The church in question had a sanctuary whose seating was arranged in a semi circular array about the area where the minister would preach from, total square footage of floor space was roughly 1500 square feet, the ceilings, as previously mentioned, consisted of a vaulted cross shaped ceiling with the top of the arches standing at roughly 35’, this was a room with a lot of volume. The music styles used during worship was south American, with a heavy accent on bass content from percussion, drums, bass guitar, etc. The main problem lay in the fact that the music was too loud, and the system’s sound quality was very poor.

They needed a system capable of producing crisp, intelligible vocals, but which had an extended low frequency response with enough power to handle the musical accompaniment. The final system consisted of a combination of new and existing equipment, and involved running cable through walls, crawl spaces, and various chambers throughout the church.

This is what the final equipment list looked like:

• 4pc. JBL EON 1500 2 way cabinets
• 2pc. Cerwin Vega EL36-B Subwoofers
• 3pc. Galaxy Sound Hot Spot Monitors
• 1pc. QSC PLX2402 power amp
• 1pc. QSC PLX3002 power amp in bridged mode for subs

The original system’s console, outboard equalization, dynamics processing and electronic crossover where more than adequate for this installation; so those where left alone.

You will notice some pretty hefty power amplification, one of the things we had to ensure was that the system had plenty of clean power, so the moment was taken advantage of to improve the electrical service to the church, which was essentially untouched since the early fifties, with some of it dating much earlier. I actually found bare wire runners with porcelain insulators spanning the crawl space up above the ceilings! I know some of you out there know how far back that goes! No additional bracing of the area above the arch was necessary, although some parts of the roof also needed work and that was also taken care of. This job could have been a great deal harder to do had it not been for the fact that a great deal of restoration work was being done to some of the upper rooms and the bell tower, so access to the upper crawl spaces was not difficult at all. Often you may find yourself in such a case where you have to coordinate your installations around the work of other contractors, and often you may be working in the same areas. Get used to it, you are not alone!

The four JBLs where arrayed in a center cluster, hung from a custom made aluminum rigging frame. Two of the hot spots where hung at the bottom of the cluster firing back at the organ loft, where the musicians where eventually going to be moved to.

This installation had to take into account the existing acoustic properties of the space, structural weight limitations (thus lending favor to the molded cabinets used by the JBL EON series, as opposed to much heavier Baltic Birch or composite plywood cabinets whose weight could not have been supported without additional structural bracing that would have affected the acoustic properties of the space. This was something I very much did not wish to do, since the space was designed to work a certain way, and my experience has taught me not to fight with the room if it was well designed, but to use it’s properties instead.

The main concern in this installation was that in the area where a central cluster was to be most effective, there was only one beam of sufficient strength to support even the weight of this cluster, which with it’s aluminum rigging frame was weighing in at 176 pounds. While this single beam, a 12” X 6” timber spanning the full width of the sanctuary was certainly capable of supporting the weight, being only one beam it made for a rather unbalanced hang, the solution I found was to make the frame from which the speakers hung triangular, and putting all the weight on the flat front side of the triangle. This allowed me to control the tilt of the cluster from the back point of the triangle and not have any real weight supported from that steel cable. The tension o the rear cable does not exceed 15 lbs as opposed to the front beam of the triangle, which is hung directly below the large wood beam and supports the entire weight of the cluster. Additional bracing in the middle of the triangle was installed strictly to make hanging and suspending the array easier, and was removed afterwards when the array was in place.

The actual raising of the cluster was done by assembling it in place directly below the hang point, and using a chain hoist to raise the array to about shoulder level so we could fine-tune the aiming of the individual speakers. We then erected scaffolding around the array as a safety precaution, and slowly raised it up the middle of the scaffolding while other workers with ropes guided it up the middle of the scaffolding tower. Once we had it roughly at the required height, we manually jogged it into it’s final resting position and clamped the 2000lb break strength wire rope as per industry established rigging regulations. The total number of holes that had to be drilled in the ceiling was four. Two ½” holes for the front wire rope rigging lines, one ½” hole for the rear, and one 1” hole in the center of the triangle from which the chain hoist was suspended, and afterwards was used to run the speaker cables through the ceiling. All holes where lined with rubber grommets and sealed with silicone sealant. The steel cables, and rigging frame was sprayed semi-flat black. I’ve found that the semi-flat is actually a less reflective finish. A full flat black appears somewhat like a dark gray when ambient light hits it.

Many question my use of scaffolding, but I’ve found that this is the easiest and safest way, assuming that the scaffolding is erected properly, to raise a cluster to any reasonable height. Should for some reason the chain hoist fail, the speaker cluster will still be held by the ropes and workers on the scaffolding. Neither person nor speaker shall be in peril, since no one is under the cluster while it’s being raised, they are all above it on the scaffolding. The chain hoist handles the lifting and everyone is safely out of the way. I was once a witness to the rigging for a chain hoist failing. Fortunately it was while being tested and not while the hoist was lifting anything substantial. Nevertheless it could have led to some pretty severe injuries if it had given way during the presentation. Hoists, even small ones, are not light!

I will close this section by mentioning a few of the disciplines involved here. Knowledge of building codes, construction practices, and a basic knowledge of regional electrical codes is helpful. You don’t have to be a licensed electrician, I personally have electricians do the work for me, but it saves a great deal of time if you are able to spec things out in a way that conforms to code.

