How Hard is to Recone a Speaker?

[1audiohack]

With me it's all about the education, the cost of tuition is of little concern.

The knowledge shared by those with experience just speeds the process.

[Harvey Gerst]

I couldn't get the first link to load, but the second link pretty well covers it. The key points are:

1. As soon as you remove the old cone assembly, either clean the gap and then tape over the gap, or; tape the gap, and save the cleaning till just before putting in the new cone assembly.

1.a To clean the gap, use a stiff piece of paper (like a 1" x 4" piece of manila folder and a "V" of 1 or 2" wide masking tape, (sticky side out). Slip the tape into the gap, and use a lifting, sliding forward motion to try and pull any particles out of the gap. If you see particles on the tape, use a new piece of tape and continue around the gap till you're satisfied it's as clean as you can get it.

2. The other tricky process is placing the new cone assembly into the basket and getting it aligned correctly. There should be heavy paper shims that came with the new cone assembly that go between the pole piece and the inside of the voice coil former (to keep the cone centered in the gap while installing the new cone).

2.a Make sure you keep the surround and spider from touching the wet glued surfaces till you get the cone perfectly centered, then push the cone down till the spider and surround just touch the glued surfaces evenly.

2.b Once everything is centered, you press the spider and surround into place. You can now remove the shims and let the glue dry. Stick a foam plate over the speaker to prevent airborne dust particles from getting into the gap.

3. If it's an aluminum dome, handle it very carefully and apply a very thin bead of glue to cement it to the end of the voice coil former. It must make a solid contact or it will buzz at high frequencies (which is an easy fix - more glue), but it's better if it's done right the first time.

[1audiohack]

Both opened for me, thanks Guido.

Harvey, thank you for sharing! My kits came with a plastic tube for coil alignment. OK?

It will be a couple of weeks before I get to it.

I will be standing by for any other tips. Thank you.

[89-300ce]

I had an experienced audio pro help me do one of mine and then I repeated the steps on the other myself. Not too difficult but quite time consuming and a little un-nerving. It's best to have somebody take you through it. Cones are pricey. For me it was worth it just to see the working parts of a transducer.

I'm thinking of picking up some k145 cones as spares before they become unavailable.

Jorg

[boputnam]

My kits came with a plastic tube for coil alignment. OK?

Should be - many kits nowadays come with plastic shims.

wrt the whole question, there are numerous areas that can ruin your day:

- is the spider assembled to the cone? JBL kits are (you can read this elsewhere here), but kits by other makers may not be. When not, this can make the task more tedious - doubles the work required.

- aligning and glueing the dust cover with a nice-looking thin bead is incredibly challenging. Good luck - you will not do well the first 1,000 times...

- a tone generator is a very important tool. Even using shims, there can be alignment troubles. It can all seem to be going swimmingly, and then you remove the shim and things aren't good. :dont-know It happens.

Best to get expert work on this, unless you're dead-set on trying it. Sure, there are good and bad providers out there, but find a good and reliable reconer and stick with them!

[1audiohack]

They are OEM kits, it would be sacrelige to use anything else if JBL parts are avaailable. The coil / cone is assembled.

Funny that you should mention the dust cap glue bead. That is actually the part that has me most concerned. I will pre-run that on something else until I'm comfortable. I do have spectacular dexterity however!

I have a tone generator.

What else?

Thank you!!!

[boputnam]

What else?

Just one thing...

Unless this is a real strong desire for you to do yourself, pack-up the kits and the baskets and send them to edgewound and ensure the job get's done right.

[1audiohack]

Hi all;

I appreciate the tips, and the concern. Don't think for a moment I don't.

I work in a four million dollar facility that designs and builds powertrain for endurance racing, engineered packages from the water pump to differentials. No street stuff here, but our own of course. I have assembled and tested every part in powertrain packages costing $122,500.00 USD. Precision is what I do, all the day long.

I am not one bit afraid of a loud speaker, nor the cost of a cone kit.

I want to do it myself for my own gratification. If for some reason I can't get it done to my satisfaction I will be glad to send it to Edgewound. He seems like the kind of guy I would like to get to know anyway.

I realize that there are tricks of the trade that can be shared, and developed skills that cannot be.

