Christmas on the Potomac with L-Acoustics
- Details
Bringing this production sonically alive was the task of an L-Acoustics Kara system, designed and installed by Showtime Sound LLC of Frederick, Maryland. The system was split between the atrium’s lower and upper terraces: the former comprised a left-right design of one SB18 subwoofer ground-stacked with five Kara enclosures per side to cover the ticketed seating areas, and a flown LCR delay system of three hangs of one SB18 over seven Kara for standing and balcony areas.
Six LA12X amplified controllers powered the delay system while three LA12X were used for the ground-stacked enclosures. The system also used the L-Acoustic P1 processor for system management, routing, and time alignment, as well as for its AVB compatibility for long-distance signal transport. Audio came into the P1’s AES inputs and was sent as AVB over fibre to the amplified controllers.
Showtime Sound LLC had two distinct challenges on this project. “The atrium is huge,” explains Showtime Sound LLC director of operations and production Brian Linnemann. “It’s also surrounded by hard, reflective surfaces, including a huge glass wall and ceiling, plus concrete balconies. We had to keep the sound directly and precisely on the seating and away from the reflective surfaces. Fortunately, the Kara enclosures can be aimed extremely precisely. We used L-Acoustics Soundvision modelilng and prediction software and the result was perfect - great, uniform coverage with high intelligibility and plenty of impact for the music.”
The second challenge was to move the audio signal around this yawning canyon while keeping the cabling and components out of sight. The LA-RAK II amp rack for the ground-stacked array was within 50ft of the stage, but the other two racks for the flown system were located on a balcony about 120 feet vertically from the stage, necessitating substantial fibre and Cat 5 runs. That, says Linnemann, is where L-Acoustics’ compatibility with the AVB networked protocol made “a huge difference”.
(Jim Evans)
