Bad Woofer?

I noticed today I was getting weird distortion/sound from one of my sda2b woofers. Specifically the left Woofer on the left speaker. It is a 6511. Is there anything I can do? There aren't any on eBay and they aren't made anymore.

Thanks
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Comments

  • windstriker
    windstriker Posts: 136
    edited April 2020
    I'm assuming there isn't much I can do then..... I will probably hook up the right sda woofer to the left side to make sure it isn't a electronic problem. From there I will keep a eye on ebay. What other speakers did Polk use the mw6511 in? According to the handbook it was used in the 1.2, 1.2tl, 3.1tl, and the crs+(pin/blade). Did they use it in any non sda speakers(I'm assuming not)? If I have to I will keep a eye out for a crs+ to cannibalize but that is not my first choice by far.

    Also can both mw6511s be replaced by another woofer or is this a bad idea?
    Post edited by windstriker on
  • Tony M
    Tony M Posts: 11,009
    I'd say keep checking ebay or...

    Somebody here on the forum will hook you up with one.

    Good luck.
    Most people just listen to music and watch movies. I EXPERIENCE them.
  • xschop
    xschop Posts: 4,635
    edited April 2020
    [/quote] can both mw6511s be replaced by another woofer or is this a bad idea?[/quote]

    I have replaced mw6511's with mw6502's in a set of CRS+ and a set of SDA-converted Model 10B's
    You will lose a little bottom end extention, but the trade-off is better articulated SDA midrange frequencies... IMO


    Don't take experimental gene therapies from known eugenicists.
  • I'm have the same problem with one of my mw6511 in my 2.3s. I switched it to the other speaker and it is still the same. The speaker sounds like it is clipping but I'm not listening to it very loud. I know it isnt the amp because I just recently changed from a mcintosh mc2200 to a mc2500 and it's still the same. Plus both these amps let me know if I'm clipping.. The mw6511 moves in an out freely without any rubbing and plays well until I play at louder volumes then it starts making a crackle/pop sounds but still continues to play. I am currently looking for a mw6511 as well. I feel your pain windstriker
  • F1nut
    F1nut Posts: 49,704
    Remove the driver in question. Inspect where the spider attaches to the cone. You will likely find the spider has become unglued. Use Aleen's tacky glue to reattach.
    Political Correctness'.........defined

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    President of Club Polk

  • westmassguy
    westmassguy Posts: 6,850
    You cannot use a MW6502 in place of a MW6511. Vastly different T/S parameters. Just because it doesn't sound horrid, doesn't make it suitable. Wait until Midwest has fresh stock, if they ever do, or do a saved search on eBay. Whenever a MW6511is listed, you'll get an email.
    I get several emails a day with new listing for Polk woofers.
    Home Theater/2 Channel:
    Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
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  • windstriker
    windstriker Posts: 136
    Ya Im not sure if I'm going to go the 6502 route... maybe as a stop gap if I'm desperate. Otherwise I will just have to be patient with ebay. It doesnt seem like midwest will get new 6511s. This is the description for the 6502. "Great replacement woofer for the MW6502 Polk Monitor Series.Also, is the closest replacement woofer for the MW6511 and MW6512." Ya I'm not holding my breath....

    For now... As soon as I can I'm going to take F1nut's advice and see if the current woofer can be repaired. I am hoping that I can just do that.
  • Let us know what you find out. I looked at my woofer and didnt find any problems with it
  • F1nut
    F1nut Posts: 49,704
    akkkd43zsntm.jpeg
    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

  • audioluvr
    audioluvr Posts: 5,420
    Let us know what you find out. I looked at my woofer and didnt find any problems with it

    Look closer. I've found out these minor flaws aren't easily noticeable. Like @F1nut says, check the spyders. If there isn't voice coil damage they are fixable. I'd also try to find out what caused the failure. These drivers are pretty tough but not foolproof.
    Gustard X26 Pro DAC
    Belles 21A Pre modded with Mundorf Supreme caps
    B&K M200 Sonata monoblocks refreshed and upgraded
    Polk SDA 1C's modded / 1000Va Dreadnaught
    Wireworld Silver Eclipse IC's and speaker cables
    Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)


    There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus
  • Ok I will take the advice and look it over again really good. I looked at the spider and cone very well the last time and didnt notice anything but I will check it again.
  • F1nut
    F1nut Posts: 49,704
    Push the cone down and release watching the spider to see if it separates from the cone.
    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

  • Gardenstater
    Gardenstater Posts: 4,133
    Ok I will take the advice and look it over again really good. I looked at the spider and cone very well the last time and didnt notice anything but I will check it again.

