The Baltimore Basilica, the first Roman Catholic cathedral built in the U.S. dating back to 1821 and a National Historic Landmark, recently underwent a sonic upgrade to overcome the the 1200-seat room’s challenging acoustic environment in a project headed by Renkus-Heinz digitally steerable arrays.
As with many houses of worship, the basilica’s high ceilings and ubiquitous hard surfaces it a highly reverberant space, with reverberation measured 4.5 seconds at mid-frequencies and 6.1 seconds at low-frequencies. To improve acoustic performance, the Archdiocese of Baltimore turned to Neil Thompson Shade, FASA president and principal consultant of Acoustical Design Collaborative.
With experience in over 1,000 projects, many dealing with historic preservation and houses of worship, Shade was well-positioned to help alleviate the basilica’s acoustic issues. “‘Breathtaking’ is the only word I can come up with to describe the architecture,” he says. “Everything in the 200-year-old church’s interior had been restored to its original condition. The high, domed ceilings in the nave and above the congregation are beautiful but certainly added to the reverberation challenges.”
The church contracted with HP Electronics to install and commission the four IC16-RN digitally steerable loudspeakers called for in the audio redesign. Their triple tweeter “array within an array” configuration is designed to reduce the distance between high-frequency sources for improved performance with more consistent, broad horizontal dispersion.
After commissioning, the average room Speech Transmission Index for Public Address Systems (STIPA), a quantitative measure of speech intelligibility, increased from 0.42 (poor) to 0.55 (fair), a gain based solely on four loudspeakers. The archdiocese staff and clergy are satisfied with the improved speech intelligibility and minimal disruptions during installation to ongoing worship services.
“Because the basilica is a historic building, sensitivity to aesthetics was an important consideration when selecting new loudspeakers. We could immediately tell that the Renkus-Heinz Iconyx loudspeakers were the right way to go,” Shade concludes. “The basilica has a full calendar of activities and services, seven days a week, so the ease of installation and commissioning were significant factors in the success of this project.”
