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y60kuro
08-09-2016, 02:39 AM
Hello all

I am from Japan here nice to meet you . sorry poor my English I must say first. This photo is when I first met with the my 4343 . I heard this 4343 is sleeping in a few years in the my friend's garage in this state, so I went to see. The Urethane edge (2231A,2121) was damaged by aging. However, since the overall condition was good, have to be working to repair it myself, I decided to pick it up to my home.  4343 was released 1976 in Japan , hear to have been about a million sets import. JBL was surprised "so much whether the studio is located in Japan ?" . In fact it seems audiophiles had been bought as a status. but it is so expensive (about $5000 /piece 1978) those days . This 4343 is one of them . I will try to introduce a state of my 4343 repair story of here. 

Regards

7301573014

mortron
08-09-2016, 05:17 AM
You got all the good cars already over there... now I find out all the good speakers are hiding there? I need to get back in touch with my friends over there and see what's in their garage ;)

Gonna be a great project to work on with great reward. Looking forward to following.

JeffW
08-09-2016, 06:29 AM
Your English is fine, welcome!

Those 4343 appear to be in nice shape, the restoration should be fairly straightforward.

Congratulations on some very fine speakers.

y60kuro
08-09-2016, 03:46 PM
You got all the good cars already over there... now I find out all the good speakers are hiding there? I need to get back in touch with my friends over there and see what's in their garage ;)

Gonna be a great project to work on with great reward. Looking forward to following.

Hi mortoron
Thank you your comment. My old nissan safari LWB works good for JBL transporter .Yes there is so many good speakers sleeping now . DIATONE,SANSUI,YAMAHA,,,,etc . When do you come from here ? :)


Your English is fine, welcome!

Those 4343 appear to be in nice shape, the restoration should be fairly straightforward.

Congratulations on some very fine speakers.

Hi JeffW
Thank you your comment . Here is humid weather than USA so this humid is problem . bolt and unit rust ,box damage etc,,,, my 4343 has rust and little crack on the corner connection point . yes, 4343 is very nice shape I love this one. my 4343 has some problem but repair is my fun too.:)

y60kuro
08-09-2016, 06:21 PM
The day came I took the 4343 to my home from a my friend's garage. Transportation was done on my nissan. And laid down next to fit into the luggage compartment. Woofer and mid-bus(2231A,2121) for the protection and for total weight off so these unit put off. Since remove these large units then turn off the under 70kg and can move and handle easy by myself.

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The urethane edge of the unit had been destroyed in the aging. In order to prevent the voice coil in the vibration hurts, leave connection each terminals. Unit caused the repulsive force of the electromagnetic induction in doing so will stabilize, it is apparently difference you know. packing is OK, take into the cargo space , tighten by belt , let's go my home .


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The garage becomes lonely no longer stay 4343 , but my friend are willing it is the best 4343 will be active again. However, this 4343 is the speaker is a presence.

y60kuro
08-10-2016, 04:57 PM
Once put the 4343 in the garage, I will try to the maintenance of the unit and give the wax into the box of walnut. I've hidden units into the VAN cargo so as to defense from my boy and girl mischief .


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Oh! what a very unpleasant.:banghead: One of the top that had been put in the back, crack was in the right corner. Apparently the full-length seems to have peeled off from the adhesive surface is about one-third of the piece. This was at a loss. A new work has been increased. The need to remove the front baffle to also check the situation from the inside came out.  Perhaps Years of humid and 40 years have damage to the adhesive and the panel. In hot and humid in Japan, that has damaged the interior of most of the JBL is clear from this thing.


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berga12
08-11-2016, 12:51 AM
this "crack" seems more a Fall down from one side of the box.

with a cutter I would clean the crack as much as possible, insert a lot of Glue and clamp the box together, then during clamping and drying like you wrote, open the front baffle and reinforce from inside with some brakets (L shape).


Again, don't touch the blue :) looks superb.:bouncy:

y60kuro
08-11-2016, 03:50 PM
this "crack" seems more a Fall down from one side of the box.

with a cutter I would clean the crack as much as possible, insert a lot of Glue and clamp the box together, then during clamping and drying like you wrote, open the front baffle and reinforce from inside with some brakets (L shape).


