Replacing frozen vintage MW 6503

charlied7401
charlied7401 Posts: 8
in Speakers
After great Input and help from Gardenstater and Boston 1450 decided to replace with aftermarket replacements, the originals have been discontinued for quite sometime . Spoke to Polk tech this morning, very helpful and confirmed not aware of any possible repair of old units,recommended parts express and Mid West speaker.Per Gardenstater’s suggestion looked at EBay but not comfortable with used given age and no returns too risky and too expensive for me.
Found Dayton DCA -160-8 on parts express their p/n 295-305 . Does anyone have an opinion on these?
Thanks
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Comments

  • pitdogg2
    pitdogg2 Posts: 25,549
    edited January 2020
    Yes the opinion is going to be buy used. We all have many times. Ask the seller to pack very well and you should be ok. I've bought about 10 mw drivers off ebay and have never had one show up seized. I'm not saying it can't happen but ebay will refund if it is no matter what the seller states.
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  • Gardenstater
    Gardenstater Posts: 4,497
    And if you decide to go used, which is what I'd do as well, definitely pm the seller to confirm no voice coil rubbing sounds when dust cover/cone is depressed manually. In my experience they will usually respond and if they don't you can decide whether to take a chance anyway and rely on eBay return policies.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    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
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  • boston1450
    boston1450 Posts: 7,652
    I also have bought off Ebay with good results. Always ask ?'s about item & that it be packaged well for magnet shifting issues.... Charlie you messaged me pictures of your SL 2000 tweeter with a pushed in dome. You also stated there was some issue with the back of it & something fell off. Correct ? You also mentioned it was working now. Good.... You can probably use a tweeter with it pushed in. SHOULD you ever have to replace that tweeter I would "recommend" that you upgrade to Polk RD 0194 tweeters ( I think I heard Polk has those ? ) They are far better than the sl 2000 tweeters. If for some reason you have to replace 1 why not upgrade both to a far better sounding tweeters. Just some friendly advice.... You stated you bought these in the 80's (awesome) & after 30+ years I think you could easily enjoy them for another 20+ years........ Keep in mind the crossovers are old & tired. They may need refreshing soon. That is a whole different ballgame & that can of worms need not be opened now. There is a lot of good advice here. Dont hesitate to ask any question
    ..
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  • Faustin
    Faustin Posts: 1,149
    Is Lawdogg still repairing 65xx drivers?? Maybe send him a pm and ask
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  • ken brydson
    ken brydson Posts: 8,772
    Faustin wrote: »
    Is Lawdogg still repairing 65xx drivers?? Maybe send him a pm and ask

    He posted in another thread that he was too busy right now.
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  • Gardenstater
    Gardenstater Posts: 4,497
    edited January 2020
    The two he is considering are:

    https://www.parts-express.com/dayton-audio-dc160-8-6-1-2-classic-woofer--295-305

    and

    https://www.midwestspeakerrepair.com/shop/home-audio/woofers/polk-audio-1/mw-audio-mw-6503-8-6-5-inch-polk-audio-copy-woofer/

    We would have to compare the Thiele Parameters with the ones for the MW6503, to see if the crossover in the Polks would be compatible and then you would also have to replace them in pairs, in my opinion, because it's highly unlikely that they wouldn't sound a bit different from the original Polk MW6503.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    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
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  • lawdogg
    lawdogg Posts: 455
    ken brydson wrote: »
    Faustin wrote: »
    Is Lawdogg still repairing 65xx drivers?? Maybe send him a pm and ask

    He posted in another thread that he was too busy right now.

    Sorry I must have been drinking when posting (shocking, I know), I do have bandwidth for anyone in need.
    <3 my 3.1TLs

    I will fix your shifted magnets for free. :)
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  • F1nut
    F1nut Posts: 50,643
    edited January 2020
    Gardenstater wrote: »
    The two he is considering are:

    https://www.parts-express.com/dayton-audio-dc160-8-6-1-2-classic-woofer--295-305

    and

    https://www.midwestspeakerrepair.com/shop/home-audio/woofers/polk-audio-1/mw-audio-mw-6503-8-6-5-inch-polk-audio-copy-woofer/

    We would have to compare the Thiele Parameters with the ones for the MW6503, to see if the crossover in the Polks would be compatible and then you would also have to replace them in pairs, in my opinion, because it's highly unlikely that they wouldn't sound a bit different from the original Polk MW6503.

