BSkyB has purchased eight of SoundField’s stereo-to-5.1 upmix processors for live use in its studios and outside broadcast facilities.
The SoundField UPM-1 is a 1U, 19-inch rack processor which can create a convincing, phase-coherent 5.1 surround panorama from stereo audio in realtime, without adding any reverb or unwanted additional phase shifts. It does this by adaptively analysing the two-channel stereo material, separating the content into its ambient and direct components, and placing any material from the centre of the original stereo mix, such as commentary or dialogue, into the Centre channel of the resulting 5.1 panorama.
For HD broadcasters, the UPM-1 ensures that most audio can be broadcast in fold-down friendly surround sound, without obvious moments when the broadcast soundscape narrows to stereo during the transmission of older, stereo-only material.
“The UPM-1 is already proving its worth here at Sky,” commented Keith Lane, operations manager at BSkyB. “Nearly everything we produce for HD transmission ourselves on our main sports channels is now in 5.1, and the material we receive for transmission from Germany, France and Italy is in 5.1 as well. However, that makes the material that’s still only in stereo rather obvious to viewers at home. For example, all of our sound libraries, stock music and effects are in stereo – and even during an HD sports broadcast, we’ll transmit short roundups of older match clips that often only have stereo audio. Some of the coverage of international matches from other broadcasters still comes to us in SD, too. We already up-convert the video, but now, with the UPM-1, we can up-convert the audio too. The good thing about the UPM-1 is that the upmixed results are stereo compatible, so viewers who are still only listening in stereo don’t suffer. It provides a quick, effective way of rendering stereo into convincing 5.1, and helps us to give our HD viewers more of a seamless surround-sound experience.”
The eight UPM-1s are gradually being installed in Sky’s main sound control rooms at their broadcast headquarters in Isleworth, London, and also into outside broadcast facilities that Sky uses. According to Keith Lane, the UPM-1 in Sky Studio 6 has already seen use on live Champions League football coverage, and will be used on HD coverage of boxing and rugby over the coming weeks. The other studios at Sky’s broadcast centre will receive their UPM-1s following the next round of software and algorithm upgrades, currently in progress.
“SoundField has always been very responsive to our feedback, and the UPM-1 has already been upgraded a couple of times to incorporate suggestions our engineers have made from using the unit in Studio 6,” explains Lane. “We’ll be installing the others shortly, as the unit is turning out to be useful to us in more ways than we’d imagined. Over the next few years, Sky will be moving towards a complete production and transmission chain in HD, but while that process is still on-going, the UPM-1 is going to be very useful to us.”