How Hard is to Recone a Speaker?

[BigT]

Occasionally speakers come up on Ebay that need reconing. Normally these go for pretty cheap. I've never done a recone. How hard is it to recone speakers, particularly woofers? Can you do as good a job as shops? Finally, assuming it's done right, is a reconed speaker as good as the original?

[Allanvh5150]

Hi, A while back I had the same thought as you. I have done many successful refoams and a few recones. It is an easy task if you have the inclination to do it. If you use genuine factory parts and take care to do a good job, the reconed speaker will be as good as the original.:)

[BigT]

Hi, A while back I had the same thought as you. I have done many successful refoams and a few recones. It is an easy task if you have the inclination to do it. If you use genuine factory parts and take care to do a good job, the reconed speaker will be as good as the original.:)

What is involved in reconing a woofer?

[johnaec]

Also, if you plan on doing the reconing yourself, be aware that you'll have to convince an authorized repair shop, (at least for JBL), to sell you the recone kits - JBL does not sell them to the general public.

John

[Rolf]

Also, if you plan on doing the reconing yourself, be aware that you'll have to convince an authorized repair shop, (at least for JBL), to sell you the recone kits - JBL does not sell them to the general public.

John

Well, but there are ways to go beyond that. I changed the diaphragm's om 2420 myself ... worked perfectly, but I am not sure if I would try it on a woofer.

[Mr. Widget]

I have done many successful refoams and a few recones. It is an easy task if you have the inclination to do it.Pulling a tooth is also a simple task... I'd prefer to have an experienced professional do it... one who has had the proper training and years of experience. That said, there are sloppy practitioners of every trade.


Widget

[Rolf]

Pulling a tooth is also a simple task... I'd prefer to have an experienced professional do it... one who has had the proper training and years of experience. That said, there are sloppy practitioners of every trade.


Widget

Agreed! Just been to the dentist. Can't do it myself!.:crying:

[johnaec]

Agreed! Just been to the dentist. Can't do it myself!.:crying:I also just went - I'll bet reconers wished they got paid like dentists! Over $900 in one hour, in my case... :jawdrop:
Thank God for dental insurance!

John

[Rolf]

I also just went - I'll bet reconers wished they got paid like dentists! Over $900 in one hour, in my case... :jawdrop:
Thank God for dental insurance!

John

For one hour? And I thought it is expensive here ... about $200 an hour. Not possible to insurance.

[johnaec]

For one hour?Well, it's just the amount the dental plan assigns to the procedure, whether it takes the dentist one hour or five, or whether it's simple or complicated. It was apparently easy for the dentist in my case - he definitely made out like a bandit!

John

[Harvey Gerst]

Occasionally speakers come up on Ebay that need reconing. Normally these go for pretty cheap. I've never done a recone. How hard is it to recone speakers, particularly woofers? Can you do as good a job as shops? Finally, assuming it's done right, is a reconed speaker as good as the original?
Well, it can be done at home, with a modicum of skill, assuming you have a clean work area, a carpet knife, a roll of drafting tape, some acetone, some compressed air, a few manila folders to cut up, a steady hand, and a lot of patience.

I can run thru the procedure, if you're really interested.

[BigT]

Well, it can be done at home, with a modicum of skill, assuming you have a clean work area, a carpet knife, a roll of drafting tape, some acetone, some compressed air, a few manila folders to cut up, a steady hand, and a lot of patience.

I can run thru the procedure, if you're really interested.

Well - I'm interested, but your description makes me awfully wary that I'll ever attempt it.

[1audiohack]

Harvey, I am definitely interested!

I have four 2123's that need it. None are burned up.

I have the JBL kits, and everything you listed as needed but "drafting tape"?

I'm sure I can do it, I would be more comfortable with instruction from one with experience however.

Thank you,
Barry.

[Harvey Gerst]

Well, I can tell you exactly how we did it in the 60's, and maybe edgewound can help by pointing out what's changed since then. Give me a day or so to make sure I've got the steps in the right order.