    Neither of those are that close to the specs of the MW6503. Most notably the Fs of the MW5603 is 29Hz. The Dayton is 35.7Hz and the other is in the 50Hz range.
    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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  • Gardenstater
    Gardenstater Posts: 4,497
    @f1nut yes I noticed that. Definitely a deal breaker said I to self.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    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
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  • PeteB77
    PeteB77 Posts: 15
    Do you have the T&S specs for the original MW6503?
    Monitor Series RTA 8T Restored, Technics 1210, Xindak Pre/power amps
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  • pitdogg2
    pitdogg2 Posts: 25,549
    edited January 2020
    1 Driver Type Q BL Compliance DC Resistance Fs

    5 MW 6503 1.82 5.24 N 3.55 E - 3N/M 6.54 Ohms 29 Hertz
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  • Gardenstater
    Gardenstater Posts: 4,497
    Driver: MW 6503 Driver's model #.
    Brand: Polk Driver's brand name.
    Fs: 29.8600 Hz (Free air resonance)
    Vas: 3.0017 ft^3 (Compliance volume)
    Qts: 0.3100 Total Q
    Qms: 1.7680 Mechanical Q
    Qes: 0.3760 Electrical Q
    Sd: 0.0130 M^2 (Piston area)
    Xmax: 3.1800 mm (Cone excursion, linear)
    Revc: 6.5400 ohms (DC resistance)
    Znom: 8.0000 ohms (Nominal impedance)
    Pmax: 35.0000 watts maximum rated power
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    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
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  • PeteB77
    PeteB77 Posts: 15
    Thanks, let me think about those numbers.
    Has anyone looked at Misco drivers?
    Monitor Series RTA 8T Restored, Technics 1210, Xindak Pre/power amps
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  • PeteB77
    PeteB77 Posts: 15
    There used to be an 8 ohm version of this driver, might work well if they get more:
    https://www.madisoundspeakerstore.com/approx-6-7-woofers/madisound-6102-4-6-polypropylene-cone-woofer/
    Monitor Series RTA 8T Restored, Technics 1210, Xindak Pre/power amps
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  • PeteB77
    PeteB77 Posts: 15
    Has anyone tried to have Miller Sound repair a woofer?
    Monitor Series RTA 8T Restored, Technics 1210, Xindak Pre/power amps
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  • halo71
    halo71 Posts: 4,603
    I have had some success repositioning shifted magnets in the past. Using a jig made of PVC pipe and thumb screws. Believe I found the plans for it on Audiokarma many years ago.
    --Gary--
    Onkyo Integra M504, Bottlehead Foreplay III, Denon SACD, Thiel CS2.3, NHT VT-2, VT-3 and Evolution T6, Infinity RSIIIa, SDA1C and a few dozen other speakers around the house I change in and out.
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  • PeteB77
    PeteB77 Posts: 15
    That jig is a great idea, I've seen pictures on AK.
    Monitor Series RTA 8T Restored, Technics 1210, Xindak Pre/power amps
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  • DAC
    DAC Posts: 4
    Just acquired a set of Monitor 10s. One is working well, the other has two shifted magnets on the MW6503s made in Jan 1986. Otherwise very solid cabinets with few marks and the Peerless tweeters are working great.

