Refurbishing of a pair of 2395 lenses

[Lee in Montreal]

I purchased a complete set of 2241 drivers, horns and 2395 lenses. They were not in the best shape, but honestly, I have seen worst. Some blades were bent and I am missing 6 aluminum blade spacers. Those I will machine. The intention is to keep them as original as possible, but straight. Scratches in the paint will remain as testimony of prior life.

Basically, here's what I brought home. One driver works, the other doesn't.

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I took the lenses apart and laid them flat so that they could be scrubbed to remove 30 years of dust, grit and paint fume. You can see that JBL didn't spend much in term of production value here. Makes me wonder why people pay $1k for a set of those... :eek:

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[richluvsound]

Nice ..... How much would they cost to make from new ..... $300 anodised included ?.

[Lee in Montreal]

Nice ..... How much would they cost to make from new ..... $300 anodised included ?.

Yup. At most. And that is for one set. Increase production numbers, then prices decrease. Actually I was thinking drafting them and having a set laser cut just for the fun of it. The top and bottom blades are a bit thicker aluminum, while the center blades are very thin and highly flexible. Basically, the strength comes from the bolting. Speaking of bolting. What holds the fins together is a thread rod with two nuts. I expected a long 4.5" bolt with one nut at the end. I wonder why JBL used a threaded rod instread of a long bolt.

While browsing my local Kijiji, I found another guy selling 4 sets of horns, diffusers and stands for... three thousand dollars. Effing crazy. But hey, the 5 cents hockey and baseball cards that I collected when I was a kiddo now sell for a few hundreds ;)

if you have $3k to spare
http://saguenay.kijiji.ca/c-acheter-et-vendre-instruments-de-musique-materiel-audio-pro-4X-JBL-2395-horn-lens-W0QQAdIdZ337668785

[louped garouv]

you may be able to find those spacers at a hardware store....

[Lee in Montreal]

you may be able to find those spacers at a hardware store....

I'll check. They are:

OD 10.3mm / 0.40"
ID 6.9mm / 0.265"
Length 11.1mm /0.44"

BTW I have finished straightening all the blades. They look quite nice, except that some paint has started chipping. Therefore, chances are that I will chemically strip the blades, sand them and repaint them in dark grey or satin black. I managed to save the original foilcaps. So, they'll still look good.

[Lee in Montreal]

Just back from my local hardware store. I purchased sixteens 1/4x5" UNC bolts and some spray paint. I was lucky to find a 100% exact similar paint. It is dull and slightly textured. This is Tremclad's Texture serie. Therefore, tomorrow, I will glassbead the horns and repaint them to new.

Lee

[Lee in Montreal]

I beadblasted the horns and painted them. One can for two horns. Finish is dull with a light texture. It is very similar to the original color. Just much cleaner now.

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[Mike Caldwell]

Of the two drivers which one is dead, the first one pictured looks like it has a 2445 titanium diaphragm in it. The second one has either an aftermarket or some early JBL four inch voice coil diaphragm that I'm not aware of. The dark gray color makes me think titanium anything early would have been aluminum.
JBL used that tangential style surround on some early one inch drivers.

You refinishing look great!

[Lee in Montreal]

Thanks for the info. So, it appears I need to find another 2445 Ti diaphragm.

As for the horns' grey paint, I am very happy with it. It dried up by the fireplace, therefore it has nicely cooked. ;) The finish seems very tough. It is dull, yet not powdery. The paint was easy to work with, and dry to the touch in half an hour.

Now working on restoring the pair of 2441. The foam behind the diaphragm was obvioulsy rotten. Stripping the back cover will be easy. Is the cardboard gasket available? I also sanded the meeting surface around the diaphragm, as well as the mating surface to the flange. I am dropping some Isopropanol alcohol (99% pure, no deposits) into the throat, with the intention of diluting any possible gunk. I wish I could remove the plastic phase plug, but I think it's not possible.

BTW One of the rear covers was stuck because a screw was dead frozen. Even after hitting the head, it woudn't bulge. So I had to drill its head on my press drill, pop the cover, and pry the bolt out with a Vice-Grip. Job was cleanely performed. Screw is 10-32 x 2" and I will probably source eight of them with Allen head. I doubt I can get any new part #52602

[Mike Caldwell]

The 2441's originally came with aluminum diaphragms, they look just like the 2445 diaphragms only shiny aluminum instead of flat brownish color. After all of your driver clean up be sure to clean the gaps REALLY good. If you have not done so yet you may want to tape over the gap to help keep it clean. Dirt and dust is not so bad to clean and blow out of the gap, rust, metal filings and fine metal dust stuck in the gap take a lot of cleaning and re cleaning with tape to get it all out.


Mike C.

[Lee in Montreal]

The top blades were heavily scratched. Paint was removed with chemical stripper. Then some sanding.

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Once painted. Finish is very slightly textured.

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[herki the cat]

Yup....What holds the fins together is a thread rod with two nuts. I expected a long 4.5" bolt with one nut at the end. I wonder why JBL used a threaded rod instread of a long bolt....

I expect the hole in the fin has a thread like a nut to bond the fin tight with the threaded rod. This of course requires rotating the rod in removal or instalation. It is very tempting to construct a pair of lenses for my 2440's Many thanks, Lee in Montreal.herki[Quote/]

[Lee in Montreal]

It is very tempting to construct a pair of lenses for my 2440's, thanks to you. herki[Quote/]

The problem would be getting the horns themselve. They only fit the 2395 lenses as far as I know. But perhaps if somebody would make a fiberglass repro... :D Rich?

In regard of the blades' hole, they are a tad over 1/4". Therefore they are not threaded. Mechanically, it wouldn't make sense anyway. BTW top and bottom blades are thicker at 2.2mm while the 8 intermediate blades are 1.35mm

[Mr. Widget]

The problem would be getting the horns themselve. They only fit the 2395 lenses as far as I know. But perhaps if somebody would make a fiberglass repro... :D Rich?At one point someone was... along the way I picked up some fiberglass clones that no longer had any badge or name plate. The pair I had came with the Hartsfield style serpentine lenses. Someone might know who was making them.

Even in fiberglass they certainly had plenty of "that vintage horn sound"... for those seeking it.


Widget

[Lee in Montreal]

Things are taking shape

Horns were blasted and now painted
Top and bottom blades were stripped and are now painted
The drivers' back covers were stripped (the foam's yellow glue was a bitch - but it is now all gone and clean as new, thanks to a lot of chemical stripper to liquify the gold glue). Now painted and drying.
I tested some of my aluminum stands to work with the 2395 and it seems it'll work as self standing horns, replacing the expensive H stands and the brackets on the front bottom.

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL parts factory/DSCN0900.jpg
http://img.photobucket.com/albums/v668/Lee_Vuong/JBL parts factory/DSCN0901.jpg

[Eaulive]

So that was a productive weekend! :applaud:

[Lee in Montreal]

BTW It seems there has been a 36" lens knock-off by DAS. Perhaps horns can be sourced from this supplier.

http://www.audioheritage.org/vbulletin/showthread.php?19445-McCauley-Lens-Horns&p=195663&viewfull=1#post195663

[Lee in Montreal]

With the paint almost dry (at least to the touch), I assembled the first set. Pictures were taken in a dark place and the blades haven't yet been adjusted. Nonetheless, they now look much better than when I brought them home, in sorry condition, after being dumped in a barn.

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[4343]

BTW It seems there has been a 36" lens knock-off by DAS. Perhaps horns can be sourced from this supplier.

http://www.audioheritage.org/vbulletin/showthread.php?19445-McCauley-Lens-Horns&p=195663&viewfull=1#post195663

The DAS 36" lens is serpentine, not really apparent from the pic in that thread. Also the horn front flange is a little bigger than the JBL, with some semi-circular notches on one of the long sides, IIRC. Flare seems identical, but Ive never seen them together.

[Lee in Montreal]

Just mentionning that I had several requests to repro the lenses. This is a possiblity that I am studying. Nonetheless, lenses are useless without horns. Therefore, unless somebody comes up with a good idea for sourcing horns, the project will remain shelved. After esearching, I found that the horns for the 2395 are similar to the ones for the Paragon.

A modern model number would be 2343 and H5038. I think they differ only by the mounting holes in them. For this project, I'd prefer to work with a horn that has four moutung holes on the face, instead that 9 holes on the perimeter as stock

Lee

http://katzassaudio.com/JBL Booty! 2245H's, Paragon Horns, 2441 drivers, 2123 drivers..JPG
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[doucanoe]

This has been a fun thread to watch, Lee. I have a pair of these also and are in similar condition to what you started with. The only thing holding me back from doing a restoration to mine has been their size. I would really like to go ahead with it but just not sure I would have the room to run them in when it was all said and done.

Nice work!


RC

[Lee in Montreal]

Not much development over the past two days. I ordered all new 10-32 bolts and had 20 aluminum H-stands laser cut. I also enquired with my usual CNC supplier for a quote for making those aluminum sleeves (144 required per kit). I will probably go ahead and produce 4 sets of the 2395 diffusers. They'd be exact repros of the original, and will come with alu H-stands as well as the front feet. Even repro stickers will be supplied. Just paint them to the colour you want and add your own horn. ;)

[Chas]

Nice work Lee, the pics of the finished items take me back to the days down by the lake at Le Transit in Pointe Claire. man, those things could rock!

[jw5115]

Classic Audio Reproduction/Loudspeakers has plans to make a batch of these again next yr 2012.
jw5115

[Lee in Montreal]

Classic Audio Reproduction/Loudspeakers has plans to make a batch of these again next yr 2012.
jw5115

Interesting. Where did you read that? Oups. If you are John Wolfe, you must know it first hand... ;-)
Any link to the ones produced previously?

[grumpy]

I don't think J.W. of Classic Audio Loudspeakers had to -read- it anywhere...

[Lee in Montreal]

I don't think J.W. of Classic Audio Loudspeakers had to -read- it anywhere...

Ah, ah, ah, I must have edited my post while you were typing yours. I indeed realized that jw515 may have been John Wolfe :D

Still interested to know more about the 2343 repros.

[Robh3606]

You did a great job on them.

Rob:applaud:

[Lee in Montreal]

I assembled the second 2395, but without the rear baffles this time. I will test them next week. Supposedly that fitting the baffles allow 500Hz and the unbaffled set-up allows 800Hz. We'll see. For now I temporarely stored them on top of the records shelves. This is basically 6 feet wide of 2395 diffusers... I still have to slightly adjust the blades so that they align perfectly. But hey, they look much better than when I got them, last week.

BTW I had quotes for the machining of the aluminum spacers, as well as for the laser cutting and folding of the blades. It is quite expensive and I even question if I will ever risk money on the project. :eek:

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[JeffW]

But hey, they look much better than when I got them, last week.



They look killer, really nice job on the refurb.

[Lee in Montreal]

They look killer, really nice job on the refurb.

And I am extremely happy with the paint I found. It has the right JBL feel: industrial grey with a slight touch of green. Easy to apply and quick to dry. I am tempted to redo my 2350 the same colour, with an undercoat of automotive body shutz for damping. Being into vintage cars too, I love bringing old parts to a new condition. It's always a challenge that is rewarding when it works fine. ;)

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[Lee in Montreal]

Here's my verdict after listening to music with the 2395 lenses for half a day. Magic. The sound is clear, transparent and has a lot of air. I am very positively surprised. Totally different from a conventional horn.

[grumpy]

Those came out really nice... They always appear larger when there's something else in the pic to provide scale :jawdrop:

[Eaulive]

Nice Lee :applaud:
Where did you cross them with the 4520?

[Lee in Montreal]

Nice Lee :applaud:
Where did you cross them with the 4520?

Currently crossed at 500Hz

I tried several ways to locate the horns and I think I found the most practical solution. I used a set of stands that I produced last year, and drilled the end to allow using long Allen bolts for adjustability.

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[Ruediger]

It's parallel to the horns axis, just shifted a few cm downwards. Your horn + lens radiate above Your head.

Ruediger

[Lee in Montreal]

It's parallel to the horns axis, just shifted a few cm downwards. Your horn + lens radiate above Your head.