When working with buildings that have historical or landmark status, the restrictions on what you can or cannot do should be known ahead of time. It helps to have an architect who regularly deals with the landmarks commission. I’ve seen the landmarks commission send an inspector to a site that then proceeds to demand that the entire installation be taken down, immediately! Yea, they can be pretty unreasonable, so know what you can and can’t do BEFORE YOU DO IT!!!!

Rigging regulations and codes for weight limits, standard accepted practices, and minimum safety factor requirements are essential unless you plan to sub out that portion of the installation and pay a licensed rigger. At the very minimum, be intimately familiar with OSH regulations part 15, which covers a lot of common sense items but at the same time gives you a starting point on what you should know, as well as introducing such terms as WLL (working load limits). By the way, it’s not that difficult to get certified, it merely takes time and effort on your part to go and get it done. Rigging classes are held regularly and go for about $1400 to be certified as a level one rigging gear inspector. Your certification will be valid for three years. I was surprised at how much more there was to hanging things than I was aware of.

Obviously, a thorough knowledge of acoustics, and the physics of how sound vibrations behave both in open air and in an enclosed space is required before you can solve anyone’s problems. Knowing the acoustic properties of various materials is critically essential. Your understanding of how sound behaves; and how different materials change that behavior will either make or break your installation in the long run.

You must stay up to date on the current technology, there is always a better way to do something right around the corner. What I’ve found is that while the new thing is not always practical, I often get new ideas from it on how to use older gear in new ways.

You must be intimately knowledgeable on the equipment you spec and install. Speakers not only have a frequency response, but resonant frequencies, dispersion patterns that vary with frequency, and a host of other characteristics of which if you know them well, enables you to use them in many ways and in many applications, some possibly not previously considered by their designers. I have found, without exaggeration, more than a hundred ways of using an SM58 microphone to pick up the sound of everything from drums (center overhead mic, aimed straight down, nested in a 12” square of Sonex to kill back reflections), to use as a theatrical spot mic (an interesting anomaly of that microphone’s pickup pattern is that if you lay it sideways against a flat surface, say a table where several people are seated having a conversation, there is a certain gain setting where the mic will couple to the flat surface and act like a pressure microphone, essentially turning the table top or whatever other flat surface into a microphone surface. I have successfully picked up the conversation of five people seated at a table in a theatrical production this way, But back to what you need to know to succeed at an installation like this one.

Some architectural sensibility is required, and a feel for the esthetic of a particular installation is helpful. I know it doesn’t make sense on a technical level, but what looks good to the client sounds great! It’s just that simple.

Some AutoCAD skills are helpful for drawing out floor plans, wiring plans, and the like. It is also helpful to be able read architect’s drawings. I’m in the middle of an installation for a brand new space currently under construction; where I am dealing with the architect, electricians, the owner (who is my actual client), and some of the construction crew. Without knowing how to make sense of the myriad of floor, ceiling, lighting, plumbing, AC ventilation, and Hi voltage/Lo voltage electrical drawings, I’d be lost with all these people looking to me (the consultant) for a clue.

It is also helpful to have some graphics editing skills so you can create custom graphics to illustrate your proposals. A picture, even a line drawing, is worth a thousand words.

Finally, while obvious, the importance of skills in dealing with people should not be underestimated. Conflict resolution is a skill worth more than your weight in gold. This is especially true when you are not the only contractor working in the same space. You each have a job to do, if you are all professionals, you can all sit down and discuss what needs to be done, when, and in what order. No one will be in anyone’s way and the work will proceed on schedule and smoothly.

In a small one or two man company, these skills to some basic extent must be present in the one or two who are the company. If you are fortunate enough to have grown to the point where you can hire specialized personnel to handle these tasks, then you really don’t need me to tell you that these are required skills. I congratulate you for having gotten there by the way….

So that is the basic installation and a short introduction to what you need to know before you can tackle a job like this. The amplifiers and rack gear are pretty basic and nothing really special was done there. The complications of this job all centered on hanging the cluster. Every installation is different; others will have problems with running cable, or any of a long list of variables.

However, before you can get started tackling these problems, before you can start to have thousands of feet of wire drop shipped to the client’s location, it is essential to first convince them that—

1. This will be a substantial improvement over their existing system or equipment
2. You can deliver and complete in a timely and professional manner the finished installation and any additional services defined in the contract
3. Finally, that you will be there for them to assist in the inevitable period of adjustment required as they settle into their new installation

That last point cannot be stressed enough. I have seen so many exceptional installations get partially disassembled, or even completely torn out simply because there was no one who could understand and operate the system properly. I have also been called back to correct a perceived problem that essentially stemmed from operator error, or simply an insistence on trying to run the new system according to how they did things with their old system. Some hand holding is essential, and makes the difference between a satisfied customer and one who feels that you have simply left them to sort out their own problems. Remember, people skills are priceless!

In my next post I will speak more on this, and the actual writing and presenting of the proposal. Hopefully this will be of some help to someone out there and will help in encouraging installers to hone their people skills as well as their technical chops.

So until next time...

Have a wonderful time making great sound!