[Guido]

Maybe these links help?

http://www.eighteensound.com/index.aspx?mainMenu=service

http://www.stageaccompany.com/en/support/download/docs/recone.pdf

You'll waste at least one or two cone kits at the beginning. So if you want to recone 2 or 4 speakers it's absolute nonsense to try it yourself.

[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... :p

- 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.... :scold:

[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:applaud:

[4313B]

Someone is beginning to see the light:applaud: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.

[rek50]

Wow Edge, .002 of an inch.........., the man said precision is what he does all day :D

While .002 may seem precise, PRECISION is more into .0001 or microns. If you have ever worked in microns or tenths, .002 is a walk in the park. I'm not slamming your chosen skill here, just adding some "Light" .

1audiohack , I watched a guy do some dust caps, using a "Poster Board" mask. He cut the PB into a circle, cut a slit in it, then slipped it together to form a cone. Stapled it together. Cut the cone tip off to yeild a hole slightly bigger than the dust cap. Lay the "Mask" on top the speaker cone, hold your tongue just right, and have at it.

4313B, your sense of humor reminds me of a Giskard..........

carry on......

[edgewound]

Wow Edge, .002 of an inch.........., the man said precision is what he does all day :D

While .002 may seem precise, PRECISION is more into .0001 or microns. If you have ever worked in microns or tenths, .002 is a walk in the park. I'm not slamming your chosen skill here, just adding some "Light" .




Wow....you're right. Maybe we should start press-fitting these cone assemblies in. That way they won't make a sound.

The light is shining brightly.

[1audiohack]

Hey, I think your on to something with the press fit thing!

Just think how many issues that resolves, no need to clean the gap, no need for those nasty adhesives, and you wouldn't even need dust caps!

The sound quality would change a lttle:blink:, just guessing there.

rek50, Thank you for the tip.:)

Edgewound, I PM'd ya.

[Thom]

Edgewound, I have no desire to put reconers out of business or suggest that they don't deserve whatever level they live at (I don't have a clue) but they tend to get grumpy at questions and at experimentation and that sort of leaves one to ones own devices. Seems with individual parts you could mix cones and still put the voice coil where it should be but also seems with individual parts there is more need for an expert. It would be nice to know an expert that could tell you why you should or shouldn't do a particular thing and then would do it for you anyway. With that I'd lose temptation to cone myself. Instead I find purists and /or uncurious technicians who will put what you want where you want it with no clue of the results.

[edgewound]

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

Who said anything about you wanting to run reconers out of business? Some are perfectly capable of doing that on their own. Three or four others in my area have done just that.

Please just keep in mind that the scope of this here particular forum is restoring and maintaining Lansing manufactured products....we're not here to redesign or reinvent them.

You had a previous comment about how JBL changes driver characteristics when updating models. Well...those are factory improvements that come about in the evolution of of a particular model...very common in every industry...done with extensive and published testing on how to make it better.

When it comes to restoration and maintainence, your quote above says it all.;):applaud:

[Thom]

Who said anything about you wanting to run reconers out of business? Some are perfectly capable of doing that on their own. Three or four others in my area have done just that.

Please just keep in mind that the scope of this here particular forum is restoring and maintaining Lansing manufactured products....we're not here to redesign or reinvent them.

You had a previous comment about how JBL changes driver characteristics when updating models. Well...those are factory improvements that come about in the evolution of of a particular model...very common in every industry...done with extensive and published testing on how to make it better.

When it comes to restoration and maintenance, your quote above says it all.;):applaud:

So modifying and upgrading crossovers is OK, perhaps even recommended. Putting in newer drivers to "upgrade old systems is good, but to modify a driver is sacrilege. It's got to be all those hours I put in. I obviously slept through something again. Please explain. Why is it OK to throw away an old driver in favor of a newer one and change the crossover thus changing the speaker system totally. (Well we did keep the cab) but thou shall not modify the driver. And, if you want to get into expertise and knowledge I don't think that always stops people in the other areas. I'm no driver expert, that's for sure but I may know more about them than some of the crossover people know electronics. A lot of what Gordon has to say in another thread makes a lot of sense to me. Too bad he's so far away. I have a feeling that reconers like him are rare. That's not a knock on "factory types". All run there businesses in the way that makes sense to them. If I lived in your area I'd feel comfortable having you re-cone my speakers but to have someone knowledgeable who was a freer spirit and more curious would be a treat. I'll bet not all JBL drivers came of a drawing board. Serendipity is responsible for lots of things. I'll bet more than once someone said I want this cone on that frame. Or something like that, and someone else liked it. When you are making PA equip fit your living room sometimes a little tailoring is in order.

