The historic 20-story building sits prominently on Chicago's Loop, somewhat dwarfed by its larger skyscraper siblings but exuding an air of Old World class. Inside, the building's Main Hall plays host to events ranging from formal dinners to addresses by heads of state and other national and international dignitaries. It's an exquisitely appointed room with high ceilings and massive mahogany beams and columns. As David Hecht, managing principal at Wheaton, IL-based Sound Planning Associates explains, the room's architecture is impressive to behold, but creates some rather interesting acoustical challenges.
"The columns are literally around four or five feet square, and their size does make it a challenge to achieve uniform coverage everywhere in the room," says Hecht. "In addition, the room is used for a range of different events, and the stage and seating setup can vary from one event to another. Inevitably someone will end up sitting behind a column."
To meet the challenge, Sound Planning Associates designed a multi-faceted audio system based around 28 Renkus-Heinz CFX81 8-inch two-way complex conic loudspeakers. The system offers several different matrixing options. "It's essentially three systems," says Hecht. "Depending on where the stage is set up, the speakers fire from that direction, and the others are delayed across the room. So different groups of speakers are set up to work together, depending on the event."
DSP is provided by a BIamp Audia with RED-1 controller. "The Biamp DSP enables us to reconfigure the system for a variety of scenarios, depending on the event," says Hecht. "They can just select a 'stage setting' - north, south, east, west - from the RED-1 touch screen, and it sets up the speaker delays and EQ, selects the correct mic inputs, sets input levels for the wireless mics, everything. It's a very easy system to use."
A Yamaha LS9 console with wireless iPad control handles mixing duties, with Shure ULX wireless systems for the presenters.
(Jim Evans)
