Why do some Polk drivers have additional magnet on woofers? SDA-2B...

Mystery
Mystery Posts: 2,546
edited October 2013 in Vintage Speakers
I just opened SDA-2B studio to apply epoxy and all drivers have additional small magnet on top of the sticker.
Is that designed for added magnet or just slapped on previous design?
Also, it's real weird to attach additional magnet on top of the paper sticker.
I mean it's not even touching the plate on the woofer.
If the paper sticker comes off, so will the extra magnet. :confused:

None of other Polks I opened (4, 7, CRS+) did not have that additional piece.
What's the idea here with extra magnet? :idea:
Thanks for info...

Polk SDA-2B Woofers (3).jpg

Klipsch RB81, KG3.5, B&W DM602.5, Polk.
Subwoofers: Klipsch RW10, Triad ProSub Bronze.
Post edited by Mystery on
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Comments

  • Conradicles
    Conradicles Posts: 6,077
    edited October 2013
    Never seen that in my days.
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  • VR3
    VR3 Posts: 28,560
    edited October 2013
    Its a "bucking" magnet. Probably added by an owner to reduce/cancel interference with a TV
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • F1nut
    F1nut Posts: 50,428
    edited October 2013
    They are bucking magnets used to make the speakers safe to use near a CRT TV. You think they are easy to get off, think again.
    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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  • scottyboy76
    scottyboy76 Posts: 2,905
    edited October 2013
    get those magnets the buck off.
    humpty dumpty was pushed
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  • Mystery
    Mystery Posts: 2,546
    edited October 2013
    Thanks for info.
    Well, it looks pretty tough to get off. Probably epoxied.
    Anywho, the real question is does that affect performance of the original woofer?
    If not, I'll leave them alone.

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.
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  • VR3
    VR3 Posts: 28,560
    edited October 2013
    I would not think so, almost all modern Polk speakers have it, they use a combination of bucking magnets and a bucking casing over the magnets in the LSi and RTi for example
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • F1nut
    F1nut Posts: 50,428
    edited October 2013
    Leave them alone.
    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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  • FTGV
    FTGV Posts: 3,649
    edited October 2013
    Mystery wrote: »
    Thanks for info.
    Well, it looks pretty tough to get off. Probably epoxied.
    Anywho, the real question is does that affect performance of the original woofer?
    If not, I'll leave them alone.
    Yes most likely epoxied since they will be of opposing pole to the main magnet so will want to push away from instead of being attracted to.

    It's addition may have some minor changes in parameters and sensitivity but those will have been accounted for in the box and crossover design.
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  • Mystery
    Mystery Posts: 2,546
    edited October 2013
    VR3 wrote: »
    I would not think so, almost all modern Polk speakers have it, they use a combination of bucking magnets and a bucking casing over the magnets in the LSi and RTi for example
    F1nut wrote: »
    Leave them alone.

    Okay... thanks.
    I hope the drivers are correct as I can't see the label anymore. :confused:

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.
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  • MAD
    MAD Posts: 105
    edited October 2013
    I got excited for you and thought you had some sort of prototype when I first saw them. lol
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  • PolkieMan
    PolkieMan Posts: 2,446
    edited October 2013
    If I could get them off I would. You would be original to the design besides CRTS are gone so why leave them unless it is really hard and a chance of messing them up.
    POLK SDA 2.3 TLS BOUGHT NEW IN 1990, Gimpod/Sonic Caps/Mills RDO-198
    POLK CSI-A6 POLK MONITOR 70'S ONKYO TX NR-808 SONY CDP-333ES
    PIONEER PL-510A SONY BDP S5100
    POLK SDA 1C BOUGHT USED 2011,Gimpod/Sonic Caps/Mills RDO-194
    ONKYO HT RC-360 SONY BDP S590 TECHNICS SL BD-1
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  • F1nut
    F1nut Posts: 50,428
    edited October 2013
    They are original to the design. Polk installed and/or sold the bucking magnets for/to their customers.
    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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  • BrettT1
    BrettT1 Posts: 560
    edited October 2013
    Bucking magnets were on all 16 drivers in my 1.2TLs when I got them. They're still there, too.
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