A NIGHT AT THE OPERA WITH TIMAX

Performed in English, thanks to the acclaimed translation by Amanda Holden, the latest Raymond Gubbay production of Puccini’s tragic masterpiece Tosca at the Royal Albert Hall was a spectacular showcase for director David Freeman and designer David Roger.

    Featuring a distinguished cast of soloists accompanied by the Royal Philharmonic Orchestra, conducted by Peter Robinson, this was a classic adaptation of the opera, with all the blood, bells and smells its aficionados have to come to expect and demand.

    This time, however, Tosca was dragged screaming into the 21st century, not only by way of Autograph Sound’s Meyer/d&b sound system (mixed on a DiGiCo digital desk), but with the addition of a new sound automation technique that combined Out Board’s TiMax Audio Imaging delay matrix with the new TiMax Talent Tracker (TTT) radar tracking system, based on ultra-wideband (UWB) radar technology developed in conjunction with Cambridge technologists Ubisense.

    The new technology further augments the specialised ‘source-oriented reinforcement’ audio system configuration that sound designer Bobby Aitken has utilised this year and for the previous nine years of Gubbay’s arena opera productions.

    The design is based on a multi-channel speaker system driven by a TiMax audio matrix whose job is to apply varying amounts of precedence delay to each of the performers’ radio mics as they move around the stage. This ensures all audience members perceive the vocal performances to be coming from the opera singers’ mouths and not from the multiple speakers distributed around the grid above the stage and beneath grilles in the stage floor.

    Vocal intelligibility is key to Gubbay’s presentation of popular opera classics such as Madame Butterfly, Carmen, La Bohème and this year’s Tosca. His productions are unique in that the libretto is translated into English, mainly to appeal to a wider mass-market — and so it is vital the audience hears all the words.

    As the shows are also staged in the round, they have always involved close-miking of the principals and lead chorus members to make sure they’re heard, especially as their backs are turned to half of the audience most of the time.

    In keeping with Gubbay’s desire to also satisfy the opera purists, Aitken and sound engineer Richard Sharrat have concentrated on achieving a high degree of subtlety in the sound reinforcement to effectively render the sound system inaudible and focus everyone’s sonic sensibilities on the performers themselves. This is where TiMax Audio Imaging and the new TiMax Talent Tracker come in.

    The simple objective is to always ensure every audience member receives an acoustic wavefront from each performer about 10-20 milliseconds before they receive the reinforcing energy from the speakers. Within this short time difference, the brain integrates the two arrivals together but focuses the listener instinctively into localising to the precedent arrival coming directly from the performer. This psychoacoustic phenomenon is often referred to as the Haas effect.

    TiMax achieves this by setting up multiple unique delay relationships between every source (i.e. radio mic) and each loudspeaker reinforcing it. These relationships are changed every time a performer moves to a different location on stage, to maintain the acoustic precedence which makes the audience localise to the performer and not the speakers.

    The TiMax software simplifies the process by allowing on-stage localisation zones to be pre-defined as ‘Image Definitions’ which are really just pre-programmed tables of level/delay instructions to the TiMax matrix which tell it to place the actor’s audio image in the appropriate zone on stage. The TiMax DSP matrix firmware then applies special proprietary smooth-panning algorithms to ensure glitch-free delay transitions between Image Definitions.
  

 In previous years, the movements of actors between Image Definitions were mapped out in rehearsal into a series of TiMax showcontrol Cues, which the operator would step through manually during the show. In this year’s Tosca production, the TiMaxTalent Tracker system is continually following each actor’s movement around the stage with TiMax responding automatically in real-time to assign their individual radio mics on to the corresponding audio Image Definitions.

TRACKING THE TALENT
Each actor wears a small UWB transmitter tag which communicates with an array of six small sensors mounted on a lighting bar running around the Circle balcony-front just above the second tier boxes.

    The sensors analyse a combination of Angle (AOA) and Time (TDOA) of Arrival information many times a second to allow the TTT software to locate where the actors are on stage. The TTT software sends MIDI messages to the TiMax ShowControl software via an internal soft MIDI link, identifying the actors by name and also by the specific pre-defined localisation zone they are each occupying at any instant in time.

    The TiMax software then converts these messages using the pre-programmed Image Definition level/delay instructions and sends them to the TiMax DSP matrix to place the actors’ audio images in the appropriate localisation zones on stage. Each tag’s refresh rate can be dynamically varied independently for individual actors, so the system can respond instantaneously to the rapid stage movements of certain characters whilst transmission bandwidth can be preserved on the more sluggish individuals.

    This all takes place automatically and in real-time, enabling the sound to follow the actors as they cross the stage, without any intervention from the operator. Considering that it could easily take dozens of cues to achieve manually, this represents a substantial reduction in pre-programming effort and removes the need for any intervention by the operator during the show.

    The TTT location algorithms work equally well in the vertical plane, so for Tosca the TiMax system will also automatically track and localise the heroine as she performs her final aria at the top of the castle walls some 20 feet above the stage before taking her famous tragic plunge over the parapet.

    Based on specific actors moving into close proximity to each other, the software can also generate MIDI events, a facility which could be used to help automate the routing of mics between the different channels of an A/B vocal reinforcement system, for instance.

SCOPE
The TiMax Talent Tracker system can follow up to 60 actors at any time depending on refresh rate, or an indefinite number if one adds further interlinked tracking cells. The TiMax delay matrix currently provides up to 32 audio inputs and can independently localise up to 16 actors simultaneously in the same scene, across 32 different Image Definitions. Larger arena productions and more complex spaces can utilise a series of interlinked cells of TTT sensors networked together to cover the whole area.

    As the TTT sensors are mounted around the perimeter of the performance space it is ideally suited also to outdoor shows without a roof, and has already been scheduled for a major European musical theatre production on the shore of a lake during the summer.

   TiMax audio interfacing can be analogue or digital, and in the case of Tosca its inputs are connected to the DiGiCo D5 console via AES/EBU. The TiMax system’s 32 analogue outputs feed directly to the XTA speaker controllers for EQ and additional signal distribution.

TPi
Photography by Alastair Muir,
Jo Boyd and Dave Haydon