How to Make a Worship Space Sound as Great as it Looks with Fewer Loudspeakers

By: DUDLEY MCLAUGHLIN

Learn how to overcome acoustic challenges inherent in the sweeping architecture of many worship centers

The sanctuaries in many houses of worship are designed to impart a sense of awe, with high cathedral ceilings, majestic artwork or stained glass windows and areas dedicated to choirs or other musical accompaniment. The downside to those architectural features is that they often create a highly reverberant space with very low speech intelligibility.

Sound waves bounce off the floor, walls, ceiling and any other reflective (hard) surfaces, gradually losing energy over time. The harder the surfaces in the space, the longer it takes for the sound to decay and the greater the reverberation. A common acoustic measurement of a space is Reverberation Time 60 (RT60), which measures the time it takes after the sound source ceases to reduce the sound pressure level by 60 dB. While 60 dB may seem like a somewhat arbitrary number, the loudest sound level in orchestral music is typically around 100 dB, while 40 dB is a reasonable background noise level for listening to music. Loudspeakers with low directivity or those mounted in suboptimal locations can actually worsen the room’s intelligibility.

Taming the Reverberation

The first step to take in trying to improve the room’s acoustics is to establish a baseline. You can’t know what to fix, or where to apply the fix, until you have a better understanding of what you’re dealing with. Having the room’s acoustic profile modeled and measured by an AV consultant or acoustician is an excellent starting point. The results can be input into an acoustic modeling simulator like EASE software to understand the impact that different loudspeakers and their placement have on the audio performance of the space. Most loudspeaker manufacturers have performance data available in EASE-compatible formats so that you can import their profiles directly into the software for realistic simulations of the expected audio experience.

While selecting the ideal loudspeaker solution for the space and identifying the proper installation points are both critical, there’s other things you can do to the space to help reduce reverb. Breaking up the hard surfaces that sound waves bounce off of by installing acoustic treatments is a common practice for reducing reverberation. There’s a wide gamut of acoustic treatments available, but any soft surface, such as drapes, carpeting, or tapestries, will help reduce sound wave propagation. You can experiment at home by testing the acoustics in a bathroom before and after removing the towels and any rugs to see how much difference they make.

To be fair, many houses of worship prefer not to use acoustic treatments over concern that they compromise the grandeur of the space. But have faith: there’s more tools available to the integrator for creating a good acoustic outcome.

Choosing Which Loudspeakers Are the Best Fit

One benefit of a house of worship environment is that people often gather in discrete seating areas. Rather than elevating the acoustics everywhere, which can be costly, you can tailor an audio solution to give priority to that portion of the room. Choosing loudspeakers with tight dispersion patterns or, better yet, digitally-steerable arrays, delivers the audio primarily to those parts of the sanctuary where parishioners are seated.

Beam steering arrays are exceptionally well-suited for highly reverberant spaces, providing a level of flexibility and versatility that conventional loudspeakers simply can’t match. Digital arrays can be perfectly tailored to the environment with software-based adjustments, and coverage can be adjusted without the need for physical modifications if, for instance, the room layout changes.

The Power of Fewer Loudspeakers

Another great benefit of beam steering is the ability to cover multiple audience areas from a single loudspeaker. For example, loudspeakers mounted in the back of the nave could have some beams directed at the choir in the balcony while other beams were directed at the congregation. This capability also has a positive impact on installation since there are fewer cables to run and, of course, fewer loudspeakers to mount. Using fewer loudspeakers can be particularly advantageous in historic houses of worship that may have limitations on structural changes, even down to the level of where holes can be drilled.

Beam steering loudspeakers are typically much taller than they are wide and mounted flat against the wall since the beams are digitally steered. For that reason, they’re much more cost-effective than flying a line array and much easier to blend into the background of the building’s architecture. Realistically, the fewer loudspeakers deployed, the fewer visual distractions for the worshippers. If the loudspeaker manufacturer also supports custom paint schemes for their cabinets, allowing them to be exactly color matched to the architecture, so much the better for having loudspeakers “disappear” and not act as a visual distraction.

Every week, parishioners at St. Joseph Catholic Church come together under the high ceilings and stately archways of the nave, where light from stained-glass windows floods into the sanctuary. While the stunning architecture suited the sacred music of the parish choir, the space’s design led to difficulties with spoken word intelligibility. The old sound system was unable to adequately compensate, causing a “waterfall effect” of sound coming from high above. Replacing the old system with a pair of beam-steering loudspeaker arrays proved to be the perfect solution. Not only did the arrays match the soaring lines of the architecture, their height also provided the needed control to keep full-range, reinforced sound away from walls and ceilings and focused right where it’s needed: on the congregation.

Great Sound for Grand Spaces

The audio quality needs to reflect well (no pun intended) on the architecture to create truly immersive worship experiences for the congregation. When parishioners struggle to understand the sermon, they experience audio fatigue and feel disconnected from the message, resulting in a less than optimal worship environment. Acoustically modeling the room goes a long way towards identifying best placement for loudspeakers and using loudspeakers with high directivity — such as digitally steerable arrays — not only provides you granular control over where the audio is distributed but also requires fewer loudspeakers, preserving the worship atmosphere. The improvements can be a revelation.

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Dudley McLaughlin is the National Sales Manager for Renkus-Heinz. He has worked in the professional audio world for more than 30 years across multiple customer-facing roles. His day-to-day focus with Renkus-Heinz is matching the appropriate technology and solutions to the challenge at hand and adding value through technological advancements in professional audio.