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CPU Noise/Interference in Monitors

Posted: Sun May 06, 2012 6:29 pm
by Erisol
I just got my first pair of studio monitors, KRK Rokit 8s. Sorry if this is a common question but searches both in this forum and on google gets a lot of results, but all of them turn out to be related to something other than what's causing my issues.

Both monitors are plugged in using balanced XLR to 1/8th cables. The left one is powered by a power strip on that side of my room (Tried wall w/out strip, no change), and the right one is plugged directly into the wall. While my computer is starting up, all I get is a very faint hum from the amp that is totally acceptable and expected, but as soon as Windows starts to boot I get that "computer noise" very audibly. Its a dynamic sound, not just white noise, it changes in pitch and rhythm when I do things like move my mouse, open applications. Glitchy sounding (TOTALLY RECORD THAT BRO). It's obviously louder coming from my left monitor, but is definitely coming from both units. Switching which monitor was the left or right channel did NOT change what monitor made the loudest noise.

Any help is greatly appreciated. I've tried unplugging all computer components one at a time. Without opening my case however, so if it could be an internal component let me know. This is making mixing damn near impossible :(

Re: CPU Noise/Interference in Monitors

Posted: Sun May 06, 2012 8:31 pm
by VirtualMark
Sounds like a ground loop. Try them both in the same socket for a start, also google 'ground loop' as there's a lot to read about them. My krk's also have this problem, i fixed it by earthing my audio interface to the computer case. Don't know if its correct but it stopped the noise.

Re: CPU Noise/Interference in Monitors

Posted: Mon May 07, 2012 4:06 am
by Erisol
I'm not sure what "earthing means", am I going to have to being doing any wire surgery? :\ Upon more careful listening, only the KRK on the right is experiencing the interference by the way. I'll read up on that, thanks man.

Re: CPU Noise/Interference in Monitors

Posted: Mon May 07, 2012 3:16 pm
by xbubbax
earthing means grounding your equipment to earth ground. earth ground is a rod that is put into the ground about 20/40ft down to ground all your electrical plugs in your house. sometimes with computers and power strips, grounding issues can occur of your house plugs are not connected to the earth ground pole.

plug your monitors directly into the wall along with your PC......the hum should go away meaning that the computer and monitors are hitting ground without any interference. if the hum still happens, then you have a grounding issue in your dwelling. :h:

Re: CPU Noise/Interference in Monitors

Posted: Mon May 07, 2012 3:18 pm
by Sharmaji
don't use 1/8" cables, for a start. no way to keep both signaled grounded like that.

Re: CPU Noise/Interference in Monitors

Posted: Mon May 07, 2012 5:46 pm
by kingbananathe
turn the monitors on last.

Re: CPU Noise/Interference in Monitors

Posted: Mon May 07, 2012 6:34 pm
by Erisol
Sharmaji wrote:don't use 1/8" cables, for a start. no way to keep both signaled grounded like that.
So I should get an external audio interface or something? It's two XLR cables that come together into the 1/8th inch. Idk maybe that's a bad idea but the fella at Guitar Center recommended them :P

I'll try out that grounding test in just a minute.

Re: CPU Noise/Interference in Monitors

Posted: Mon May 07, 2012 7:08 pm
by deadly_habit
your guy at guitar center was an idiot, you're going from dual mono balanced to a single stereo unbalanced adapter by the sound of it
yea get an audio interface, the focusrite sapphire 6 usb is prolly the best bang for your buck in the lower price range

Re: CPU Noise/Interference in Monitors

Posted: Tue May 08, 2012 9:49 am
by Ilain
VirtualMark wrote:Sounds like a ground loop. Try them both in the same socket for a start, also google 'ground loop' as there's a lot to read about them. My krk's also have this problem, i fixed it by earthing my audio interface to the computer case. Don't know if its correct but it stopped the noise.
Did you just wired your audio Interface case to your computer case?
Or did you do something else?
My focusrite saffire had no ground Output.