Alright first of all, thanks.
I meant impedance, for some reason I wrote resistance, oops.
I talked with the one responsible for the tech we work with and he told me that its all 'High quality microphone cables' from Stagg. If I understood correctly, they just made a massive order and because we *mostly* work with sound as many of the lights are build-in, they never bothered to buy DMX ones.
I guess because its always a hastle to buy things for a school (legal stuff, since its the states money).
I suppose we haven't had any big problems, I guess maybe because our lights aren't crazy special ones.