[audiopenguin]

I have a problem on both my desktop and laptop with electrical noise coming out of the audio ports. I know on my laptop it is because of something stupid I did with a usb port that caused leakage from the usb port onto the audio port. On the desktop it is probably not caused by my audio card since the noise can come from my dedicated sound card or from the motherboard audio.
 
The characteristics of the noise from both computers consists of it primarilly being audible when no audio is suposed to be playing. There are definitely actions that cause increase in noise but in both cases the previous statement still applies.
 
When searching forums the only solutions I have found are related to grounding parts inside my computer which isn't particularly apealing to me.
The one thing I have found that works in muffling the noise is using my pair of Panasonic RP-HTF600 headphones. My guess is that it is because those headphones have a much higher impidence than my other headphones and speakers.
Is my thinking correct?
If so is there a way that I could add more impidence to other headphones?
 
I would really like to be able to use iems with my computers for sound isolation and portability reasons.

 

[nagual]

The noise from the laptop is still present even when unplugged ?  Have you tried to connect the pc  in other outlets ?  Maybe the problem is not due to your computers.

 

[StudioSound]

Are you connecting your speakers to a headphone port, or a line-out port?
Are the computer and speakers connected to the same outlet? You're probably hearing a ground loop.

 

[Frank161]

Which speakers do you use? I've had all kinds of speakers that had electrical noise which wasn't coming from the source.

 

[aprairie]

You can always hard-wire resistors into your headphone cables to increase impedance....See thread here for some pre-made ones: http://www.head-fi.org/t/601669/impedance-adapters-cables-explained-listed

Alternately, but a USB DAC/headphone amp and cut out the audio from your PC. For $99, the improvement from the Dragonfly is pretty amazing. http://www.head-fi.org/t/617241/audioquest-dragonfly-review-affordable-outstanding-tiny-dac-amp

And you can use it on both desktop and laptop as needed.

Drew