What is Dolby Atmos?
Dolby Atmos is the latest surround sound audio format to be released by Dolby Laboratories. Until recently the standard configuration for surround sound in the home has been 5.1. This would consist of a front left and right channel, a centre channel and rear left and right channels.The .1 is a dedicated LFE or Low Frequency Effect channel for subwoofers.
The reason for the 5.1 or 7.1 speaker setup is because until recently the technology on hand to sound engineers would only allow 5 or 7 audio streams.
These speakers would be placed around the viewing area to give you that cinema experience in your living room. The limitations to this come in to play if you have a movie with a scene where action is taking place overhead, say a helicopter flying over you. That sound can only be assigned to the 5 or 7 channels available when making the soundtrack, meaning while the sound can travel around you, it can’t travel above you.
Dolby have addressed this issue by creating Dolby Atmos, which can now use up to 64 channels of audio that can be placed all around, and now above you. This gives sound engineers the ability to pin point sounds to exact locations within a move theatre.
But Atmos isn’t just for helicopters, as sound engineer and mixer, Sreejesh Nair explains. “Imagine a restaurant scene and having all the elements of the restaurant placed exactly where it would be in the real sense. Or even if it is a beach side; the sound of the waves can be placed in surrounds with the full frequency spectrum”.
But I don’t want 64 speakers in my living room!
Don’t worry, to get the Atmos effect you can start by adding just two extra channels, giving you a configuration of 5.1.2.
To achieve similar results to that of a full blown cinema Dolby use something called a ‘spatially-encoded digital channel’ this allows your Dolby Atmos enabled system to work out where to send the audio based on the number of speakers you have. The likes of Denon, Marantz and Pioneer are all now producing Dolby Atmos enabled AV receivers.
Starting with the 5.1.2 setup, you have a couple of options as to where, and what type of speakers you may use.
The ideal option is in ceiling speakers, as these will give the best results.
If in ceiling speakers are not an option, don’t worry, speaker manufacturers have been quick to react to this new audio format and are now producing up firing Atmos speakers that can sit either on top of existing speakers, or any other flat surface.