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  • Speaker repair

    Would I be mad to buy a speaker “not working”? I can see no visible damage. Apparently it just stopped working. It is a Celestion G12T -75. nothing special.

    I am tempted at 15 shipped, and I enjoy a challenge. However, if there are expensive parts required, perhaps I should walk on by. Advice please!

    cheers

    steve



  • #2
    "no visible damage" doesn't mean much. It's like looking at a well kept guitar amp that has a shorted power transformer. You can't tell much by looking at the speaker. It could have a shifted gap, burnt voice coil, etc. It could also be something simple like a tinsel lead repair. You can't know without testing and inspection. At best, it's a cheap tinsel lead repair. At worst, it has a shifted gap and isn't worth the cost of repair. In the middle there somewhere, it needs a recone, which is still close to replacement cost of that speaker. I would walk away unless I could get a good close inspection and testing.
    "Yeah, well, you know, that's just, like, your opinion, man."

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    • #3
      Originally posted by Steve Blackdog View Post
      Would I be mad to buy a speaker “not working”? I can see no visible damage. Apparently it just stopped working. It is a Celestion G12T -75. nothing special.

      I am tempted at 15 shipped, and I enjoy a challenge. However, if there are expensive parts required, perhaps I should walk on by. Advice please!

      cheers

      steve

      U$60 + U$21 postage from US
      https://www.ebay.com/itm/36356304981...MAAOSwlIVe4PBO

      U$98+unspecified freight from Australia
      https://www.ebay.com/itm/26130955143...EAAOxy2O1SYISZ

      Not exact same model but as a reference, similar kits from UK hover around U$75 + postage.

      You decide.
      Juan Manuel Fahey

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      • #4
        ...... and that's if the pole/magnet structure hasn't shifted.
        "Yeah, well, you know, that's just, like, your opinion, man."

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        • #5
          Or the magnet isn't cracked in half.
          Education is what you're left with after you have forgotten what you have learned.

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          • #6
            Worst case is a recone kit. Lean Business do them at around 70 ish.
            https://www.lean-business.co.uk/esho...sort=2a&page=1
            Support for Fender, Marshall, Mesa, VOX and many more. https://jonsnell.co.uk

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            • #7
              I've had speakers where the gap has been so full of corrosion the voice coil has been locked in there solid, and others where a tinsel lead joint has cracked. You take a chance, but apart from the rewards in getting a speaker working, over here in the UK mostly reconing is not worth the labour and expense as the finished unit has cost more to fix than a second-hand working one.

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              • #8
                I feel like tissue paper repairs are worth considering provided the end user is happy with approach and aware that it is a bit of a temporary fix.

                I have a blown celestion g12 100 that I thought I would recone as an exercise in learning but since a new driver is 105 and a recone is 60+shipping from lean then it doesn't make sense economically (not that that is my main consideration).

                I have sent a few vintage speakers to Wembley speakers for recone like from AC30 and they did a good job and the charge was about 100 as I recall but took about 3 months though.

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                • #9
                  "Not Working" may mean the voice coil is open - most other faults result in distortion and/or low output. The tissue paper repairs can be improved on by using a scrap speaker, ideally the same model as the one being repaired. Cut out a piece of cone and the layers can be separated into tissue paper thickness and built up over the crack or split. I have speakers out there that are still going after a decade or more using this method after using it as a get-you-by repair in an emergency. In the end the best use I've found for most run-of-the-mill damaged speakers is to make light fittings out of them.

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                  • #10
                    Thanks folks

                    This is just the reality check I needed. It sounds like the only good reason to buy this speaker is to treat it as a cadaver to dissect and learn more about dead speakers, on the basis that if it can be brought back to life, that will be a bonus.

                    cheers!

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                    • #11
                      If you buy it and if it measures open at the terminals, check tinsel leads first before dissecting. It's a relatively common failure for tinsel leads to burn or break- often right at the terminals. There's no reason to start cutting it apart if that is the case. The first thing I do with an open speaker is stick the probes inside/under the cone and measure resistance right on the tinsel leads bypassing the terminal connection. If you get a resistance reading on the leads and not the terminal, you know you have a broken lead somewhere.
                      "Yeah, well, you know, that's just, like, your opinion, man."

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                      • #12
                        Originally posted by The Dude View Post
                        If you buy it and if it measures open at the terminals, check tinsel leads first before dissecting. It's a relatively common failure for tinsel leads to burn or break- often right at the terminals. There's no reason to start cutting it apart if that is the case.
                        After this, it is worth cutting off the dustcap and checking for a break between the tinsel lead eyelets and the coil. Sometimes you get lucky.

                        "Everything is better with a tube. I have a customer with an all-tube pacemaker. His heartbeat is steady, reassuring and dependable, not like a modern heartbeat. And if it goes wrong he can fix it himself. You can't do that with SMD." - Mick Bailey

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                        • #13
                          Agreed! These are simple steps that can save you the cost and hassle of a full recone. Years ago, I worked at a JBL authorized recone center. Too many times, I saw a tech go straight for the utility knife instead of doing a few simple tests first.
                          "Yeah, well, you know, that's just, like, your opinion, man."

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                          • #14
                            So. The seller is a top guy and has let me have the speaker for the cost of postage (10) if I get it working I will give something to his favourite charity.

                            when I get it I will do my best to take my time and slowly work through as many tests as I can before doing any work.

                            cheers folks!

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