The gig is a kickoff concert for orientation week at the local University. No problem, 700 to 800 kids with a four-piece band. Well, they don't have a large budget for the show, which will be outside under a tent, so we'll need a medium-sized PA with monitors and a light rig. Nobody wants to rent a generator, so we'll use the outlets that are used for plugging in cars.
In Alaska, we have to plug in our cars in the winter — it operates heaters that are in our oil pan, engine block, batteries, etc. This row of outlets (each with two 20-amp circuits) runs down the edge of the parking lot spaced 20 feet apart. The closest one to the stage end of the tent is 75 feet, which means no runs under 100 feet on 12/3 power cable. After running over 1,600 feet of individual power cables for sound and lights (this is all added up with cables ranging from 25 feet to 100 feet), the rig is up and running fine. We did sound check and everyone is happy. We then proceed to setup a small system with a wireless mic and three powered speakers another 150 feet out from the far side of the tent. We sound checked it with the lav mic and it was working great.
Here comes show time, this is when the real fun begins. We start the event at the small system with a presenter out in the field, and as soon as he speaks on the mic, a huge WOOMP sound shoots through everyone’s skulls, and again, so I quickly hand him a wired mic and trouble shoot the wireless. Anytime there is sound coming out of the speakers the wireless makes this noise (have it soloed in headphones), so I run and get another wireless unit, but the same thing happens.
About this time my other tech comes running out and tells me that he is measuring 100 volts at his power for lighting! So, I hand off the controls to him and go running into the tent to troubleshoot. At this point, I shut everything down, and remarkably none of my equipment has died. I went to the outlets to measure, and at this point, I'm measuring 95 volts. Keep in mind that the powered speakers are somehow still operating.
After some frantic calls to the University physical plant and realizing that it is a Sunday night and they are all at home, I measured the next six out-lets in the row and found they were at 113 volts. So, with five minutes until show time, we remarkably found more power cables to extend five of our circuits another 100 feet or so from the working outlets for audio and left poor lighting to run on 95 volts. The show started on time and had no problems; afterwards, I told them that next year they will be renting a generator.
Josh Bennett
Sound Reinforcement Specialists
Fairbanks, Alaska
