Recentering magnets on speakers
dcmeigs
Posts: 708
I have a MW6501 that is frozen. The cone won't budge. I read that this can be fixed by "recentering" the magnet.
Does anyone have any experience with this? Is this a DYI project? If so, How is it done?
Does anyone have any experience with this? Is this a DYI project? If so, How is it done?
The world is full of answers, some are right and some are wrong. - Neil Young
Post edited by dcmeigs on
Comments
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Its done. You need a replacement.
Sorry for the bad news. I have tried it many times.Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
Thanks
Ben -
It should fit perfectly in your trash can.
Customer Service & Tech Support:
polkcs@polkaudio.com
800-377-7655, Option 1 toll free
410-764-5470 fax
International +1-410-358-3600CTC 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. -
WTB- One 6.5 inch round trash can. Oh yeah, an MW6501 too.The world is full of answers, some are right and some are wrong. - Neil Young
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If you can find a well equipped speaker repair shop locally, they can maybe help you if they have a magnet demagnetizer machine (very large and expensive).
I had a similar problem years ago when I had to partially dissassemble a magnet sandwich to remove some broken VC wires. Once loosened, the magnets had a mind of their own and as much as I tried recentering them, it was basically impossible due to their strong pull. Obviously, I don't have one of those units.
Otherwise, the trash can suggestion is probably the best. -
I know it was for cost savings( Along with vibrating cheap stamped steel frames ), but the cheap **** glued on magnet assy's on their 6 1/2" drivers is a long lived black eye for Polk.
At the time they were being manufactured, both much better frames and bolted on magnet assy's were commonplace...just cost a bit more ...which is what SDA-SRS series customers were happy to pay for.
I can see Polk saving money on the lesser Monitor/RTA/etc series...that stands to reason , but the higher end SDA series ( FOR SURE the " Hand built" SDA SRS series ) should have had their own better built speakers inside.
Alloy frames ( Or even thicker steel frames stamped with some ridges to them ) and bolted on magnet assy's should have been minimum on the highest end Polks. I have seen some taiwanese flea market speakers with better frames then these 6 1/2" drivers.
Nowadays, the better drivers even have USER replaceable bolted on top assy's that dont require a jig to center the voice coil in the air gap.
Could you imagine how much more trading/selling/shipping would be going on today if all of us Polk fans werent so damn afraid of one of those glued on magnets coming loose in shipping and pinballing around inside the cabinet destroying EVERYTHING inside. I have seen AWESOME deals on Craigslist/Ebay that I would have jumped on hadnt it of been for the need to ship the speakers.
Rant over....pls continueThe first rule of Fight Club is you don't talk about Fight Club -
On the flipside, Polk still sells replacement drivers for the SDA/Monitor series, of which most are 20 years or older. Try getting replacement drivers for other 20 year old 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 -
On the flipside, Polk still sells replacement drivers for the SDA/Monitor series, of which most are 20 years or older. Try getting replacement drivers for other 20 year old speakers.
I second that. You can even buy upgrade parts (tweeters) for your 20 year old speakers. How many companies release those...
Have you tried looking on ebay or your local craigslist for the driver? If that doesn't work out, give Polk a call as mentioned above. Good luck. -
Excellent rant!
I orderd replacements from polk today. At $48 is not the end of the world.
BUT, since its going in the can anyway, I'm going to jig it up in a vice and see if I can recenter it by tapping it with a hammer. If it is out of whack, the glue must be ineffectual. Slight tapping might work if I can determine the correct heading to send it. Or I could hit it with the pnumatic rivet gun and a bucking bar!The world is full of answers, some are right and some are wrong. - Neil Young -
On the flipside, Polk still sells replacement drivers for the SDA/Monitor series, of which most are 20 years or older. Try getting replacement drivers for other 20 year old speakers.
No doubt Polk kicks **** in customer support....thats a fact.The first rule of Fight Club is you don't talk about Fight Club -
shadowofnight wrote: »I know it was for cost savings( Along with vibrating cheap stamped steel frames ), but the cheap **** glued on magnet assy's on their 6 1/2" drivers is a long lived black eye for Polk.
