Re: Inteference from laptop to monitor speakers

I am receiving a similar problem with my Dell C610. I'm using an
external sound card, the problem seems to be the LCD screen, when I
switch off the screen the noise goes away, the only problem with this
is that it shoots up the latency in the sound card for some reason
(windows trying to do more than one thing at a time is always a recipe
for disaster) I've tried using an external monitor and then switching
it off when we hit record, but a monitor isn't always practical to drag
around when mobility is the key..the noise extends to the amps aswell
the monitors and so is being recorded...its a high pitched sort of
whine, not the usual mains hum...anyone have any ideas? The soundcard
is a transit USB.


Pooh Bear wrote:
> Zigakly wrote:
>
> > > I agree that it's a common occurrence with laptops, but I'm not sure
> > > that isolation transformers will solve the problem. Some crappy
> > > built-in audio hardware just puts out noises like that. The difference
> > > is that with the Genelecs rather than the crappy PC speakers, you can
> > > hear it.
> >
> > I think you're talking about EMI from other componentry, usually the hard
> > drive and video card, this is much more severe. You don't hear it over PC
> > speakers because they don't create the ground loop. It would be plenty
> > audible with them too if it were present.
>
> Mike has a point though. Some PC audio is truly dreadful, especially the
> integrated motherboard implementations of 'sound cards'. Like on laptops for
> example.
>
> I've heard those 'birdy tones' and buzzes as you move the mouse etc.... on a
> cheapo PC just by plugging in some decent hadphones ( no ground loop required
> ).
>
> There is nevertheless entirely another issue regarding ( legal ) ground
> leakage currents from the EMI filter.
>
> Graham

.

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