    I had a cracked spider in one of my midbass drivers and it was hardly noticeable. I had to manually press the cone in quite a large distance to make it appear, while looking with a magnifier on my head and good lighting. That driver is currently on the sidelines because, even after 2 repairs, it started to exhibit the voice coil rubbing and was driving me crazy.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
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  • windstriker
    windstriker Posts: 136
    edited April 2020
    Ok I figured out the problem. The glue connecting the spider to the cone is fine. The glue holding the surround to the cone is not. This is the woofer that I had to replace the surround on due to a hole in the original surround. Now it looks like 1/4 of the surround has dettatched from the woofer. The surround looks fine. I'm going to see if I can get some more glue from Midwest. I'll try regluing it on.

    Thanks f1 you out me on the right track.
  • F1nut
    F1nut Posts: 49,704
    There are no proper replacement surrounds for Polk MWxxxx drivers.
    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

  • F1nut
    F1nut Posts: 49,704
    Hmmmm.......
    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

  • windstriker
    windstriker Posts: 136
    At anyrate I'll work with what I have and see if I can reglue the surround. I'll also keep a eye on eBay and replace the woofer entirely when available.
  • lawdogg
    lawdogg Posts: 449
    Good to know @westmassguy ! Thanks!
    <3 my 3.1TLs

    I will fix your shifted magnets for free. :)
  • windstriker
    windstriker Posts: 136
    *update* So re-gluing the woofer did not fix distortion I was hearing. I think the woofer had been permanently damaged when the glue on the surround failed. My SDA's have been out of service since April. Finally found a mw6511 on Ebay and I couldn't hit buy now any faster than I did. I've been listening to a pair of Klipsch rp600m which sound fantastic but they just aren't on the same level as my 2Bs. Now I'm impatiently waiting on the mail............ Sure hope it works..... Ironically I saw the ebay listing right after I purchased a diy kit for a pair of anthology speakers. I might have waited if I had seen the ebay listing first. O well the Anthologys will be the backbone of a HT set up. NOT getting rid of my SDAs.
  • I hope it's not the same one I was looking at on ebay not to long ago. There was a mw6511 on ebay for sale but if you look closely at the picture you can see a small hole in the lip of the woofer. Its not on ebay no more so just giving you a heads up
  • windstriker
    windstriker Posts: 136
    *Sigh* Ya I noticed that after the last post.... Ive contacted the seller. If he does send it to me I will dispute it with ebay because he doesn't mention it in the description and it is hard to see. Thanks for the warning. I'm not sure what is worse potentially getting ripped off, or not being able to repair the SDAs....... Wait on second thought not being able to repair them is much worse....
  • I feel your pain.. I'm also looking for a mw6511. Very rare gem lol. I found one 6511 on ebay once and it was for sda 1c. I'm not sure if the mw6511 was designed different for different models. But the original mw6511 in my 2.3s have a taller lip on the woofer and the dust caps are thicker. The mw6511 out of the 1c have a more rounded lip and the dust cover is thinner ( easier to see through).. so something else to look out for.
  • F1nut
    F1nut Posts: 49,704
    The same MW6511 was used in a multitude of Polk speakers.
    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

  • Gardenstater
    Gardenstater Posts: 4,133
    Would it be at all possible to disassemble the woofer's magnet assy and attempt to determine if it can be re-centered (a la xschop)? Is the DCR measurement still good? Perhaps before you go to such extreme measures you could attempt to carefully remove the dust cap with an exacto knife and check the centering there to see if something is amiss in that regard.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • windstriker
    windstriker Posts: 136
    So I contacted the seller and he said he had another one he could send. We will see how that turns out..... *crosses fingers*
  • mackdrool
    mackdrool Posts: 26
    Don't lose hope! They are rare to find but they do pop up on ebay pretty consistently. Going back through my email alerts there have been at least 17 listings since last July. If you haven't set list alerts yet I HIGHLY suggest you do.
  • windstriker
    windstriker Posts: 136
    Got the woofer and it seems legit with no wholes in the woofer. Since it is a sda how do I test for functionality just plug it in? Any way to test that it is a 6511?