Again, don't touch the blue :) looks superb.:bouncy:


Hi berga12

Thank you . Yes I checked this crack depth by wire it is so deeper than I thought :eek: My face is JBL blue . The outside of the crack to adhere to as small as possible, I will try to reinforce the corners of wood from the inside. Also coated with urethane varnish to the inside to the future of humidity measures. It deviates from the original, but, Ok in the remake. :) By the way ,I boy's name is "Ken" . This is KenDad sound :)

y60kuro
08-11-2016, 04:05 PM
The first is scheduled to open did not. But opened the baffle in order to see the situation from the internal crack is found. Removal of the woofer, removal of the front baffle is referred to as a daunting task in the 4343 owner our Japan . I can open and easy for 30 seconds in the assistant help. :applaud:


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Hello guys nice to meet you !

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ARMED
08-11-2016, 07:46 PM
y60kuro, do you mind measuring how long the ports are..please, thanks!!! i know they are 4 inches diameter

y60kuro
08-11-2016, 08:04 PM
y60kuro, do you mind measuring how long the ports are..please, thanks!!! i know they are 4 inches diameter

Hi ARMED
OK, It is very easy for me . please wait a moment :)

y60kuro
08-11-2016, 10:58 PM
port inner dia:4 inch

Total lengthface-port end :210mm
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face inner-port end :184mm
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face inner Fig
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face-port face :7mm
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baffle thick :25mm
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Is this OK?

ARMED
08-11-2016, 11:40 PM
8.25 inches long..........(8.26 inches)??

ARMED
08-12-2016, 12:00 AM
arigatou ne...

y60kuro
08-12-2016, 12:07 AM
8.25 inches long..........(8.26 inches)??
is that right?
can anyone confirm?


Yes 8.26 inch (include baffle surface + duct length)

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JeffW
08-12-2016, 07:22 AM
Those drivers look to be in really fine shape, KenDad.

y60kuro
08-12-2016, 03:37 PM
Those drivers look to be in really fine shape, KenDad.

Hi JeffW Yes this is THE JBL ! :) KenD.

y60kuro
08-12-2016, 04:08 PM
Put off front baffle , lovely shape unit guys hello . but .....

There is a clear gap in the seam of the plate. In addition there was a gap in between the cross wood bars of the reinforcement and the box . Adhesive is aging, it can be easily removed with a finger.

Can I say OMG ? ( is this right ?)

73101

Red line is clear gap :eek:
I thought almost old JBL is same condition in Japan . If it is beautiful outer box but inner box is aging because they are same age as my 4343 . JBL, which is sold at a very expensive audio shop also I think for the most part has become this way. They applied the wax in the maintenance of the outer surface there, modification of internal reinforcement and adhesion failure point is that there is no seen. I dont know Anymore and not sure then.




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Anti JBL faction say the 43 series is not good sound because the resonance of the box is. This may have the influence not have any countermeasure such internal degradation. I think unit, with the interior of the strength maintenance of the box as well as the maintenance of the network is required. I thought I will not talk about done not when the 43 series of things to the reinforcement of the box.

How do you think ?

ivica
08-16-2016, 04:11 AM
port inner dia:4 inch

Total length-face-port end :210mm

Is this OK?

Hi y60kuro,

I think than with such length Fs about 30~31Hz is something expectable for 2231/2235 bass driver in the box such as 4343 size with two vents.

regards
ivica

mortron
08-16-2016, 07:07 AM
Y60kuro,

Looks good! Restoration always has hidden surprises I find. Risk is worth the reward in this case.

I haven't been to Japan, but always wanted to visit. I like that you drive a Nissan. All I have owned are Nissan: 2 cefiro and one Pathfinder (not sure model name in Japan). Very low maintenance costs... saves money for fixing JBL's ;)

If the split in cabinet is large enough and cannot be clamped tighter, could one use a thin piece of veneer to fill the gap? That is a shame. I have seen far worse condition speakers online in very humid countries... I am starting to understand why Kenrick builds new cabinets.

Maybe you mentioned already... Will you recone and recharge the woofers too?

