A Closer Look at a One-of-a-Kind Installation Project
Last month, we touched briefly on the sound installation at The Home Church in Lodi, CA, where the thriving congregation is now housed in a new 800-seat auditorium. Nothing out of the ordinary there, but what is different is the state-of-the-art sound system comprised of custom components, rather than the off-the-shelf approach for speakers in most church systems. But this may be expected when one of the church members is Mark Sweet, who runs the contracting half of Spider Ranch Productions, which offers both contracting, design/build and systems integration, as well as live concert services for national acts. Rocky Giannetta of GIA Design Group/Layer 8 handled acoustic modeling, with custom wall treatments hand-built by the church construction crew.
A major challenge in building the audio system was handling dozens of amplification channels for everything from triamped LCR main clusters, subwoofers, 12 monitor rigs (six floor/six flown) to 70-volt, full range outdoor speakers. Powersoft Quattrocanali 1204DSP+D and 2404DSP+D and Mezzo amplifiers with Dante made this possible in many ways.
Powersoft’s Armonia Plus 2 software was used to advantage, “having the ability to process and tune every channel individually is essential in a system this complex,” says Duane Klose, the project’s electronics and software system tech. The Quatrocanali amps are supported within Xilica Designer, so adding the amplifiers into the DSP design simply involved dragging/dropping the amps into the design. There is even a scenario to repurpose some amp channels from delay speakers to serve as surround speakers for movie showings.
In addition to audio DSP functionality, Xilica also enables the hardware and software to be used for touch screen control functionality, with a building-wide A/V control network built on an IP backbone connecting dozens of networked A/V devices controlled via custom screens designed by Sweet and Klose.
The Mains Attraction
The speaker system is old school quality — no line arrays here. Harbinger Audio (no connection to the current Harbinger “speaker on a stick” company) was owned by Gil Deliso in Menlo Park, CA from 1975-1983. In those years, Deliso partnered with design engineer Mark Wayne to produce high-performance, concert quality speakers, based on Wayne’s horn-loaded designs. Later, Sweet collaborated with Wayne, designing/building systems and custom solutions.
The premise of the audio design was an attempt to demonstrate how good solid, well-implemented horns could sound, so no compromises were acceptable.
The centerpiece of The Home Church system is the Sweet-designed custom center cluster, based on nine vintage Harbinger M800 2-way Fiberglas horns each housing a 2” exit Radian 950 neo HF driver and custom 12” JBL E120 cone mids. The upper five horns crossfire downward to cover the wide horizontal front seating; the lower four horns reach the rear of the main floor. LF is extended by two dual-15 Electro-Voice EVF-215D subs, flown behind the horn cluster to provide natural extension in the lower range. An overhead catwalk (hidden behind a scrim) offers easy access to all components in the LCR clusters. The E-V boxes are suspended two inches above the catwalk floor to avoid any vibration caused by the woofers. Sweet also designed a steel exoskeleton around the horn modules, providing suspension points so each box can be adjusted individually within the cluster design.
To protect the 12” mid drivers from LF over-excursion, a steep 200 Hz LF frequency cutoff was effective. Wayne’s design goal has always been to move crossover points outside the vocal range as much as possible. Based on this, he wanted the 12 to go down to 200 Hz to fully utilize the mid horn. Researching to find a box/driver complement with enough upper-range response to cover the transition, it turned out that most 2×15 boxes these days are optimized as subwoofers, rather than a low-range box required for a 3-way system used in component level systems. ”We knew we needed reasonable response up to 200 Hz in order to transition into the 12” mid drivers,” Sweet says, “yet many 2×15 woofer boxes run out of gas between 80 and 150 Hz.”
Coverage is Everything
The center cluster provides good coverage of the main floor from the centerline out in a semi-fan shaped coverage pattern. The left/right stadium seating areas each seat 200 people. Their first row of seating starts where a normal rear wall of the main floor would be and slopes up from there. These areas are not insignificant areas that can be “filled” and needed bandwidth, coverage and component voicing matched to the center cluster.
The top “nose-bleed” stadium rows are up near the ceiling, which provide challenges, both acoustically as well as line of sight to the video screens across the room. The design that was finalized and implemented used four more M800 2-way horns and extra Harbinger 1208 HF horns as top fill to improve the area’s vertical coverage. Sweet designed a box with its 12” mid horn in a custom landscape-oriented box to allow good line-of-sight for congregants in the upper seating areas. Speaker fabricator/carpenter Mike Thompson built the stadium boxes to Sweet’s specifications. Steel fabricator Quinn Meadows, who built the steel rigging for the center cluster horns, also built custom yokes for the landscape enclosures.
The left/right speaker clusters are composed of another past project that Wayne and Sweet worked on in the mid-to-late 90’s. Each of these outer left/right clusters has three Wayne/Sweet-designed Model 1257 “Triple-Horn” enclosures.
The design objective was a tall, slender 3-way design with a good musical character, a strong midrange presence and controlled directivity that would help keep feedback to a minimum. Each speaker is only 15” wide, 15” deep and 60” tall, with the 3-element horn in the center, each loaded with a 2” compression driver flanked by two 7” cone mids — and two 12” woofers.
The triple horns were hand-fabricated using Fiberglas by Edward Masington. Above each cluster are Radian compression drivers on three M800-style HF horns, with custom adjustable horn brackets for aiming a driver/horn combination in nearly any axis and orientation. Individually aimed, these three horns crossfire down much like the center cluster orientation, acting as down-front fill from about 1,500 Hz and up, adding more vertical directivity for the front of house areas. These clusters provide 110° of horizontal coverage from each side, allowing for a good stereo image through most of the room.
Wrapping It Up
Concrete soffits poured below the stage provide for expansion for integrated ground subs, and an Allen & Heath S7000 with three GX4816 stage boxes bring the input count up to 144 channels. House audio engineer Ben Burnett spec’ed the mic selection, which includes Earthworks FW730MP choir mics and an Earthworks PM40 Piano Mic, which he has been very happy with. Another nice touch for the project is a LynTec 200-amp/3-phase power sequencer. The entire project wrapped up in time for opening earlier this year and the performance of the sound system is described as “heavenly” — which seems somehow appropriate in this case.
For more info about Spider Ranch Productions, visit spiderp.com.
