SDA-CRS crossover loose

ratpin
ratpin Posts: 85
in Vintage Speakers
I purchased a set of early CRS speakers last year. When I was transporting them I noticed something clunking. When I got them home I realized one of the x-overs was a little loose in the cabinet. I went to tighten the button head bolt on the rear. It would spin but would not draw tighter. I opened up the cabinet but cannot see where in the x-over this threads into or how to try and capture the threads to be able to tighten/loosen it. At this point it just spins with about 1/4” of play, not allowing me to tighten it or loosen to remove. Any ideas?kr5cavjwqit2.jpeg
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Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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Comments

  • pitdogg2
    pitdogg2 Posts: 25,576
    The nut is held in place by a bunch of hot melt glue. You will need to remove the board off the top of the inductor to tighten and run more hot melt glue on top of it.
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  • ratpin
    ratpin Posts: 85
    Got it off.removing the rear passive made things much easier. Are there any good upgraded x-overs available for these or not worth the trouble?
    Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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  • ratpin
    ratpin Posts: 85
    I’ll just use a lock washer to reattach. Not sure why Polk used hot glue to set the nut. Save 3 cents?

    Figure I’ll glue and mat these drivers while they are out. 6” polishing pads work great for MW work stands.g5s3irgqfwgc.jpeg
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    Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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  • pitdogg2
    pitdogg2 Posts: 25,576
    To compress the lock washer enough could crack the plastic for the inductor and board
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  • ratpin
    ratpin Posts: 85
    edited August 2023
    I used a flat washer and a lock washer and just snugged it up enough to collapse the locker a bit. It may come back out at some point as during my initial testing last year, that SDA tweeter was not producing sound. I had also found one of the drivers had the leads soldered directly to the terminals on one of the mid woofers. So at some point someone had been in there tinkering.
    Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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  • F1nut
    F1nut Posts: 50,654
    edited August 2023
    during my initial testing last year, that SDA tweeter was not producing sound

    It is highly recommended to disconnect the SDA tweeter as it causes a phasey effect.
    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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  • pitdogg2
    pitdogg2 Posts: 25,576
    Older Polk speakers the wires were in fact soldered to the drivers. Having only one soldered IS highly unusual.
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  • ratpin
    ratpin Posts: 85
    Trying JB superweld on the magnets. It seems to flow well and sets up clean.

    7kbbksrs7kjx.jpeg.

    The rear grills had a couple tiny blems and I have a blast cabinet, so why not?

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    Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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  • pitdogg2
    pitdogg2 Posts: 25,576
    The best to use is two part regular JB weld. I've used the JB super weld stuff, even though it says it can be used on metal it is not a long lasting solution. Sooner or later it will release from the metal. The regular JB weld 2 part epoxy I've had on some drivers for over 20+ years now.
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  • F1nut
    F1nut Posts: 50,654
    edited August 2023
    pitdogg2 wrote: »
    The best to use is two part regular JB weld. I've used the JB super weld stuff, even though it says it can be used on metal it is not a long lasting solution. Sooner or later it will release from the metal. The regular JB weld 2 part epoxy I've had on some drivers for over 20+ years now.

    ^THIS^

    In addition, you need to do the top and bottom.
    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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  • ratpin
    ratpin Posts: 85
    Good to know. I do have some JB epoxy, but figured I’d give the superweld a try. I plan on doing the other side of the mag tomorrow once this has had 24 hours to set. I’ll use superweld on this set and potentially run the 2-part on the next set, although I may stick with this. It’s just so clean and easy.

    My testing on this superweld has been pretty good as well on metals with bare, zinc and galvanized finishes, where I have had failures with the pictured 2-part JB product. The superweld also has a viscosity that allows it to flow into the seam unlike the 2-part JB that must be smeared into the corner and gets no penetration.

    My go-to epoxy is a marine grade made by TAP. It flows, grabs and holds anything forever but the mixing and application is a chore and it’s probably overkill for this. I have a ton of drivers to glue so I would like to keep the process efficient and effective. Not always possible, but I’m hopeful. It’s not like this is a high stress area once installed.

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    Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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  • pitdogg2
    pitdogg2 Posts: 25,576
    edited August 2023
    I've never used that. This is the recommended JB Weld. Mix and use craft (popsicle) stick to apply. Tedious and time consuming but solid. That you have may be the same but I personally have never seen it come in a plunger before.
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  • Gardenstater
    Gardenstater Posts: 4,502
    They have a Super Weld Extreme as well that is touted as flexible cyanoacrylate.

    xpvlr2z99bra.png
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
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  • F1nut
    F1nut Posts: 50,654
    edited August 2023
    For marine epoxy I highly recommend West Systems. Mixing the resin and hardener is a breeze with their 4 to1 ratio plungers and they have 4 different fillers you can/should add depending on the application.
    Post edited by F1nut on
    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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  • ratpin
    ratpin Posts: 85
    Lol. When I buy this one they’ll release “superweld extreme plus Sx” ‘with retsin’

    I just wonder if the gel would flow. This stuff flows in and gives a nice profile. We’ll see what kind of shrinkage we end up with tomorrow.
    885hufzlt00f.jpeg

    Gardenstater wrote: »
    They have a Super Weld Extreme as well that is touted as flexible cyanoacrylate.

    xpvlr2z99bra.png

    Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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  • ratpin
    ratpin Posts: 85
    So I ended up going over them with PL premium after using the superweld. Hopefully this combo holds up for at least another 40 years.

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    Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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  • ratpin
    ratpin Posts: 85
    I refinished a pair of old sl2000 to fill the unused tweeter hole. I two-toned the finish to look like the 0194.

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    Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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  • bcwsrt
    bcwsrt Posts: 1,927
    That looks great!

    Brian

    One-owner Polk Audio RTA 15TL speakers refreshed w/ Sonicap, Vishay/Mills and Cardas components by "pitdogg2," "xschop" billet tweeter plates and BH5 | Stereo REL Acoustics T/5x subwoofers w/ Bassline Blue cables | Rogue Audio Cronus Magnum III integrated tube amp | Technics SL-1210G turntable w/ Ortofon 2M Black LVB 250 MM cart | Sony CDP-508ESD CD player (as a transport) | LampizatOr Baltic 4 tube DAC | Nordost & DH Labs cables/interconnects | APC H15 Power Conditioner | GIK Acoustics room treatments | Degritter RCM
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  • hytekrednek
    hytekrednek Posts: 127
    which of the 2 tweeters is the sda tweet that should be unhooked? I need to try this with my pair that is in my shop stereo. Running 2 rdo194's per side right now. They sound good, but I am always up for improvements.
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  • pitdogg2
    pitdogg2 Posts: 25,576
    hytekrednek wrote: »
    which of the 2 tweeters is the sda tweet that should be unhooked? I need to try this with my pair that is in my shop stereo. Running 2 rdo194's per side right now. They sound good, but I am always up for improvements.


    Outside tweeter on left or right speaker.
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