At the time they were being manufactured, both much better frames and bolted on magnet assy's were commonplace...just cost a bit more ...which is what SDA-SRS series customers were happy to pay for.
I can see Polk saving money on the lesser Monitor/RTA/etc series...that stands to reason , but the higher end SDA series ( FOR SURE the " Hand built" SDA SRS series ) should have had their own better built speakers inside.
Alloy frames ( Or even thicker steel frames stamped with some ridges to them ) and bolted on magnet assy's should have been minimum on the highest end Polks. I have seen some taiwanese flea market speakers with better frames then these 6 1/2" drivers.
Nowadays, the better drivers even have USER replaceable bolted on top assy's that dont require a jig to center the voice coil in the air gap.
Could you imagine how much more trading/selling/shipping would be going on today if all of us Polk fans werent so damn afraid of one of those glued on magnets coming loose in shipping and pinballing around inside the cabinet destroying EVERYTHING inside. I have seen AWESOME deals on Craigslist/Ebay that I would have jumped on hadnt it of been for the need to ship the speakers.
Rant over....pls continue
What speakers from the 80's had the construction you're speaking of exactly? What modern, mass market manufacturers have user replaceable top assemblies?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. -
B&W has rebuildable tweeters (at least my 602S3s did). You could separate the top and bottom pieces of the housing, then remove and replace the dome on the tweeter if you needed too. I don't think the same applies to any mid-drivers I've ever seen.
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That's a nice feature.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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What speakers from the 80's had the construction you're speaking of exactly? What modern, mass market manufacturers have user replaceable top assemblies?
From the same time period as SDA-SRS line was inplemented and in full swing ( Mid to late 80's ) there were more manufacturers then you could count that had rubber surrounds/aluminum or magnesium frames screwed together so they didnt fall apart.
I used to order them from the pages of Speakerbuilder magazine for speakers I was building at the time ( I saved my entire collection of Speakerbuilder magazines for future custom builds...I can dig out all of the manf and specific models from there ) Lets just say there were a LOT of 6 1/2" drivers in the late 80's that fit the description. I still have one set of Vifa's here as well as some ACI kits that I did just a couple years later in 92 that have those qualities as well.
As for user replaceable top end assy's, those have been implemented for some time now with subwoofer drivers . Here are some I have here at home awaiting my monster sub build.
The redesigned 45 pound titanium monster
. 160 Newtons2/watt Motor Force
. 1000 Watts Continuous Power
. 3" Anodized Aluminum Voice Coil
. Single Dish Titanium Cone
. High Excursion Tall NBR Surround
. 215 Ounce Magnet Structure
. Anti Flux Modulation Shorting Ring
. 30mm XMax
. 10" Diameter Suspension System
. Custom Cast Aluminum Frame
. Quick-Detach Top AssemblyThe first rule of Fight Club is you don't talk about Fight Club -
B&W has rebuildable tweeters (at least my 602S3s did). You could separate the top and bottom pieces of the housing, then remove and replace the dome on the tweeter if you needed too. I don't think the same applies to any mid-drivers I've ever seen.
Many tweeters do...here is few more...
http://www.madisound.com/catalog/index.php?manufacturers_id=153
http://www.madisound.com/catalog/index.php?manufacturers_id=173
http://www.madisound.com/catalog/index.php?manufacturers_id=143The first rule of Fight Club is you don't talk about Fight Club -
I think that the longevity of Polk drivers under most circumstances (ie not abused) is rather good. I also think the price and availability of the replacement parts is pretty remarkable.
BDTI plan for the future. - F1Nut -
I think that the longevity of Polk drivers under most circumstances (ie not abused) is rather good. I also think the price and availability of the replacement parts is pretty remarkable.
BDT
Totally agree. If they don't take a hard hit I would not be surprised to see them lasting 50 years;) Even driven hard:)Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
Thanks
Ben -
shadowofnight wrote: »From the same time period as SDA-SRS line was inplemented and in full swing ( Mid to late 80's ) there were more manufacturers then you could count that had rubber surrounds/aluminum or magnesium frames screwed together so they didnt fall apart.
So who again?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. -
Plus the fact that they have rubber surrounds. You could be refoaming them too like a lot of other brands, so I count my blessings that they rarely have to be replaced, and most of the time it's "user error".