Effects Of Magnetic Fields On LCD Displays

[rpatt]

I Googled this subject but got conflicting results. I have seen what magnetic fields can do to CRTs but I’m new to LCDs. Has anyone seen any bad effects on their LCDs from speaker magnets or any other source of magnetic fields?

[Odin75]

LCDs don't get affected by magnets, or at least not in the traditional sense that I know of.
If placing huge speakers next to your LCD is what worries, then stop, because nothing will happen to your LCD.

I mean, is not like you plan to put a magnet with the power to lift an entire house next to your LCD, are you? lol

[Blu-Dog]

Originally Posted by Odin75

LCDs don't get affected by magnets, or at least not in the traditional sense that I know of.
If placing huge speakers next to your LCD is what worries, then stop, because nothing will happen to your LCD.

I mean, is not like you plan to put a magnet with the power to lift an entire house next to your LCD, are you? lol

If you get a refrigerator magnet and put it right next to the screen, you'll get some weird stuff going on.

If your TV is sitting right on top of a huge unshielded center speaker, you might get some limited problems. Magnetic field strength falls off very quickly - it takes a very large magnet to support a field that will affect a TV. I wouldn't put a massive sub under one, but even then, it probably wouldn't do anything.

Left and right speakers, I've never seen any effect. If the speaker is more than one foot away, you won't have any problems.

You will see discoloration and image skewing (the actual field pattern of the magnet) if it has an effect.

[Steve]

I've always heard that LCDs and plasmas are unaffected by unshielded speakers.

[Odin75]

Originally Posted by Blu-Dog

If you get a refrigerator magnet and put it right next to the screen, you'll get some weird stuff going on.

If your TV is sitting right on top of a huge unshielded center speaker, you might get some limited problems. Magnetic field strength falls off very quickly - it takes a very large magnet to support a field that will affect a TV. I wouldn't put a massive sub under one, but even then, it probably wouldn't do anything.

Left and right speakers, I've never seen any effect. If the speaker is more than one foot away, you won't have any problems.

You will see discoloration and image skewing (the actual field pattern of the magnet) if it has an effect.

Are you sure you are talking about LCD, and not a CRT?

My work nametag has several magnets to hold itself, and I always leave it on top of the screen of my cellphone, so I know I won't loose it (LCD touchscreen). I'd never seen a problem with that.

Also, my center channel (dual 5.25" woofers + .75" tweeter") is about 3 fingers (how many inches is that?) away from my 37" LCD. I see no problem there either.
Then there's the LCD screen in front of my receiver, I don't see it affected by the receiver itself, nor by the 6.5" woofer bookshelf speaker that is like 1 finger away from it.

I really don't think LCDs get affected by magnets, unless is an extremely powerful one, and even then, I would think that if something happens, is because the magnet is physically moving the parts inside.
Don't quote me on that though, that's just my guess. Is just that I've never seen an LCD messed up because of a magnet. CRTs Yes, but not LCDs, and I've seen people with HUGE speakers next to their LCDs.

I just want to say, that we have a 10" 188 watt (RMS) subwoofer in the living room, siting about 1.5 feet away from a ~32" CRT, and we've never had a problem with it. I can't imagine the kind of magnet required to affect an LCD.

[rpatt]

I'm planning on wall mounting my TV just high enough to clear my center which will on the cabinet below the TV. The closer the better. I guess I could test it before doing the mounting.

[Odin75]

Originally Posted by rpatt

I'm planning on wall mounting my TV just high enough to clear my center which will on the cabinet below the TV. The closer the better. I guess I could test it before doing the mounting.

You have nothing to worry about man, nothing will happen to your LCD. I have seen people with WAY BIGGER speakers next to their LCD, and none of them have problems with that.

BTW, I just checked you gallery, and your setup looks sweet. It's very clean, I like that. Is there a reason you plan to wall mount the tv? You don't like the glass? hehe.
I ask this, because when I had the B750, I was afraid of breaking the stand. I saw the pictures online and I said "Oh nice, a glass stand". But when I got it home, it was like "OMG, this is real glass, I'm so gonna shatter it."