[Robh3606]

but thou shall not modify the driver

Do you just like to argue or do you simply not understand what the difference is?? It's only been said 3-4 times in as many different ways. This post looks like a troll to me.

Rob:)

[edgewound]

Serendipity is responsible for lots of things.
That's true. Just ask that 10 year old in SoCal about his serendipity with playing with matches that started a 40,000 acre fire destroying peoples homes.

My point is....again.....most JBL drivers can't be improved with aftermarket parts, and the full circle journey to get there isn't worth the trouble or the cost.

But, Thom....what the hell....do what ever you want, say whatever you want. I'm done debating with you.




Do you just like to argue or do you simply not understand what the difference is?? It's only been said 3-4 times in as many different ways. This post looks like a troll to me.

Rob:)


That's ok, Rob.

I learned something here today...again.

It's not a good idea to pee into the wind. Better to just flush it down the toilet.

[4313B]

edewound, I know it's tough, sometimes I have a hard time doing it too, but you just have to put these guys on ignore. Even the guys at JBL have said "You know, you start reading this stuff and you almost have a stroke. You get so f*****g pissed off at some of these people and you can either humiliate the hell out of them or you can just push away from the keyboard and go into the lab and eventually forget about it."

Humiliating them gives one a negative ding more often than not unless one is extremely good at it so it's probably best to just walk away. It rankles for a little while but by the next day it shouldn't be too bad. The real problems start when each of these little incidents begin to add up, then the good guys leave and never come back.

[edgewound]

...just push away from the keyboard and go ...

...mow the lawn...then change the oil.

Now....that's advice I can use today.:applaud:

Thanks Gis....er...4313B;)

[Harvey Gerst]

I can't speak to the newer JBL products, but the older JBL products were built to a standard and a devotion that would be hard to instill in today's workers. The standards were such that a line worker had veto power over any of the management people, clear up to Bill Thomas, the president.

We didn't have "seconds" - it was either perfect, or it didn't go out the door. That was the policy at JBL during the "golden years"; maybe that's why they're so highly prized today, and maybe that's why so many are still working.

[edgewound]

Harvey,

In today's waaaayyy more "complicated" audio world where most new users seem to think everything should be "plug and play" with zero education on what these things are supposed to do with proper application...

They're still pretty damn good built to a very high standard...especially within their pricing parameters.

If you want better still, we know where to go and what to expect to pay....and to expect a long wait.

Thanks for all of your wise insight into the "golden days". Many times I wish we were still there.

[Ian Mackenzie]

Edge,

Do you subscribe to Voice Coil?

Ian

[4313B]

.

[Thom]

I don't particularly like to argue and it's quite likely that I'd be unhappy with my "frankenwoofer" were I to build it. I just don't like the choice of either you who says if the factory didn't do it it shouldn't be done, or OC who will put anything I want anywhere it will fit with no care as to if the VC depth will be right or anything else. I think if I want to put a 2225 cone on a 145 frame I should be able to count on the reconer explaining why I shouldn't, after which it would be my choice, which would be no. If I could get the VC centered I might try it. (I know underhung overhung but I think the biggest problem is symmetry. It's not a debate and I don't think I'm being held back from creating "the greatest woofer of all time", it's just service. When I did auto repair I tried to inform my customers to the greatest extent possible. I had no problem with modifying things, but not blindly. For many I think (from conversations) that they may just be technicians who are good at replacing cones with little understanding of how and why things work as they do. You are probably just a purest. That is totally defensible and I respect it. I just wish there was a reconer like Gordon sounds like he is in my backyard. No argument. No right or wrong. Just different viewpoints. Most important, I'm sure you know much more about drivers than I do and that is fact not sarcasm. I do wish I had a dime for every time a reconer has told me an aftermarket part sounds the same, and I know he doesn't know if it does or not.

