Hum in speakers

I try connected MPC1000 whit PC (I use Reaper) using the cable jack-xlr or jack-jack. When I do this my speakers terribly hums. Is the fault of the cable? Is a bad connection? What its wrong?
Please help!

Teach a man to fish time.

http://www.audioholics.com/home-theater ... m-and-buzz

http://en.wikipedia.org/wiki/Electromag ... terference


Just letting you know that the points made in both of these links will be moot if your cabling is bad/wrong. Assuming your gear is made well and kept in good condition then maybe these articles (and a few more) are worth a peep.

Point blank - Trouble shooting humming can be a rigorous task but it is completely worth it. Start with your cables. A good dielectric (or insulation) is key.

wut did he say a di-what?