JBL 4343 restoration, progress and quite possibly a lot of question along the way

[DingDing]

I've had these speakers for approximately two years now and they've been in dire need of restoration. Have not come around to it as they sound so darn good, and I didn't have any good substitutes to use while I put in the work until now.

I don't know everything about these speakers, but as far as I know these began their life in the JBL factory as the grey utility versions, they were then painted black with a blue baffle by Guido in Germany, but later left for Norway and was owned by Rolf. Rolf upgraded the speakers with what I think may be the charge coupled N3145 networks by 4313B on these forums. The networks were built by Guido. The crossover network does not have a passive section between the bass and mid, so they require active crossover. There was also an attempt to put American walnut veneer on the cabinets, but after some time the glue came loose and it has to be redone.

The drivers in these are 2235h for the lows and 2121H for the mid. Other than that they're stock with 2420 on a 2307 horn, and the wonderful 2405 for uhf. The 2308 lenses are also original JBL.

The idea is to restore the speakers into the beautiful walnut version. This is my first attempt at anything like this, so I'm sure there will be a lot of questions as the thread progresses. I also hope that people who see anything that doesn't seem right make some noise so I can correct it. I will spend a lot of time on this project as I want them to be in pristine condition when the job is done. These will be in my possession for the rest of my life and the thread can act as a fun resource for those who end up with them after me. :)

67149

67150

Pulled the veneer and getting ready to remove the crossover.

67152

Closeup of one of the networks.

67153

Removing the internal insulation and getting ready to remove the front trims and sand the whole thing down.

[DingDing]

67154

Removed the front trims using fein. Got most of it off after this image by using a sharp knife, but I will also have to recess the front a bit to fit the new walnut front trims as it's too far away from the baffle. If anyone has a 4343, please measure the distance from the lower baffle to the edge of the trim.

Will use a flush trim bit to get it shorter before gluing the walnut in place, then do the veneer and lastly route the angle on the trim.

It's a shame I can't remove the lower baffle, it seems to be glued in place. Would make a lot of the sanding work easier if I could remove it.

---

Do I have to sand all the way down to the wood before putting on the veneer? The people who know veneering says the substrate must be completely level. Can I use a car filler type product to remove any dents or uneveness before veneering?

[DingDing]

Sanding almost complete on one of the enclosures. This went faster than anticipated. Thank you Bosch! :)

67156

Contemplating adding some light weight bracing to the mix. Any suggestions where I should add them?

[Ed Zeppeli]

Great project.....following.

[DingDing]

Thanks Ed! Hopefully the result will be as great as the enthusiasm I got for this project :)

67157

67158

Some corners on the boxes have some ugly dents to them. Was thinking I could use my new fancy pants plunge saw to do a 90-degree cut or use the router to make a cut for an inlay which is glued in place to get sharp corners before veneering. What's common practice in these situations? Not a wood worker by a long shot :)

[macaroonie]

Router. Take as much as you need to remove the error. Make an inlay +1mm of the size of your rout then use a flush trim bit to clean it up.

Simple :)

Nice project

Did you eventually score those PA boxes ?

[DingDing]

Router. Take as much as you need to remove the error. Make an inlay +1mm of the size of your rout then use a flush trim bit to clean it up.

Simple :)

Nice project

Did you eventually score those PA boxes ?

Thanks (again!). That's a very good plan. Will be painful to route in them, but no turning back now.

I've tried to reach the seller on multiple occasions but no replies, so I guess they're long gone :( I'm using 2404 [>10khz] + (2360A w/2446 [800-10khz]) + 2 x 2226 [40-200/800] per side now, active xo w/miniDSP 4x10 HD. It rocks, and I haven't even optimized it yet. The dynamics are off the chart!

[DingDing]

My Gawd, these restoration pictures from another chap made me excited!!!! GORGEOUS!!!

http://www.audioheritage.org/vbulletin/showthread.php?33213-Latest-project-!

[DingDing]

http://i.imgur.com/YoGMzZh.png

These cabinets must be routed a bit because the front "lip" extends too much. But by how much?

Can't find plans for 4343 on the site.

[Chas]

I like the meow factor you are adding!:D

[Odd]

4343 cabinet, some info

[DingDing]

I like the meow factor you are adding!:D

Good eye there! :D


4343 cabinet, some info

Thank you very much, Odd. Appreciate all the help you've given me!

I know there are some baffle plans on here too, but can't find them even though I've been searching like crazy. The PDF file you attached doesn't have the dimensions I'm after unfortunately.

[DingDing]

One of the enclosures were not perfectly rectangular. There was about 1mm too much around the middle of the enclosure on one of the sides. Quite possibly a mistake by JBL QC back in the days as there is no indication that it's a result of something else. It was the center bracing and baffle which was a little off, so I used Fein to correct for it. Will make it look pretty by using car body filler and expanding glue. The prior front trims were build around the 1mm bump and it had to be corrected to make a seamless integration between the veneer and the trim because 1mm off at the center made it look much worse on each corner.

67291

[DingDing]

The restoration is moving forward, albeit a bit slow. As I've said, I want these to be pristine and there are small blemishes which are time consuming to fix here and there. I was thinking about making new upper baffles, but are going to do my best to restore the originals.

67352

Got the foilcals off using a heat gun, patience, spackle knife and a women's touch. They've been off before and unfortunately the job was not as gentle as mine, so they are probably due for replacement. Kind of sad, as replacements are expensive and lack the serial numbers... :( Got to think hard about what to do. They will be cleaned up and hidden in a plastic pocket inside the cabinets behind damping if they're replaced.

67353

This tear out needs to be fixed, and I had to remove the original gaskets on the baffle to get to it.

67354

I is the jiggermeister

67355

Cut

67356

It fits! Have glued it with expanding glue and will flush trim the thing later.

[DingDing]

67364

Turned out all right.

67365

The baffle was screwed in with some wood screws on one speaker, so I drilled the holes bigger

67366

and are gluing in wood pegs. Ran out of wood pegs, so need to get more tomorrow. When it's all done I will use car body filler and sand to make everything even.

