The Eastman Theatre, crown jewel of the Eastman School of Music at the University of Rochester, is acclaimed as one of the world's most majestic concert halls. The classically influenced 3,094-seat theatre serves as the prima ry performance home for the Rochester Philharmonic in addition to scores of visiting performers gracing its stage on a regular basis. The ornate aesthetics of the space are deemed almost as crucial as acoustics, so any alterations have to be carefully conceived and executed.

Such was the case when funding became available to upgrade the facility's outdated, RF-based assisted listening system. Brighton Sound, a Rochester-based systems design and integration firm, was tapped to come up with an upgrade, albeit one fitting within the 76-year-old venue's strict requirements.

Senior designer John Voelkl of Brighton Sound, working with theatre production personnel, settled upon a Sennheiser infrared (IR) system for the application. Research into the most frequently utilized assisted listening systems in critical professional theatre and concert hall situations led Voelkl to focus on Sennheiser, which scored very well in crucial factors of flexibility, audio quality, and reliability.

One of the most significant challenges of the project proved to be defining acceptable locations for the eight Sennheiser model SZI1029 and SZI1015 IR emitter panels distributing signals to the IR receivers utilized by audience members. The design team settled on affixing the compact panels to the house sound reinforcement system's main loudspeaker arrays, flown left, center, and right above the stage floor.

"There were challenges in making the panels fit within the space as unobtrusively as possible," Voelkl explains. "Theatre staff proved incredibly helpful in this regard--the stage manager, as well as the assistant stage manager, knew all the 'secret' hiding places where we could conceal all wiring."

Mounting hardware, also from Sennheiser, allows the emitters to be panned and tilted as needed and then locked into position. The panels are flown at varying heights, with an extensive testing process involving hearing-impaired patrons providing final information for attaining the most effective and consistent coverage throughout the venue.

All of the panels are fed by the main component of the IR system, a Sennheiser SI1015 Modulator. It's stored in the theatre's central rack room located backstage along with the house sound system's signal processing and power amplifiers.

The modulator can be fed audio signal two ways. A split from the house sound system's mixing console feeds a compact mixer dedicated to the IR system. Or, a Schoeps microphone flown discreetly in the house captures programming which is then routed, via a patch panel, to the compact mixer.

Audience members request IR receivers at the theatre's box office prior to any performance. A wide range of Sennheiser receivers are available, including models RI250 or RI250-J, the latter fitted with an accessory jack accommodating either earphones or Sennheiser EZ120 silhouette induction plates for hearing aids.

"This system will easily take the theatre well into the next millennium as far as meeting any assisted listening needs that might arise," Voelkl concludes. "Coverage and quality have been phenomenal, and the system is virtually invisible."