help with monitor5JR series 2

Hi All,

So glad to find this forum. I bought a pair of monitor 5JRs at a garage sale without testing them out. Brought them home and found only the tweeters working and no bass from either speaker. After checking a few things, finally opened them up and found that the large coil was disconnected on both crossovers. Why would someone do that? The fact that it happened on both, makes me think it was intentional, but I can't figure out why.

The question part: can someone share exactly where I would reconnect the large coil? I've never played around with crossovers (or circuits) before but I'm thinking of taking the crossover to a local makerspace and solder it back on. Just don't want to screw anything up.

Also, I've tried to make sense of the crossover upgrade posta but the external links are dead. What/where should a newbie like me look to upgrade the crossover?

Appreciate any advice you all can provide.

Comments

  • Mureed
    Mureed Posts: 8
    edited March 2018
  • F1nut
    F1nut Posts: 49,711
    Looks to me like they simply fell off. The white wire would connect to the other lead on the inductor.
    Political Correctness'.........defined

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  • FestYboy
    FestYboy Posts: 3,861
    I can grab a pic as soon as I get home of a stock unit for comparison.
  • Mureed
    Mureed Posts: 8
    FestYboy wrote: »
    I can grab a pic as soon as I get home of a stock unit for comparison.

    Thanks FestYboy, that would be great.
  • Mureed
    Mureed Posts: 8
    F1nut wrote: »
    Looks to me like they simply fell off. The white wire would connect to the other lead on the inductor.

    So I opened it up again to confirm that the white wire in the pic is actually connected to the board at point 10. It looks like it's a loose wire because one strand came loose, but the white wire is soldered to that point.

  • FestYboy
    FestYboy Posts: 3,861
    edited March 2018
    tqebr4brgokp.jpg
    This is a 5jr+ XO from '90. The one end of the inductor goes to "L1" on the PCB, the other attaches to the + lug in the cup.
  • FestYboy
    FestYboy Posts: 3,861
    edited March 2018
    My 4.6s may be a closer match to your XO
    gohyaq48f60h.jpg

    Here we go: the broken lead attaches to the far corner of the PCB (bottom left in the pic), which is directly attached to the + terminal. The black wire should run to the driver.
  • FestYboy
    FestYboy Posts: 3,861
    Mureed wrote: »
    FestYboy wrote: »
    I can grab a pic as soon as I get home of a stock unit for comparison.

    Thanks FestYboy, that would be great.

    Well it's confirmed: my 4.6 and your 5jr+ xo are layed out the same. The inductor on yours pulled out of the same place mine is attached. Some solder and a little hot glue will get you running again.
  • Mureed
    Mureed Posts: 8
    FestYboy wrote: »
    Mureed wrote: »
    FestYboy wrote: »
    I can grab a pic as soon as I get home of a stock unit for comparison.

    Thanks FestYboy, that would be great.

    Well it's confirmed: my 4.6 and your 5jr+ xo are layed out the same. The inductor on yours pulled out of the same place mine is attached. Some solder and a little hot glue will get you running again.

    This is awesome, thanks FestYboy! I think I can get to a solder on Wednesday night, I'll try it out and report back.
  • Mureed
    Mureed Posts: 8
    anonymouse wrote: »
    Upgrade those crossovers with new capacitors and they will be amazing.

    Hey anonmouse. It looks like the capacitor on there right now is a 13.5. I checked the sonicaps and they have 12, 13 and 15. Do I go with the 12 you recommended or the 13? Or do I replace with another 13.5? I remember reading somewhere that they can make a 13.5 if I ask nicely (and I can figure out where on the site to make that request).

    Thanks again for the advice!
  • F1nut
    F1nut Posts: 49,711
    Sonicap will not make you a custom value cap.

    The service they offer is like this. So, you need a pair of 13.5uF? Ok, they will test their stock of 13uF to get a pair valued closest to 13.5uF. You will pay a little extra for that service.
    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

  • Mureed
    Mureed Posts: 8
    anonymouse wrote: »
    I recommended a 12? When?

    I'd go with whatever is close to what is in there right now. If there is a 13.5, then a 13 will be fine. Yes, you could have a custom one done and that would be even better, but a 13 is close enough to what you have in there.

    On my own set, I used Dayton caps. I figured it's an entry/mid level speaker, and I did not want to put too much coin into it. Even with just the Dayton's, they sound awesome.

    Sorry, confused you and Smallies.... I'll check out the Daytons, thanks for the recommendation.
  • westmassguy
    westmassguy Posts: 6,850
    If you going entry level, Dayton or Clarity PX, you can also parallel two 6.8uf caps for 13.6 total. Sonicap is the only affordable vendor that will custom match for 13.5uf.
    In any case, you'll need to get creative fitting those caps on the small circuit boards, and getting them through the existing opening.
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  • kevinko
    kevinko Posts: 165
    You'll need to get creative fitting those caps on the small circuit boards, and getting them through the existing opening.

    Ha ha! Ah, the memories....
    aukxapuvrex0.jpg
    uqh3n428vh22.jpg
    Monitor 4.6 with Sonicap upgrade by WMG
  • Mureed
    Mureed Posts: 8
    edited April 2018
    Hey All, just wanted to thank you to everyone for the advice. I ended up buying a cheap soldering iron and reconnected the inductor based on FestYboy's pics and......it worked! I thought my $50 garage sale impulse buy was gonna haunt me, but thanks to you all they work.

    Loving my "new" polks. Thanks!

    Spent most of my time shoving everything back in the box...between that and the pics above, I'm going to hold off on the new caps, for now.

    And here's what the speakers look like
    9mmoi6w2anm5.jpg
  • F1nut
    F1nut Posts: 49,711
    Nice looking set up. If you bring the speakers slightly forward of the shelving unit plane and toe them in slightly you should find the sound stage much improved.
    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