rules when putting in a new install

Rule of thumb when planning conduits underground in a building.

If you need 1, put in 2.
If you need 1" pipe, put in 2" pipe.
For main runs from FOH to amp or stage location never use anything smaller than 4" .
A pipe filled more than half full is full.

PVC pipe is relatively cheap and the cost difference between 2" and 4" is negligible. It is extremely, significantly (can I make the point even stronger?) cheaper to put pipe in the ground when the building is being built than later.

Always put your pipe the deepest into the ground, save sewer and water.
Never run your pipe within 2 feet of electrical.


Electrical rule of thumb.

Always run your own ground and ground rod.
Spec an isolated ground buss bar in the breaker panel.
Don't forget to use isolated ground receptacles.
Get audio/video on its own isolation transformer.
Make sure that every location that the audio/video system is plugged in is run back to the same box.

the subsnake style of wiring

I can't tell you how many churches that I have been in where there are cables running from one side of the stage to the other. Interesting phenomenon. Like a audio spider web set up to entangle whoever is walking across stage that is being "managed" through judicious use of tape that will eventually mess up the carpet.

What causes this mess? Well, designers have always assumed that once you decide where things are going to be on stage that you will never change. Therefore, they have created this notion that you put floor pockets here and there to meet the current needs. That may have worked years ago, but today's production environment is in constant flux.

So why not do what I did at the last church I worked for. Before settling into a situation with an installed PA system, my experience was with portable and roading systems. You utilized the sub-snake concept.

The concept is simple. You have the main bundle of inputs (snake or whatever) come to either one or two locations and run smaller bundles or snakes from there.

In my auditorium, I had the main snake run to an XLR patch panel in the amp room which was located just behind the stage. This represented the back of the console, so I never needed to crawl over the large console to make patches. Plus I knew that 1 on the snake to the FOH was 1 on the console.

From back stage I had 6 locations permanent boxes (in one auditorium there was a privacy wall and we put panels on the backside of the wall to save cost) on the stage. Drum booth, Stage Left Back, Stage Right Back, Mid center stage, Pulpit Left, Pulpit Right. The general rule was to put in more inputs in these locations than what you needed. So 12x4 in drum booth, 24x4 stage left and in stage right, 8x2 mid center stage, 2x1 in both pulpit locations. All of these locations came back to that patch panel and I used 2 foot XLR's for patching.

Why XLR patchbay? Normal patchbays need to be "cleaned" at least once a year with the expensive ones or monthly on cheap ones. You have to buy patch cables and enough that you don't run out. In the XLR patchbay, you can use any mic cable in a pinch, or make your own (try making a TT cable someday!). I had one patch that took over 5 years before it failed and all I needed to do was unplug and plug back in with the XLRs.

When the stage was being designed, we made sure to make it hollow. The architect didn't understand but we knew that the current setup would change inside of a year. The hollow stage allowed us to put holes wherever needed at later dates. In fact, we ended up putting in a hole in the front far left and right and used just the floor box cover in those locations. I could feed a snake or drop the mic cable under the stage and route it back to the backstage patch panel (another good reason for XLR).

Next, we purchased little 6 input snakes and ran them from the primary locations to central areas where needed. Like the keyboard location, who had a guitar player close so I just ran the guitar cabling through the keyboard snake.

Amazing! Its a flexible system. Want to move someone, then just take their stuff and re-route the snake to the closest location, re-patch backstage so the new stage inputs go to the same console inputs.

In one auditorium, we had a digital console that had a "stage box" with just the control cable going back to FOH. So I placed the "stage box" on stage and ran sub-snakes to it, since it literally represented the inputs to the console.