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Need an acoustical intervention?

By Nick Colleran and Jim DeGrandis

The No. 1 cause of poor sound in a large space is inappropriate reverb time, or RT60 — the time it takes for sound to fully decay, 60 decibels down, from its initial impact. While a large, open hall might enhance a traditional choir and blend or average pitch, it’s not acoustically friendly for modern, high-energy music wherein amplified sound reaches parallel walls, high ceilings and other hard surfaces.

Begin by asking people if they can hear everything clearly. If not, then it’s time to call an acoustical professional. Fortunately, many will offer a basic assessment for free if provided with photos, dimensions and information regarding surfaces and intent. A recorded balloon pop might also be used to analyze a room’s acoustics.

Originally designed as acoustical wall panels for custom field painting, Tone Tiles™ are now  available in larger sizes that mimic drywall but absorb sound rather than reflecting echoes back into a room.  (Photo courtesy of  Acoustics First  Corporation)

Originally designed as acoustical wall panels for custom field painting, Tone Tiles™ are now available in larger sizes that mimic drywall but absorb sound rather than reflecting echoes back into a room.
(Photo courtesy of Acoustics First Corporation)

Keep the look (but lose the surplus sound)
If your worship space is historic or “vintage,” and you want to preserve the look of the facility, the sound of music can be improved discretely. Keep in mind that a historic space with a magnificent look and sound for its time wasn’t intended for modern amplification or high-decibel music. To preserve the austere appearance, existing curtains can be thickened with more layers or replaced with acoustic or theater stage curtains. Alternately, double-wide curtains will produce more pleats and capture more sound when closed.

Padded pews will generate sound improvement. On the walls, some sound absorbers can be painted and are available in drywall sizes.

Finally, to help tame sound at its source, make sure the loudspeakers are effectively decoupled from the structure. Generally, older structures weren’t designed with decoupling in mind; therefore, they tend to vibrate and resonate, destroying sound clarity.

More uses, more problems
A multipurpose space usually means multi-challenges. If a venue must accommodate traditional worship in the early morning, modern praise music at midday, and intimate acoustic performances in the evening, the acoustical requirements move from one extreme to another.

One solution is to create a space that’s acoustically “dry,” and then to add reverb electronically when appropriate. While electronics can’t change the acoustics of a room (a function of room geometry), they can help “fake it” and add ambience back in as needed.

A portable church might require portable acoustics. While it’s difficult to justify the cost of variable acoustics (such as rotating sound stage walls) in a permanent facility, a portable church might rely on acoustical quilted curtain blankets that roll up and store. These are industrial-grade products, so they’ll take the abuse of the road.

Nick Colleran is a principal at Acoustics First Corporation in Richmond, VA.


READER SNAPSHOT:

More than half — 56% — will invest in new A/V equipment for their churches within the next 18 months. Source:
“The Church Executive Reader Survey”


 

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