it's less than the # of speakers... than the technology to positition things exactly as it should. the premise behind atmos/mda isn't to add spaekers (although you can) but to dislodge sound from radiating from a single speaker.
that's the big thing i feel has been missing from HT is sound is often localized (no matter how expensive of HT demos i've been to). i know it's that way in cinemas too but at least with proper calibration it can sound like it doesn't come from it. but with atmos/mda, we can finally realize audio that isn't locked to the speakers (like center speakers) that's alawys been a pet peeve of mine. that dialogue is always locked in the center. it might make sense for dialogue heavy films but films like gravity it should be localized to 'objects floating in space'.
I can't tell if you're complaining that sound is localized or that it's not localized. In Film Sound mixing, the first rule of thumb is to never distract the audience from the screen.
In the 1950s 6-track 70mm mixes, dialog was frequently panned with the action, but like "ping-pong" stereo in records, that was soon considered "déclassé" and abandoned. It was also more expensive to mix that way. Aside from off-camera sounds, dialog is always going to be mixed center channel.
When the original 70mm version of "Close Encounters" was released, even though it had mono surround, the scene where the alien craft blasts an audio signal and blows out the glass in the viewing tower had that crashing sound appear in the right surround. It did this by panning it to the right front and mono surround. In the theatre when I saw it, everyone's heads turned to the right. That's considered a big "no-no". IIRC, that was changed for the special edition.
Dolby Atmos most certainly locks sound to particular speakers. That's the whole point. The difference is that at least for the objects, it's done at playback time by the system finding the closest appropriate speaker based on the location of the sound in 3D space rather than by pre-determining the channel/speaker at mix time.
My previous post point was that, if one is mixing a flyover, for example, and using Atmos the end result is that at some point the sound is primarily in the 4th side surround and then it moves to the 5th side surround, that works in a theatre, because those two speakers are separated by at least several feet, but in a home, they're probably going to wind up being right next to each other and you won't get much differentiation between them anyway…..unless you have a REALLY BIG theatre room.
IMO, unless you add a bunch of speakers the Atmos mix wouldn't sound any different from a 5.1 or 7.1 mix. And if you did add speakers, but they were each right next to each other and especially if they have a wide dispersal pattern, you wouldn't hear much of a difference either.
Again, IMO, Atmos should be left for theatrical presentation. Putting it in most homes is like trying to race a Ferrari on a go-cart track in a back yard. You can do it, but why would you want to?
Edited by zoetmb, November 08 2013 - 03:41 PM.