Surely just move the speakers away from the laptop power cable?

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Look if your Speakers have a ground lift switch. If they have, switch it on. If not, you can buy 2 passive DI-boxes and put each signal through, doing the groundlift there.

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"nee, de plaat heeft geen kras! dat hoort zo!!!"

Agenda 2009:

WinterWorld, Sporthalle Oberwerth, Koblenz
Trance Energy, Jaarbeurs Utrecht
Mayday, Westfalenhallen, Dortmund
Nature One, Pydna, Kastellaun / Hunsrück

quote:

Originally posted by Johnny Cache Look if your Speakers have a ground lift switch. If they have, switch it on. If not, you can buy 2 passive DI-boxes and put each signal through, doing the groundlift there.

Thats absolutely spot on thank you so much

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1999 Mix series

Rare Vinyls spinning on video If you like that sort of thing

Just wanted to add for any future reference for anyone with a similar issue

this solved my problem, by inserting the DI in between my external soundcard and monitors

Thanks Johnny

Tascam US-122L >> Ultra-DI D120 >> Yamaha HS 50M

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1999 Mix series

Rare Vinyls spinning on video If you like that sort of thing

this is a common problem. can´t really describe it in english as my technical english sucks.
the problem is that two power consuming units (e.g. laptop and soundcard) are running over the same power source. if they have a different ground voltage, you will hear the typical humming.

feels great that I have helped someone !

___________________
"nee, de plaat heeft geen kras! dat hoort zo!!!"

Agenda 2009:

WinterWorld, Sporthalle Oberwerth, Koblenz
Trance Energy, Jaarbeurs Utrecht
Mayday, Westfalenhallen, Dortmund
Nature One, Pydna, Kastellaun / Hunsrück

what is DI-Ultra D120? tell me more i have this problem too, tho im pretty sure its my fucked up electricity that does this.

When working with mixers, effects and synths, i.e. in studio environment, you have two different ways in that audio data can be transmitted.

(a)
Unbalanced Mode. This is usuall for Hi-Fi-Systems but is also used sometimes in HomeStudios. This means that only one signal is sent through a cable.


(b)
Balanced Mode. This is the professional way to connect audio signal sources. If you look at your soundcards, speakers etc. etc. you will find balanced and unbalanced outputs.
If an audio signal is trnasmitted in balanced mode, there are two signals in the cable, one "normal" signal and one "copy" of the signal which is phase-swapped (180°).

The original thought behind this approach is that if you have the signal in both the "normal" and the 180° phase-flipped way, you can still re-flip the phase at the audio "in" and use the other signal if one occured an error (for example humming to due failed grounding like the-sixth encountered it)

Now, a DI box does nothing else than converting an unbalanced signal into a balanced one i.e. adding the phase-flipped signal. They are most widely used to plug instruments like guitars or basses directly into mixers, hence the name Direct Injection Box.
Plus they change the amount of resistors (this is where I can´t use my tech english anymore, sorry)

I´m really sorry, my technical english SUCKS big time...

But you can check wiki:

http://en.wikipedia.org/wiki/DI_box
http://en.wikipedia.org/wiki/Ground_lift

___________________
"nee, de plaat heeft geen kras! dat hoort zo!!!"

Agenda 2009:

WinterWorld, Sporthalle Oberwerth, Koblenz
Trance Energy, Jaarbeurs Utrecht
Mayday, Westfalenhallen, Dortmund
Nature One, Pydna, Kastellaun / Hunsrück