Ruediger


Interesting. But considering the slants are 45° downward, don't they offset the radiation more than a few degrees down? Not to mention that on most discotheque installations, they are aimed horizontally or slightly upward, while covering down toward the crowd.

This set stands on a 48" tall Bertha plus a 60" tall Waldorf. That's 2.8 meter high.

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[Ruediger]

Interesting. But considering the slants are 45° downward, don't they offset the radiation more than a few degrees down? Not to mention that on most discotheque installations, they are aimed horizontally or slightly upward, while covering down toward the crowd.

The shift is a few cms, not a single degree, See http://www.lansingheritage.org/html/jbl/reference/technical/lens.htm It's elementary refraction, like in optics. In optics, the trick is that the speed of light in glass is less than the speed in air. With acoustical lenses the trick is that the path through the lens is longer. See the 2390 as an excellent example. Or see the potatoe mashers.

The TADs on top of the Waldorf in 2.8 meters height generate plenty of indirect sound and very little of direct sound. Whoever has done it - he did not know what he was doing.

Ruediger

[Lee in Montreal]

Fixed :D

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BTW Found this great cut-out of a 2440/41 driver this morning

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/compression_driver_cut_off.jpg

[Lee in Montreal]

I have finally settled with the most convenient way to organize the 2395 and tweeter. I drilled an extra hole on the 2504 adapter to bolt the bracket on the top of the lense. It is very stiff. I also cut some wood to make stands and lower the front of the lenses. Very stable. I'll paint them in dull black when I have time. In the mean time, I have changed the shape of those wooden stands from the pictured "L"¨into a reversed "T" for even better stability. ;)

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN0961.jpg

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN0963.jpg

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN0964.jpg

[Wardsweb]

But what I really want to know is how does this setup sound?

[Lee in Montreal]

But what I really want to know is how does this setup sound?

I love it. Currently the 2441s have 2445 Ti diaphragms and I will install some Radian units on the spare set of 2441 I have. I will report.

Lee

[Lee in Montreal]

I refinished the pair of 2441 drivers. I stripped the old paint effortlessly with a chemical stripper. The glue at the bottom of the caps was difficult to get rid of. Occe the covers were painted with 4 coats of dull black paint, I literally cooked them to speed up the curing process. The bodies were also stripped, sanded and repainted, with the aluminum plate polished. Spent some time cleaning up the voice coil gap. The foil caps were cleaned but they are a dull yellow. I will make some repro vinyl stickers. Won't be original, but at least they'll ne perfectly white. Good enough for me.


http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN0999.jpg
http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN1003.jpg
http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN1005.jpg
http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN1008.jpg
http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN1009.jpg

[Mr. Widget]

I've used this stuff before... it looks great if you get the right amount on the surface and can control the temperature.


Widget

[grumpy]

I literally cooked them to speed up the curing process.

LOL, I remember putting a pair of valve covers in the oven after painting them
with enamel ... worked out really well, but boy did I catch hell from my mother. :D
The smell -did- eventually dissipate in a day or two...

[Lee in Montreal]

LOL, I remember putting a pair of valve covers in the oven after painting them
with enamel ... worked out really well, but boy did I catch hell from my mother. :D
The smell -did- eventually dissipate in a day or two...

Putting stuff in the oven... I did it until I had a fireplace. What us, vintage car mechanics, often do, is to recycle working diswashers to degrease engine parts. Basically, the workshop would have its own diswasher... It works great on aluminum parts. Obviously, you wouldn't do that with the dishwasher in the kitchen (even though I know a few guys who did it - need I mention they slept on the couch for a week?). Being older guys, their spouse was initially surprised they would even touch the diswasher (not knowing what was really happening :D ).

But when painting dark parts in the summer, the sun is usually hot enough to speed-up the curing process.

[Dave G]

I bought two pairs!54597

[Dave G]

Thanks Lee for info, will be asking more questions soon.

[Dr.db]

The foil caps were cleaned but they are a dull yellow. I will make some repro vinyl stickers. Won't be original, but at least they'll ne perfectly white. Good enough for me.



Do you have some pictures of your vinyl stickers?

[richluvsound]

https://www.facebook.com/Edleyy/

Richard