The primary sites that DPA worked on were the Borups Højskole, a glass-ceilinged school hall; the Øksnehallen, a redeveloped slaughterhouse; and the jewel of the festival: the beautiful 1,000-seat Glassalen in the Tivoli Gardens. Thorough acoustic evaluations of the venues were carried out by DPA¹s audio specialist Eddy Bøgh Brixen. In the Glassalen he calculated reverberation time, low frequency distribution and frequency response, which revealed an uneven sound distribution at low frequencies, and a vast difference between sound at the front of house position compared to most of the auditorium, Brixen came up with solutions for these problems and improved onstage sound by designing an isolation base for the bass amp to separate the vibrating cabinet from the stage floor.
In the Øksnehallen, Brixen calculated an optimum position for the stage. The hall is divided in two by a wide aisle with a raised glass ceiling, and normally the stage would be positioned in this aisle to achieve a sense of symmetry. However from an acoustic perspective, reflections bouncing around in the extra space created by the glass ceiling caused problems, so Brixen recommended moving the stage away from the centre aisle again a drastic improvement. Meanwhile in the Borups Højskole, Brixen suggested a reflector for improving sound distribution.
"The Copenhagen Jazz Festival is very pleased with the support from DPA Microphones regarding acoustical improvements in our very different venues," says Festival manager Signe Lopdrup. "Each year we select new and often not very well tested venues for our concerts, and it¹s particularly important to have the kind of professional support we¹ve received from DPA over the last two years. The sound in the Glassalen is really improved, and I don't think the concerts in Øksnehallen would have been as successful if we hadn't had support from Eddy Bøgh Brixen concerning the exceptional conditions in the old slaughterhouse." The festival committee has now asked DPA to evaluate a number of new sites to be used in 2006.
(Jim Evans)
