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    • Early Model 7 Midwoofers

    Posts: 4,563
    edited November 2024 in Vintage Speakers
    Could 1975 Model 7 have possibly used this 6W10R CTS midwoofer, as this eBay seller is saying? Date code is 7503; 3rd week of 1975. Serial # pretty high at 44922.

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    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
    Post edited by Gardenstater on
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    Comments

    • Posts: 127
      edited November 2024
      I ran across that sale when I was searching for woofers for my minis. I do believe that was probably used by Polk in some of the early 7s. If the guy had 2 I would have bought them just to check them out.

      fyq6lfj4cxes.jpeg
      1rwufgdy7sy0.jpg

      Thats from another seller. Apparently he has a pair of 7s he's parting out. One came with a peerless and the other with above pictured audax.

      I think it would be cool to see a 7 with those CTS woofers and the Audax tweeters.
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    • Posts: 127
      I see what you’re saying about the serial number but are we sure how Polk kept track of the serial numbers from back then ?

      9n24cn8o8tb0.jpeg

      That’s mine from early 1980. So a lower number than one from the 70s? Strange.
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    • Posts: 4,563
      They definitely started over with the 7A and the 7B, probably with the 7C and Series II as well.
      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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    • Posts: 127
      Who was JM ? He signed most all my early drivers and crossover JM or JMH
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    • Posts: 4,563
      Qts of 0.29 compares to MW6500 0.2190. Vas is 35L vs 75L (2.6486 ft^3) for MW6500, so it was a stiffer suspension.

      2xkc5e9wt8kb.jpg


      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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    • Posts: 4,563
      edited December 2024
      Apparently Polk wasn't the only one at the time pairing the Audax tweeter with a square magnet midwoofer, although it does look different compared to the one above.

      akawqpklrrod.jpg

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      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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    • Posts: 127
      Looks like those had 3 big felt pads around the tweeters and whole front covered in felt around the mid woofer
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    • Posts: 127
      They look sort of like the monitor 4s without the port
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    • Posts: 127
      I was looking for stuff online the other night and ran across an old Polk woofer but was uncertain because it didn’t have a label on the back. Gardenstater confirmed for me that the woofer was indeed an MW6500

      ispv30empt1n.jpeg

      I thought it was cool that it predates the Polk labels on the back.

      Thanks Gardenstater for your help on this one!
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    • Posts: 4,563
      Here's an anomalous midwoofer to add to the thread. Black basket when all the ones of the period are silver basket, black back plate/T yoke with flats, voice coil wires go almost all the way out to the perimeter of the cone/surround. I wonder who made this one for Polk.

      962huo8jn1gq.png

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      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
      · Share on FacebookShare on Twitter
    • Posts: 127
      edited February 4
      What's funny with those old 1970's Monitors is that when purchasing the speakers back then to get consecutive serial numbers was near impossible. This would make the chances that your speakers had mismatched woofers pretty high.
      Post edited by DeRod on
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    • Posts: 342
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    • Posts: 127
      I said near impossible 😂

      That’s a rarity to see conservative numbers.
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    • Posts: 4,563
      I've got a pair of consecutive crossovers too 🤣

      But regardless, if Polk was putting "MW6500" stickers on midwoofers sourced from different vendors, and treating them as interchangeable, theoretically there could be different sourced ones in consecutive serials. If they only have so many oddball ones they have to start and end somewhere.
      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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    • Posts: 127
      edited February 4
      Well both you guys are special 😂

      Just saying look at the guy that had 2 different tweeters in his.
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    • Posts: 4,563
      DeRod wrote: »
      Well both you guys are special 😂

      Just saying look at the guy that had 2 different tweeters in his.

      Yes to both 🤣

      It would be interesting to look inside those speakers and see if the crossovers were different. I believe the Audax sensitivity being lower than the Peerless made Polk do the crossover differently regarding the resistors. I have seen only 1 resistor vs. 2, and the resistor is a much lower value in the Audax XO.
      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
      · Share on FacebookShare on Twitter
    • Posts: 127
      I think he was selling the crossovers as well. They were the original ones that preceded the round circuit boards.

      I can’t imagine that your left speaker having one tweeter and your right speaker having a different one would be a good thing.
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    • Posts: 127
      b5bo98zastep.jpg

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      https://www.ebay.com/itm/306057753253?

      He still has both tweeter as well
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    • Posts: 4,563
      I couldn't see any dates on the tweeters or XOs but both XOs are the same. Single 2.7 ohm series resistor for the tweeter (not 4.5 or 4.7). I'm betting one of the original Audax got toasted and was replaced with a Peerless.
      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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    • Posts: 25,994
      God God those are artifacts
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    • Posts: 127
      Gardenstater wrote: »
      I couldn't see any dates on the tweeters or XOs but both XOs are the same. Single 2.7 ohm series resistor for the tweeter (not 4.5 or 4.7). I'm betting one of the original Audax got toasted and was replaced with a Peerless.

      Thats a fair assumption and the one that would probably make the most sense.

      Still would have drove me crazy having 2 different tweeters :D
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    • Posts: 51,032
      Bunch of nerds
      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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    • Posts: 127
      F1nut wrote: »
      Bunch of nerds

      Yes 😂😂

      I always hated the term “audiophile”. I much more prefer “audionerd”
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    • Posts: 302
      4motlda2ssqy.jpg
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      Close but no cigar! Can't expect much for $20.
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    • Posts: 462
      Gardenstater wrote: »
      Here's an anomalous midwoofer to add to the thread. Black basket when all the ones of the period are silver basket, black back plate/T yoke with flats, voice coil wires go almost all the way out to the perimeter of the cone/surround. I wonder who made this one for Polk.

      I had one of those come across the bench for re-centering. The magnet is much larger in diameter than the normal MWs, so I had to make a new tool to do it. Anyway so whoever made it, still didn't use good enough glue :expressionless:
      <3 my 3.1TLs

      I will fix your shifted magnets for free. :)
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