Dolby Atmos: a brief review
I’m current doing interviews for a BBC Radio 3 programme which forms part of the BBC’s autumn season on cinema sound. On Tuesday I was lucky enough to hear the new Atmos system in Dolby’s screening room in central London.
Compared to most cinemas, the most obvious differences you can see in thetheatre, is that there are many more loudspeakers, including two lines of speakers above the audience. These overhead speakers allow sound sources to be properly placed above the listener, something that was really well demonstrated by a jungle soundscape where some of the insects could be heard buzzing right over my head.
The sound system you currently hear in your local multiplex only allows off-screen sources of sound to be relatively crudely placed. The increase in the number of loudspeakers in Dolby Atmos, the improvement in the quality of the surround speakers, and the fact that they are using audio objects, allows much more precise placement of off-screen sounds.
Object-Orientated Audio is attracting a lot of interest in acoustic research at the moment. In old reproduction systems, like stereo, you have two channels of data and sound engineers in the studio using panning to place objects somewhere between the two loudspeakers. An audio object contains a sound file of the audio plus additional information about where the object should be located. The decoder in the cinema then decides how best to use the loudspeakers available to place the object in the right place around the audience. One of the demonstrations I heard had a classical guitar player walking all around the theatre in a circle, including behind me. This was a great demonstration of how the new surround system allows audio objects to be precisely moved.
I also watched short clips of Women in Black and Life of Pi. The creepy scene from Women in Black showed how the improved sound from above and behind can increase scariness. As my colleague Ben Shirley blogged earlier this year ‘A clip of The Woman in Black in particular (mixed for Atmos by Ian Tapp) was startling and quite unnerving with floorboards creaking overhead and the voice of a ghost coming from the rear of the cinema.’ The Life of Pi soundtrack shows how 3D sound can be incredibly effective even when the director isn’t trying to unnerve or scare the audience. I was most taken by how the music soundtrack was brought off the screen so it seemed to be enveloping the front of the audience. I can’t wait for a Dolby Atmos system to be installed in Manchester.
Have you heard Dolby Atmos, what did you think?