Speaker repair

[Steve Blackdog]

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

[The Dude]

"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.

[J M Fahey]

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.

[The Dude]

...... and that's if the pole/magnet structure hasn't shifted.

[Enzo]

Or the magnet isn't cracked in half.

[Jon Snell]

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

[Mick Bailey]

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.

[mikeydee77]

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.

[Mick Bailey]

"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.

[Steve Blackdog]

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!

[The Dude]

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.

[g1]

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.

[The Dude]

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.

[Steve Blackdog]

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!