Originally Posted by almo89
So what is this new Dolby Atmos all about? Will home theatres sounds significantly different? And do speakers have to be built differently for this?
It's a new way of positioning sounds in a three-dimensional space (x/y/z coordinates). There is a height element and more speakers for more accurate sound placement and effects/dialog panning. The more speakers you have (and your room can handle), the better the 3D sound scape (the speakers are like pixels in video - the more pixels, the more "resolution" and sound "detail").
Dolby Atmos (and DTS-UHD) is currently a hybrid format with a fixed channel bed and a certain number of metadata controlled objects. The basic layout is 7.1.4 (seven base channels, one low frequency effects channel, and four over head/height channels). The objects allow the system to expand or contract depending on the processor's (called a renderer) capabilities. Again, Atmos tops out at 24 mains + 10 overheads (or about half of the commercial version).
The renderer knows how many speakers you have and where they are and then plots the best locations for the objects to travel in space based upon the three-axis coordinates embedded in each object file during the initial soundtrack mix. The final soundtrack is completed in real time in your home.
The best speakers for the job are timbre matched monopoles. The overhead/height speakers will need to have a wider dispersal pattern than the other speakers (not dipoles), but probably different styles of tweeters and perhaps more of a bipolar pattern. We just don't know all the details yet.
There will be some "add-on" speakers that can sit on top of your current speakers and fire upwards at the ceiling, in case you cannot hang speakers there. It helps approximate the height effect using reflected sound waves. You need a flat, hard ceiling surface. This is a compromise. If you can do it, put the height speakers on the ceiling.
Atmos tracks will be available on certain remixed Blu-ray's starting this fall. There are speculations that Gravity- Special Edition, Frozen 3D, Godzilla, The Edge of Tomorrow, and other pre- done Atmos mixed titles will be among the first discs with this feature.
Any Blu-ray player can bitstream the Atmos track to an Atmos renderer because it is contained within the Dolby TrueHD lossless audio codec.