64 cinema technology • june 2010 • www.cinematechnologymagazine.com SOUND DATASAT AP20 Datasat Digital Entertainment recently intro- duced the AP20, a completely new design of 16-channel digital audio processor, which of- fers an impressive collection of all the features that any cinema operator is going to need, plus the Dirac Live® high performance sound shaper and controller, which corrects impulse responses and smooths out the frequency re- sponse of any cinema auditorium to eliminate the inevitable distortions created by the room and the speakers. Although you wouldn’t expect this rather staid reviewer to go along with the company’s some- what over the top PR line that “The AP20 is as revolutionary to cinema processors as digital is to film”, there is no doubt that the AP20 can provide all the facilities that a cinema operator could require, both for the latest digital and for legacy analogue sound systems. To provide these facilities, in essence, Datasat Digital Entertainment has combined its vast experience in conventional analogue sound systems with state-of-the-art digital signal processing technology. The resulting AP20 Audio Processor is one of the most flexible and powerful general-purpose audio processors available today. It has been engineered to deliver precise repro- duction of both analogue and digital sources, making use of the power of six Analog Devices 400MHz Digital Signal Processor chips. The AP20 can cope with 16 channels of digital sound and 8 channels of analogue inputs, and these are coupled to the 16 digital and 16 analogue outputs. In addition to one S/PDIF and two TOSLINK inputs, the AP20 features four HDMI 1.3b inputs with Blu-Ray HD, DTS, Dolby or satellite delivery decoding, and active loudspeaker crossovers. Each of the 16 channels Includes • 31 bands of 3rd octave equalization • 3 bands of parametric equalization • Channel gain & phase inversion control • Individual Bass & Treble controls • Variable delay line adjustable from 0ms to 1000ms Adaptive Audio Equalization In recent years there has been much practical development of adaptive audio equalisation techniques for domestic and small listening rooms, but apart from the adaptive audio system that comes as part and parcel of the complex IMAX Digital installations that we have reported on in Cinema Technology, (see Odeon IMAX Southampton article in this issue) these techniques have not generally been applied to cinema auditoria. We know that creating the perfect listening environment can be difficult – we can’t always have the loudspeakers ideally placed in a room and nor can we always be sit- ting in the perfect spot to listen to a programme. Adaptive audio techniques can eliminate these problems and maximise the areas of locations where the ultimate in sound quality is available. Real time adaptive equalization of room acous- tics in the frequency domain depends upon first obtaining the frequency response characteristics of the room by inserting a number of acoustic probe signals into the main audio spectrum and then picking up the loudspeaker outputs from a number of strategically placed microphones. A spectral analysis of the resulting audio signal is developed, which can include modifications based on a psychoacoustic model of frequency masking, so taking greatest account of the sounds which are most important to the human hearing system. Since the system knows the exact location of the loudspeakers, its complex algorithm can make the necessary calculations and compensate by adjusting timings and fre- quency responses for the particular loudspeaker placement. I have also seen and experienced the results of software which suggests that you would be best advised to move some of the loudspeakers to other positions, and gives the coordinates. These techniques mean that you get the best possible sound experience without having to turn your living room into a sound studio. It is these techniques that Datasat Digital Enter- tainment has now incorporated for the cinema, based on cutting edge research from Dirac Research AB, founded by scientists at Uppsala University, Sweden. http://www.dirac.se/ And one of the most compelling features of the AP20 is the inclusion of Dirac Live® room optimisation technology. Dirac Live® is a state-of-the-art digital room correction technol- ogy that improves the listener experience by correcting for room modes and anomalies using high-resolution filter technology. The idea is that you configure the cinema auditorium once and never have to touch it again. The results are claimed to be improved musical staging, clarity of dialogue and a generally enhanced listener experience. Key Features: The AP20 offers: • 16 Channels (digital & analog) • 31 Bands of 3 rd Octave EQ (per channel) • 3 Bands of Parametric EQ (per channel) • Memory Settings for all EQ • 3 Expansion Bays • Dirac Live® Room Optimization • Individual & Global Channel Delays • 4 HDMI audio/video inputs (with video pass-through) • Inputs & Active Crossovers A cinema sound processor with several significant differences ... Datasat Digital Entertainment AP20 Formerly better known to Cinema Technology readers as DTS Digital Cinema, but reborn in recent times as Datasat Digital Entertainment, the company is a special- ist provider of digital entertainment services for content owners and exhibitors. A leading innovator and supplier of 5.1 digital surround sound for motion pictures, the company specialises in hardware products for the exhibition of movies and other content in digital form, with a dedicated focus on supporting the film industry’s transition to digital cinema.