"He Wears Black and Has a Beard"

XLR Pink Noise Generator

Toby Roworth

Mar 4, 2013

I've mentioned my most favorite company ever (if we discount any that pay my salary) in a previous post about PLASA. OptoGate make the things for PA everyone else forgot to think about, and then throw in Axel Joost's slightly zany flair to make an,amazing, if not slightly ridiculous product.
I like these guys!
Since I first saw their stand at PLASA, one product caught my eye - a pink noise generator that fits in an XLR. This year I finally bought one for £15, quite a step down from the asking price. I've yet to regret it.
How it works inside I'm not 100% sure of, as the boot's glued to the chassis, but I expect it's a couple of passive components to tame the incoming phantom power, a reverse-biased transistor and an opamp to add the 3dB/octave filter and get the output level right. There might be a μC in there too.
It's extremely simple to use - plug it into a phantom powered XLR and it spits out some lovely pink noise. It needs roughly no gain, but a bit can help. I'd suggest a flat EQ to start with...
Pink noise is good because it should sound the same volume at any audiable frequency. This means by listening to it you can tell which bits are too loud/quiet by whether they sound too loud/quiet, and then adjust them on a graphic or something.

I've tried this at a couple of venues and have found some interesting sonic oddities. I've noticed a couple of funny spots at Crown - of course these aren't actual recommendations, but mere hints at where in Bishopshalt's hall doesn't sound quite so good:
Here's a helpful map: