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Old 1st June 2003, 01:47 PM   #1
Flavius is offline Flavius  Romania
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Default Interference, speakers --- > computer screen

While listening at a decently high level, any power spike will be shown on my computer screen I see sort of "flashes" like in those psichedelic winamp spectrum displays.

I'm not sure what causes this though. It is either from the xover coils, or maybe the voice coils, or is the amp itself ? ( doubt that, amp sits on a side, while computer is in the center between the speakers and the screen distorsions are symetrical, like the magnet distorsions are too (they are not shielded - dont do as I am, placing 12" woofers 5 feet away from a screen)
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Old 1st June 2003, 02:49 PM   #2
kneadle is offline kneadle  United States
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I have 6.5 inch woofers placed 18" from my screen, and I'm not having any distortion problems. I mean, what you described certainly sounds like the magnet pulling on your display, but at 5 feet? And with the spikes? I don't know...

Do you think it could be the power itself being sucked out of your circuit to feed the amp?

Dave
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Old 1st June 2003, 03:37 PM   #3
Flavius is offline Flavius  Romania
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If your magnets are not shielded, I dont see how they dont affect your screen. I tried almost 7 feet, my speakers still affect the image - thats the most I can get them apart without serious moving. The trick is that not everything is affected. I only see this on certain backgrounds of a light color, to be specific, the light green-yellow background of the Microsoft Outlook Calendar.
They are sort of rainbow type of stripes but of course in 2 colors only, a stripe of the real color then a stripe of modified color and so on. Their patter isnt modified when I move away the speaker, but when i rotate it.


But this is no mistery. The mistery is with the spikes, they dont have nothing to do with this sort of passive alteration from the magnets. They are dynamic and related to the music.

I'm not sure if the amp sucks that much current. Its pluged to another mains than the computer. Its just a 2x30W amp and the volume is set to app. the middle of the run....
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Old 1st June 2003, 03:39 PM   #4
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How big is your amplifier? My larger amplifiers (anywhere from 350 watts a channel to 500-1400 bridged) can dim the lights in the house on large trasients. Have you tried plugging the amplifier into a different outlet? If the speakers are several feet away from the monitor it should be fine. Do you have access to a UPS? You could try plugging the Monitor into the UPS.



Scott
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Old 1st June 2003, 03:43 PM   #5
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I use a 20" CRT CAD screen with stripe mask. The amp is class a so current will not increase at peaks and take effect on the screen. My drivers are far enough away and magnetic shielded. At loud enough volume there happen visible effects on the monitor because the stripe mask starts to move around.
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Old 1st June 2003, 04:01 PM   #6
Flavius is offline Flavius  Romania
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Kneadle, in case you dont have Outlook Express, here is a test for you. I discovered why this background is affected by the magnetic field; it is a very fine chess pattern, one pixel green one pixel yellow. The field does not affect continous colors.
Open the image in a window and move it all around the screen, this way you will see if stripes appear.
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File Type: jpg test.jpg (53.5 KB, 144 views)
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Old 1st June 2003, 10:24 PM   #7
kneadle is offline kneadle  United States
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Quote:
Originally posted by Flavius
Kneadle, in case you dont have Outlook Express, here is a test for you. I discovered why this background is affected by the magnetic field; it is a very fine chess pattern, one pixel green one pixel yellow. The field does not affect continous colors.
Open the image in a window and move it all around the screen, this way you will see if stripes appear.

Could you explain that again? I'm not sure I understand.

Dave
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Old 1st June 2003, 11:50 PM   #8
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Quote:
Originally posted by Flavius
Open the image in a window and move it all around the screen, this way you will see if stripes appear.
I get stripes and I have no speakers (shielded or otherwise) within 6m of my monitor?!?
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Old 2nd June 2003, 12:25 AM   #9
Duo is offline Duo  Canada
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Lol, this is interesting. I had my speakers each about 6' away from the TV and running at 200w they'll make the picture wobble a lot.
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Old 2nd June 2003, 06:25 AM   #10
Flavius is offline Flavius  Romania
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Pinkmouse, ) not the two black horizontal lines. Those are from the picture


Kneadle:

Perhaps this might help. An old photo from where I managed to cut a piece showing the magnet interference.
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File Type: jpg stripes.jpg (14.9 KB, 87 views)
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