Where you say its your laptop power cable, you mean its the cable being in vicinity creating the electrical noise? If it is, you could try insulating the cable and see if that stops the interference

*waits for Sab for knowledge *

It's like this: You propably are using non shielded cables for your monitors. In which case if they are near a badly insulated power chord the monitor cables might pick up static noise from that said power cord. So this far your assumptions are correct.

The hum eliminator you linked to might work, I have never used one and it also depends on the exact specs of your problem here.

The monitors should in essence be silent no matter how high up you cranck the volume, untill they are fed with audio signal that is. If there is any noise while nothing is playing then it is a intereference in your signal chain. So to determine the source of the electrical noise try the following.

Connect the power cord to your laptop and move your speaker cables away from the cord (and/or try to shield them) and the power modulator. Does this lessen the presence of the electrical noise? If yes, then the problem is the badly shielded cables and it can be rectified by getting some shielded ones instead.

If not then it's propably a case of your laptop being connected to the power outlet that is causing internal noise. This is a very real possibility if you are using the built in soundcard of the laptop. (you didn't mention this) In which case the hum eliminator you linked to might just be what the doctor ordered.

EDIT: I forgot to mention that you can do test in a slightly different way aswell. You can for example fire up a audio editor like cool edit, audition or any other one with a line in level metering. In case of cool edit/Audition, load a new empty track and hit F10 for the monitoring meters to pop up. Look at you noise level floor while the power chord is connected and while it's not.

I use an external soundcard. I think it helped a bit when I moved the laptop power cord away from the monitor power cords. Its hard to determine because the sound isnt constant and its really low (sometimes I think I imagine them). But do you think that standard KrK cables isnt properly shielded? and how do I know wich cables that is?

thanks for replying

Shielded cables say shielded cables on the box when you go buy them they are a tad more expensive but, meh.

Idk, about standart KRK cables mine didn't come with cables.

this is just an idea, but maybe get a power conditioner. it helped me get rid of the white noise. im not sure if its the same as the hum.

yup i got me a power conditioner. removes hum, noises, infrasonic garbage, + prevents from power serges so my equipment never gets ruined.

thanks, I have to consider what I should get.

The power conditioner idea and the shielded cable is also a good idea, when you can.

Radio Shack used to sell something called an AC Line Filter that is about the same exact thing as the E tech.  I don't know if they make it anymore but you could check.

Eliminates ground loops... it's ten bucks if they still have one at your local Radio Shack.

I dont have a local radioshack I tried to find out what it is online but its not that easy, its the cheapest solution tho. but thanks, I will probably figure it out.

is this something similar to what you guys have?

http://accessories.musiciansfriend.com/product/Furman-SS6B-Surge-Block-?sku=181297