grinding feedback into krk v4's from laptop power adapter!?

Tangka · Post by **Tangka** » Thu Nov 15, 2007 4:59 pm

so this is what happens with my setup

sony laptop + power adapter plugged in (charging, ac/dc power?
1/8" stereo audio out split into XLR L/R into 2 KRK V4 series 2 studio monitors
(the signal to speakers is not coupled or converted anywhere, just 1 single cable)

this setup results in grinding fuckedup feedback, seemingly sensitive to cpu use. speakers play nicely, but with feedback in background

sony laptop + BATTERY POWER (not plugged in) + same speaker setup = FINE

laptop + AC/DC POWER (plugged in) + HEADPHONES = FINE, GREAT

i dont know if i'm an idiot or what, but i have a couple ideas, and i read something in the manual about an unbalanced signal requiring a converter for the XLR's 3 pin functions

anyway thanks for reading this

cheers

forensix (mcr) · Post by **forensix (mcr)** » Thu Nov 15, 2007 5:01 pm

get yourself a grounding loop (google it)- should sort out the problem.

chunkie · Post by **chunkie** » Thu Nov 15, 2007 5:19 pm

forensix (mcr) wrote:get yourself a grounding loop (google it)- should sort out the problem.

yep

had this with my old dell laptop - very embarrassing when on p.a systems!

Tangka · Post by **Tangka** » Thu Nov 15, 2007 5:29 pm

would you happen to mean an audio line isolation transformer?

this seems really complicated and obscure for simply connecting a laptop to some monitors

thanks man, dont know where where i would be without you

ikeaboy · Post by **ikeaboy** » Thu Nov 15, 2007 8:53 pm

Earthling wrote:
this seems really complicated and obscure for simply connecting a laptop to some monitors

This is common enough, its a feedback loop going from

laptop>power cable>house electric supply>Monitor power cables>monitors>speaker cable>laptop

At least that the explaination that made sense to me. The CPU spikes is an odd one, are you sure they don't happen when you run from batteries?

Tangka · Post by **Tangka** » Thu Nov 15, 2007 10:50 pm

ikeaboy wrote:
Earthling wrote:
this seems really complicated and obscure for simply connecting a laptop to some monitors

This is common enough, its a feedback loop going from

laptop>power cable>house electric supply>Monitor power cables>monitors>speaker cable>laptop

At least that the explaination that made sense to me. The CPU spikes is an odd one, are you sure they don't happen when you run from batteries?

thanks, i've figured it out, i'm off to buy an isolator asap (i just hate all the accessories you end up needing every time you buy an expensive piece of equipment)

and what i was saying about the cpu was that the feedback seems to get louder and more gravelly with cpu use (open folder, open application, etc), just a little detail about the sitch.

cheers to you all i'll post a follow up when this is cleared up

drwurst · Post by **drwurst** » Fri Nov 16, 2007 11:17 am

so you running the sound from the build in soundcard?

get an external soundcard...?

Tangka · Post by **Tangka** » Fri Nov 16, 2007 5:05 pm

drwurst wrote:so you running the sound from the build in soundcard?

get an external soundcard...?

i have been told that a USB audio interface and/or a power conditioner can also solve the problem.

any words on that?

at this point i'm just waiting because i'm having trouble even figuring out what the hell kind of isolator to get. i have to go to this pro audio shop this weekend because (of course) guitar center employees suck DICK, and hopefully this pro audio shop will be able to put an end to all this, proper store.

cheers but as i said any words on a power conditioner/ usb interface?

thanks fellas

grinding feedback into krk v4's from laptop power adapter!?

grinding feedback into krk v4's from laptop power adapter!?

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