Flight of the ten million bumblebees

OK, a couple of weeks back i had the biggest show i'd yet done. It was a brass band performance with about 400 high school children doing their thing with the trumpets, trombones and whatnot. The install went well and smooth, the hang went up by lunch (24 EV XLC for FOH and another 10 for sidefill, all driven with GOOD quality gear [Klarkteknik, midas etc]) and the rehearsals were hitchless.

15 mins into the show however, one sidefill stack began humming at ear-slitting levels. Nobody could figure out what was wrong. After about ten minutes, it just went away.

How can you prevent things ike this happening? We did all the usual prep work, like testing the leads, replacing dodgy clips etc, but it obviously did no good. All the amps and speaker leads were new nothing had come unplugged, but there were alot of kiddies running around.

any suggestions would be appreciated.


Active Member
Was your power source clean? Sometimes if your on the same power leg as lights, whenever the lights changes you get noise. It could also be something small like a fridge or something, which only causes noise when the compressor is running.


Well-Known Member
Possible you have a cable with an intermittent problem, even with a dedicated power lock it is POSSIBLE that something else on the main supply could be causing the problem, this is why in some instances on a big gig you need a complete isolation transformer.


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