[Thom]

.

NT: It is possible. But years ago, I learned an important truth. If you want to know whether something can be done, ask an older engineer. If he says yes, believe him. If he says no, don’t believe him.

Quoted from above link

[edgewound]

Edge,

Do you subscribe to Voice Coil?

Ian

Yes, Ian.

[4313B]

I just wish there was a reconer like Gordon sounds like he is in my backyard.Why waste a wish? Just send your stuff to Gordon.

You are probably just a purest.Yeah, probably so. I'm purpose driven. I buy JBL transducers for a specific reason; Not so I can sit around day and night measuring all kinds of different combinations because I have no clue what to do with what I just bought and not so I can try a bunch of coils, cones and spiders in JBL cores to see what I could create on my own. And since this is a Lansing Heritage website instead of the bloody catch-all some members are hell-bent on creating the focus is naturally going to be on Lansing Heritage products, procedures, etc. If that bores anyone then perhaps they should go to a generalist website. You see, there are a whole bunch of people who come here for ONE reason and that reason is because it is specifically the Lansing Heritage website. They have absolutely, positively zero interest in NOT doing it the Lansing way. Anything else is just noise.

I can't speak to the newer JBL products, but the older JBL products were built to a standard and a devotion that would be hard to instill in today's workers.Agreed. I sense a general apathy, or perhaps it's more of a disengagement or preoccupation with other things, that simply wasn't there years ago. Plus, I think you guys had a genuine shared passion as opposed to merely a shared profession. I admire that.

[Thom]

Why waste a wish? Just send your stuff to Gordon.

I'd rather not ship


Yeah, probably so. I'm purpose driven. I buy JBL transducers for a specific reason; Not so I can sit around day and night measuring all kinds of different combinations because I have no clue what to do with what I just bought and not so I can try a bunch of coils, cones and spiders in JBL cores to see what I could create on my own. And since this is a Lansing Heritage website instead of the bloody catch-all some members are hell-bent on creating the focus is naturally going to be on Lansing Heritage products, procedures, etc. If that bores anyone then perhaps they should go to a generalist website. You see, there are a whole bunch of people who come here for ONE reason and that reason is because it is specifically the Lansing Heritage website. They have absolutely, positively zero interest in NOT doing it the Lansing way. Anything else is just noise.
Agreed. I sense a general apathy, or perhaps it's more of a disengagement or preoccupation with other things, that simply wasn't there years ago. Plus, I think you guys had a genuine shared passion as opposed to merely a shared profession. I admire that.

Only on this is there religion. It's OK to totally change crossovers, to change out drivers, to swap diaphragms (as long as they are JBL), to aquaplas diaphragms that weren't, to modify porting. I'm actually not advocating anything. I'm just trying to understand the mindset.

[Harvey Gerst]

Only on this is there religion. It's OK to totally change crossovers, to change out drivers, to swap diaphragms (as long as they are JBL), to aquaplas diaphragms that weren't, to modify porting. I'm actually not advocating anything. I'm just trying to understand the mindset.
Well, back in the "Golden Age" of JBL, we didn't have access to Thiele & Small, or have the benefits of modern materials and techniques, so some of this new stuff, when applied to older units, may improve the performance. It still needs people who know what they're doing and why.

For example, Aquaplas is wonderful for increasing the stiffness to weight ratio on most speakers, but it may not help a D130F or a D123, if you want the nice coloration these speakers provide as guitar transducers. It may (or may not) improve the sound of a D140F - I don't know.

Crossovers can certainly be tricked out to achieve flat response, but you're also messing with a lot of time constants and phase shifting. One of the best sounding systems I've ever heard was Ed May's 3 way, which just had a single capacitor per section and L pads on the mids and highs.

[edgewound]

I'm just trying to understand the mindset.


You're not capable of that, Thom. We've beat this to death....again...and you still refuse...yes, that's right...refuse to understand.

That's because this website is entirely defined by the title...but you want it to be more than that, and it isn't.

To address the original question regarding how hard it is to recone a speaker: It depends on your skill level and your patience and practice.

It's probably easier for me than brain surgery, because I've never done brain surgery.