[Wagner]

Not 100% but preferable to replacement non numbered foilcals.
Give your originals a very HARD press between sheets of glass
I mean HARD with wood blocks and "C" clamps
Clean them thoroughly after pressing for a day or two and then shoot them with a light even coat of Testor's "Dull Coat"
The patina will no longer be the final word on accuracy but all the little flaws and imperfections will blend together beautifully to the pint of being invisible; what you'll wind up with is a very presentable pair, perfectly flat and any little dinks and surface imperfections will be GONE
I have done this myself and was very pleased with the results
My pair was so bad this technique was a last resort before giving up and buying the reproductions
Worked out fine

[Challenger604]

Hi there!
I don't know how to post a new note so I'm using this one! Sorry!
For anyone interested!
Cheers!
Christophe

http://www.canuckaudiomart.com/details/649224230-jbl-4343b/?utm_source=CanuckAudioMart+List&utm_campaign=c40f335bf9-Top_Classifieds_Oct02_2015&utm_medium=email&utm_term=0_f2f60e60a2-c40f335bf9-70327121

[DingDing]

Not 100% but preferable to replacement non numbered foilcals.
Give your originals a very HARD press between sheets of glass
I mean HARD with wood blocks and "C" clamps
Clean them thoroughly after pressing for a day or two and then shoot them with a light even coat of Testor's "Dull Coat"
The patina will no longer be the final word on accuracy but all the little flaws and imperfections will blend together beautifully to the pint of being invisible; what you'll wind up with is a very presentable pair, perfectly flat and any little dinks and surface imperfections will be GONE
I have done this myself and was very pleased with the results
My pair was so bad this technique was a last resort before giving up and buying the reproductions
Worked out fine

Thanks, I thought nobody was reading as it was so quiet and my detailed posts and images of minute details are probably boring people to death, lol.

That's very good advice, I will give the the process a try and clamp them between two sheets of glass or other hard materials. The dull coat is not readily available here, and will be imported together with something else to save on shipping.

Could you do a mug shot of the present state of your foilcals if possible? Would be nice to see how the dull coat looks.


Hi there!
I don't know how to post a new note so I'm using this one! Sorry!
For anyone interested!
Cheers!
Christophe

http://www.canuckaudiomart.com/details/649224230-jbl-4343b/?utm_source=CanuckAudioMart+List&utm_campaign=c40f335bf9-Top_Classifieds_Oct02_2015&utm_medium=email&utm_term=0_f2f60e60a2-c40f335bf9-70327121

Oh, you, you cheeky bastard!!! Hahahaha, just flipping with you. They look good. Are they yours? If so, can you do me a favor and measure the front trim edge to baffle for me?

67399

There are two measurements as you can see by the arrows. One where the massive walnut starts and all the way from the baffle to the walnut trim.

You can post a new thread to the marketplace here if you'd like: http://www.audioheritage.org/vbulletin/newthread.php?do=newthread&f=5
(http://www.audioheritage.org/vbulletin/newthread.php?do=newthread&f=5)
edit: Didn't realize it was you until later, Challenger604. So I guess they're not yours. :D

[DingDing]

The baffles are finally done. It has been quite a lot of routing, gluing, sanding and fixing. I've used car body filler to make things flush and will probably paint the rare side as it looks very ugly with all the inlays. Been using very good glue which expands and can't imagine any weak spots on these now.

Have also plugged the hole for the midrange driver as I want to install terminals to make sure it's sealed.

First one.

67459

67460

67461

67462

[DingDing]

Baffle numbero dos.

67463

67464

67465

67466

[DingDing]

Still wondering about what kind of cut I need, so need to do more research on that.

Will most likely be ordering from Oakwood Veneer and use Saeman's technique which is to use Titebond II and an iron. Some people are using contact cement, but I think it may be harder to align the grain properly using that method. Will probably be using paper backed veneer unless they have wood backed. Seems like professionals prefer wood backed.

Was thinking going about it like this: Veneer the bottom, then the sides and lastly the top. Not looking forward to this process as a lot can go wrong when you're a noob and veneer is expensive.

Another thing is the front trim. That needs to be glued in place first, and I don't have a router which supports 1/2" collets, so I was thinking about purchasing a Triton router. Some people say the trim is 30 degrees, some people says it's 60 degrees. They may both be right, but talking about different angles. I also need a bit with the correct degrees and a ball bearing. This is particularly scary as a failure here will damage both the trim and the veneer... YIKES!!! Scary times ahead.

[Challenger604]

Still wondering about what kind of cut I need, so need to do more research on that.

Will most likely be ordering from Oakwood Veneer and use Saeman's technique which is to use Titebond II and an iron. Some people are using contact cement, but I think it may be harder to align the grain properly using that method. Will probably be using paper backed veneer unless they have wood backed. Seems like professionals prefer wood backed.

Was thinking going about it like this: Veneer the bottom, then the sides and lastly the top. Not looking forward to this process as a lot can go wrong when you're a noob and veneer is expensive.

Another thing is the front trim. That needs to be glued in place first, and I don't have a router which supports 1/2" collets, so I was thinking about purchasing a Triton router. Some people say the trim is 30 degrees, some people says it's 60 degrees. They may both be right, but talking about different angles. I also need a bit with the correct degrees and a ball bearing. This is particularly scary as a failure here will damage both the trim and the veneer... YIKES!!! Scary times ahead.

Hello Ding Ding!
I'm going to use contact cement and the trick to align perfectly the veneer is to use a sheet of drawing paper (little thicker) that you can find at Micheals. When you laid one coat of contact cement on the paper back and two on the speaker and you let it dry as supposed to. You put the drawing sheet on top of the speaker and then the veneer on top of the drawing sheet. You will be able to align perfectly both then you slide of the drawing sheet...

As you may have seen here, the 30 degrees router bit is mostly used. Someone here that I helped to build his 4355's had his trims pre-cutted and it works very well to my surprise! I think I should've done that too!

Yep! No mistake allowed but relax! You'll be fine!!
C

[DingDing]

Hello Ding Ding!
I'm going to use contact cement and the trick to align perfectly the veneer is to use a sheet of drawing paper (little thicker) that you can find at Micheals. When you laid one coat of contact cement on the paper back and two on the speaker and you let it dry as supposed to. You put the drawing sheet on top of the speaker and then the veneer on top of the drawing sheet. You will be able to align perfectly both then you slide of the drawing sheet...

As you may have seen here, the 30 degrees router bit is mostly used. Someone here that I helped to build his 4355's had his trims pre-cutted and it works very well to my surprise! I think I should've done that too!

