Sound at the Bregenz Opera Page 4
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Sound Areas
Ideally one would divide the stage into 20 sound areas. 10 speakers for each area would require a total of 200 speakers which is neither possible nor practical. Instead Fritz uses just 56 speakers by channelling different signals into each. Their positions are shown in the composite speaker diagram.
Fritz in fact divided the stage into 16 sound areas. Based on the law of the first sound wave-front, it is the singer's (original and undelayed) voice that gives the listeners' ears the direction. In order to assist the singers, who are the most important sound sources in terms of timbre and direction, but who cannot sing towards all parts of the audience at one time, he needed directional loudspeakers within each area. These could be built into the set or might pop-up when required on a pneumatic telescopic stand. (It is surprising how little one notices these devices within the large stage expanse). Each speaker in each of the sound areas can be programmed with a time delay - between one and 120 milliseconds - to change the focus of the sound source and all these factors can change as the singer moves from one sound area to another.
Delay units in the sound booth are patched into the loudspeaker chains via the Ghielmetti patch panels, also located in the soundbooth.
Just to keep things complicated, there are three casts (playing consecutive nights) who strictly follow the same blocking but variations - both planned and spontaneous - do occur especially when cast members cover for each other. So whilst the main plot may be recorded, each performance has to adapt moment by moment to the eccentricities of that cast.
Balancing Act
It is just about manageable to manually follow two singers as they move left to right and front to back across the stage. But there may be as many 8 singers moving independently at any one time. The mixing console is therefore programmed with automatic cross-fades on separate times for the main cues with manual override to cover any unexpected changes. Fritz uses a loudspeaker matrix system with a moving time delay of between 10 and 20 milliseconds.
In all, three sound systems are in operation. One, described as 'the moving system', provides directional sound as a performers moves between sound areas.
Movement of sound between speaker complexes is accomplished with the ribbon controller.
The matrix system then channels a combination of 6 or 7 different sound patterns with appropriate time delays into each speaker. These take into account volume, frequency, balance, wind adjustments and whether a singer is facing up stage.
The third is a digital mixing control system with step by step variations operating cue by cue much like any lighting control.
This console adapts to increased numbers of channels by using the same controls for different pages: one for principals, one for orchestra, one for chorus, one for effects, live stage band etc. Bregenzer Festspiele use a TOA:IX9000 digital console with 156 inputs and outputs.
Control
The sound control room is situated undercover
at the back of the seating with the windows open. 
A maximum of 110,000W is required for sound.
The amplifier room is located in a special room located underneath the stage.
A special patch panel connects the output of the matrix mixer to each amplifier, allowing technicians to monitor the audio, and to quickly substitute amplifiers in case of equipment failure.
Crossovers in the amplifier room divide each sound signal into separate frequency ranges.
One of the staff sound technicians demonstrates how the crossover networks integrate with their own special patch panel.
There are 4 sound crew on stage, 2 in control (one on TOA:IX9000, one on Direction); 1 sound designer, 1 technician, 1 security/back up, 1 in the remote studio and 1 on focus camera work.
Members of the sound crew pose for the OISTAT cameras.
Contingencies
With so much riding on each performance it would be a disaster if anything went wrong - especially for the House staff who have to send 7,000 disappointed people home early. The Festspiele cannot afford to cancel a performance and as each is also continuous (150 minutes) there is no point at which to rectify an error.
Each performer therefore has two radio mics, with 2 transmitter packs.
Wolfgang Fritz demonstrates the harnesses used to mount the wireless mics on the actors.
Wolfgang Fritz demonstrates the placement of the wireless microphones harnesson the actor's head.
Wolfgang Fritz demonstrates the special wireless microphone patch panel which allows quick and efficient repatching of wireless microphones in case of sweatouts, or other failure.
When required, additional mics complete with their own power packs can be thrown-on round the neck of a performer. There are two digital mixing consoles plus a further analogue back-up.
An analog Soundcraft Europa console provides a completely independent backup to the main digital mixing console
Regular maintenance and routine checking is essential. The permanent speaker system is always checked thoroughly before each performance. Sometimes cables can get dislodged or torn, electrical faults are also noted. But when things do go wrong the policy is to switch off the problem rather than suffer the interference.
Inclement Weather
If it rains particularly badly, there is a scaled down version of the production which can be performed in the indoor theatre but only to 1,700 people; the rest get despatched home with or without a refund. But of course it does rain in performance, sometimes quite badly, and thunder and lightening are also regular hazards.
We were "fortunate" to be treated to an example of inclement weather at the very end of the closing night performance. The cast and crew remained undaunted, however, and refused to let the elements "rain" on their closing night celebration, rising to the occasion in impressive fashion.
The risk can equally be from bad weather in the run-up to the show as much as during it. Speaker coverings get soaked which adversely affects the sound. Water gets into everything but the noise it creates can be as problematic as the electrical damage it does. Wind is also a problem. When it exceeds 80km/hour the stage has to be evacuated even though the structure is tested to withstand far greater wind speeds.
Whether from rain or sweat, the principals' microphones can easily get damaged. As a consequence they wear a head-set with two AKG mics in place. One has a wind cover, the other acts as a back-up; both are 'sweat-safe'. It is possible for a costumed sound technician to run up to a singer and throw a third one round their neck to rectify faults.
Last summer in rehearsals a singer even fell in the lake with mics intact and clambered back on stage to continue; a new mic would have been the only solution in this instance had the rehearsal not been discontinued after this historic diving incident by King Gustav!
Good weather also presents its challenges. At temperatures of 30 degrees [Celsius]
during the day, the heat affects the high frequencies. As the air gradually cools the sound needs constant re-balancing.
Dreams for the Future
Fritz offered two potential developments for future projects. As opera is normally heard within an architectural environment he would like to add the equivalent of room reflections to the acoustic. This might include speakers behind and to the side of the audience. The LARES Lexicom system points the way forward.
Wolfgang Fritz envisions a day where the current surround sound system can be replaced with a more sophisticated electroacoustic architechtural system.
The second dream is a combined mix and matrix system with automatic sound-following: 100 sound areas would be possible with moving time delays. He reckons this might take a further 3 years to develop.
I draw attention to the wonders of designing and managing a sound design for spectacle on this scale. The important thing to remember is that you are largely unaware of the technology, merely impressed that the sound is clear and appears to come from the character that is singing. However, it is impressive how seriously the company takes their work and that all eventualities are anticipated to ensure the production is always of the highest standard.
The new production of 'La Bohème' opens on 18 July 2001 with performances through to 21 August. If you intend to fly there, Zurich is the nearest international airport. A very pleasant two hour local train journey then takes you direct from the airport into the heart of Bregenz. Hotels can be at a premium at festival time but the local tourist board can offer a range of prices or cheaper hotels out of the city. If you do not choose to go in 2001, Bregenz is an absolute must at some time in your career.