The current system comprises Meyer, d&b and Duran Audio loudspeakers, a DiGiCo D5 Live digital mixing console,a substantial amount of XTA processing equipment, Sennheiser 5012 transmitters with 1046 receiver racks and DPA microphones. But perhaps most interesting is an Out Board TiMax Audio Imaging delay matrix with a new automated tracking system developed by Norwegian company Track The Actors (TTA). And the combination works extremely well.
It's a complex output system," explains Aitken. "We rig about 120 loudspeakers in total. The stereo orchestral system is at the end of the hall, above the orchestra position. This year we have worked with Duran Audio and installed two drops of Target T280 cabinets with U16s asnear-field fills. The low end is covered by a drop of six B215 cabinets double-spaced and flown up-stage centre and the system deliversa better vertical coverage than we are used to.
However, the most critical part in the audio design is the vocal reinforcement system. "We have to cover a seating area of about 320 degrees horizontally and 130 degrees vertically," he continues. "To do this we use a circular truss hung over the arena floor from which we rig 16 drops of four Meyer UM1s. In addition to that, we have floor speakers (d&b E3s) built into the set, which are central to the design. We rely quite heavily on them to pull the image back down to the stage. The vocal loudspeakers are divided into 32 groups, all fed from Timax and equalised individually using 16 XTA DP224s and 226s, with a further four speaker groups for the orchestra fed directly from the D5 and processed by another pair of XTAs.
For the past five years, Aitken has used TiMax to create what Out Board describes as a 'source-oriented reinforcement' system, using Haas Precedence delay psychoacoustics to make the actor's voices actually appear to be coming from their mouths, wherever they are on the stage. The TiMax delay matrix ensures that every audience member receives the acoustic output from the actors just a few milliseconds before any output from the speakers, thereby causing them to localise to the actors and not the PA.
Our big challenge at the RAH is that it's such a huge performance space," continues Aitken. "It's 30 metres across the stage, but you can still hear the actors acoustically from one end to the other, so the loudspeaker timing has to be referenced to the actor. If an actor is standing in one position, hearing him and then hearing a loudspeaker coming at you 30ms later would be no good. It has to all tie-in. So we use this quite complex system of the DiGiCo D5 with the outputs coming straight out of the channels into TiMax, and we then have a 16-input,32-output TiMax matrix. Effectively, it's a very complicated delay system, but it works very well. As the performers move about the stage, their reinforced image appears to travel with them.
To this effect, each actor wears a small TTA radio tag that communicates with a TTA Tracker panel suspended above the stage to continually send positional data to the TTA software. This in turn sends MIDI messages to the TiMax ShowControl software that identifies the actors both by name and by specific pre-defined localisation zones, of which there are 15 on the stage. With 32 loudspeaker groups, it means there are 15x32 measurements to make, so this is a very complex system, but Aitken is happy and knows that it gets better each year.
We used to sit and plot the cast's movements during rehearsal so that Richard Sharratt, who mixes the show, would know at the beginning of each verse where t