1984 m7's with mw6500?

I picked up a pair of m7's that are mint, like they never had been out of the box. Not a scratch, grill covers tight and perfectly clean. I went to epoxy the magnets and the drivers are 6500 from 84. No stamp on the sticker just hand written date and initials.
Do all 7's have mw6500?i thought they would be 6502.
BTW the magnets are not centered at all way off by as much as an 1/8 but drivers move perfectly.

Comments

  • GardenstaterGardenstater Posts: 1,063
    edited July 31
    What's the month? The earliest schematic we have is from 11/26/84 and that shows the MW6502, so if we have your month we'd have a pretty good idea of when they switched over from MW6500's. My 79's have MW6500 and Danish Peerless tweeters. The hole in the magnet is much larger than the O.D. of the voice coil so they can slip quite a bit and still not rub on the voice coil. The clearance of the OD to the outer pole piece and the ID to the inner pole piece is not a lot. You may be lucky for now, but you might find that it scrapes at some times, perhaps on difficult bass sections of music. You might want to just put a few short beads of adhesive that would be easily removable with an xacto knife, just to make sure they don't slip any more than they already have. You may have to realign some time in the future and being able to remove the adhesive will be advantageous. I don't think I'd use epoxy in your case because it would be very difficult to remove. I'd use some sort of construction adhesive. I like Gorilla Max Strength Clear, but make the beads very short, like 1/2" and I'd only do 3 of them per side of the magnet.
    George / NJ

    Polk 7B main speakers (1979, orig owner)
    Martin Logan Dynamo sub
    Crown D150 amp
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14 gauge, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • wispolkboywispolkboy Posts: 12
    Thanks for your reply!
    I pulled the drive again and upon closer evaluation of the date, '82
    I epoxied the driver on each side.
  • GardenstaterGardenstater Posts: 1,063
    If you get a chance snap some photos and post em. People love seeing minty examples. What tweeters and crossover schematic do you have?
    George / NJ

    Polk 7B main speakers (1979, orig owner)
    Martin Logan Dynamo sub
    Crown D150 amp
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14 gauge, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • GardenstaterGardenstater Posts: 1,063
    Well they certainly do look nice! Mine are 190xx serials and have the same crossovers as yours. Are these real walnut veneer? Sometimes its hard to tell if vinyl or not, they did such a good job. Mine have different grills and pegs, with the Polk Audio on the grill and grill covers entire front. Those are attractive (custom?) stands. Are they tippy at all? Have fun doing the rest of the mods and enjoying the improvements to come.
    George / NJ

    Polk 7B main speakers (1979, orig owner)
    Martin Logan Dynamo sub
    Crown D150 amp
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14 gauge, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • wispolkboywispolkboy Posts: 12
    stands from amazon, $60, a little tippy, thinking of making a bigger base or making the height a bit shorter.
    not real veneer, just vinyl.
    I have an old NAD 7155 but i think it needs some tlc on it. it was powering some sda's 2b. switched them for the 7's

  • GardenstaterGardenstater Posts: 1,063
    My stands are 24" tall also and I find that height is perfect for my listening position, putting the tweeters right about at ear height. Honestly though I think those stands are not stable enough for these speakers and it doesn't really look like they are fillable with sand/lead shot. My stands have 2 16" x 16" concrete blocks as the base (36lbs ea) and a steel column that is filled with sand/lead shot.
    George / NJ

    Polk 7B main speakers (1979, orig owner)
    Martin Logan Dynamo sub
    Crown D150 amp
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14 gauge, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • wispolkboywispolkboy Posts: 12
    I like the idea of increasing the weight.... I'm thinking about a 1/4 steel plate on the bottom.... Cut to the shape and painted... Thanks for the tip
  • GardenstaterGardenstater Posts: 1,063
    I think I'd go with 1/2" steel. A 16" x 16" piece of that'd be about 36 lbs.
    George / NJ

    Polk 7B main speakers (1979, orig owner)
    Martin Logan Dynamo sub
    Crown D150 amp
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14 gauge, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • wispolkboywispolkboy Posts: 12
    I think I can cut 1/4" to the shape. 1/2 would be difficult.
    And 1/4 on the very bottom would give a very low center of gravity.
    Better than what I have now
  • GardenstaterGardenstater Posts: 1,063
    edited August 3
    OK good luck. If you don't increase the dimensions of the base you won't get that much more stability, even though the increased weight certainly helps. 16" works great for me. If you really like the way the base looks now (rounded 3/4" MDF?), just make a bigger one and put one or two 1/4" steel plates underneath it with Gorilla Super Strength const. adhesive or the like, and maybe 4 screws.
    George / NJ

    Polk 7B main speakers (1979, orig owner)
    Martin Logan Dynamo sub
    Crown D150 amp
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14 gauge, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • F1nutF1nut Posts: 44,820
    edited August 3
    An even better idea, buy the 4 post stands from www.skylanstands.com
    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

  • wispolkboywispolkboy Posts: 12
    F1nut wrote: »
    An even better idea, buy the 4 post stands from www.skylanstands.com

    Thanks for the site.... however I really don't like the look of those. (or price, lol)
    OK good luck. If you don't increase the dimensions of the base you won't get that much more stability, even though the increased weight certainly helps. 16" works great for me. If you really like the way the base looks now (rounded 3/4" MDF?), just make a bigger one and put one or two 1/4" steel plates underneath it with Gorilla Super Strength const. adhesive or the like, and maybe 4 screws.

    I was thinking the same as far as how to add the plates to the base.
    thanks for all your coments!
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