All the correct tips and tricks those with experience will share, will greatly increase my chances for success in this endeavour. I cannot develop the skill unless I try.

I have learned much from this forum, and am grateful to those willing to impart their knowledge to those of us with much to learn.

Without information sharing, we would still be hunting animals with sharp sticks!

Thank you, sincerly.

[Harvey Gerst]

Without information sharing, we would still be hunting animals with sharp sticks!

Wait!! We don't hunt animals with sharp sticks anymore? Why wasn't I told? Was there a memo on this that I missed?

Anybody wanna buy some NOS JBL sharp sticks?

[Zilch]

Anybody wanna buy some NOS JBL sharp sticks?

Forget it, Harvey.

They'll put their eyes out, it'll be allegedly and presumptively your fault, and you'll get sued....

[Thom]

Seems like it would be hard to go astray with the preassembled kits. I see all sorts of pit falls with individual pieces.

[edgewound]

Seems like it would be hard to go astray with the preassembled kits. I see all sorts of pit falls with individual pieces.

Someone is beginning to see the light

[4313B]

Someone is beginning to see the light

Yeah, some people take longer than others. It took one guy something like 3,000+ posts to figure out that there wasn't any such thing as a quick & dirty 4430... go figure... :dont-know

[John W]

Funny that you should mention the dust cap glue bead. That is actually the part that has me most concerned. I will pre-run that on something else until I'm comfortable. I do have spectacular dexterity however!

I've had good luck on glue beads by attaching a longer and thinner plastic tip to the end of the moyen glue bottle with some tape. A metal tip with a hole in the end doesn't give me enough control. The one I use is from a bottle used for writing with paint on fabric. It is long and skinny with a very small hole in the end similar to this:

[edgewound]

Hi all;

I appreciate the tips, and the concern. Don't think for a moment I don't.

I work in a four million dollar facility that designs and builds powertrain for endurance racing, engineered packages from the water pump to differentials. No street stuff here, but our own of course. I have assembled and tested every part in powertrain packages costing $122,500.00 USD. Precision is what I do, all the day long.

I am not one bit afraid of a loud speaker, nor the cost of a cone kit.

I want to do it myself for my own gratification. If for some reason I can't get it done to my satisfaction I will be glad to send it to Edgewound. He seems like the kind of guy I would like to get to know anyway.

I realize that there are tricks of the trade that can be shared, and developed skills that cannot be.

All the correct tips and tricks those with experience will share, will greatly increase my chances for success in this endeavour. I cannot develop the skill unless I try.

I have learned much from this forum, and am grateful to those willing to impart their knowledge to those of us with much to learn.

Without information sharing, we would still be hunting animals with sharp sticks!

Thank you, sincerly.

I appreciate your enthusiasm....and especially what you do for a living. I bet it's fun. Care to trade some recone work for a Weber inducted 289/302?...yeah, right...lol

There's reasons why the factory doesn't sell recone kits. Many little things that can go wrong that will make the speaker unsuable, especially when it comes to gluing on dust caps, cleaning the gap thoroughly, giving the lead wires the optimum amount of slack, making sure the coil isn't out of round, using the right amount of glue so the compliances are quiet....lots of little things that one can take for granted with "just a speaker". These aren't "just a speaker". They're JBL's. Tolerances to within .002" that move up 1/2" or more without making contact with anything metal for it to work right.

Assembling an engine takes the same kind of care, but there's one difference.

If you torque a sequence of bolts wrong, you can loosen the bolts and do it again.

Once you glue the cone kit in, it's very, very difficult to get it back apart with no disassembly damage, and if you damage the cone kit, you're stuck with a part that won't work right. The cone kits are relatively expensive.

I can't resell recone kits according to my Servicer Agreement with JBL. The parts aren't meant to be field replaceable, unlike compression driver diaphragms, which are to a degree...but should be done on the bench to ensure good performance and reliability.

I'd be happy to do your recone work with this exception. I don't know where the kit came from and where it's been and for how long, or what model it's for. A twenty year old kit with a foam surround might be rotton out of the box. If the parts are bad, there is no recourse...just a loss, and it wont' be mine.

JohnW's advise looks good for the glue line around the dome.

Good luck with your recone.

Oh....BTW...it's easy when you know what you're doing...but sometimes it's not.