Keep up the good work!

y60kuro
08-16-2016, 08:12 PM
Hi y60kuro,

I think than with such length Fs about 30~31Hz is something expectable for 2231/2235 bass driver in the box such as 4343 size with two vents.

regards
ivica

Hi ivica

Thank you for the information . well, I agree .:)



Y60kuro,

Looks good! Restoration always has hidden surprises I find. Risk is worth the reward in this case.

I haven't been to Japan, but always wanted to visit. I like that you drive a Nissan. All I have owned are Nissan: 2 cefiro and one Pathfinder (not sure model name in Japan). Very low maintenance costs... saves money for fixing JBL's ;)

If the split in cabinet is large enough and cannot be clamped tighter, could one use a thin piece of veneer to fill the gap? That is a shame. I have seen far worse condition speakers online in very humid countries... I am starting to understand why Kenrick builds new cabinets.

Maybe you mentioned already... Will you recone and recharge the woofers too?

Keep up the good work!

Hi mortron

I did not even think to restore the first time in the Big Old JBL. :eek: Also the influence of humidity of the box with the car of the rust is formidable. I know your Nissan . It is Both currently not been released in Japan, but it was a good car. (pathfainder=terano) My Nissan deprive the budget and the time of the re-cone of my JBL. Oil leak was found yesterday. This time, I have to repair the 4343, but I think that will try to remake in 4333 or 4341 someday because 4343 is too large for the Japanese housing . This repair is a shortcut for that familiar with JBL.

y60kuro
08-16-2016, 10:26 PM
Box was removed all components so becomes necessary observation and repair. 2405 and 2420 also requires the maintenance there is corrosion in appearance.  The capacitance measurement of the network of the condenser, replace if necessary, to the replacement or cleaning of the attenuator. Whether the attenuator was changed once? Although it is good in addition, the changeover SW is corrosion of 40 years.:eek:

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A few days the sun drying when the weather is nice in front of the repair work.Sun drying of, including pest control, such as mites that lurk in, such as sound-absorbing material. during this time, how to repair in any way? It was to prepare the information collection.

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y60kuro
08-18-2016, 10:43 PM
I began the repair of the box. First is from the cleaning of the adhesive surface. It is the repetition of work to blow off by air ,in polishing the with a file. Cracking of the rear face of the box is very weak, decided to cut out so does not make sense to also fixed with the adhesive.

This weak of looks like this is serious in the aged deterioration due to moisture.When the state of the board to use a chisels remove until firm part, it opened a big hole in this manner.The same as the repair of the rust of the old car, requires removal of the lesion.

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Krunchy
08-19-2016, 06:14 AM
I wouldn't be too concerned, seems like you are doing a good thorough job, take your time. Most important is to re-glue the corners and get them Squared, the hole can always be filled in later. If you truly had serious pest issues with mites I would probably remove all of the insulation, clean the hell out of the interior and put in new insulation as part of the restoration process.
Have fun & keep the pictures coming. :)

y60kuro
08-19-2016, 04:03 PM
I wouldn't be too concerned, seems like you are doing a good thorough job, take your time. Most important is to re-glue the corners and get them Squared, the hole can always be filled in later. If you truly had serious pest issues with mites I would probably remove all of the insulation, clean the hell out of the interior and put in new insulation as part of the restoration process.
Have fun & keep the pictures coming. :)



Thank you Krunchy
Although I thought I can be more easily repaired, condition is not so good. I feel the strength of the board at the moisture is reduced. Therefore it is determined that strongly involves the risk is to clamp, right angle of the corner was a compromise slightly. But I thought that as much as possible the original at first but it so unreasonable likely to think in the direction to be sound-absorbing material exchange. This repair is one of my fun .:)

y60kuro
08-19-2016, 06:22 PM
In order to adhere the box is required big clamps . But I dont have,and dont have a plan to buy large clamp now. I tried to somehow thinking or not can be substituted with a hand-held ones. And those that use a long screw, but I thought the various prototypes, finally decided to go with this method using a jack.;) I admire the men who make the new box here of forum is a real craftsman. I'm just fun .

look my funny " free style clamp " :)

This type is first , but need more idea ,,,. lack of power ,,,NG :banghead:

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Finally I will go this freestyle clamp . Yes very funny ,but works good I can adjust compression by jacks and weight :applaud:
This is cooperation of toyota and nissan .

