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"Helping You Sound Your Best" |
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First Christian Church Bettendorff, Iowa WORSHIP CENTER SYSTEM UPGRADE FCC has been worshiping in this room for three years, but have suffered with inappropriate sound reinforcement that whole time. A local music store sold the church a system based upon marketing rather than engineering. Many of the pieces were of good quality, but the speaker system was poorly applied. A complete acoustic treatment design has been completed, but only the first phase has been installed. This involved adding R13 fiberglass insulation to the top sides of the suspended ceiling elements. In the future when additional funds area available the remaining surface treatments will be added. AUDIO SYSTEM REINFORCEMENT The new system is designed to help overcome an overly reflective room. An additional design consideration was the more aggressive, guitar driven worship music that has become a norm for the congregation. We wanted to maintain the energy of the worship team while providing adequate intelligibility for speech reinforcement. The three box, expanded speaker array uses constant directivity horns with 1.4" throat compression drivers to allow the mid/high frequencies to be aimed at the audience rather than the wall and ceiling. The larger center speaker in the array is biamplified while the two smaller side speaker uses internal passive crossovers. The existing Soundcraft GB8 mixing console was reused. It is a very good choice for this application. The existing DBX driverrack was also reused. The speakers, speaker processor and amplifiers (some old some newer) were all replaced. Since the amplifiers needed to remain inside the AV control booth, we designed the system upgrade around Stewart amplifiers. Most of the amplifiers built by Stewart utilize passive cooling (no noisy fans.) These were used to power mains and monitor systems. The larger amplifiers needed for sub woofers, have fans that operate on demand. These amplifiers are located deep beneath the control booth counter to aid in masking any noise. Because the sub woofer feed is mixed from a passive auxiliary channel, when talking is the primary activity the subs will not be working, thus the fans will not be required. The previous system utilized a small powered sub woofer hidden up in the ceiling. This of course did not add impact to the music. The new sub woofer arrangement uses two Concert Systems LLC SSB sub woofers custom built to fit in the space beneath the platform. This aligns the systems to maximize their output due to quarter load with the floor plane. The two Stewart amplifiers provide 1350 watts of bridged mono power per sub woofer. The results are powerful bass sound with lots of impact. The dbx Driverack 260 provides control for the overhead array and control for the sub woofer system. The church hired a local contractor to suspend the speakers, but volunteers from the congregation pulled wires and made the changes in the control booth.
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Soundcraft GB8-40 mixing console
Stage right showing unfinished sub woofer installation.
Hidden in the darkness is the center main speaker and an overhead choir monitor.
One sub woofer - up close.
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