10.2

"10.2 also refers to Mac OS X 10.2."

10.2 is the surround sound format developed by THX creator Tomlinson Holman of TMH Labs and University of Southern California (schools of Cinematic Arts and Engineering). Developed along with Chris Kyriakakis of the USC Viterbi School of Engineering, "10.2" refers to the format's slogan: "Twice as good as 5.1". It has been touted as the audio equivalent of IMAX - spectacle beyond what can be achieved by any other format.

Description

The purpose of 10.2 is to allow much greater flexibility for sound designers and create a far more immersive environment for the audience. With these channels, it is possible to recreate the acoustics of nearly any location with astonishing realism, assuming the audience is facing a screen in front of them. In research, Mr. Holman found that the second most important sound wave to hit the audience - after the one from the source - is the one that comes from a point on the ceiling, halfway between them. This is because most rooms have hard and reflective ceilings, but the walls are semi-absorptive due to objects in the room; while the floor, usually covered with carpet, absorbs most of the reflected sound. So this first, overhead reflection reaches the ear at a slightly different time, allowing the brain to both localize the primary sound and compute the size of the room. By placing two speakers 45° above and to the left and right the audience, this key sound wave can be recreated. The other speakers can fill in the other major reverberations from the sides and off the back of the room, recreating a full acoustic signature.

Of course, the speaker placement can be used, much as other surround systems are, to place sound images around the audience to create a sense of the scene. A well-designed sound mix, like the one at the beginning of "Saving Private Ryan", offers the audience the opportunity to sit within the battle, not just in front of it. 10.2 simply heightens that ability to a level far beyond most other surround sound formats. There are few other systems, for instance, that would allow an airplane to fly overhead while a bee encircles you at only a few feet away.

The strength of traditional 5.1 surround is that its left and right surround speakers are diffuse; they spread the sound around the entire area. This helps to prevent the "Exit Sign Effect" - audience members looking away from the screen at the source of a localized sound, not realizing it is part of the movie. However, this diffusion carries a cost in flexibility. Therefore 10.2 augments the LS (left surround) and RS (right surround) channels by two point surround channels that can more finely manipulate sound - allowing the mixer to shift sounds in a distinct 360° circle around the movie watcher.

The 14 discrete channels are:
*Left
*Center
*Right
*Left Wide
*Right Wide
*Left Height
*Right Height
*Right Surround Direct
*Right Surround Diffuse
*Left Surround Diffuse
*Left Surround Direct
*Back Surround
*LFE Left
*LFE Right

The ".2" of the 10.2 refers to the addition of a second subwoofer. The system is bass managed such that all the speakers on the left side use the left sub and all the speakers on the right use the right sub. The Center and Back Surround speaker are split between the two subs. The two subs also serve as two discrete LFE (Low Frequency Effects) channels. Although low frequencies are not localizable, it was found that splitting the bass on either side of the audience increases the sense of envelopment.

Examples

There is currently only one film generally available that uses this format, a 30-minute short called "".

Competitors

There is only one direct competitor offering better quality and spectacle, though there are a few that are better than traditional 5.1:
*22.2 developed by NHK (22.2 channels)
*Dolby Digital EX (6.1 channels)
*SDDS (7.1 channels)
*DTS-ES (6.1 channels)

Recently, Dolby introduced Dolby Digital Plus, which is capable of transmitting 14 channels (enough to support 10.2), but there is no playback standard associated with it. Dolby has also introduced Dolby TrueHD, a lossless codec which can support even more channels.

Advantages

*Spectacle: can bring back the sense of the cinema experience being substantially more intense than what can be achieved at home, even with high-end systems.
*Allows for more accurate placement of sounds.
*Allows greater range of locations where sound can be placed.
*Allows recreation of acoustics from any location assuming a frontal position.
*Can be added to the 6 speakers currently used by the 5.1 systems, keeping costs down.
*Is scalable to any size room, assuming the ceiling is high enough.
*Can create Low Frequency Effects that cannot be reproduced with any other system.
*Compatible with Pro Tools or other Digital Audio Workstations (ie. Nuendo, Pyramix) when mixing inside the workstation.
*Has a process to easily mix the 10.2 down to 5.1 for older release formats.
*The effects can already be experienced, as one new film uses this format, a 30-minute short called Seven Swans.

Drawbacks

*There are only three theaters using the format as of January, 2006.
*It is very expensive to install, though not as much as the new digital projectors.
*It is expensive to install in mixing rooms, especially if they are not currently Pro Tools or Nuendo-based (in that case the mix would be done "in the box", or inside the workstation).
*Very few or no mixing consoles support the format.
*No studio has adopted it as a release format.
*No feature films have been mixed in it.
*It does not fit without multichannel compression (such as Dolby E or DD+) on any digital or audio tape format.
*There is no room on a strip of film to add the coding necessary to support the formatFact|date=May 2007, so one of the existing formats (Dolby SR, DTS, or SDDS) must be willing to adapt for it to be used along with 35mm film projection (used by 99% of theaters today).
*Only DTS has the ability to add 10.2 to existing prints with backward compatibility, because the actual sound playback comes from an external disc.
*It is still a Vector-Based Amplitude Panning (similar to stereo), in opposition with physical reconstruction systems (such as Wavefield synthesis), the latter being supposed to achieve a near-perfect reconstructed sound field

External links

* [http://www.tmhlabs.com/products/10_2.html TMH Labs]
* [http://www.matterworks.com/seven_swans/sound.html 10.2 use on film "Seven Swans"]
* [http://www.avrev.com/equip/tomholman/ "Audio Video Revolution" article]