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y60kuro
08-19-2016, 07:07 PM
Woodworking adhesives vinyl acetate is the mainstream in Japan . I checked on the net about adhesives Titebond is good and stronger than the vinyl acetate-based adhesive yes I was ordered this. Further syringes were also prepared in order to fill the adhesive in the gap crack. Special nail to other wood part cracking and peeling measures were also secured.

73215

For example 1  wave nail
Use the time to fix the plate to each other.

73216

For example 2 hide nail

Nails in pink and green plastic is attached type . After drftingnails, nail head is brought into contact with the plastic in this state,
Next to hit the plastic from the side and broken nails at the lower end portion of the plastic, not only see a small hole in the thickness of the shaft. Use fix little wood parts . but dont want to see nail head .

mech986
08-19-2016, 07:31 PM
y60kuro, do you mind measuring how long the ports are..please, thanks!!! i know they are 4 inches diameter

Armed, you're very lucky to get the information so quickly!

KenD, your methods have been ingenious and very MacGyver-like. Looks like you will be able to glue down and reinforce the loosened corner. What filler and glue did you use? Some have used automotive bondo filler, others use combinations wood dust and construction wood glue, and of course a lot of pressure and elevated temperature. I've not seen humidity damage like that but have seen it in cabinets that were directly exposed to water spills or maybe open windows or poorly insulated garages?

Not sure if you have access to this but you may consider adding additional bracing to the walls, top, bottom, and back panel. You can also consider adding damping material (in the UK, bitumen sheets, in the US, Dynamat or similar adhesive backed, mass loaded) and then re-place or completely replace the insulation with new fiberglass.

Regarding the crossover and wiring, there are a few options. First, the L-pads can be cleaned - sometimes they can be opened up directly and the wiper and resistance element cleaned directly, would recommend using DeOxit Red and Gold (D5 and G5 respectively) to treat and preserved. Otherwise, they can be sprayed internally and exercised at least 50 times to get the gunk out. In some cases, people will spray and clean until no dirty residue comes out. I do not know if available in Japan, but I suspect some Audio or electronics stores will carry it.
http://store.caig.com/s.nl/sc.2/category.188/.f
http://store.caig.com/s.nl/sc.2/category.292/.f

Yes, they have a Japanese distributor who should be able to supply you.
http://www.tosy-corp.com/products-caig_new.html

The biamp switch is a difficult to clean device and to get reliable contacts, even with thorough cleaning. Considering how much corrosion is there, it may be better to consider wiring the input terminals for a direct biamp set up (bass and mid-treble-super separated and crossover wired), or just tie the inputs together for a single amp set up. Many have done that for the 43xx series biamp crossovers.

Capacitor substitution should be considered if there is a lot of corrosion, component lead or solder joint damage. They are all mylar (polyester) film types, and can be substituted with quality polypropylene or metallized polypropylene film types or other "Audio grade" types, assuming they fit the space and crossover box. The inductors are usually ok unless really corroded but wires can be restripped and reconnected. Wiring can also be repalced if needed, but usually not, just ends cut, newly stripped and re-soldered. Many will replace the input connectors with nice gold plated binding posts to allow for options on connecting speaker wire.

y60kuro
08-19-2016, 08:15 PM
Armed, you're very lucky to get the information so quickly!

KenD, your methods have been ingenious and very MacGyver-like. Looks like you will be able to glue down and reinforce the loosened corner. What filler and glue did you use? Some have used automotive bondo filler, others use combinations wood dust and construction wood glue, and of course a lot of pressure and elevated temperature. I've not seen humidity damage like that but have seen it in cabinets that were directly exposed to water spills or maybe open windows or poorly insulated garages?

Not sure if you have access to this but you may consider adding additional bracing to the walls, top, bottom, and back panel. You can also consider adding damping material (in the UK, bitumen sheets, in the US, Dynamat or similar adhesive backed, mass loaded) and then re-place or completely replace the insulation with new fiberglass.

