Constructed between 1806 and 1821, the Baltimore Basilica was the first Roman Catholic cathedral built in the United States. A National Historic Landmark, the 1200-seat Basilica underwent extensive restoration between 2004-2006 to implement modern systems throughout the building while restoring the interior to the original design. As with many houses of worship, the high ceilings and ubiquitous hard surfaces made for a challenging acoustic environment. Room reverberation measured 4.5 seconds at mid-frequencies and 6.1 seconds at low-frequencies. Digitally steerable arrays from Renkus-Heinz were the perfect solution to improve speech intelligibility.
To improve acoustic performance, the Archdiocese of Baltimore turned to Neil Thompson Shade, FASA president and principal consultant of Acoustical Design Collaborative, for help. With experience in over 1000 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,” said Shade. “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. A member of the Renkus-Heinz ICONYX Gen5 Series, the IC16-RN gives sound system designers the power to create a system to cover even the most problematic spaces with up to eight steerable beams that can be individually shaped and aimed. Their triple tweeter “array within an array” design reduces the distance between high-frequency sources for vastly improved performance with 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 significant gain based solely on four loudspeakers. The Archdiocese staff and clergy were delighted 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,” said Shade. “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.”
