Beam-Steering Arrays Drastically Enhance Church Sound Clarity for Oldest American Catholic Basilica

Beam-Steering Arrays Drastically Enhance Church Sound Clarity for Oldest American Catholic Basilica


Acoustics in Catholic churches present a unique and often challenging environment for sound engineers and architects alike. The grandeur and architectural design of these sacred spaces–with high ceilings, stone walls, and expansive nave–can create a captivating visual experience, but it also introduces significant acoustic complexities that impede church sound clarity.

The combination of hard surfaces and vast dimensions results in prolonged reverberation, causing sound waves to bounce, echo, and overlap, thus impacting speech intelligibility and musical church sound clarity. With these challenges in mind, the Renkus-Heinz ICONYX product line has been specifically created for these to address these acoustical objectives.

Unique Challenges of Catholic Church Sound Clarity

The intricate detailing in many Catholic churches, such as ornate sculptures, stained glass windows, and decorative elements, further contributes to the scattering and diffusion of sound waves. Balancing the need for a reverberant ambiance for choral performances and liturgical music with the requirement for clear and understandable speech during sermons and readings poses a formidable task in optimizing the acoustics of Catholic churches. 

Impeccable craftsmanship, strategic placement of absorptive materials, innovative sound reinforcement systems, and beam-steering arrays are often employed to address these challenges, ensuring that the faithful can fully engage in worship and appreciate the sacred sounds within these awe-inspiring spaces.

Baltimore Basilica Renovated for Improved Acoustical Performance

Constructed between 1806 and 1821, the Baltimore Basilica was the first Roman Catholic cathedral built in the United States. A National Historic Landmark, the 1,200-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. 

Historic Preservation Presents Challenges for Houses of Worship

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,” 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.

Beam-Steering Arrays Drastically Enhance Church Sound Clarity for Oldest American Catholic Basilica

Speech Intelligibility Massively Improved by Renkus-Heinz ICONYX Arrays

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.”

What is the Speech Transmission Index for Public Address Systems (STIPA)?

The Speech Transmission Index for Public Address Systems (STIPA) is a standardized objective measurement method used to assess the intelligibility of speech in public address systems. It provides a quantitative evaluation of how well speech can be understood by listeners in a given acoustic environment. STIPA takes into account various factors that affect speech intelligibility, such as background noise, reverberation, and frequency response.

To measure STIPA, a reference signal containing speech-like signals is transmitted through the public address system. This signal is received by a microphone positioned in the listening area, and the captured audio is then analyzed using specialized software. The software compares the transmitted and received signals, considering factors like modulation, temporal and spectral characteristics, and ambient noise levels. The result of the STIPA measurement is a single value, typically ranging from 0 to 1, where 1 indicates perfect intelligibility and 0 represents a complete lack of intelligibility. This value serves as an objective measure of the quality of speech transmission in a specific environment.

STIPA measurements are commonly used in various settings, such as auditoriums, conference halls, airports, and houses of worship, to evaluate the performance of public address systems and make necessary adjustments to optimize speech intelligibility for listeners.

About Renkus-Heinz

Founded in 1979, Renkus-Heinz, Inc. is a leading manufacturer of professional loudspeaker technology and the recognized world leader in digitally steerable arrays. Known for cutting-edge innovations and exceptional customer service, Renkus-Heinz delivers premier sound solutions to the world’s most prestigious projects.

With an award-winning product suite including ICONYX Gen5 Series steerable column arrays and UBX Series passive column loudspeakers, Renkus-Heinz has sound solutions for a wide range of applications from performing arts venues, transportation hubs and houses of worship to educational, corporate and governmental facilities.

Renkus-Heinz is headquartered in Foothill Ranch, California, USA, with additional offices around the globe. For more information about Renkus-Heinz, please visit

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The WAVE conference focuses on audiovisual and lighting first and is a traditional conference and expo with the best church AVL exhibitors and vendors in the industry. At WAVE, you and your tech team will have the time to talk with exhibitors because our expo floor is less crowded and better organized than other AVL conferences. WAVE offers the opportunity to see what others are doing and even boasts and church tour local to the conference. Experience roundtable discussions during meals and after sessions. Visit the biggest manufacturers in your area. Maximize your team’s time for education, training on equipment, and industry connection and collaboration. Lastly, WAVE offers incredible value for the education, exhibit access, networking, worship, and amenities for the price of the ticket. Lastly, we at WAVE want to see your church grow, help others find God, and feel personal satisfaction with their jobs by being educated and connecting within the AVL church tech industry. Register for WAVE today!

Lauren Hunter assists organizations in reaching their goals through her unique blend of freelance writing, content marketing, SEO, and public relations consulting and coaching. She founded in 2007 and has many years of expertise in the church tech and software space. She is also a musician and self-published author of two books. She loves exploring the big picture of the journey we are all on together. Lauren is married to her high school sweetheart, and they live in Northern California with their four teens. She can be found online at