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Permanent Install

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Luke Richison:
My church bought an old strip mall and gutted it. We've got a (relatively) blank slate to design our stage, which we'd like to be flexible enough to double as a small venue. I've got a pretty good handle on the audio but none at all on powering it. So, I was hoping someone on here could give some advice on what is ideal for a House of Worship / Small Venue (and if this post belongs in that forum).

Here are a few things I'm pondering:

* Should we run a sub panel to the FOH and have dedicated circuits for each element (PA, FOH, Lights, Stage / Instrumetns
* Do we leave the sub panel and run home runs to each element
* Dedicated 60a service instead of sub panel?
* Should we group PA, FOH, and Stage on one larger circuit (20a, 30a?)
* What about a power conditioner or sequencer
I would also appreciate advice on what is practical given our limitations (this is the relatively part of our blank slate):

* powerwed Mackie HDAs and subs for PA
* Presonus StudioLive mixer
* No floor monitors - we use in ear monitors
* No backline - everything goes direct
* LED lighting, and we're considering par cans
* Being a church, the budget is (as always) quite minimal
Thanks in advance

TJ (Tom) Cornish:
A few non-complete thoughts and suggestions:

Thinking about this now is a good idea.  A sub panel for all audio and video power has some benefit if it shortens the distance between the grounds of the different receptacles in the system, but there's very little noise immunity benefit to separating lighting, unless there's a transformer in-between.  Modern equipment and non-garbage dimmers (and possibly getting rid of single-coil electric guitar pickups) should be all you need to be noise free.

My priorities would be in the following order:
1.  Getting enough power
2.  Getting enough power in the right places - amp room, dimmer room, etc.
3.  Getting modern equipment that doesn't have noise immunity problems
4.  Sourcing all audio and video power from the same panel
5.  Sourcing lighting from a different panel from audio/video

Even if you're going to use a portable PA system now, plan for an install.  Depending on the size of your auditorium, you may want to reserve a few 20A circuits for amplifiers all the way up to a dozen or more in the place your amplifiers will go in the future.

For lighting, LED fixtures for color wash really make a huge difference in usability and power consumption.  In my opinion, white front light is still better done with tungsten fixtures, which take a lot of power.  For larger systems, dimmers are usually done in a monolithic dimmer rack.  For smaller installations, a couple circuits feeding multiple locations of tree-mount or dimmer-bar units is likely more economical.

You can't feed standard receptacles from anything greater than a 20A breaker - multiple circuits is your solution.

Telling us a little more about your space, your plans, and your constraints will help get more relevant and specific advice.

Kevin Graf:
Before you start,  spend some time and read the following papers:
They total about 145 pages, but it's time well spent.

"Power White Paper" from Middle

The Bill Whitlock of Jensen Transformers Seminar paper

The Jim Brown of Audio Systems Group white paper
"Power and Grounding for Audio and Audio/Video Systems"

Tom Young:
Kevin's reply contains VERY good sources for how to do this right.

I would add that while you do not use stage monitor wedges and backline now, what happens in the future is a question mark..... even if you think it isn't. You would be wise to place a few 15A-20A ckts around the platform and add a few in your amp rack or where amps would be racked if they are used in the future.


Mike Sokol:

--- Quote from: Tom Young on October 10, 2013, 02:51:15 PM ---Kevin's reply contains VERY good sources for how to do this right.

--- End quote ---

Agreed.... So while I'm teaching seminars in Texas this week (and not at my desk) I don't have a lot of time to thing about your questions this week. However, I would suggest that to future proof your system you add at least one "house power" connection. In the old days (before LED lights and Class-D power amps) I would have suggested camlocks and a 200-amp circuit breaker. However, I think it's time to revisit a trick I first used some 40 years ago in my misspent youth at the Old Mill Inn. A 50-amp/240-volt Range Outlet (NEMA 14-50) fed by a double-pole 50-amp circuit breaker in the service panel would allow most any medium size act to plug in their own power distro and run quite a large sound and lighting system. Unless you are doing major shows, then 100 or 200-amp camlocks seem like expensive overkill. But a 50-amp/240-volt range outlet located near the stage would give you a lot of future expansion options since that's 100 amperes of 120-volt power which is sufficient for a 10,000 watt PA system and a pretty large LED lighting system. I'll have to double check with my code monkeys, but this should be perfectly code compliant and WAY more legal than letting a visiting band hang some camlock pigtails out of your open circuit panel.

I would appreciate some input from the other sound pro's here. Does this seem like a reasonable distro power idea for a small/medium church or club, or is it too simple/crazy to work? Of course, really big productions need really big power from camlocks, but how much room do you have on stage for potential acts?


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