Regarding the crossover and wiring, there are a few options. First, the L-pads can be cleaned - sometimes they can be opened up directly and the wiper and resistance element cleaned directly, would recommend using DeOxit Red and Gold (D5 and G5 respectively) to treat and preserved. Otherwise, they can be sprayed internally and exercised at least 50 times to get the gunk out. In some cases, people will spray and clean until no dirty residue comes out. I do not know if available in Japan, but I suspect some Audio or electronics stores will carry it.
http://store.caig.com/s.nl/sc.2/category.188/.f
http://store.caig.com/s.nl/sc.2/category.292/.f

Yes, they have a Japanese distributor who should be able to supply you.
http://www.tosy-corp.com/products-caig_new.html

The biamp switch is a difficult to clean device and to get reliable contacts, even with thorough cleaning. Considering how much corrosion is there, it may be better to consider wiring the input terminals for a direct biamp set up (bass and mid-treble-super separated and crossover wired), or just tie the inputs together for a single amp set up. Many have done that for the 43xx series biamp crossovers.

Capacitor substitution should be considered if there is a lot of corrosion, component lead or solder joint damage. They are all mylar (polyester) film types, and can be substituted with quality polypropylene or metallized polypropylene film types or other "Audio grade" types, assuming they fit the space and crossover box. The inductors are usually ok unless really corroded but wires can be restripped and reconnected. Wiring can also be repalced if needed, but usually not, just ends cut, newly stripped and re-soldered. Many will replace the input connectors with nice gold plated binding posts to allow for options on connecting speaker wire.



Hi mech986 Thank you so much imfo
Wow! I am so surprised by your comment . you are champ. I cant write enough comment as same as yours sorry my poor English . but I can read and understand your comment well OK :) haha OK I am ingenious repair man . I am carefully injected deep into the repair of the corner portion of this adhesive with a syringe. The narrow gap between the needle of the syringe does not turn on,The adhesive a hole was injected with a syringe with a fine drill. It is the same way as the ground improvement work. After that, the piece of wood was processed in accordance to this excised size, it was implanted with the adhesive. This is how to use well the time to repair the house of Japan's carpenter was corrosion.

Crossover network is the next of the fun of the repair of the unit after the end of the repair of the box. Since there is no knowledge about the network, I am going to study in this forum. Switching SW of bi-amp is not necessary for me. Direct to or placed in a network, I think that if try to bi-amp in the woofer and the rest of the unit who is using the network.

Information of seller also Thank you very much. It is very helpful :)

y60kuro
08-21-2016, 04:00 PM
Bit off topic sorry
I got new my toy old 4311 junk model from another friend . This 4311 is he got his friend had been used in the shop for BGM ,but a few unit was gone ,not so beautiful .Yes this 4311 is sleeping in the his room about 10 years . I have 4312A and interested in OLD original 4311 sound .
Yes I got his old 4311 exchange for beer pack .


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I played little 4311! WOW ! very nice sound ! I love 4311 sound than 4312 . :eek: Is this ALNICO magnet sound ?
Drived SANSUI and marantz 7T+ ALTEC 1520 replica tube amp both is good !

73261


OK next my repair story is this 4311 after 4343.:)

y60kuro
08-22-2016, 12:13 AM
I was injected the adhesive using a syringe to crack. The corner parts were removed brittle became part has been carefully injected.

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y60kuro
08-22-2016, 04:51 PM
OK 1000 watches thanks .
My adventurous repair continues. Space cut the brittle became part was closed with a piece of wood. Than at least brittle became board strength comes out. Also it may become volume after drying is small like a putty, cracking of the case where the amount is larger does not occur. Not the best but I think that it is a better choice that can be relatively simple.

First, by processing the shape of the piece of wood to measure the dimensions of the space,
also adjusted so to be as uniform as possible shape at the same time the board side.

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The crack of the main body side and sufficiently filled in advance adhesive, ensuring the adhesive strength Place the overnight time.
The piece of wood and the space and install with the adhesive.

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Fit perfect ! looks good. wait one night .

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Cut off the use pop-out wood piece of the hand saw for precision machining.State in which leveling scraping the surface.
perfect !

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y60kuro
08-24-2016, 04:00 PM
I put the reinforcement to all corners by the board of deterioration. Although it was also thought to hold to use screws, to adhere to the position out from that has been degraded, to hold the total has structure has also considered whether better.