Yep! No mistake allowed but relax! You'll be fine!!
C

Hi Challenger :)
That's very good advice, as a lot of folks feel that the process of using contact cement is easier than iron on. I saw that some people used wood dowels between the substrate and the veneer, but your idea for a big sheet of paper is much better. Maybe I will do contact cement instead. Sent Oakwood veneer an email yesterday asking them some questions and will get a response later today when their specialist returns. Since I'm in Norway I think I have to let the veneer adjust to the climate and humidity here before it's glued.

As for the front trims I don't dear to pre cut them because I really want that veneer to blend smoothly with the solid front trim. In a thread on this topic which I made a couple of years ago user christo showed us how he did it and he got excellent results (http://www.audioheritage.org/vbulletin/showthread.php?35044-JBL-4343-restoration-questions&p=355431&viewfull=1#post355431). Saved the old trims to test cut in walnut to set the router speed. I think the best method is what you and christo are doing, all though I'm sure other alternatives may yield good results as well.

Haha, yes, being relaxed is key for that job. Don't want a pounding heart and subsequent shaking hands when doing it. Going to dry rout a million times and set up a jig not even King Kong could destroy for that job.

[macaroonie]

Read from here on


http://www.audioheritage.org/vbulletin/showthread.php?17238-Backyard-Box-Building-The-Build&p=185031&viewfull=1#post185031


I have since veneered using Titebond + Iron and have to say it is much easier. Other than that the method is the same.

[DingDing]

Read from here on

http://www.audioheritage.org/vbulletin/showthread.php?17238-Backyard-Box-Building-The-Build&p=185031&viewfull=1#post185031

I have since veneered using Titebond + Iron and have to say it is much easier. Other than that the method is the same.

Read the whole thread. Skill! They really turned out looking like vintage speakers with the treatment you did on them. Great work!

Thank you for documenting the process so thoroughly, more confident in dressing these babies up now, and will stick to the Titebond II method. Will ask Oakwood for some scraps for practice.

67468

The veneer in front of them is the old I pulled btw. Saved it for use on smaller projects.

[macaroonie]

Are you planning to do the edge solids first and veneer over or veneer first and fit the edge after ? On balance I think I would do it the first way.

Looks like you have those cleaned up nicely and are very much ready to go :)

For your veneers you could try contacting these people http://www.veneeredpanels.com/contact.php

They are H Shawyer and Sons , in England. I used them recently to lay up some oak panels for a job I was doing. Their product was excellent but better than that they were super helpful. They do sell veneers on their own.

67469

PM sent

[richluvsound]

Definately the Titebond 2 / iron using the paperback veneer from Oakwood Veneers .
I always apply the walnut trim after veneering ...... ,but I'm not a beginner . Cut front detail in 3 passes. Speed 5/6 on the Dewalt . Just take your time and concentrate . :)


Rich

[macaroonie]

Rich , you might want to detail your routing method in the mitre joint region. Tearout is a big possibility.
Ding Ding is new to the router game.

[DingDing]

Are you planning to do the edge solids first and veneer over or veneer first and fit the edge after ? On balance I think I would do it the first way.

Looks like you have those cleaned up nicely and are very much ready to go :)

For your veneers you could try contacting these people http://www.veneeredpanels.com/contact.php

They are H Shawyer and Sons , in England. I used them recently to lay up some oak panels for a job I was doing. Their product was excellent but better than that they were super helpful. They do sell veneers on their own.

[removed image]

PM sent

My thinking process has gone like this: (1) Edge solids goes on first, then veneer over them and lastly rout the angle. The reason why this method is preferred is that the blending of the veneer and the solid will be easier. (2) If the front trim is routed before the veneer and you want to veneer over it you have to cut and sand the excess veneer against the awkward angle (getting the seam exactly at the start of the angle). There will be slight sanding when it is routed together with the solid too, but you don't have to poke a knife in there to cut it.

If the veneer is put on before the trim there will be a seam between the veneer and the front trim. That seam is probably hard er to blend in for someone with my level of skill, so I will take the risk and do it like christo and have the seam blend in with the angle. Reposting a picture he made in my other thread linked a few posts back.

(Oh Lord, I'm wordy!)... :)


http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=60707&d=1385324332

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=60708&d=1385324400

I like how he adds those two scrap pieces to avoid tearouts. It's risky, if you mess up and have some luck you may be able to remove the front trims with a flush trim bit and put on new ones which are pre routed and get a seam between the solid and the veneer.

Thank you for your PM (will reply when I've contacted them). A supplier in the UK is preferable for many reasons, one being shipping cost. Thank you! :)


Definately the Titebond 2 / iron using the paperback veneer from Oakwood Veneers .
I always apply the walnut trim after veneering ...... ,but I'm not a beginner . Cut front detail in 3 passes. Speed 5/6 on the Dewalt . Just take your time and concentrate . :)

Rich

Thank you Rich, will definitely be using the Titebond and iron after seeing so many of you prefer it. I was under the impression it could be a little messy, but being careful and masking already veneered sides against spills is probably the way to go.

Do you guys wait long between veneering each side?

Thank you, yes, putting it on after veneering demands extreme precision from both man and his tools, I'm not going to get a good result trying that I think, so will try the flush rout method.


Rich , you might want to detail your routing method in the mitre joint region. Tearout is a big possibility.
Ding Ding is new to the router game.

That would be nice! :)

[richluvsound]

Apply glue with a small foam roller 3 coats on back of veneer and cabinet . Allow to dry to the touch between coats ..... iron on .... once the veneer cools its set ... go at your own pace .

You've all ready figured out how to avoid ripping the end grain out . :) sharp tools are a must ..
:D

[macaroonie]

That more or less covers the process. You do need to practice routing on scrap wood first to learn the ' feel' of the router in use. Direction of routing is important. For your own learning draw a diagram of the cutter , it's rotation , depth of cut direction of travel and think about the material removal and potential of tearout.

Cheers Rich

[Challenger604]

Read the whole thread. Skill! They really turned out looking like vintage speakers with the treatment you did on them. Great work!

Thank you for documenting the process so thoroughly, more confident in dressing these babies up now, and will stick to the Titebond II method. Will ask Oakwood for some scraps for practice.

67468

The veneer in front of them is the old I pulled btw. Saved it for use on smaller projects.

Very nice clean up! You are racing!!!

[JeffW]

If you apply the solid trim first, then veneer over that, then router the angle on it, is there a chance to see the tiny edge of the backing paper with the paper-backed veneer?

Never done it myself.

[DingDing]

Apply glue with a small foam roller 3 coats on back of veneer and cabinet . Allow to dry to the touch between coats ..... iron on .... once the veneer cools its set ... go at your own pace .

You've all ready figured out how to avoid ripping the end grain out . :) sharp tools are a must ..
:D

Nice, then both speakers can be done in an afternoon. Thank you for the advice.


That more or less covers the process. You do need to practice routing on scrap wood first to learn the ' feel' of the router in use. Direction of routing is important. For your own learning draw a diagram of the cutter , it's rotation , depth of cut direction of travel and think about the material removal and potential of tearout.

Done. So moving with the direction of the bit then, because then the blades cut towards what has already been cut and not against it. Maybe also try to cut with the grain if possible and always use some scraps on the ends.


Very nice clean up! You are racing!!!

Thank you, there are still small things being done, but they are close to ready for being dressed. Now waiting ensues as all parts need to be sourced and bought. Will replace all T-nuts with wooden inserts from EZ LOK for example. They are far superior to the T-nuts. Some of the T-nuts has also been lost in this pair and that was probably why the upper baffle was screwed in with self taping wood screws.


If you apply the solid trim first, then veneer over that, then router the angle on it, is there a chance to see the tiny edge of the backing paper with the paper-backed veneer?

Never done it myself.

Hmmmmmm, interesting observation. I don't think so, as the paper backing is very thin and you will also get a little bit of oil on it when finishing, probably making the exposed paper semi transparent.

[macaroonie]

Done. So moving with the direction of the bit then, because then the blades cut towards what has already been cut and not against it.

No , draw it till you get it.

[DogBox]

Hey DingDing, Nice work on the restore!

I haven't been as fortunate as you as I [(?)still?] haven't "got" boxes as I figured after all the "measurements" I had - it still wasn't enough...

to be able to "build" some boxes from scratch and have them turn out like they were "original"... :(

So, I hope I am not too late in saying: "I hope you have made 'detailed' drawings of your boxes "while you had them apart" so others could benefit?" [Like me!!:)]

I am pretty sure I asked the same question about the distance from 'baffle face to trim edge'... I will endeavour to find what I was given, for you to check..

Good to see you are not rushing this. They will be wonderful when finished! Search the site too... there's an abundance of info here - but you gotta "look"... :blink:

DB

[DingDing]

Hey DingDing, Nice work on the restore!

I haven't been as fortunate as you as I [(?)still?] haven't "got" boxes as I figured after all the "measurements" I had - it still wasn't enough...

to be able to "build" some boxes from scratch and have them turn out like they were "original"... :(

So, I hope I am not too late in saying: "I hope you have made 'detailed' drawings of your boxes "while you had them apart" so others could benefit?" [Like me!!:)]

I am pretty sure I asked the same question about the distance from 'baffle face to trim edge'... I will endeavour to find what I was given, for you to check..

Good to see you are not rushing this. They will be wonderful when finished! Search the site too... there's an abundance of info here - but you gotta "look"... :blink:

DB

Hello,
I will gladly make detailed plans of 4343 available for everyone. Not a savvy user of Autocad or any other advanced modeling software, but I can make a model with the true dimensions in Sketchup and make it available through the forums, no problem. :)

[Guido]

Congrats DingDing!

Very impressive work till now. Nice to see these Speakers back in action.

[DingDing]

Hello, Guido :)

Thank you for the kind words. It's not up there with building a pair of Everest clones from scratch but it's a humble beginning, haha.

I'm sure your charge coupled crossover networks are a big part of the magic. They sound super clean and dynamic. Hopefully they will look the part too. :)

[DogBox]

Hello,
I will gladly make detailed plans of 4343 available for everyone....but I can make a model with the true dimensions in Sketchup and make it available through the forums, no problem. :)

:applaud:Bless You! man, Bless You!

Weird things like: How far up does that front baffle that you can't remove [leave it there!] come & sizes of the removeable one,...sizes of bracing used, - so as to

"re-create" a Cabinet with all its 'foibles'.. if that's what you want to do [I know some don't, well...?]

It can go into the cool Information on the 4343 that H. James has put together! Have you had a look through that? She's done a fine job! :bouncy:

And you will make A LOT of people VERY HAPPY INDEED!!! :banana:

Really appreciate the effort!!

DB
[Steve]

[DingDing]

:applaud:Bless You! man, Bless You!

Weird things like: How far up does that front baffle that you can't remove [leave it there!] come & sizes of the removeable one,...sizes of bracing used, - so as to

"re-create" a Cabinet with all its 'foibles'.. if that's what you want to do [I know some don't, well...?]

It can go into the cool Information on the 4343 that H. James has put together! Have you had a look through that? She's done a fine job! :bouncy:

And you will make A LOT of people VERY HAPPY INDEED!!! :banana:

Really appreciate the effort!!

DB
[Steve]

:D Already working on the plans but can't say for sure when they're done. May need some help with identifying screws as I'm used to the metric standard and UNC is driving me up the wall, haha. Some screws are due for replacement and it would be nice if we could find suppliers. KenRick Sound has some screws, but they are quite expensive and it's not all of them.

Maybe someone could help us make vector graphics of the back panel silk screen / foilcal where the terminals goes too? I can provide pictures. If nobody in here is up to the task I can try to find someone on fiverr.com that can do it for us.

To get some help with details I will make a new thread where people can help out, and when the plans are done we could ask if they could be put into the 4343 reference thread H. James has made. Have to agree that the thread is really nice. Have been reading it a number of times. :)

* I'm taking measurements of the utility version now, but once we figure out the exact front panel trim etc for the walnut version we can have separate plans for them. I'll try to get in touch with people selling them to ask if they can measure for us.

[DingDing]

Veneer is on the way and the model is beginning to take shape.

67641

I think JBL has routed a grove for the lower baffle in the side panels and the bottom. Will make note of that so people can replicate it. Not sure how deep those grooves are, maybe 1/3" or somewhere around there. The corners are also not just 45 degrees but have a lock miter joint. I will make the model without these details as I'm not skilled enough to model it, but will take pictures and make notes of it together with the plans.

