Church Sound Profile: Inside The New System At Calvary Chapel Of The High Desert In California
A system professional's first-hand account of meeting design goals in the development of a sound reinforcement system matched to a new youth sanctuary

November 24, 2009, by Donald C. Cicchetti

church sound profile

Calvary Chapel of the High Desert (CCHD) in Hesperia, California is an energetic, modern church that enjoys immense popularity in the local area. 

With a full rock band, qualified and dedicated audio volunteers and a spirited pastoral staff that expects excellence in all they do, they are serving their community in a real and powerful way. Due to rapid growth, the church decided to add a new Sunday School and youth sanctuary building. 

My systems firm, DJL Audio/Video Specialists of San Dimas, had previously renovated the system in CCHD’s main sanctuary and advised on acoustical treatments, so we were asked to design and install the new sound system for the youth sanctuary.

The new facility was to be a medium-sized, high-ceilinged room of open and generous proportions with a slightly elevated stage, good sightlines, and lots of natural light.

There is a dedicated mixer location in front of the rear wall, with two equipment racks directly behind the operators as they mix. These racks contain all patchbays, FX processors, recorders, A/V interfaces, wireless receivers, and wireless in-ear transmitters. 

All system DSP and amplification is in the stage-right green room, and the system has its own, dedicated, isolated-ground AC service.

System Design Goals
The design goals changed several times during the programming and design process, varying from “just a simple system that won’t cost too much” to a concert-grade system, with effects and patchbays that a pro level touring group would be happy to use. 

Our goal, as a company, was to give the client something they would never find inadequate for all the conceivable uses of this new space, so a simple, small system was not our first choice. 

Perspective of the new youth sanctuary at Calvary Chapel, with the main loudspeaker array and subwoofers flown above the platform. (click to enlarge)

We knew that eventually a touring band would use the room, or the excellent band from the main sanctuary would use the room, and we did not want anyone to be disappointed with the new system. To that end, we wanted to avoid giving them less than they need, but also avoid what our company president, Darryl Lima calls “gold-plating the system.”

What he means by that is adding every gadget, touch panel, automation, and/or the latest half-million dollar mixer or loudspeaker system. What was needed was that level of performance without the very high price it often brings; in other words, a system that would perform like a million bucks but cost a whole lot less.

Start With The Loudspeakers
Any system is only as good as its loudspeakers, so this was the first area we looked at during the design process. We’d heard good things about the new VQ Series from Tannoy, always seeking excellent pattern-control and low distortion as top priorities, and we love these aspects of Tannoy’s line.

We picked up a demo loudspeaker from the testing lab that verifies Tannoy performance specs, and the engineer said, “this is the best loudspeaker we’ve ever measured”.

We had the same thought upon hearing them. As an added bonus, the price is very reasonable, so we specified the Tannoy VQ60 loudspeakers for the main array, joined by a pair of Tannoy VS18 DR subwoofers.

Every sound project must deal with the inevitable “where to put the subwoofers” issue, and on this project, the architect and project supervisor had already decided they were going to be flown with the main loudspeakers.

This is a workable solution, but flying the subs or putting them at stage or floor level both entail compromises.

Putting them on the floor or stage can overwhelm the front rows and the musicians with bass, and there are all sorts of delay and phase issues that can arise when separating subs from the main cluster.

On the other hand, when the subs are flown, their visceral impact on the crowd is reduced. Our view is the you just have to know your client and do what is right for them.

Two views of the main loudspeaker array and flown subwoofers. (click to enlarge)

Once the loudspeakers were selected the rest of the design came together quickly, as did the drawings and the growing equipment list. We selected the Tannoy VNET SC1 networkable system controller for its included VQ Series presets and processing power, along with QSC power amplifiers and the requested patchbays for incoming mics as well as effects and mixer insert patching. 

We also chose the front-programmable Bittree 969 series TT Bantam patchbays for the various FX, recording, playback, and other line-level patching uses. The church owned an older (but renovated) Soundcraft Venue console that they wished to continue using, so we included that unit in our plans.

Some of the new system’s extensive patch bays, as well as effects devices.

The mic patchbays needed a different solution - the TT patchbays were not designed nor intended for patching microphones, and Bittree recommends against it, so we designed a custom gold-contact XLR patchbay where all the mic lines and all the mixer inputs terminate. 

This way, any mic may be assigned to any mixer channel without repatching the back of the mixer all the time. We’ve found that the practice of using the rear of the mixer as a patchbay causes enormous grief, missed cues, and general unhappiness for the operators since they never know what is patched into which channel.

As a result, we’re firm believers that when you plug into “1” on the stage, you should get “1” on the mixer.

The mics and mixer are physically patched together via short XLR cables and “Mic 1 out” is directly above “Mixer 1 in” on the mic patchbay so it is easy to see if anything has been cross-patched by a previous operator. This is as simple a mic patchbay as we have seen, the operators are able to use it without a problem, and it is utterly reliable.

Once the client approved the system design we got to work as construction schedules wait for no man! (or subcontractor)  The client had already decided on a center cluster array and had installed hard-points for flying the loudspeakers with that assumption. 

Some plotting, lasering, and measuring the room confirmed this to be a workable solution, so the VQ60 loudspeakers were arrayed as a stereo center-cluster, with the subs tightly behind them but not touching the ceiling.

This was a labor-intensive installation, as in addition to flying the loudspeakers, there were 48 mic lines and 14 aux. lines to be run and terminated at the mic patchbay, and then the mic patchbay terminated at the mixer (not to mention house system lines to the DSP processor and intercom lines to be run and terminated). There were also three 96-point TT patchbays to be wired and terminated.

With some extra help and some long days we got the loudspeakers flown, the wiring done, the DSP set up, and had the new system up and running in time

We’re pleased with the results. 

The head pastor is a big music fan, and I had been warned that he likes it loud. Really loud. So, when showed up with some Tower of Power on an iPod, I was expecting a real workout for the new system, but I had no idea…

How the room looks from the front podium.

I started playing the music at what I consider to be “loud” levels, but he just grinned and said “turn it up!” So I did. One of the best things about the loudspeakers is that their inherent distortion is so low and their maximum level so high that there are no obvious signs of loudspeaker or amplifier/processor distress that many people use to decide what “loud” is. 

Back to our demo: The head pastor had the system at about 125 dB, and I thought, “oh that will do it.” But no, he says, “louder - I want everything they have!”.

I pushed it further, but not quite to the limits, and it was breathtaking. I have rarely heard music that overwhelmingly loud, like a wave breaking over you, yet as clean as could be, with no harshness in the mids or highs and perfect solid bass.

He grinned and yelled out, “good work!” At that moment, the project was a success.

Donald C. Cicchetti performs systems design and engineering at DJL Audio/Video Specialists in San Dimas, California.



Return to articleReturn to article
Church Sound Profile: Inside The New System At Calvary Chapel Of The High Desert In California
http://www.prosoundweb.com/article/church_sound_profile_inside_the_new_system_at_calvary_chapel_of_the_high_de