Will a standard subwoofer magnet wreck havok on my PC?

[electricd]

I am thinking of mounting an 8" subwoofer inside my cabient firing down at the floor.  This would put the magent about 8" from my PC.  It will be about 3.5' away from the monitor.  I am wondering if this will be hazardous to my PC?  I realize the vibration isn't great for moving parts, but I just am not sure about the magnet.  Thanks in advance!

ED7

[Craig]

I would keep it a foot or more from your computer.

[rdagger]

Probably shouldn't put to close to the monitor either.

[Craig]

He said it would be 3.5 feet from the monitor. Which is fine. I'd try and keep all large magnets 2 or more feet from monitors.

[freezen2001]

as long as the speaker u use is sheilded it should be alright

[Craig]

You don't need sheilded speakers unless it will be very close to equipment.

[electricd]

Well, my space is extremely limited so I can't get it any further away from the PC than it is.  I don't think I will have a problem with the monitor, but wanted to be sure that the magnet won't screw with the magnets in the hard drive or something weird like that.  It is just a standard Kicker subwoofer, so it is not shielded.  Thanks for the advice.

Ed7

[Ghoward]

My Sub is right under my pc  but it is sheilded.

Gary

[Trimoor]

You're forgetting the basic physics of magnetism: it will only react with the HDD if it is moving.  Since the magnet in the speaker doesent move, it will do no damage.

The electromagnetic coil on the speaker might cause problems, but consider this: the little unshielded PC speaker has been sitting about 2" from my high speed/capacity drive for over a year, and I have not noticed a single problem.

Also, is your computer in it's case? Is it metal?  If so, this should protect it just fine.

[electricd]

Correct, it is in a metal case.  Thanks all for the info, I think I have my answer!

ED7

[Darkstalker]

"it will only react with the HDD if it is moving.  Since the magnet in the speaker doesent move, it will do no damage."

Umm...what?  You do realize that a magnet constantly exerts force lines between the north and south poles and they are what cause the damage to magnetic sensitive equipment, right?  It has nothing to do with movement...

"The electromagnetic coil on the speaker might cause problems, but consider this: the little unshielded PC speaker has been sitting about 2" from my high speed/capacity drive for over a year, and I have not noticed a single problem."

The coil magnet in a 2" speaker doesn't have enough field intensity to do any damage unless it's in very close proximity to your hard drive.  The coil in a sub, however, will be much larger and more hazardous.  I've lifted 20 pound weights using a 10" sub coil magnet.

"Also, is your computer in it's case? Is it metal?  If so, this should protect it just fine."

Actually, a PC case being metal will more than likely extend the magnetic flux due to magnetic induction than protect the contents.  Depends on the strength of the magnet to determine the amount of risk.

In short, keep magnets away from anything sensitive to magnetic induction (i.e. CRTs, and magnetic storage media).  The stronger the magnet, the more space you need.  3.5' should be fine from your monitor, but your PC may be a different issue.

[Trimoor]

Actually, a PC case being metal will more than likely extend the magnetic flux due to magnetic induction than protect the contents.  Depends on the strength of the magnet to determine the amount of risk.

What do you think shielded speakers are?  It's a metal box around the magnet/coils.
And don't forget that the HDD itself is enclosed in a thick metal box.

Also, a non-moving magnet will do no harm to a CRT. Really.  If it causes the colors to swirl, just degauss it, that will reset the magnetism of the shadow mask to compensate for the magnet.

Ever got one of those old AOL floppies in the mail?  I got bored one day and took a HDD magnet (the super powerful rare-earth type) and started rubbing it along the floppy.  I did that for about 20 minutes, and it was still able to read it perfectly. (no, I did not install AOL!)

Umm...what?  You do realize that a magnet constantly exerts force lines between the north and south poles and they are what cause the damage to magnetic sensitive equipment, right?  It has nothing to do with movement...

