Anyone usubstitute MW6501 with MW6503 replacement drivers?

Astropet
Astropet Posts: 25
in Vintage Speakers
I have a pair of SDA 1As with 3 frozen drivers. Has anyone
replaced MW6501s with new MW6503 replacement drivers?

The impedance is similar, but I'm curious to know if there is a
perceivable difference in sound?

Thanks!
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Comments

  • pitdogg2
    pitdogg2 Posts: 25,446
    Look for MW6600 they are a better match. Glue the magnets before you install the speakers to help keep the magnets from slipping. We have a couple of members who have reset the magnets maybe you could ship them to one of them to see if they could help.

    @lawdogg @FestYboy
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  • lawdogg
    lawdogg Posts: 455
    Absolutely I'm sure one of us can help.
    <3 my 3.1TLs

    I will fix your shifted magnets for free. :)
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  • K_M
    K_M Posts: 1,629
    pitdogg2 wrote: »
    Look for MW6600 they are a better match. Glue the magnets before you install the speakers to help keep the magnets from slipping. We have a couple of members who have reset the magnets maybe you could ship them to one of them to see if they could help.

    @lawdogg @FestYboy

    Your point is very valid, but reminded me of a post I saw a while back.

    This was from years ago, but it was one of the Polk Engineers (supposedly) talking about the MW drivers, and he commented that despite the small differences, they were mostly interchangeable and more similar than different.

    Just found that interesting, but who knows.
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  • pitdogg2
    pitdogg2 Posts: 25,446
    edited January 2020
    Look at SDA 1 schematics. They show mw6600 in the first gen then mw6501 in the SDA1a the crossover is the same. My SDA 1 signatures came with mw6600 in bass and stereo position and mw6501 in dimensional. Looking back at other speakers that use the mw6600 they eventually went on to use the mw6501 same xo
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  • Astropet
    Astropet Posts: 25
    The frozen drivers are all in the right speaker. I pulled all four drivers, and to my surprise, the stereo driver is an MW6510. The other three are all MW6600. These are 1As, they do not have the vent or plaque.

    I bought them second hand in 1988. They were stored in various homes 1500 miles away since 1997. I recently had them shipped to me. Unfortunately, they weren’t packed well and I suspect they shifted in transport.

    @pitdoggg2 It seems the MW6600s are as hard to come by as the MW6501s.

    @lawdogg That would be super cool of you if you can try to fix them! I will send a pm to see if we can work something out.

    Thanks everyone for your help.
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  • Astropet
    Astropet Posts: 25
    Thanks @lawdogg! The drivers are working great!

    To answer my original question, I can’t hear the difference between the mw6510 next to the sda driver in the right speaker compared to the mw6600 in the same position in the left speaker. I suspect the same would be true for the mw6503.
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  • F1nut
    F1nut Posts: 50,561
    edited February 2020
    Addressing a previous comment. There's nothing small about the difference between an 8 ohm and 4 ohm driver or the Fs of 29Hz and 44Hz.

    Polk didn't make all those different MWxxxx drivers because the engineers were bored.
    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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  • ChrisD
    ChrisD Posts: 101
    I often wonder how out of spec these drivers are after 30 years.

    It probably really doesn't matter which one you use now...
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  • F1nut
    F1nut Posts: 50,561
    edited February 2020
    Why do you think they would be out of spec and what do you think would be out of spec?
    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: 4,468
    edited February 2020
    These speakers were very well made and not likely to go out of spec. The surrounds are great and long lasting. Now the magnet adhesive could've used a little improvement but as long as adhesive failure has not occurred I don't think anything will be out of spec.
    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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  • pitdogg2
    pitdogg2 Posts: 25,446
    The hardest drivers to find are the MW6501 for some reason. The MW6600 does come up more often on that auction site. YES it can and does get dry for a spell then you will see scads of the MW6600 all of a sudden. Be patient and you will be rewarded. I have bought many for my SDA1 Signatures along with several MW6501's. I paid way more for the MW6501 drivers than I did for the MW6600's.

    A few years ago you couldn't get hardly any MW6510 drivers. In the last couple of years they are always on the auction site in a range of prices high to low, and sometimes if you catch someone with several they will more than likely be happy to sell the lot to you at a better price.
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  • ChrisD
    ChrisD Posts: 101
    F1nut wrote: »
    Why do you think they would be out of spec and what do you think would be out of spec?
    I'm just wondering because they are so old now. It would be interesting to send one off to get tested.
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  • Gardenstater
    Gardenstater Posts: 4,468
    edited February 2020
    Or I think you could do it yourself with some software and hardware like this, on sale for $129.

    "DATS V3 is a unique, multipurpose test system that works with your PC and full-featured test software to measure the impedance response of a speaker driver and derive a complete set of Thiele/Small parameters that describe its operation. It's as easy as connecting a driver and starting the test! The DATS V3 measurement module provides the electrical stimulus to the driver, measures the driver's impedance on the fly, and then creates a high-resolution graph (30,000 data points!) with no additional hardware required."

    https://www.parts-express.com/dayton-audio-dats-v3-computer-based-speaker-audio-component-test-system--390-807
    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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