BBC Sport implemented the TSL SoundField X-1 Upmix/Downmix Processor as an integral part of its production process at MediaCityUK. The X-1 takes stereo content within the production process and converts this into phase coherent 5.1 for HD transmissions.
“BBC Sport is the part of the organisation that brings a diverse range of sports broadcasts to our audiences through multi-platform distribution,” says Dave Lee, lead sound supervisor for BBC Sport. “We recognise the need to have a high-quality upmix system in our arsenal of equipment to ensure that we offer consistency of image to our surround sound viewers. However, it’s essential that all upmixing is free from artefacts and compatible with the downmix process required to provide audio for stereo viewers.”
When looking at the content that goes into making a surround sound program, some sections might be 5.1, as with live ambiance and crowd, while other elements might consist of stereo music, legacy video clips, commentators, and interviews in stereo or mono. The X-1 provides the means to mix and inter-cut between genuine 5.1 and standard stereo and mono material, without collapsing the delivered track on an HD feed into stereo for the viewers who were expecting it to be 5.1 surround sound. It provides a phase coherent upmix that accurately translates from what can be heard in the studio, via an often torturous signal path into the home environment.
BBC Sport moved into the new Manchester facilities in 2011 and began broadcast operations in 2012. The decision to use the X-1 came from the successful experience already gained through using the TSL SoundField UPM-1 and through extensive listening tests.
The X-1 anchors dialogue to the front and allows operators to perform divergence/convergence, while placing the appropriate amount of ambient sound into the rear speakers and, if desired, the front of the image. The accurate coherence and algorithm design of the X-1 ensure the 5.1 material also downmixes using the department’s Dolby Downmix coefficients without artefacts – which is essential to maintain sonic accuracy.