Wow, you must have flunked physics...a magnetic force acts upon an object ONLY when it is moving perpendicular to the magnetic field. (if the object is moving at an oblique angle, only the perpendicular vector of the motion acts upon the object.)

[electricd]

whoa...there is some serious flux capacitor language in here!

[Trimoor]

whoa...there is some serious flux capacitor language in here!

HEY, WATCH IT! Do you want to get sued?!?

It's "delux capacinator" language.

[Darkstalker]

"What do you think shielded speakers are?  It's a metal box around the magnet/coils.
And don't forget that the HDD itself is enclosed in a thick metal box."

It's an alloy placed around the magnet.  In the strictest sense, magnetic shielding isn't actually shielding at all. Magnetic shield materials create an area of lower magnetic field in their vicinity by attracting the magnetic field lines to themselves.

"Also, a non-moving magnet will do no harm to a CRT. Really.  If it causes the colors to swirl, just degauss it, that will reset the magnetism of the shadow mask to compensate for the magnet."

Given the fact that we're talking about relatively small magnetic charges, I agree.  If it's a strong enough charge to pull the electron beam inside the CRT and distort the image, that's a different story.  Even at 3.5', a spot will most likely appear on the lower part of the screen

"Wow, you must have flunked physics...a magnetic force acts upon an object ONLY when it is moving perpendicular to the magnetic field. (if the object is moving at an oblique angle, only the perpendicular vector of the motion acts upon the object.)"

You're right, my appologies.  I must have been thinking more in the terms of electromagnetic forces.  BUT, instead of discussing the finer nuances of Lorentz law and magnetic and electromagnetic forces and fields and getting way more complicated than this needs to be,  I'll leave this last thought to this thread:

It is better to be safe than sorry.

[Xiaou2]

Btw - One thing that hasnt been brought up is vibration damage to hard disks.

 If a drive isnt spinning... it can take a bit of vibration without harm... but at 7200 rpms... a subwoofers thump will end up damaging the internal heads inside the drive.   I believe these heads are near microscopic at the ends... and are the reason for most drive failures.
 
 This may not seem apparent right away... but youll probably reduce the drive life expectancy by 1/2 or more.

  My thought is that youd want to make a bungee cord type suspention system.  Something that will hang the drive in midair and keep in from getting affected from vibrations.

  Also... about the magnetic stuff...  Id add a thick board about 1" above the magnet to help absorb the feilds.  

  Ohh - and dont forget to point a strong fan to  blow air across the hard drives to keep them cool.   Heat expands the metal - which causes problems in allignments,  which destroys the drives.  General cooling isnt enuff in my opinion.. and I speak from a previous 3 drives failures before discovering why.  After installing fans in front of all my drives... they have lasted 3+ yrs so far... (i run 4 drives in my pc - 2 are backups)

[Trimoor]

Unless the subwoofer is attatched to the computer case, it will do nothing to harm the drives.  Subwoofers just aren't that powerful.

If you try using bungee cords, more likely it will end up oscillating, which will cause much more damage than a subwoofer.

Also... about the magnetic stuff...  Id add a thick board about 1" above the magnet to help absorb the feilds.

Sorry, but wood will do nothing to absorb magnetic fields.  The proper material to use is ferrite, but it could be hard to find and be expensive.

Cooling the drives is always a good idea.  Whatever you do though, don't take the case off to aid in cooling.  This reduces the airflow, actually causing it to be warmer than with it on.

[danny_galaga]

to add to the magnet moving problem in physics. dont forget its all relative. the hard drive is moving in that magnetic field. as well, the physics you talk of is mostly to do with generating a current. if the speaker were close enough to the hd, then the fields might (theoretically) align the magnetic information on the drive in the same manner, moving or not. a thought experiment here. put a floppy disk with info on it directly on the speaker magnet. leave it a while. its not moving, but you can imagine that youve probably ruined the info...

still i reckon youd be able to have the hard drive safely away from the speaker regardless. the best insulation is distance