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The crack of about needle of the syringe does not turn, was pressed into the adhesive drilled. The entrance of the hole was plugged with a bar of fine wood.

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mortron
08-25-2016, 06:32 AM
y60kuro, Good fortunes keep coming for you my friend. The 4311 look like another fun project.

I am so glad to see people taking time to do repair work well. I can't tell you how often I've seen or heard someone planning to fill gaps in wood with non-wood products... I can't understand it. Keep up the good work.

y60kuro
08-25-2016, 04:46 PM
y60kuro, Good fortunes keep coming for you my friend. The 4311 look like another fun project.

I am so glad to see people taking time to do repair work well. I can't tell you how often I've seen or heard someone planning to fill gaps in wood with non-wood products... I can't understand it. Keep up the good work.


Hi mortron Are your nissan and Lansing is OK ? Yes I think so too . I am running 4312A and victor SX-3 .4312A is for jazz ,SX-3 is for another music classic, vocal and FM radio. I think my 4312A is bit loud mid range to my ear I dont like this, so I will exchange 104H-3 to LE5-2 . This time I got 4311 yes it has LE5-2 mid unit ,but it is broken no sound . I think it will re-corn or import good condition used unit from USA .

4343 repair is my first work on the these speaker system . That is right you said speaker board is non-wood product but one of wood product I think . I think if they have problem it is ”The difference between the expansion rate due to moisture absorption” . real wood piece is bigger than 4343 box board . :eek: but no problem I think and it is better Laminated lumber than real wood.someday I will need to repair again . I will go to make 4344,4341,4333 box . this is my 4311 next fun . I have a time to think which box is good for me :)

y60kuro
08-25-2016, 11:48 PM
OK I decided to remove glass wool for check and reinforce 4343 box . so long times makes wood parts smaller and adhesive is week and board is damaged by humid . I will show you how it is . We cant hear loud volume revel ,very smaller volume than you, because we are very small housing situation . so I cant ignore box resonance at these small volume . These aged box (loosen connection )occur more box resonance than good condition box I think . I dont know what design concept to make these box structure .It is a very loose structure from a sense of Japanese speakers. Or probably because resonance of the box is intended to be used at high volume which is not worried. Yamaha, ONKYO, DIATONE box is very amazed by robust. Which is feel to be a difference in the design concept rather than good or not . I am very interesting these difference .


At first the take gloves and mask , it peels off from the adhesive surface with a scraper.

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Remove 4 brackets for hang on

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I can buy these reinforce wood at DIY shop lol . not so special wood.

73320

Basking in the sun shine G'day .

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y60kuro
08-26-2016, 12:02 AM
7332273323733247332573326

y60kuro
08-26-2016, 12:13 AM
enough clearance !
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aged adhesive
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Is this love letter for me ?? in the left box . :eek:

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Very interesting works on the board by using adhesive. Left box seem to be made on Friday afternoon this guy want to go movie with girl friend ??
OK I can remove glass wool very easy than right box thanks ! ;)

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y60kuro
08-26-2016, 03:48 PM
This is love letter from JBL .

7334973350

:confused:

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This box is unfinished .:p

73352

My old sansui AU9500 come back ! :)

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ARMED
08-26-2016, 08:00 PM
looking good keep up the good work...

audiomagnate
08-27-2016, 05:27 AM
This is love letter from JBL .

7334973350

:confused:

73351

This box is unfinished .:p

73352

My old sansui AU9500 come back ! :)

73354

Is that a copy of an original assembly checklist from JBL for your speakers? Where did you get that? Did that come with every speaker?

1audiohack
08-27-2016, 06:21 AM
Is that a copy of an original assembly checklist from JBL for your speakers? Where did you get that? Did that come with every speaker?

Look all the way back to post 38. ;)

Barry.

srm51555
08-27-2016, 07:18 AM
Its super cool to find something like that. Back then you had a blank master copy of that form in a file cabinet somewhere and you would copy the heck out of it, nowadays it would be on some e-library within JBL, what's the fun in that.:)

y60kuro
08-27-2016, 04:17 PM
looking good keep up the good work...

