DIY Magnetic Shielding?

[cameronthorne]

I will soon have a non-shielded speaker that I will be placing close to my direct-view television, and I would like to shield the speaker. The tweeter is naturally shielded, but the midrange is just a standard Peerless HDS 850488. My current plan is to wrap the magnet in two layers of MagnetShield, followed by one layer of JointShield. I would line the inside of the enclosure with one layer of a single layer of magnetic shielding foil.

However, this adds up to $100 for just one speaker! :E

If any of you have effective methods that are significantly less money, without bucking magnets or similar T/S altering methods, then I would be mighty obliged to ye. ;x(

-- Cameron

[ThomasW]

http://www.htguide.com/forum/showthread.php4?t=16379&highlight=shielding

[cameronthorne]

Thanks Thomas!

However, I don't think I could get away with a sheet metal/wood plank sandwich between the TV and the speaker. The TV is not in an entertainment center, but out in the open. I might as well build a shielded dog house.

So I guess I asked the wrong question before. Let me reword it: Is there anything wrong with the shielding method using LessEMF Mu-metal products, either technically or from an effectiveness standpoint, other than their high cost? I really need to keep the shielding hidden in the enclosure. I've already burned through my SAF political capital on this project. :roll:

[---k---]

???



Thomas and Tibor got fancy and made the speaker box by placing the steel layer in between two layers of wood. It was in the walls of the box. AFAIK, it wasn't fancy metal, just regualar stuff from HD.

If you go to Home Depot and get the 16ga Steel Roofing flashings (Do NOT buy the Aluminum sitting next to it on the shelf, and often mixed in), then line the inside or outside of your speaker box, you should be good to go. If you got problems, use more layers. Put on the outside, like Thomas said in the link, just use the PE fake wood contact paper veneer. Put on the inside, just cover in the typical felt.

I dont' beleive that the MuMetal offers significant benifit for the price premium. It works. But does it work that much better? Most discussion I've seen on this topic is from people looking to spend less. Spending less and using a little overkill usually works well.

[ThomasW]

The sheetmetal construction described regarding Tibors speaker cabinets was of course inside the enclosures themselves, this means nothing was visible.

[cameronthorne]

How flexible is 16-gauge steel flashing? Since there are Linkwitz PLUTOs (link in my first post), the top of the midrange enclosure is a very irregular shape consisting of cylinders and cones. Thomas mentioned a bucking magnet as well in reference to Tibor's MTM center. I don't think there is room for a bucking magnet in there. How much of the shielding was accomplished because of the bucking magnet, and how much because of the sheet metal?

[ThomasW]

How flexible is 16-gauge steel flashing?

It's not flashing, it's sheet metal, and it's not flexible.

How much of the shielding was accomplished because of the bucking magnet, and how much because of the sheet metal?

Beats me.

Bucking magnets are cheap and they aren't very big...check PE Part Number 329-215

[---k---]

Since there are Linkwitz PLUTOs (link in my first post),

I didn't think I had to click on a link to figure out what kind of speaker you were using. But, I guess you're not using something typical.

Every speaker is differnt, and every tv is differnt. You're just going to have to experiment after you get the speakers. or is this a deal breaker in whether you get them?

[cameronthorne]

Not a deal breaker. I suspect the Mumetal will work as a last $100 resort.

I wonder how I can work a new magnetic-field immune Plasma/LCD/D-ILA/DLP/SXRD display into this project somehow. "But honey, I saved $100 by not having to buy Mumetal shielding!" :lol: