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View Full Version : tft monitors creating a hum in speaker cables....?!



Jimfish
07-12-2004, 09:01 PM
Anybody had a problem like this?

Ive just installed a couple of gnr tft monitors and now they are making a hell of a racket through my speakers when switched on.
It seems that they are creating interference in the speaker cables theselves as when i unplug the speaker cable (balanced 1/4" jack into my active PM-2's) the noise stops.
Ive tried changing the cable to my most expensive cables but its still the same - anybody got any ideas?
cheers..

xfive
07-12-2004, 09:27 PM
Damn yo sounds like you need to build some sort of interference blocker around the screens.

Not to bash your lcds but are they sorta low-end ? I bet they aren't shielded for shit.

Jimfish
07-12-2004, 09:46 PM
i dunno, probably they were pretty cheap considering they are 18" - about £220 each i think..

Jimfish
08-12-2004, 12:43 PM
bumping in case anyone has any thoughts as to how i can combat this.. ;)

xfive
13-12-2004, 11:50 PM
There are places that sell stuff like this that may help:

http://www.rfi-ind.com.au/product/mms.htm


-Chris

Jimfish
14-12-2004, 01:16 AM
hey cheers..
its weird this though..

ive realised the sound is coming straight out the back of my digi001 soundcard (which i have moved miles away from the screen)..

I tried disabling that and enabling the crappy onboard motherboard sound and presto! no more interference!

Now why is it that a decent semi-pro soundcard suffers from incredible interference from the monitors but the shite onboard soundcard doesnt??

my brain hurts :cry:

xfive
14-12-2004, 01:27 AM
Hmm ok

This makes me think its a power issue.
Make sure everything is plugged into the same circuit (sometimes different outlets are on different circuits).

I've had crazy hum on gear if plugging one into one source and the other into another circuit and then connecting their audio.

I'm willing to bet your digi is plugged in elsewhere, whereas the onboard sound is obviously powered by the rest of the pc (and presumably where your screens are plugged into as well). :)

dan the acid man
14-12-2004, 01:33 AM
if its and internal card, im guessing you've tried plugging it into different pci slots

Jimfish
14-12-2004, 01:39 AM
no i havent..

jeez i must be some kind of retard.. why the **** didnt i try that?!

Ill try it tomoorw and post the result.. cheers dan :)

xfive
14-12-2004, 01:49 AM
Hmm I dunno man.. my years of computer building experience tell me that switching slots isn't going to do anything in this case.
The audio signals and power are still coming in and out of the same sources.

Stuff like that doesn't change from slot to slot, only resources themselves do in regards to how everything is configured in Windows.

dan the acid man
14-12-2004, 02:17 AM
it can make a difference, epsecially if it's near to a graphics card, my dmx 6 fire picks up interference from mine unless i put it in the bottom 2 slot's, the furthest away from my graphics card

xfive
14-12-2004, 02:27 AM
Ah yeah that could be the case if he's got some heavy hitting gfx card. I guess I'm used to fairly shitty ones lol :)

Jimfish
14-12-2004, 09:44 AM
ah bollocks yes.. i thought i was being clever buying a fancy graphgics card!! man.. you cant win can you?!

Im thinking of swapping the digi001 over to an 828 for other reasons anyway.. do you think ill still have a problem (the 828 is firewire btw) as my firewire comes from a pci card too.?

Cheers for this boys, you are crank starting my brain here

gumpy green
14-12-2004, 12:31 PM
you could try getting good sheilded cables for your tft.

if they are properly sheilded(ie outer is earthed) then NO signals should be getting out(to yer soundcard)...

also if you have good sheilded audio cables then nothing should be getting in to them..

have you suffered interferance form anything else?phones tv etc?

gumpy green
14-12-2004, 12:38 PM
just thought--

it could be interferance from the mains cable for the monitior....does it sould like a 50hz hum?

what about keeping the cables far away from each other- does that help..

even then i still think if you have a proply wired audio cable....signal down the centre and 0v/earth on the sheild then the noise would just be pulled to ov by the sheith.

it would be worth checkin the audio cables to see if the signal is down the centre(i have found sum that are not :dontevengothere: )

if you can unscrew the connector to check then try some other audio cables to see if the problem persists.....

Traxx
14-12-2004, 04:33 PM
I have active pm-1's & get the same noise. Its a pain in the arse :roll:

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