The screening room needed a system that satisfied exacting requirements, notably unsurpassed sonic detail. With a huge variety of films passing through the facility, finding a system that could cope equally well with every one was a challenge for audio consultant Laurence Claydon of Cinefilm.
"UPI deals with many foreign language dubs. Being able to determine if, for example, a dialogue insert or edit is acceptable is difficult on all but the best systems - sometimes the only clue is a slight shift in background reverb on the track," he says.
"Quality control for digital cinema also has its own particular requirements. Digital Cinema Packages (DCPs) are split into 20-minute 'reels' of picture and audio, joined together by a Composition Playlist that makes up part of the package. It is up to the replay system to join these together. Some systems crossfade the audio, but some do a hard changeover. If the audio is not mastered to be zero-crossing at the reel join, you can get clicks, and some of these are at low level and difficult to identify against the many other sounds that may be legitimately in the mix."
Having done extensive tests with products from three manufacturers, a system comprising three Alcons CR1 ultra-shallow (18cm deep) three-way cinema front system cabinets, a BF181i 1x18" subwoofer, six CCS8 two-way co-axial surround cabinets and two ALC2 amplified loudspeaker controllers (including analogue processing modules) was specified. Other equipment includes a Dolby CP750 audio processor, Doremi DCP2000 digital cinema replay server (with facility for additional replay servers) and an NEC NC800C 2k digital cinema projector.
"We had built a good room with a smooth RT60 curve, so I fully expected excellent performance from the CR-1," says Claydon. "I wasn't disappointed - the detail and lack of distortion at the top end is a real bonus for those of us used to traditional compression-driver based systems."
He adds, "This is one of the best sounding rooms in London, and undoubtedly one of the best owned by a film studio. So often with audio, you only know they you are doing things right if you don't get complaints. But this system has been such a success that we have received very positive comments from everyone. To say the client is happy is a genuine understatement."
(Jim Evans)