    Going to reach out to those who have experience with gluing them to get the job done right. None of the "replacements" look to be as competent as the originals with the possible exception of the one offered by The Speaker Exchange, which has an identical Fs spec:

    https://reconingspeakers.com/products-page/6-5-woofer-with-butyl-surround8-ohm-6028/

    Has anyone tried those?
    Marantz 2238 / KLH Mod 6 / Monitor 10 / 2xSL-1210 / Hell PR40 / Joemeek ThreeQ
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  • pitdogg2
    pitdogg2 Posts: 25,549
    HOLY DUSTCAP Batman
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  • Gardenstater
    Gardenstater Posts: 4,497
    edited January 2022
    Go with used on eBay just make sure you message them and ask them to make sure there is no voice coil rubbing and to pack them with lots of cushioning. Then try to repair or have repaired your others to have as backups.

    That speaker you posted from The Speaker Exchange is not at all comparable. Just look at the power handling and the voice coil diameter and the relatively low sensitivity.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    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
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  • DAC
    DAC Posts: 4
    Thanks for putting your eyes on the Speaker Exchange driver. I wanted to make sure it was on the radar and that when others search for this, they find your analysis.

    I'm getting the drivers repaired by a generous forum member. I hope they're in serviceable shape and that I can get these back up and running soon. If there are any issues with them I would definitely find a second hand driver to be repaired instead of settling for a substandard alternative.
    Marantz 2238 / KLH Mod 6 / Monitor 10 / 2xSL-1210 / Hell PR40 / Joemeek ThreeQ
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  • Hansvelton
    Hansvelton Posts: 151
    So yeah, it is not that the Dayton Classic midwoofer, is truly bad at all, I have heard a DIY speaker made using 2 of them, that had really great deep bass......

    https://sites.google.com/site/undefinition/floorstanding-speakers/classix2-5

    But using one of them to replace a Polk midwoofer, it will not obviously be an exact match as F1nut said above.

    Looking over the specs, the Dayton one is more ideal actually in a smaller enclosure than most of the vintage Polks used.


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  • Hansvelton
    Hansvelton Posts: 151
    edited January 2022
    This is the actual speaker they are using...



    https://www.goldwood.com/goldwood-sound-gw-6028-rubber-surround-6-5-woofer-170-watts-8ohm-replacement-speaker/


    But calling it this.....

    https://reconingspeakers.com/products-page/6-5-woofer-with-butyl-surround8-ohm-6028/
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  • DAC
    DAC Posts: 4
    I had these pair repaired by the generous @lawdogg since the first post. I must thank him for the service to the community this is. I've never owned any Polk Audio gear in the past, but these Monitor 10s will be staying with me for a long time.

    I'm incredibly impressed by the sound these drivers, in a pair, with the passive radiator, can make. I've had to adjust my receiver's bass down, which I didn't expect, having enjoyed it at that setting for years with my KLH Model 6. The mid- and high-range is far more full with the Monitors and I understand completely why this speaker exists. I also get why two of the MW drivers, with radiator, in this sealed cabinet, work so well.

    So, please have your drivers repaired or get them replaced with working units. Don't cheap out and put something else in.
    Marantz 2238 / KLH Mod 6 / Monitor 10 / 2xSL-1210 / Hell PR40 / Joemeek ThreeQ
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  • F1nut
    F1nut Posts: 50,643
    I've had to adjust my receiver's bass down,
    Should be flat, preferably disabled.
    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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  • DAC
    DAC Posts: 4
    F1nut wrote: »
    Should be flat, preferably disabled.

    Running bass flat, Loudness disabled. Just a little boost on mid and high. Lovely sound.
    Marantz 2238 / KLH Mod 6 / Monitor 10 / 2xSL-1210 / Hell PR40 / Joemeek ThreeQ
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  • bone42t
    bone42t Posts: 1
    edited October 2023
    Hello everyone! If I may ask is anyone familiar with a gentleman by the name of Trey? DHS (Dave) is now retired. He recommended this gentleman to perform the upgraded capacitors/crossovers for the polk audio RTA 15TL's
    Post edited by bone42t on
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  • pitdogg2
    pitdogg2 Posts: 25,549
    Probably should have started your own thread. That being said, last I heard Trey @VR3 has slowed considerably. Maybe he will get the bat signal
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