Many years have passed since audio professionals felt they were stuck with whatever room geometry they inherited.
In a more ambitious church, perhaps a few weekend warriors hand built wall frames filled with fiberglass or other absorbent material. Depending on the situation, these DIY efforts could help. But these were the exceptions, not the rule.
In general, however, acoustics were largely left to consultants with special education, training, and many failed projects in which the mathematical models just didn’t fit the reality of real-life construction. But thankfully, that has changed—at least in part.
We now have predicative software that can do a good job of estimating the outcome of acoustical treatment, as well as providing recommended loudspeaker placement. And while such software may not be the first choice for multi-million dollar new construction, the current crop of affordable programs has the ability to land the spaceship in the proper corner of the ballpark in most cases.
But what can be done when the room optimally requires a given amount of absorption, diffusing, or controlled reflection, but the walls are too small, the budget’s too tight, or the materials won’t work with the decor? Then compromise may be in order. A certain amount of trial and error may be necessary until the designers and installers have settled on an optimum solution.
Some advanced acoustical systems even offer “push button” control to change the position of the absorbers and diffusers, which gives the sound engineer broad latitude when preparing the room. For example, an intimate, heartfelt sermon will benefit from drier acoustics than Handel’s “Messiah.” And what a rush to be able to change the acoustics while content is in progress. It’s like changing reverb settings but with 100 horsepower more effect.
To find out what’s leading edge, CDM checked in with several manufacturers whose acoustic products are commonly spec’d within worship spaces.
Acoustics First Corp.
Acoustics First sells a comprehensive line of diffusers and absorbers with many choices for standard and custom decor. The company has learned to combine diffusers with absorbers, synergistically, for greater efficiency in each.
One standout product is its Double Duty Diffuser/Bass Traps that tune to absorb low frequencies with their center frequency of absorption following size. A two-foot by four-foot unit absorbs in the region of 125 Hz. Doubling both length and width shifts its range down an octave to 63 Hz.
The company is also now using 3D printing technology to create full-scale models of its new diffuser designs.
This allows new designs to be laboratory tested to confirm predicted performance before final tooling is made to manufacture quantities for sale. The process saves both development time and eliminates unnecessary prototyping costs.
One recent church project-applicable product is the Model D Art Diffusor for which Acoustics First Corp. has issued a patent. In a related project the company recently tested a full series of traditional diffusers and new designs.
Results are available for download from the company website: (visit link)
The polycylindrical (barrel shaped) diffuser will act to scatter high frequency sound and trap bass in any location. Bass absorption will vary with size. A 2’ x 4’ unit has maximum absorption at approximately 125 Hz. Increasing size to 4’ x 8’ lowers center frequency of maximum absorption to 63 Hz. Mid to high frequency absorption is typically 0.10 to 0.25.
Another sought after product is the company’s Double Duty Diffuser, available in white thermoplastic, standard Guilford of Maine FR701 Style 2100 fabric, or other factory-approved finish. Units have the option to be lined with a 1.5-inch layer of glass fiber batting to increase absorption and prevent resonance. Lining is standard in larger sizes.
Double Duty Diffusers are wall-mounted using provided “L” brackets, according to the company. Configurations are available to fit a standard T-bar suspended ceiling grid.
Auralex Acoustics
Auralex, a reported leader in acoustic panels, will manufacture multiple thicknesses, different densities, and a range of finishes in its ProPanel Line.
One outstanding strength that the company offers is a Room Analysis Service at no charge, helpful in determining strategic placement of materials to get the best performance from every nook, cranny and open space in the room, according to Auralex.
Regarding space vs. absorption, the company representatives report that Fiberglass, in the case of the ProPanel Line, was specifically designed to absorb particular frequencies in a small-profile package.
Auralex reports that it prides itself on knowledge, technical support and free personalized room analysis. The company offers a range of absorption, bass trapping, diffusion, construction, and sound isolation products; all materials are Class-A fire rated.
