C12Q Speaker Recone Parts

[Ptron]

I'd like to take a stab at reconing a 70's Jensen C12Q that has an open coil. Would anyone be kind enough to tell me which of these Weber parts are needed to do the job? They are intentionally obscure in their part listings to keep newbs like me from trying this but I'd really like to give it a shot. Have to start somewhere, right? and if I screw it up, I'm out a speaker that didn't work anyway. Suprisingly, I'm not seeing any recone kits for this particular speaker from Jensen or any other vendors.

[Enzo]

Why not call Weber and ask them?

Weber doesn;t have area franchises as far as I know, so I doubt they intend to keep people from trying anything.

[Ptron]

Why not call Weber and ask them?

Weber doesn;t have area franchises as far as I know, so I doubt they intend to keep people from trying anything.

Heh. s'pose I could do that. I'll see what they say.

They do say this in bold on their recone parts page "We DO NOT sell recone kits. The parts listed are meant to be purchased and used only by those who are familiar with reconing speakers and are aware of the modifications necessary to adapt some parts to a particular application. You must define the kit yourself. " which sure sounds to me like they don't want amatuers messing around with their stuff (and possibly giving it a bad name).

[Enzo]

What they are saying is that they don't sell the parts with instructions. It isn;t about not wanting amateurs buying their stuff, it is about TELLING the amateurs that this is not some consumer oriented situation. If you are expecting to be able to tell them "I need a kit for a model ABC123 speaker" and have a box arrive with exactly everything you;'d need for that, then you will be disappointed. They carry a line of replacement speaker parts, it is up to you to order what you need. They are selling to the people who know what they are doing and are telling you they do not provide instructions.

Think of it like tubes. Some company may sell 12AX7s, 6L6s, EL34s, 12AT7s, EL84s, and so on. Then they may add a note saying we DO NOT sell amp re-tubing kits. It is up to you to know what tubes your amp needs. Doesn;t mean they don;'t want to sell you tubes. it means they are not going to sit down and look up what each amp model needs, then package up combinations of tubes for each along with charts and instructions on which socket each tube belongs in and how to adjust the bias. That's all. They don't have the time - or at least don;t want to spend the time - to look up which cone, spider, voice coil, surround, tinsel wires, dust dome for each make and model of speaker, and then package them up.

[J M Fahey]

*At least* they offer a quite wide selection of parts which, when combined, allow you to properly repair a ton of regular speakers you may find in this trade.
They should be doubly commended because nobody else (that I know of) offers such a service, or that flexible.
Even better, instead of labelling parts as "Voice coil for C12Q" or whatever , which looks good but does not tell you much, they specify *measurements* in mm, so you can order the proper parts for obscure (or house label) speakers with confidence.
Excellent service.

[Ptron]

They don't have the time - or at least don;t want to spend the time - to look up which cone, spider, voice coil, surround, tinsel wires, dust dome for each make and model of speaker, and then package them up.

Well that's pretty much what I'm asking them to do . I sent them an email. We'll see what they say. I'll also get some measurements off the speaker tonight. Maybe the correct parts will be pretty clear once I do that.

[J M Fahey]

Well, in case they take too long to answer, you will ned
1) Voice coil, series 1250 (Nomex) in a suitable impedance for a more traditional sound, or 1250H series (Kapton) for higher power handling and a more modern sound.
2) Cone: here you have it spelled clearly:
WC12Q , for the original sound, although the inner VC diameter they state is a little too too high (1.31"), hope it's a typo.
I , for one, prefer closer tolerances.
3) Dustcap: DCQ (easy)
4) Spider: SQ1 ; I think SQ2 is meant for 10" speakers.
5) Gasket: G12.
6) Tinsel wire, cheap, buy 4 or more as spares .
Use contact cement "as if it were glue" on every surface glued to the frame, and epoxy on VC to cone to spider.
Use the "slow" industrial type, which takes hours to set.
Mix it well, heat it *slightly* with a heat gun as to be able to spread it smoothly with a toothpick and then apply a touch more hot air, until you see it visibly becomes softer , so it "wets" better the porous cone and spider.
Don't overdo it; bubbles are a bad sign .
Next day, you pull the centering strips (with speaker pointing down) , blow some air to avoid little debris, then cover the exposed coil wires with some glue to fix them to the cone and attach the dust dome with same glue.
You can use some vinyl carpenter's glue.
Let it dry a couple hours and enjoy.
Post some pictures.

[Ptron]

Well, in case they take too long to answer, you will ned
1) Voice coil, series 1250 (Nomex) in a suitable impedance for a more traditional sound, or 1250H series (Kapton) for higher power handling and a more modern sound.
2) Cone: here you have it spelled clearly:
WC12Q , for the original sound, although the inner VC diameter they state is a little too too high (1.31"), hope it's a typo.
I , for one, prefer closer tolerances.
3) Dustcap: DCQ (easy)
4) Spider: SQ1 ; I think SQ2 is meant for 10" speakers.
5) Gasket: G12.
6) Tinsel wire, cheap, buy 4 or more as spares .
Use contact cement "as if it were glue" on every surface glued to the frame, and epoxy on VC to cone to spider.
Use the "slow" industrial type, which takes hours to set.
Mix it well, heat it *slightly* with a heat gun as to be able to spread it smoothly with a toothpick and then apply a touch more hot air, until you see it visibly becomes softer , so it "wets" better the porous cone and spider.
Don't overdo it; bubbles are a bad sign .
Next day, you pull the centering strips (with speaker pointing down) , blow some air to avoid little debris, then cover the exposed coil wires with some glue to fix them to the cone and attach the dust dome with same glue.
You can use some vinyl carpenter's glue.
Let it dry a couple hours and enjoy.
Post some pictures.

Thanks for the info, J M. Good stuff. Can't wait to try this in the future. As for this speaker, it's toast. I found it had a much bigger problem than an open coil. The pole peice is actually off center and pinching the voice coil in so much that I can't get it out.

BTW Enzo, you were right (of course). I contacted Weber and they were quite willing to help me get the right parts. Too bad I no longer need them. I still say the wording on that web page sounds discouraging but yes, they are quite friendly and helpful.

[J M Fahey]

Oh sh*t.
Most probably the cabinet fell on its back on a hard surface, and either the magnet+backplate unglued from the front plate, or just the backplate separated from the magnet; either way the strong magnet attracts the pole piece to one side (which pinches the Voice Coil).
If it's a ceramic magnet, it can be repaired, but you need a friendly Lathe man willing to waste 1 hour on you, to make a re-centering device (preferably brass, or in a pinch, aluminum).
If it's Alnico, forget it, moving it makes it lose most of its power.