[microsound] speakers_unwanted noise

[Kim Cascone]

there are other lists that are more appropriate for this subject
but I'll let this slide since it sounds like you need help

first a few questions:
- are you running shielded *balanced* cable from your mixer to the  
speaker inputs?

- the krk vxt4 inputs are configured as follows:

Input:
XLR-1/4 in. TRS Combo
10k Ohm Blanced
Pin 1 + Sleeve = Ground
Pin 2 + Tip = (+) High
Pin 3 + Ring = (-) Low

are you sure your cables are TRS and that your sleeves are actually  
grounded to the mixer chassis and electrical ground?
buy a cheap continuity tester at your local Radio Shack or Conrads  
and check the grounding on your equipment

- have you checked for ground loops?
   - try plugging in your active speakers into a different circuit on  
the AC power in your house

other than that Google for ground loops since there is a lot of info  
on how to battle grounding and shielding demons