater. "Butter" was indeed grease from 5 gallon jugs. Nacho "cheese" was something thick and yellow that was not cheese. Hot dogs often had green stuff on them when they came out of the box, but the green was covered by accumulated gunk (we called it seasoning) from the rollers of the heater, and could make the trip between freezer and rollers several times before purchase.
If it's not prepackaged, be afraid. Be very afraid.
Because ears are a miracle of engineering, and the signal processing the brain does is similarly brilliant. The shape of the pinner - the fleshy bit - means that sounds sound different if they get into your ear canal from different directions - otherwise (and I used to wonder this as a kid) how could you tell whether a sound source was directly ahead or directly behind?
As I recall, your brain can also use the tiny timing difference (on the order of 1/3000s) to determine distance and direction
You can fake all of this with just two speakers (the virtual haircut is highly recommended: http://onemansblog.com/2007/05/13/get-your-virtual-haircut-and-other-auditory-illusions/), but only if the two speakers are completely isolated to each ear - i.e., through the use of headphones. And then you have to resort to a "one size fits all" mix. They record these things using dummy heads with realistic inner and outer ears - brilliantly simple.
If you tried to do the same thing with two external speakers, both ears would hear both speakers and the effect is ruined.
systemd is Roko's Basilisk.
Since the post goes to a blog that contains no information here is a link to Dolby talking about it. Why would this link not be in the article? http://www.dolby.com/us/en/professional/technology/cinema/dolby-atmos.html
There's nothing wrong with the term "subwoofer". It generally refers to speakers which have a response intentionally limited to somewhere between 100 and 200Hz, which is well below the 500Hz-4kHz woofer crossover frequency you'd find in typical two and three way enclosures. Probably the best definition is "a speaker that can only reproduce frequencies of wavelengths too long for us to detect the source direction" (this is why you can put a true subwoofer almost anywhere in a room, and you only need one even for stereo).
Old woofers were huge because the enclosures were usually either simple folded baffle or sealed; the lowest wavelength that can be reproduced by such designs is proportional to the diameter of the speaker cone and either the length of the acoustic feedback path from back to front of speaker or volume of the enclosure. Thanks to the work of Neville Thiele and Richard Small in the 70s, CAD and modern manufacturing techniques it's now possible to design speakers matched to enclosures that use resonant acoustic delay lines (ports) to extend the frequency response dramatically. For these designs the speaker's excursion range, suspension stiffness and the volume of air it moves (among other factors) are more important than diameter alone*, so it's easily possible to have a 5" speaker that can reproduce down to 40Hz in a very small enclosure.
Your mention of quadraphonic reminds me of the old joke "quadraphonic is the sound system for people with four ears". I have to agree with you about surround sound in general: the sound of anything on the screen should come from where it is on the screen because our eyes follow audio cues (something to do with millions of years of wanting to avoid being eaten I suspect). But surround ambient background noises can be quite effective when used subtly (that too is natural), extreme low frequencies that are more felt than heard do add to special effects movies, and the centre speaker doesn't hurt, so 5.1 is plenty IMO. I doubt there'd be significant benefit from extra speakers in the Y dimension, since we're less sensitive to vertical displacement and the spacing of the speakers may be too narrow for more than the first few rows to really hear a difference, but it makes more sense than 62 speakers.
And I'm with you 100% on spoken vs written, though what I don't get is that since speaking is much slower than reading you'd think people with short attention spans would prefer...ooh, a shiny!
*Note to nitpickers: yes, this is vastly oversimplified.
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