Dolby Atmos

From movies to music, home entertainment has wholly embraced Dolby Atmos. But what does it offer above regular surround sound, and is now the best time to upgrade?

- Steve May

George Lucas famously said that sound was 50 per cent of the moviewatching experience. G With Dolby Atmos, we think it could be a good deal more.

Basically 3D for your ears, it’s the biggest thing in home cinema audio since the launch of Dolby Digital 5.1, and has opened up a totally new way for TV and films to deliver sound.

A big change in Dolby Atmos is that sounds become ‘object-based’, rather than ‘channel-based’ as in Dolby 5.1. With channel-based tech, the engineers could direct sounds to specific speakers. In an object-based system, audio designers can place individual sonic elements inside a 3D soundfield, with their movement and position reflected by the speaker arrangement. This technology, says Dolby, creates an ‘illusion of an infinite number of speakers’ and it can fully immerse you in the action.

ATMOS ORIGINS

Of course Dolby Atmos, like so many proprietary Dolby sound formats, made its debut in the cinema. The award-winning Disney Pixar’s Brave was the first movie released with an Atmos soundtrack, and the sound system has since become a common attribute of premium screens.

The loudspeaker array embraces a 360-degree configuration in a Dolby Atmos cinema. Enclosures reach right to the edge of the screen, bolstered by additional speakers overhead. Within a Dolby Atmos-encoded soundtrack, every element within a frame can effectively become a separate sound object. Adaptive rendering in the cinema’s audio decoder determines exactly where a sound should be heard in any particular theatre. So while the number of loudspeakers in a screen may vary, mandated by its size and layout, the listening experience will be uniform.