Hi ARMED thanks comment how goes your 4343 project well too? :)


Is that a copy of an original assembly checklist from JBL for your speakers? Where did you get that? Did that come with every speaker?

Hi audiomagnate thanks comment
Yes this is original checklist for my 4343 . No it is in the only one side 4343 (serial No.13403) under the glass wool beside the left duct .:eek:

73362


Look all the way back to post 38. ;)


Barry.

Hi 1audiohack thanks comment .
Yes that is right :) I was very surprised to find this love letter st first .



Its super cool to find something like that. Back then you had a blank master copy of that form in a file cabinet somewhere and you would copy the heck out of it, nowadays it would be on some e-library within JBL, what's the fun in that.:)

Hi srm51555 thanks comment

Yes ! Surely I thought it was what are hidden in a treasure map. This It is also a collector's item of JBL fan and passed 40 years.

mmm... it is seem to be my 4343 was not done outer finish works :blink:

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y60kuro
08-29-2016, 03:57 PM
A little another topic

It was sounded by connecting the removed units(2405,2420) to the network,

It feels like the volume is small.

I wonder if the magnetic force of the unit is down to extreme? Re-magnetized might need.

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BMWCCA
08-29-2016, 04:03 PM
There's not really a huge output from those even in the cabinet when compared to the woofer and mid-bass drivers.

pyonc
08-30-2016, 04:51 PM
The first is scheduled to open did not. But opened the baffle in order to see the situation from the internal crack is found. Removal of the woofer, removal of the front baffle is referred to as a daunting task in the 4343 owner our Japan . I can open and easy for 30 seconds in the assistant help. :applaud:


73058

73059


Hello guys nice to meet you !

73060

Well done! How did you open the upper cabinet or enclosure?

y60kuro
08-30-2016, 05:33 PM
There's not really a huge output from those even in the cabinet when compared to the woofer and mid-bass drivers.

Hi BMWCCA 
Thank you info. OK I understand . sometimes I hear alnico magnet reduce magnetize 5%/10year ,and any audio mania do re-magnetize here. They say reduce magnetize makes small sound .I am first time to have these JBL professional unit and dont know what is usual .thank you


Well done! How did you open the upper cabinet or enclosure?

Hi pyonc
Thank you coment. I done like this


1:remove all screw
2:remove 38cm unit
3:put jack on under upper baffle lower end
4:slowly up jack , easy to open upper baffle

73426

pyonc
08-30-2016, 05:55 PM
Hi BMWCCA 
Thank you info. OK I understand . sometimes I hear alnico magnet reduce magnetize 5%/10year ,and any audio mania do re-magnetize here. They say reduce magnetize makes small sound .I am first time to have these JBL professional unit and dont know what is usual .thank you



Hi pyonc
Thank you coment. I done like this


1:remove all screw
2:remove 38cm unit
3:put jack on under upper baffle lower end
4:slowly up jack , easy to open upper baffle

73426

Nice job!:applaud:
By the way, can you explain how you opened the L-Pad? It looks like you used something like hair dryer.
As a big fan of 4343, I'm curious. Thanks.

y60kuro
08-30-2016, 06:47 PM
Nice job!:applaud:
By the way, can you explain how you opened the L-Pad? It looks like you used something like hair dryer.
As a big fan of 4343, I'm curious. Thanks.

Hi Thanks man . Sorry I am poor English L-Pad is aluminum plate is oK ? Yes I used hair dryer to heat and Loosen warm a pressure-sensitive adhesive, it was peeled off slowly. I think to use heat gun first but I can do heir dryer .:)

y60kuro
08-30-2016, 11:56 PM
Little progress

Add brace : all corners  / center (top,bottom, middle brace)

This such as an image of the reinforcing fixing of front baffle and adhesion reinforcement of the every corners. Is this produce good results, is or not I do not know.Better to mood reinforced is the idea say it would be good.

73429

Also reinforced in the same way as the other side.

