hi stuart - I don[t really get the pink noise - but when I turn the amp up to about 3 o'clock there is a hissing / crackling noise - but I'm not sure if thats just down to the fact that the volume is so high...  but as mentioned above - before I start the auto eq the mic does pick up sounds from the room anyway - it's just when I start the auto eq and the it's not able to hear to pink noise...