[Ian Mackenzie]

Great thread

[Fangio]

Have to agree :)


... * I'm taking measurements of the utility version now, but once we figure out the exact front panel trim etc for the walnut version we can have separate plans for them. I'll try to get in touch with people selling them to ask if they can measure for us.

A bit late to the party, anyway I have walnut 4343s. Maybe these pics will help

67645

I did these once for Hardy aka Düse here at LH, another member who has veneered 4341 uitility cabs (http://i268.photobucket.com/albums/jj35/MacFangio/Hardy/4341_Hardy_Front_li_cc2.jpg) a while back. If you want the fullsize pics or need more dimensions let me know.

Do you consider building grilles? If so you could have a look here..

http://www.audioheritage.org/vbulletin/showthread.php?9830-4343-Grill-plans&p=100805&viewfull=1#post100805

Cheers

[ivica]

:D Already working on the plans but can't say for sure when they're done. May need some help with identifying screws as I'm used to the metric standard and UNC is driving me up the wall, haha. Some screws are due for replacement and it would be nice if we could find suppliers. KenRick Sound has some screws, but they are quite expensive and it's not all of them.

Maybe someone could help us make vector graphics of the back panel silk screen / foilcal where the terminals goes too? I can provide pictures. If nobody in here is up to the task I can try to find someone on fiverr.com that can do it for us.

To get some help with details I will make a new thread where people can help out, and when the plans are done we could ask if they could be put into the 4343 reference thread H. James has made. Have to agree that the thread is really nice. Have been reading it a number of times. :)

* I'm taking measurements of the utility version now, but once we figure out the exact front panel trim etc for the walnut version we can have separate plans for them. I'll try to get in touch with people selling them to ask if they can measure for us.

Hi DingDing,

Nice work has been done.
After Your CAD work, we would have 'fabulous 4343' DIY documentation.
Do You plan to do any measurements?
I am especially interesting in the bass response, measured very near the dist cap, and port response too.

Is there any idea why JBL on the 4344 model placed ports between bass and mid-bass drivers, while on 4343 ports are at the bottom?

regards
ivica

[DingDing]

Got a little more work done today. Still plenty left as I want to triple check everything.

67648


Great thread

Thank you :)


Have to agree :)

A bit late to the party, anyway I have walnut 4343s. Maybe these pics will help

[REMOVED IMAGE]

I did these once for Hardy aka Düse here at LH, another member who has veneered 4341 uitility cabs (http://i268.photobucket.com/albums/jj35/MacFangio/Hardy/4341_Hardy_Front_li_cc2.jpg) a while back. If you want the fullsize pics or need more dimensions let me know.

Do you consider building grilles? If so you could have a look here..

http://www.audioheritage.org/vbulletin/showthread.php?9830-4343-Grill-plans&p=100805&viewfull=1#post100805

Cheers

Thank you very much for the measurements. :bouncy: They will certainly come in handy when I model the walnut version and recess the fiberboard on my speakers. I want to make sure they're just like the original as this will probably have (minute) effects on the diffraction of the speakers, beneficial or not, who knows.

If it's not too much trouble I'd love some more dimensions. I'm sure the trim is very close to 25.4mm (1") from your pics, but doesn't hurt to know for sure. If you could check with a caliper I'll be very happy. Same with the flat outer edge. If I know both of them I can calculate the angle precisely.

Different numbers are thrown around, it's most likely 30 degrees (which some call 60 degrees), because they're talking about the same router bit but seen from another angle.

The grilles I have are DIY and not up to spec. It's not first priority to be honest, as the speakers deserve to have them off to show their glory :D

67649


Hi DingDing,

Nice work has been done.
After Your CAD work, we would have 'fabulous 4343' DIY documentation.
Do You plan to do any measurements?
I am especially interesting in the bass response, measured very near the dist cap, and port response too.

Is there any idea why JBL on the 4344 model placed ports between bass and mid-bass drivers, while on 4343 ports are at the bottom?

regards
ivica

Thank you. :)

As for the ports I'm afraid you are a far more advanced than me. Maybe it has something to do with eliminating floor bounce? I noticed that Greg Timbers recommended getting 4345 up off the floor and we also see KenRick Sound elevate their 4343's in their beautiful showroom.

I do have some measurements (didn't find the near field freq graph right now, sorry). Keep in mind that these have charge coupled crossovers, are actively xo'ed between bass and mid, utilizing 2235h, not 2231A.

This is the impedance of the woofer loaded in the cabinets without any modifications to the ports.

67650

So tuning around ~31 Hz w/2235h

If I can't find the old measurements I'll just take new ones.

[Fangio]

... Thank you very much for the measurements. :bouncy:

If it's not too much trouble I'd love some more dimensions. I'm sure the trim is very close to 25.4mm (1") from your pics, but doesn't hurt to know for sure. If you could check with a caliper I'll be very happy. Same with the flat outer edge. If I know both of them I can calculate the angle precisely.

Different numbers are thrown around, it's most likely 30 degrees (which some call 60 degrees), because they're talking about the same router bit but seen from another angle.
I don't have a caliper right now (did have one though when I took some measurements back then), but this might be better.. another fellow who had some 4341 cabs veneered, has used my 4343 values and made a drawing for his carpenter (thanks Michael).

67655
I'm sorry, metric system again.. :duck:

[DingDing]

I don't have a caliper right now (did have one though when I took some measurements back then), but this might be better.. another fellow who had some 4341 cabs veneered, has used my 4343 values and made a drawing for his carpenter (thanks Michael).

67655
I'm sorry, metric system again.. :duck:

Thenk you Fangio. Metric system is highly welcome and preferred. It's std here in NO too. Thank you.

67656

What is that 2mm notch? From your pictures it seems like a small groove between the fiberboard and the solid. Probably a silly question, but better to know for sure than to assume.

[Fangio]

Thank you Fangio. Metric system is highly welcome and preferred. It's std here in NO too.
I know. ;) The sorry was adressed to the US/UK folks.


What is that 2mm notch? From your pictures it seems like a small groove between the fiberboard and the solid. Probably a silly question, but better to know for sure than to assume.
I'd say that is safe to ignore, should have edited it out. He probably included it looking at my pics, however there isn't a real gap. Actually the notch where the outer angled trim sits on the side panels is rather ~1mm (compare to the other pics in post #44).

