Magnetic fields & TFT screens

[RichL]

Probably a silly question, but I thought I'd go ask the obvious before I start waving a 12" subwoofer around next to £600 of new TFT screens...

Having no guns and therefore no magnetic controls to be bu99ered up, a TFT display should be practically immune to the strong magnetic fields generated by hi-fi speakers, right?

[spadnos]

Probably a silly question, but I thought I'd go ask the obvious before I start waving a 12" subwoofer around next to £600 of new TFT screens...

Having no guns and therefore no magnetic controls to be bu99ered up, a TFT display should be practically immune to the strong magnetic fields generated by hi-fi speakers, right?

Interesting question, and I'm sure Rylan has the correct answer

But, failing that, I'd say that a subwoofer would be OK, but a high power tweeter might not be. The reason being, that a changing magnetic field creates an electrical field, and the LCD changes based on electric field changes. The faster magnetic field changes of a midrange / tweeter would create stronger electrical fields. As to whether an external device can create enough field intensity, I'm not sure.

So, try it - unless you put 2000 watts through the speaker for a few days, there shouldn't be any lasting effects on the LCD.

- Steve
(waiting to be corrected by the expert )

[rylan]

Well, the key is n what you said... "TFT display should be practically immune to the strong magnetic fields generated by hi-fi speakers".

The TFT layer uses a low voltage electric field to change the rotation of the crystals, making your pixels turn on, off or partway for various colors. I'd actually be more concerned about coupled interference between the backlights in the monitors and the sub. Flourescent bulbs, even the smaller ones in an LCD, generate a nice short-range field that may cause some humming in your sub.
I don't see any reason you can't try it... the sub won't do any damage to the LCD.

Just watch to see if you see anything strange like color shift on the screen or any buz/hum in the speaker.

[spadnos]

...
Just watch to see if you see anything strange like color shift on the screen or any buz/hum in the speaker.

I'm sure there will be some buzzing or humming in the monitor if the sub is sitting on the desk right behind it

- Steve

[Marshmallowman]

Strong magnetic fields can affect any electronic device.

The main thing to worry about is induced currents when your moving the speaker near the device, so to be paranoid sure keep everything off while you arrange things.

There is also the vague possibilty that the (not moving)magnetic field will effect current flow in the device, but realisticly I don't think that will happen as the field strength needed to do that is quite large.(hall effect) But since the LCD relies on precise voltages to control the liquid crystals you might see some colour/brightness variation, however I would think this kind of effect will not cause long term damage...just look funky.