With post houses reporting growing demand for Dolby Atmos sound for drama, Kevin Hilton finds out how to deliver the very best immersive audio experience
Immersive audio was always going to appeal to the film industry, with its sensation of height and depth as well as width and length. But the home entertainment (HE) market has also recognised both the creative and crowd-pleasing benefits it can bring. The uptake of Dolby Atmos in particular for HE has been accelerated by the appearance of 3D soundbars, which get round the problem of having lots of loudspeakers in the living room.
Post-production facilities are seeing a growing demand for HE Atmos, on Ultra HD Blu-ray Disc as well as Netflix and Amazon Prime, which have partnered the audio format with 4K video. Soho facility Halo has Atmos in both its big theatrical dubbing and a HE/TV suite, Studio 5. “Now we’re seeing more HE Atmos projects than Atmos for theatrical,” says senior operations manager Richard Addis.
Addis prefers what he calls the “granular” approach of using mono or stereo tracks to build up the immersive soundtrack. “That way you can add or take out elements as you go along,” he says. “There’s no harm in having more things to play with. We do advise against going out with an Ambisonic mic [which records all the spatial information at once], capturing a single background and then thinking all the track-laying is done.”
“We’re seeing more home entertainment Atmos projects than for theatrical” Richard Addis, Halo
As for the cost of Atmos mixes, Addis says there can be some increase compared to 5.1 and stereo sessions due to the additional panning involved – particularly of audio ‘objects’ that move above and around the audience – but adds that the technology used now is highly efficient. “Dolby has done a good job in integrating Atmos into Avid Pro Tools so the mixing can be done seamlessly,” he comments.
Soho post house Molinare also has Atmos facilities for both HE and theatrical pre-mixing. Head of drama and film sound, Nigel Squibbs, points out that thought has to be given to how the sound will work with the images on screen. “If a helicopter is flying towards the camera and disappears at the top of the frame, the sound can continue over our heads and then behind us,” he explains. “If that’s the creative intent of the director then the shot needs to be held longer on set and in the picture edit, rather than cutting as soon as the helicopter leaves the frame. The more sound is considered, particularly with moving objects, the more enveloping it can be.”
Squibbs observes that the cost of both mixing in Atmos and the process of creating an immersive soundtrack are influenced by the type of production involved and its budget. “There are two ways to produce a 3D audio mix,” he explains. “Native starts with Atmos through the sound team working in 5.1 or 7.1 and selecting sounds that will be either in the Ceiling Beds or independently panned as objects. Upmixing, on the other hand, is when the finished 5.1 mix is reworked and effectively ‘spread’ into the Atmos domain. This is a cheaper method and gives an immersive feel but has less definition than a Native mix. How long it takes varies from genre to genre. A romantic comedy will usually have less scope for intensive Atmos mixing than a science fiction action project. It’s important to consider your subject matter when budgeting for sound.”
This article first appeared in the Winter 2019 issue of Televisual Magazine. Subscribe to Televisual Magazine here