And I'd go with an even value of 30° ofc.

67659

[DingDing]

I know. ;) The sorry was adressed to the US/UK folks.

I'd say that is safe to ignore, should have edited it out. He probably included it looking at my pics, however there isn't a real gap. Actually the notch where the outer angled trim sits on the side panels is rather ~1mm (compare to the other pics in post #44).

And I'd go with an even value of 30° ofc.

[IMAGE REMOVED]

Cool Fangio, then we're clear. :) Don't think it's possible to get a cutter with that awkward angle unless you have it custom built. I'm sure the original is 30° too.

---

For future readers: I've found two cutters which are affordable and will do the job.

67661

1/2" http://www.precisionbits.com/30a-chamfer-and-bevel-edging-router-bit-1-2-shank-yonico-13905.html
1/4" http://www.precisionbits.com/30a-chamfer-and-bevel-edging-router-bit-1-4-shank-yonico-13905q.html

*** for other router noobs on the metric system: 1/2" is not the same as 12mm and 1/4" is not the same as 8mm.

67660

Saeman says he uses a 60° cutter, but I think he's talking about the angle drawn in by me above. We're all talking about the same cutter here, it's a 30° bit.

This should clear up any confusion about that damn trim, haha.

[DogBox]

Hey DingDing, Coming along nicely!

As I had to deal with metric/imperial in my trade, it was easy enough just to remember if you had metric, say 22mm : 22 / 25.4 = Answer in thousandths of an inch.

Grab yourself some size charts and 0.866 is just under 7/8" [0.875] Or if you had imperial 0.875 x [multiplied this time] 25.4 = 22.225mm.

Which will get you close enough to the saw blade to cut yourself. It takes a good cabinet maker to cut within 0.006" and fine machinery to do it. That's what

sandpaper is for. :blink: I'll probably get ribbed for my workings out and carpentry skills, which is ok seeing that I normally work with metal! But, hey...!:o:

I have some "corner shots" I borrowed from Kenrick that show they use a "moulding" piece of trim that has been cut to size which they seem to glue on. Done.

Not sure if that's the norm, but clearly shown in some shots.

You can be pretty sure JBL dealt in imperial in those days too! so feel happy! to carry on as you are! Whats that Drawing Program you're using? It's cool!!

DB

[DingDing]

DogBox, I take all measurements in mm down to a 10th of a mm using caliper wherever possible. The program I'm using is Google Sketchup and it's free + there are tons of tutorials on Youtube on how to use it. The great thing about it is that you can choose the units you want to work with. So even if I'm doing this model using the metric system it's easy to see all the dimensions in imperial by changing the units. I'm sure that my measurements won't be precisely what JBL used but it will be very close.

67676

It can do very complex shapes too, but I'm not skilled. Here's a model of JBL M2 (https://3dwarehouse.sketchup.com/model.html?id=ufa83f673-6326-4567-b1b7-a6b507d2018a) and here is one of JBL 4430 (https://3dwarehouse.sketchup.com/model.html?id=uf61853ed-b93b-4655-a35d-2e3e20fc4ba3). Not made by me but available for download.

67677

Unfortunately these models are mainly exterior as there are no details on the internals. Also not sure about the scale.

67678

[DingDing]

Just a quick update:
1) Still working on the model but have not had time to do much lately.

2) Got a solid plank of American walnut (gorgeous wood) which will be cut into pieces for the front trim. The plank is 2440x200x26mm and cost about $80 from my local supplier. Lots of trims in a big plank like that. :D

3) Veneer will probably be here tomorrow. Yay!

4) 2.4kW (3 1/2 hp) Triton TRA 001 router w/ 1/2" collet and Kreg router table inlay is coming next week. Going to build a router table for future projects to get those lock miter seams and being able to copy bracing from templates I make and what not.

67800

Excited? You bet!! :D

[Challenger604]

Thenk you Fangio. Metric system is highly welcome and preferred. It's std here in NO too. Thank you.

67656

What is that 2mm notch? From your pictures it seems like a small groove between the fiberboard and the solid. Probably a silly question, but better to know for sure than to assume.


Hi Ding Ding!
Your answer is here around about the groove! If I find it I'll send you the link!

I did my edge like that! I didn't like all blue. The walnut gives a more classy look, I think.
Are you planning to build 4430?
Have fun!
Christophe

[DingDing]

Blue paint, veneer and solid walnut in the house. Got some requested veneer scraps for experimentation, so excellent service from Oakwood veneer where I ended up buying. Still waiting for Titebond II and some minor things and need to figure out the specifics about the black color for the rear and the blind panel on one of the UHF slots.


Hi Ding Ding!
Your answer is here around about the groove! If I find it I'll send you the link!

I did my edge like that! I didn't like all blue. The walnut gives a more classy look, I think.
Are you planning to build 4430?
Have fun!
Christophe

Everything about the trim dimensions are in the clear now and posted in the thread thanks to many helpful people like yourself.

Agree that the trim looks better the way you've done it. Walnut all the way to the baffle also look very good. Have a look.

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=56349&stc=1&d=1342611075

This looks spectacular, but on the other hand I want it to look original even though I'm not fooling anyone. Have not decided what to do just yet.

My brother and I may eventually end up building another pair for him (4343 or 4355) but after this project I will try to bring my own ideas to life (http://www.audioheritage.org/vbulletin/showthread.php?37404-DingDing-goes-DIY-JBL-2404-mounted-inside-or-outside-2360A-and-one-or-two-2123) having 4343 to fall back on if I fail.

I have owned original 4430's for a few years and unfortunately they fall short in comparison to 4343. I think a 4430 with an additional cabinet with 2123 and 2404 stacked on top may yield better results, but never tried it as I fell in love with 4343. 2235h does not sound that good when xo is as high as 1khz as in 4430 imo. Other than that they are fun speakers and they look awesome. :D

The reason I'm not building 4355 for myself straight away is I want to experiment with JBL components, DSP and active crossovers. If I'm unable to get solid performance I will build 4355 too, probably a fully active one with stepped attenuators replacing the L-Pads.

Hope you're (all) having a good weekend. :)

[macaroonie]

Good work chief , I'm looking forward to seeing these come back to life. I'm sure you will do a super job.