[rpatt]

Originally Posted by Odin75

You have nothing to worry about man, nothing will happen to your LCD. I have seen people with WAY BIGGER speakers next to their LCD, and none of them have problems with that.

BTW, I just checked you gallery, and your setup looks sweet. It's very clean, I like that. Is there a reason you plan to wall mount the tv? You don't like the glass? hehe.
I ask this, because when I had the B750, I was afraid of breaking the stand. I saw the pictures online and I said "Oh nice, a glass stand". But when I got it home, it was like "OMG, this is real glass, I'm so gonna shatter it."

Thanks Odin. The center in my gallery is not the center I'll be using. The new one is bigger. I have two reasons for wall mounting the TV. I want the center to be more in line with the fronts (suggested by Lou) and my new fronts will be wall mounted and I think it will look good that way. I wasn't that worried about the glass stand but mine is just a little bit off so as to tilt the TV a little to the right.

[crackinhedz]

At work we have a couple of LCD monitors sitting about 15 feet away from a 1.5 Tesla magnet (140,000 times stronger than the earth's magnetic field), no issues.

...of course the magnet is shielded as well as the room...but doesn't stop the battery in my cell phone from draining.



http://www.invivocorp.com/PEnt/esys.php

• MR Safe, RF Shielded, 30" LCD Display.

[rpatt]

That looks pretty convincing.

[Blu-Dog]

Originally Posted by Odin75

Are you sure you are talking about LCD, and not a CRT?

Do the refrigerator magnet trick, you'll see what I'm talking about. Magnetic fields can drastically affect LCD's.

Originally Posted by Odin75

My work nametag has several magnets to hold itself, and I always leave it on top of the screen of my cellphone, so I know I won't loose it (LCD touchscreen). I'd never seen a problem with that.

As I said, magetic field strength (measured in oersteds) falls off quickly from a single source. But it does have an effect, which may be barely noticeable if at all, when you bring a magnet close to a screen.

[QUOTE=Odin75;2999041]
Also, my center channel (dual 5.25" woofers + .75" tweeter") is about 3 fingers (how many inches is that?) away from my 37" LCD. I see no problem there either.
Then there's the LCD screen in front of my receiver, I don't see it affected by the receiver itself, nor by the 6.5" woofer bookshelf speaker that is like 1 finger away from it.

The cabinet itself isn't magnetized - it's the magnet on the coil of the speaker itself, which is even further away from the screen that the point where you do the "three finger" measurement. It's probably not ever going to be a problem.

Originally Posted by Odin75

I really don't think LCDs get affected by magnets, unless is an extremely powerful one, and even then, I would think that if something happens, is because the magnet is physically moving the parts inside.

Speaker drivers don't use electromagnets (a powered coil to generate a magnetic field) - they use magnetized material with a fixed strength. Whether or not the speaker is powered or unpowered, the field strength will remain the same.

Magnetic fields are relatively week, and easily shielded, for the most part. I've never seen a speaker affect an LCD - they're just too far away.

Originally Posted by Odin75

Don't quote me on that though, that's just my guess. Is just that I've never seen an LCD messed up because of a magnet. CRTs Yes, but not LCDs, and I've seen people with HUGE speakers next to their LCDs.

I just want to say, that we have a 10" 188 watt (RMS) subwoofer in the living room, siting about 1.5 feet away from a ~32" CRT, and we've never had a problem with it. I can't imagine the kind of magnet required to affect an LCD.

I've seen the same kind of setups you describe, and like you, have seen no problem.

[drummerboy_2002]

Originally Posted by Blu-Dog

Speaker drivers don't use electromagnets (a powered coil to generate a magnetic field) - they use magnetized material with a fixed strength. Whether or not the speaker is powered or unpowered, the field strength will remain the same.

Don't mean to be knitpicky, but I think you're forgetting about the voice coil, which is an electro-magnet. So the field strength would fluctuate with power.

[Blu-Dog]

Originally Posted by drummerboy_2002

Don't mean to be knitpicky, but I think you're forgetting about the voice coil, which is an electro-magnet. So the field strength would fluctuate with power.

True, my mistake.