The cinema audio processor has changed dramatically with the introduction of digital cinema. With film, audio processors were necessarily complex. Over the years, they were required to support both magnetic and optical analog formats, with and without noise reduction, with and without matrix decoding, sometimes without the surround channel of the matrix decoder, support for multiple types of digital decoding systems, and occasionally included the electronic crossovers required of the loudspeaker system. The skill set required to build such a device was itself a barrier to entry, a barrier that worked well to the advantage of companies such as Dolby and USL.
But with digital cinema, that barrier to entry evaporated. Digital cinema removes the need to support proprietary technologies such as Dolby noise reduction, matrix decoding, and the many arcane formats of older days. Instead, the required processing is limited to the everyday functions of gain control, equalization, and crossover filters. Not surprisingly, Dolby, who still thinks of itself as a leader in cinema products, has fallen behind the product curve with its 8-channel CP750 cinema audio processor. More capable 16-channel products now exist from USL, Datasat, QSC Audio, and the latest company to enter this market, Doremi.
With the flood gate open for competition, manufacturers are seeking ways to close it. The new barrier to entry that’s emerging is the auto equalization tool. It’s a feature, not a requirement, but a very useful one. Cinema owners want the best possible sound, but are not always willing to pay for the expertise to keep their systems in alignment. Auto equalization solves this problem, as it can take less time to perform than manual equalization, and doesn’t require an expert to get good results.
Automatic equalization of a cinema auditorium is not a simple task. It requires the analysis of speaker signals sampled in multiple locations of the room. To function correctly, the analysis needs to separate first arrival signals from room reflections. Reflections cause aberrations in the frequency response that are peculiar to the position of the microphone. Aberrations, in turn, are often the cause of poor equalization settings. Those who perform such tasks may appreciate that there is often a point where one throws away the measurement tool and simply adjusts to their ear.
Auto equalization can be found in the more capable home theater systems, and so far, two of those technology providers have found their way into the cinema. Datasat’s AP20 uses Dirac Live auto equalization technology, and the new Doremi Pegase audio processor, designed by Cineaudio, is using Trinnov. Datasat engineers, formerly with DTS, deserve the credit for paving the road for auto equalization in cinema. No doubt Mike Archer, also formerly with DTS, had some influence in bringing the Cineaudio product into Doremi. Keep your eye on USL and QSC, as they each have the resources to bring auto eq into their product lineups.
Oddly, the company most challenged in this area is Dolby, the most respected audio company on the planet. While other companies with cinema audio processors have little in brand power to lose by licensing auto eq from others, Dolby does not have that option. It’s more likely to acquire what it doesn’t already possess. The message to those companies that have developed worthy auto equalization technology: it’s time to get dressed up.