The greatest challenge for the system designers was posed by the room acoustics, as the reverberation time in the church of St. John the Evangelist had been measured at a full 2.9 seconds. A further stipulation of the commission was that the loudspeakers should blend unobtrusively into the background and complement the architecture of the building. Sound Engineering by Design (SED) of Dublin was the company entrusted with the task of confronting these challenges.
Horn-loaded EVH loudspeakers from Electro-Voice meet the triple challenge of high intelligibility, even coverage and an aesthetically pleasing design
To provide powerful and even coverage of the 15 x 20m congregation area, SED opted for a horizontal cluster of three loudspeakers flown centrally above the altar - a choice based on simulations of different locations and dispersion angles. The appropriate tools for the task proved to be EVH loudspeakers from the EV Innovation series from Electro-Voice
"The EVH horns we installed are operated in full-range mode and have a tight 40 x 30 degree radiation pattern," says SED's James Walsh. "The directionality of EVH horns is impressively precise - especially so at frequencies well below 1 kHz - and the performance of the system corresponds exactly to the requirements of the building. In fact, despite the problematic acoustics, we have succeeded in achieving a high level of intelligibility."
A further advantage of the tightly controlled dispersion of the loudspeakers is that it reduces the risk of feedback from the microphones. The installation here is rounded off by an Electro-Voice ZX1i loudspeaker alongside the altar, which provides side-fill for the choir. The system is driven by two Q1212 power amplifiers from Electro-Voice and controlled by an Electro-Voice DC-One system processor. "In view of the length of the reverberation time, we decided to introduce additional equalisation to optimize intelligibility," adds Walsh.
(Jim Evans)
