Clear speech, less reverberation: the cathedral’s sound system will receive a significant upgrade

One thing everyone would agree on is that the Cathedral desperately needs a new sound system. If you don’t sit in the front rows, you have difficulty understanding the readings and the homilies – and sometimes, even a seat in the first pews isn’t sufficient when the current sound system has a bad day.
 
Replacing the old system with new, up-to-date technology is a priority for the Cathedral renovation, which will begin at the end of May. Andy Miller is a partner at BAi Architectural Acoustic Consultancy, an Austin-based company specializing in architectural acoustics, audio system design, and commissioning work since 1935. He designed the new sound system for the Cathedral. “Churches, cathedrals, and basilicas are buildings with intense acoustics needs. And in the acoustic need doesn't always resonate with how the building needs to be designed liturgically,” he names the principal challenge. The space should reflect the grandeur and significance of the Cathedral, but it is also a space where we can hear the Word of God. Miller said he received many reports about poor speech intelligibility in the cathedral. He visited and performed technical measurements, confirming much room for improvement.
 
Speech intelligibility in any space is measured by reverberation time – the duration it takes for a loud sound to dissipate. This is generally a challenge in large, high rooms, but it is even more pronounced in the cathedral, as one cannot simply add curtains or carpets. Miller collaborated with the architects to identify opportunities to introduce new or different materials that would enhance speech clarity: “The key challenge is always, how do you make it look like it belongs there or disappear altogether.”
 
The solution involves a material that absorbs sound while remaining nearly invisible, as it will be applied to walls or pillars beneath the finishing paint: “Those are stretched fabric systems – but they don't look like fabric, they look like a smooth, flat surface in that fabric is stretched on top of a material that absorbs the sound.”
 
The other strategy involves examining the sound system: “We don't want the music to suffer – the organ and the choir should sound like in a spacious cathedral. So, we can't just cover every surface in the cathedral with something sound absorbing, or else the music completely loses its strength, spaciousness and brilliance, all of those things that we like to hear from liturgical music.” The solution is a specialized system that carefully controls the direction of sound, known as adaptive, steerable systems: “We will be steering the beam of the sound so that it lands on the people's ears, which is where you want it and need it, instead of just shooting sound everywhere out into the room.”  
 The areas marked in blue will be treated with a stretched fabric to reduce 
reverberation, which will disappear underneath the paint.What will that look like? The speaker on every pillar will disappear. “It is just a relatively slender column full of speakers. There are about 32 speakers in each of these columns, and there will be one on each side at the front of the cathedral.” 

Technical progress now makes it possible to direct the sound from these columns to every corner of the church. Andy Miller hopes the difference will be noticeable: “We’ve recently commissioned a system at the Cathedral in Lafayette, Louisiana, that is very similar regarding the reverberation and the acoustic character. The results were spectacular, and we couldn’t even incorporate the acoustic treatment in that room. We are really excited about the kind of result that we can expect, especially compared to what parishioners are experiencing right now.”
 
This is a relatively new technology: “What makes it possible is the immense amount of computer processing power that fits in such a small package. The physics to do this has been around for decades, but we just didn’t have the power to process the audio that quickly.”
 
In addition, the cathedral will be equipped with an assistive listening system that allows parishioners who use hearing aids to connect via Bluetooth or wear a small device that delivers sound directly to their ears.
 
Another improvement will be made for those sitting in the sanctuary, reading, or delivering a homily who couldn’t hear themselves at all until now: “We will also have some additional small speakers in different locations in the cathedral that wouldn't be covered by these main speakers, like small monitors.” The same will apply to the choir loft.
 
Andy Miller’s job is like a ministry, and God guided him there. “Going into college, I thought I would be an artist. I thought I was going to paint pictures for a living and was looking at an art school when my parents and I ended up on a tour to the architecture school,” he shares. “That’s where God put me at the end of the day.”
 
An Associate Dean handed them off to another architecture school professor, Bob Coffin, an acoustical consultant. “And after walking around with him for a while, it became clear that architectural engineering was the avenue that was right for me.” Eventually, he chose Coffin as his advisor and took a job at a company specializing in acoustic consultancy. “You can’t see God's plan until you look back at all the things that have happened and realize, ‘I’m sort of being shaped for this.’”
 
With this experience, he feels honored to work on the cathedral: “It’s just very humbling to put my gifts at the service of any community. And the most rewarding projects I work on are usually the Catholic Church projects, just because I feel like I know I'm doing something meaningful, more meaningful than anything else, doing something that will enable the Word of God to be heard and listened to… God has given me everything, and how could you not give at least that back?”

More on the Cathedral Renovation Project at https://cathedralrenovationcc.com/