Be careful with that lock mitre cutter for 1" material , it's almost 3" across. In use I would suggest that you do your cuts in stages , leaving the last cut to be only 1mm as a cleanup. You will need to create a fence for this of course. Maybe your router table has this. Make sure it is all locked down securely and that your panels are safely supported when feeding through the cutter.
Vacuum is a good idea if you can rig something up , even a Henry will lift a lot of cuttings.

Skol .

[DingDing]

Good work chief , I'm looking forward to seeing these come back to life. I'm sure you will do a super job.

Be careful with that lock mitre cutter for 1" material , it's almost 3" across. In use I would suggest that you do your cuts in stages , leaving the last cut to be only 1mm as a cleanup. You will need to create a fence for this of course. Maybe your router table has this. Make sure it is all locked down securely and that your panels are safely supported when feeding through the cutter.
Vacuum is a good idea if you can rig something up , even a Henry will lift a lot of cuttings.

Thank you for the support Mac, it's daunting to say the least but no turning back now. Must admit that this restoration has been procrastinated for the past two years partly due to sheer terror, but the hour is here now and it needs to be done. Just need to be patient.

Was gobsmacked when I saw the size of that cutter. Very good advice and it gave me an idea. The ambition is to build a router table using a table top from IKEA with a smooth surface. Also need to build a good and fairly tall fence for the vertical cut, so this is a whole project all by itself. To get to the point here: These cutters seem hard to set up, and when I need to do multiple passes it will be even harder, but I figured I could try to put a locking pin, marking or similar in the table behind the fence to set it up for each pass.

I overspent a lot on this setup already, but at the same time I'm very excited about being able to rout those seams and having a powerful router that can trim MDF like butter. It opens a lot of opportunities. I've watched a lot of videos on pros handling routers on Youtube, and it's very inspiring.

Fortunately, I have a Vac already. Been looking at cyclones too, but you got to draw the line somewhere, I'm not a pro shop, haha.

[macaroonie]

One thing to remember is that due to the larger diameter of the cutter for a given rotational speed ( RPM ) the blade speed will increase. There is always a sweet spot cutter speed , mostly depending on the material and also the rigidity of the tool system. You will most likely want to run at a lower speed than normal with that big cutter , that's if your motor is equipped to do that.

Since the profile is end-on to the sheet and since the remaining profile has a sharp 45 deg point that you want to preserve intact I suggest that you either register your work piece to a sled that is jigged to run across the cutter. Ie. no fence.

or

Use a fence at the other end of the workpiece , no fence at the cut edge. You will need to rig up repeatable stops or marks to get your sizes to repeat ( sides , tops all the same )

Go back to the build thread I posted ages ago

http://www.audioheritage.org/vbulletin/showthread.php?17238-Backyard-Box-Building-The-Build&p=181001&viewfull=1#post181001

Footnote : Those canteen tables with a steel frame and a formica top can be found at the reclaim places for pennies. Plenty of area to work with and a good surface. It's usually laminated to birch ply.

[DingDing]

Mac: The Triton has variable speed and recommended speed settings depending on the diameter of the cutter, but it didn't take account for the material density. I guess you just need to work some things out by experience.

Good ideas about the canteen tables and the sled. The reclaim places are far away from where I live and IKEA ships so I'll see what I can find. I saw a guy who built a sled that attached to his custom fence when doing the horizontal cut. Would be ideal for bigger panels.

---

Have been experimenting a little today.

67860

The blue is two coats of RAL5007 matte finish on one coat of primed MDF. It's a little less deep than the blue which was on and has a little more gray to it. The picture doesn't quite capture the color of the objects, but I think this color will work very well.

The left piece of walnut was laminated on using contact cement. I think there was something wrong with the cement as it would not stick to the paper backing properly and was impossible to distribute evenly on both surfaces (MDF). Was impossible to get rid of the uneven buildup no matter how much pressure I put on it. It was probably a problem with the contact cement or it was just a poor product. If it had distributed evenly it would have been a good choice for smaller projects which should be done as fast as possible. The sample is also oiled with two coats (will do more) of some cheap teak oil I had sitting. Going to get better oil which brings out more of the red color.

The right piece was glued on with some PVA glue I had by putting on two thin coats and letting them have a rubbery consistency to the touch. Used an iron and a scrap piece to add pressure along the grain. This method was preferred but took longer. Will practice some more with bigger pieces until I do the speakers and will use Titebond II and not what I have, because I know it works over time.

So all in all a good experience with the wood glue iron method. Saeman made a very good post of his insights a while back. Here they are again for anyone who may want to try this.

saeman's words and takeaways

For what it's worth, here's a few comments on problems I have encountered.

1. I have used paper back veneer, bubble free and phenolic backed veneers. Paper backed is the easiest to work with as it is thinner material. Phenolic backed resembles formica in overall thickness. It bonds well but since it is thicker it's harder to make sure there are no voids or bad bond spots.

2. I have talked a lot about buying some kind of commercial heating iron and never have. My wife's clothes iron works great and she hates to use it anyway. Her current iron used to be teflon coated but I've worn patches of the teflon off pressing veneer.

3. Temp setting is about 1/3 of max for most household irons, or about 160 degrees max. Too much heat and you will melt and puddle the glue under the veneer - TROUBLE - if this happens you need to turn the heat way way down and slowly dry the glue again. All you need is enough heat to re-activate the glue to allow both glued surfaces to bond (just like two surfaces coated with comtact cement.

4. Going over the veneer with a hot iron is not enough. More pressure is required to ensure a solid bond. Heat about 1 square foot at a time and immediately (while the surface is still damn hot to the palm of your hand) roll over that area with a 4" veneer roller applying all the pressure you can. Roll slowly and listen for any crackling sounds. Roll with the grain and then roll side to side against the grain. If you hear crackling it indicates that the veneer is lifting. Heat - roll - heat - roll, until there is no crackling to be heard. After doing the whole surface go aroung all edges again. Let that panel/side sit for several hours and then trim off excess veneer. Then go over the whole surface again slowly with the roller and listen for any crackling. After sitting for a while if the bond is not good it will lift. If this problem occurs hit it with the heat again. I have always used Titebond II and have heated and reactivated as long as two days after laying the veneer.

5. After you have trimmed off excess veneer - take your thumb and fan the entire edge (like you would shuffle thru pages in a book or a deck of cards) and listen for spots where the veneer is loose around the edge. Heat and roll any you find.

