Fixing MW6503

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Adam in NC
Adam in NC Posts: 2
edited September 2006 in Vintage Speakers
Hi all--new to the forum, seems like a great place to exchange info.

I'm writing to ask if anyone has tried fixing MW6503s. Mine got frozen or stuck during a move--not even a hard bump, I think just from bumps in the road & slight shifting.

The problem is that the glue connecting the magnet to the top plate breaks down over time. If you don't move the speakers, the magnetic force keeps everything in alignment. A few bumps, however, and the magnet can shift against the top plate. Since the magnet is still glued to the pole plate, this pushes the pole plate against the voice coil & pins the voice coil to the edge of the top plate.

Here's a diagram so you can see what I mean (borrowed, interestingly enough, from a manufacturer of speaker adhesives...)
spkr.jpg

The thing is, this doesn't really damage any part of the speaker as long as the bump isn't hard enough to damage the voice coil--it's just as good, except now it's in pieces. (I separated this myself, but I've heard of them getting knocked completely off--since it's a pretty strong magnet, seems like this would take quite a jolt.)

Here's the speaker (that grayish powder on the top plate is what used to be the adhesive)
2002059076842859329_rs.jpg

Anyone got any thoughts on putting things back together? Alignment is obviously the problem--but if there's a way to fix it would be nice to avoid dropping $200 for a new set of drivers...

As far as avoiding the problem in the first place, I bet that a bead of adhesive where the magnet and top plate meet would prevent.
Post edited by Adam in NC on
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  • F1nut
    F1nut Posts: 49,842
    edited August 2006
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    Welcome to the forum and great first post. I don't know of anyway to repair your problem, but maybe one of these other good folks might.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • beef316
    beef316 Posts: 154
    edited August 2006
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    How many of your drivers were affected?
    2004 IASCA Spring Break Nationals Champion - Amateur Street
    2003 IASCA World Finals Runner Up - Amateur Street
    Certified IASCA Judge
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  • Adam in NC
    Adam in NC Posts: 2
    edited August 2006
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    I haven't gotten the other speaker out yet, been put away since I moved--I think at least one of those is broken, so either 3 or all 4, sadly. Been playing with it this morning, and there may be a way to fix--the clearance isn't quite as tight as I thought--the relevant distance is the outer diameter of voice coil against the hole in the top plate, not voice coil vs. pole piece.
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  • dorokusai
    dorokusai Posts: 25,576
    edited August 2006
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    It is officially ready for the garbage.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
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  • Mike Reeter
    Mike Reeter Posts: 4,314
    edited August 2006
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    ebay is a good place to shop for replacement drivers,usually cost less than new Polk replacements...but,how much "life" is left in them is just a guess.
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  • rodman_sda
    rodman_sda Posts: 32
    edited September 2006
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    stretch the account and go NEW
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