New Speakers and Old Compass

[frank_f]

Originally Posted by mcerdos

Hmm? I thought since 304 stainless sheeting was non-magnetic (unless heated), it would serve nicely as a shield. Am I wrong?

The obvious choice would be to use iron but this is going to disintegrate and will be flush mounted in an area where it will be difficult to evaluate.

If the material is non magnetic, the magnetic field from the speakers will not be stopped by it. You need something that will contain or dampen most of the field but won't affect the compass itself.

[MBWhite]

Originally Posted by mcerdos

The obvious choice would be to use iron but this is going to disintegrate and will be flush mounted in an area where it will be difficult to evaluate.

Personally I'd just spray the cans with a couple of coats of cheap spray paint, if you wind wire around the first tin can do that first before painting but even cheap paint should provide enough corrosion protection for a location deemed safe enough for speakers. You can also get galvanized steel flashing in 6" wide rolls, Home Depot sells it in 10' X 6" rolls and you might try rolling up 5' for each speaker.

Also, I just had this crazy thought but you could get a cheap boy scout compass and put it on the ground and place the speakers on the ground where the distances are close to how they are mounted and experiment with the speaker orientation to see if you can affect the field that way, maybe if you rotate one or both you can get some magnetic cancellation to happen. Just a thought, probably won't do anything but would be a simple 10 minute exercise to experiment with. It would also make it easy to see if any shielding you do will have an effect.

[hellosailor]

Mark-
As I recall, mu metal is what is used in commercial magnetic shielding. It is a metal sheet that has a very high magnetic attraction, so it absorbs magnetic fields (energy) and prevents them from affecting whatever is on the other side of the mu metal. Stainless steel is a weak magnetic attraction at best, you want something that leaps to the magnet and soaks it all in.
Mu metal suppliers can be found on the web. Some quite pricey, others infest alibaba. I would expect that any "loud" or "powerful" speakers would be more problematic, because they'll be using bigger stronger magnets to handle high volumes. The old speakers may have been chosen for economy, making that less of a problem.
If you do decide to go speaker shopping, take a hand compass along with you, and use that to check them out in the store.

[mcerdos]

Originally Posted by frank_f

If the material is non magnetic, the magnetic field from the speakers will not be stopped by it. You need something that will contain or dampen most of the field but won't affect the compass itself.

Such as?

[hellosailor]

Such as...wait for it...mu metal.(G)

[frank_f]

Originally Posted by mcerdos

Such as?

Like I said back on post #8, mu metal or a Faraday cage.

[frank_f]

Originally Posted by mcerdos

Such as?

Try this link:
Magnetic shielding film MCF5 3 Linear Feet - - Amazon.com

Hopefully that worked correctly.