6. Bubbles under the veneer usually happen when too much heat is applied. With some practice everyone using this method will find their own settings. Not enough heat and your veneer will be crackling under the roller until your supper is cold. TOO MUCH heat will melt the glue and quite often cause bubbles. If you have a bubble that persists, it can be sliced open using a thin blade modeling knife. Let any trapped air escape, roll the hell out of it and apply less heat in that area to get a bond.

7. Applying the glue - I apply 2 (sometimes 3) coats to each surface using a 4" paint roller. Most veneer manufacturers recommend a 6 to 8 mil glue coating between veneer and substrate. If you skimp and apply only one coat you'll some day, after a big change inhumidity, find your veneer lifting from the surface. Titebond II turns clear when it's dry to the touch. When the first coat is dry you can apply the second/third coat. You can wait as long as a couple of days to apply your veneer but I have had the best results after waiting just an hour or two after the last coat is dry. It will appear dry but you will be able to penetrate the glue with your finger nail and it will feel a bit like a hard rubber surface. If you wait a day or more the glue will be HARD and even though heat will reactivate and bond, I have gotten the best results with the rubber like surface.

That's a lot of rambling and babbling but maybe my techniques will help some of you achieve the results you're looking for. I've had a lot of frustration doing veneer work but have worked out the bugs and have been getting good results.

[DogBox]

http://i.imgur.com/YoGMzZh.png

These cabinets must be routed a bit because the front "lip" extends too much. But by how much?

Can't find plans for 4343 on the site.

The amount you've got there [even going by your pictures] looks about right. What you may be forgetting is that the lens on the front of the baffle sticks out
2 1/2" in front of the 2307 when it's attatched with it's velcro and the grills extend quite a distance out - so what you have looks close... :dont-know:
Those cabinets came with the front trim, didn't they? You haven't changed anything in the boxes for it to 'be' any different have you? Well, you're ok!
Check some pictures in the Kenrick site.
You are doing a mighty job! I didn't mean to sound selfish about my carrying on about the drawings/plans. I know many others would love to be where you are at
having a build going so well!
Just do the drawings when you get time, for goodness sakes...! I meant to say - before it's all together "could you please.. make some measurements" that will
benefit the members.. while you have the chance whilst it is still apart. ThankYou!

DB

[DogBox]

Ding Ding,

Is this how your boxes started life..[or, something like!] http://jbl43.com/?pid=94861707 ?

Shows no 'trim' at the front - flat front edges.

As against http://blog.kenricksound.com/2015/09/jbl4343bwx_8.html

Shows those edges looking "very close" to what you have...!

In my packing to move.. I just can't quite lay my hands on all my drawings and measurements... :banghead:

DB

[DingDing]

Hi DogBox
You may have missed the first post of the thread where I talk about these speakers. They began as the black and grey utility versions, were then painted black and after that got a blue baffle and was veneered and got a front trim. Now I'm stripping them down and building the walnut version on that foundation.

As for the plans, I'm working on them when I have time. There will be two sets of plans. One for the walnut version and one for the utility grey. I have all the necessary measurements available for both versions, so it's a matter of modeling them and making them easy to read and follow.

I have the lenses and velcro, but will not model them as it's easy to do without plans. You just buy original lenses or buy replicas from KenRick sound. I do not have original grilles so I will not model them. I will only make the speakers. I'm not good at modeling so small things take a lot of time.

For crossovers people will need to buy them used, built, or build their own using schematics available on this site as I do not have competence to help out there.

[mech986]

Any updates to this interesting thread?

[berga12]

Is any final drawing available?

I would like to start a 4343 replica. :)

[bldozier]

Blue paint, veneer and solid walnut in the house. Got some requested veneer scraps for experimentation, so excellent service from Oakwood veneer where I ended up buying. Still waiting for Titebond II and some minor things and need to figure out the specifics about the black color for the rear and the blind panel on one of the UHF slots.



Everything about the trim dimensions are in the clear now and posted in the thread thanks to many helpful people like yourself.

Agree that the trim looks better the way you've done it. Walnut all the way to the baffle also look very good. Have a look.

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=56349&stc=1&d=1342611075

This looks spectacular, but on the other hand I want it to look original even though I'm not fooling anyone. Have not decided what to do just yet.

My brother and I may eventually end up building another pair for him (4343 or 4355) but after this project I will try to bring my own ideas to life (http://www.audioheritage.org/vbulletin/showthread.php?37404-DingDing-goes-DIY-JBL-2404-mounted-inside-or-outside-2360A-and-one-or-two-2123) having 4343 to fall back on if I fail.

I have owned original 4430's for a few years and unfortunately they fall short in comparison to 4343. I think a 4430 with an additional cabinet with 2123 and 2404 stacked on top may yield better results, but never tried it as I fell in love with 4343. 2235h does not sound that good when xo is as high as 1khz as in 4430 imo. Other than that they are fun speakers and they look awesome. :D

The reason I'm not building 4355 for myself straight away is I want to experiment with JBL components, DSP and active crossovers. If I'm unable to get solid performance I will build 4355 too, probably a fully active one with stepped attenuators replacing the L-Pads.

Hope you're (all) having a good weekend. :)


who's cabs, and which blue is it.

[Ian Mackenzie]

I never liked the stock 4430 either

Reason: the 2121/2122/2123 wiped the floor with the 2235H in the mid.

Its a dog above 300 hertz for midrange irrelative terms.

I used the 4430 horn on top of the 2122 for while. Nice.

However, the 2234H in the 4435 is much better.

I heard the 4343B bi amped and compared to the 4435 bi amped set up in the same room at John Nebel's.

The 2234H without the mass ring has more life and speed.

But I preferred the 4343B at the time on jazz. It has more precision up top.

I plan to try the 2405 direct to a digital amp as suggested by GT soon with a custom analogue crossover using Jfet zero feedback buffers

If you like the 4430 horn talk to Guido as he tried a Be 1 inch driver.

It was pretty spectacular apparently.

Guido also does a nice wave guide

[DogBox]

http://i.imgur.com/YoGMzZh.png

These cabinets must be routed a bit because the front "lip" extends too much. But by how much?

"""Can't find plans for 4343 on the site.""""


:blink: Seems like I am not the only one who struggle's...and such a Beautiful Restoration! The many measurements that could have been taken...:banghead: ah well.