Aiming Higher: Solving Sound at Crosspointe Church - Kent Morris
For Dwayne Maynard, every Sunday was a mixed blessing. As the worship leader at Crosspointe Community Church in Dalton, Georgia, he was thrilled to lead his congregation into worship, but he was disappointed as each service was interrupted by feedback and poor sound quality. Several system adjustments had made little impact on the audio response. Befuddled with the ongoing saga, Dwayne considered a complete overhaul of the sound system. However, the cost of the redo, about 30,000 dollars, precluded any major changes.
A chance referral sent Dwayne the answer he was missing. A friend told him about a consultant who specialized in correcting problems using existing products. The company sent a team armed with SIA-Soft's SMAART measurement software. SMAART allows the engineer to separate the room's response from the sound system's response and then be able to tailor the system to match the room's characteristics.
Loudspeaker LocaleUpon arrival, the team immediately saw the core issue: the speakers were mounted in the wrong location. Just as in real estate, the primary consideration with loudspeakers is location. Once the SMAART program was run, the data was taken back to the firm's office and entered into EASE, an acoustics analysis program. EASE modeling showed the optimal speaker location was several feet from its current abode. To solidify the improvement, the firm recommended the addition of a Biamp Nexia SP DSP (Digital Signal Processor). The Nexia is a four-input eight-output box capable of controlling all the drivelines for the main speakers, the subs and the monitors. By laying everything into the digital domain, complementary settings could be programmed that prevented the subs from obscuring the mains or the monitors from overlapping the subs.
The eight existing OAP T-122 main speakers were installed properly; they were simply in the wrong place. The team removed the speakers, positioned new hardware in the correct area and re-hung the array with delays mounted over the balcony areas. Several hours of programming yielded magnificent improvement in gain before feedback and intelligibility. Intelligibility indices calculate the ability of a listener to understand the spoken word when driven through the sound system into the room. The more discernable each consonant, the higher the index. Troublesome consonants, such as S, P, T and Z smear aural retention and lower the message's usefulness. Increasing articulation is the key to improving the sound system.
With the Nexia programmed to decrease lower midrange response and increase the upper mids without crossing the boundary into brittleness, the system came alive. Combined with the re-hang of the speakers, the improvements brought about with the Nexia were impressive. Each seating section can now hear and understand the sermon and the songs without resorting to excessive levels. The price to fix the system, 5,000 dollars, was money well spent. Getting from here to there is not as hard as it first appeared.
