My ShoWagon installation is coming along nicely -- the windshield is back in the car now, the subwoofers are installed totally stealth, all wiring is in place, all speakers are in place except for the center channel speaker... and thus my question.

I am installing the empeg where the HVAC controls used to be (they, in turn are going where the cupholder/coin tray used to be) and the bottom of the 5" center channel speaker, complete with neodymium magnet, is perhaps half an inch above the top of the empeg.

Is there any likelihood of this magnet erasing or writing random ones and zeroes (or even threes and fours ) to my hard drive? If so, what would I do to shield it?

tanstaafl.

Interesting question. I'd be definitely worried about the magnet that close.

When I store my player in the trunk, I always have to remind myself not to place it near the subbie for the very same reason.

I remember the weird distorted colors I got on the sides of the TV screen whenever I placed the stereo speakers too close to it, proof enough that there was enough of a magnetic field outside the cabinet to disrupt the electron beam...If your speaker has a relatively heavy magnet, I would definitely have it shielded or find another suitable location for it. I'm sure that a laptop's HDD smaller size would make it very subceptable to data erasure from exposure to a strong magnetic field. I know that some people use magnetic fields to render HDD unreadable.

I have heard that hard drives actually contain powerful rare earth magnets inside their cases. If this really is true, then I wouldn't think that a magnet half an inch from the hard drive would be of ant concern. Of course maybe I heard wrong. I really can't verify this myself.

Stu

All harddrives indeed have very powerful magnets inside them. (I know cause I've opened quite a few)
If this means that they are not susceptable to magnetic fields from the exterior, I don't know. But I would think you've got a good chance.

ISTR reading that the strength of external field to erase a modern high-density HDD is absolutely HUGE (due to the proximity of the head and the size of magnetic patch, it's practically impossible to flip the bit if you're not the read/write head) and you should have no problems at all with big speakers nearby - but I could be wrong...

Try a google search?

Hugo

The magnets in hard disks have exceptionally closed fields -- I forget the terminology -- but, essentially, you won't get any magnetic effects more than half a centimeter from the magnet pair. You don't want to get your finger stuck between the magnets, though .

Well, bugger all effect, I would have thought. Stainless steel (the case) is still steel, and although it has reduced ferro magnetic properties, it still will accept a field and route it through it's "magnetic domains" around the circuitry/disks.

I suspect you would probably need an field strength somewhere close to that in the toroid field created by the European JET to create a favourable magnetic bottle sufficient to contain nuclear fusion before a shielded drive with a 5 micron magneto-resistive head would be affected.

A beer is in order, methinks....

I suspect you would probably need an field strength somewhere close to that in the toroid field created by the European JET to create a favourable magnetic bottle sufficient to contain nuclear fusion before a shielded drive with a 5 micron magneto-resistive head would be affected.

Now I'm not sure, but I think this means no, Doug.

Now I'm not sure, but I think this means no, Doug.

Actually, I am better off than I thought. While the bottom of the speaker is indeed only half an inch higher than the top of the empeg, the speaker is located far enough forward in the dash that it is actually close to 4" away from the top rear edge of the player. So if magnetic flux adheres to any kind of distance-squared rule, I only have 1/64 as much magnetism to worry about as I had previously thought.

I guess I'm safe.

tanstaafl.

You don't want to get your finger stuck between the magnets, though.

Too late! Pinched my finger good, it did.

These things are strong enough to hold on to each other through our thick wood desks.