73430

pyonc
09-01-2016, 03:13 PM
Hi Thanks man . Sorry I am poor English L-Pad is aluminum plate is oK ? Yes I used hair dryer to heat and Loosen warm a pressure-sensitive adhesive, it was peeled off slowly. I think to use heat gun first but I can do heir dryer .:)

Yes. Did you clean the L-pad inside?
You see the three volume control knobs(UH, M, LF), and I mean, clean them inside.
You're strongly recommended to remove any possible scratch noises.

y60kuro
09-01-2016, 11:46 PM
Yes. Did you clean the L-pad inside?
You see the three volume control knobs(UH, M, LF), and I mean, clean them inside.
You're strongly recommended to remove any possible scratch noises.

Hi pyonc
No I have not done yet but I will clean it next step after box repair . my 4343 is long time sleeper old girl I agree you said thank you.

horrible :p
73444

pyonc
09-02-2016, 04:59 AM
Hi pyonc
No I have not done yet but I will clean it next step after box repair . my 4343 is long time sleeper old girl I agree you said thank you.

horrible :p
73444

Can you show some more pictures of them? It looks a bit rusty already... Thanks.

BMWCCA
09-02-2016, 02:56 PM
Looks like the bi-amp switch to me, but then I don't have one on my 4345s and that's not the greatest photo! :dont-know:

y60kuro
09-02-2016, 05:34 PM
Can you show some more pictures of them? It looks a bit rusty already... Thanks.

Hi pyonc I have L pad pic is just only this . L-pad seem to be replaced once already but over 10 years sleeping 4343 ok I will maintenance it inside thank you every time .

73471




Looks like the bi-amp switch to me, but then I don't have one on my 4345s and that's not the greatest photo! :dont-know:

Hi BMWCCA Yes this is bi-amp selector SW it is so ripen by 40 years time . I think I will off this or make terminal for direct thank you again.

pyonc
09-02-2016, 06:16 PM
Hi pyonc I have L pad pic is just only this . L-pad seem to be replaced once already but over 10 years sleeping 4343 ok I will maintenance it inside thank you every time .

73471





Hi BMWCCA Yes this is bi-amp selector SW it is so ripen by 40 years time . I think I will off this or make terminal for direct thank you again.

Nice picture. I look forward to the final outcome of your repair job at the moment.:applaud:

BMWCCA
09-02-2016, 07:07 PM
Hi BMWCCA Yes this is bi-amp selector SW it is so ripen by 40 years time . I think I will off this or make terminal for direct thank you again.

Just bi-amp and forget the switch. You'll never regret it.

y60kuro
09-02-2016, 07:09 PM
Nice picture. I look forward to the final outcome of your repair job at the moment.:applaud:

Hi pyronc thank you. I think I want to finish repair box till winter because we have sow here ,this winter I want to stay 4343 in the warm my room . unit and crossover network can repair in the room . it is good to reading Haruki Murakami novels with 4343 sound :)

y60kuro
09-02-2016, 07:15 PM
Just bi-amp and forget the switch. You'll never regret it.

Hi BMWCCA OK I will go bi-amp how it goes I am very look forward to . I think upper 3way (2405+2420+2121) is ALTEK 1520 type tube , 15inch unit is marantz solid state amp with marantz 7T or model 3300 or SC-9 .

pyonc
09-03-2016, 08:11 AM
Hi pyronc thank you. I think I want to finish repair box till winter because we have sow here ,this winter I want to stay 4343 in the warm my room . unit and crossover network can repair in the room . it is good to reading Haruki Murakami novels with 4343 sound :)

Good luck! I think you know Haruki is a great jazz fan, and his main system is vintage JBL speaker.

y60kuro
09-26-2016, 06:07 PM
I am so busy these days my4343 is resting in garage . add brace inside is finished ,next to go inside paint , fix glass wool , sanding outside veneer and pint watoco wax , paint rear baffle .... so many workshop (fun ) remain .

73798

Bit off topic. My4312A is something wrong oneside 2213H . the other side 2213H is very good to move smooth when I tap cone rightly . The wrong side 2213H cone stay bit inside , does not move smooth . I need to repair this one . I wonder how to repair ,,,, it is very clean unit I dont want to replace cone and voice coil . Should I replace edge and damper ? I found 2213H edge kit on e-bay shop but cant find damper for 23213H .


73796


and just I am playing on bi amp system using 4343 internal network for 2405,2420 and direct to 2212 on my 2nd system . this 4311's LE25-2 and LE5-5 is no sound broken unit both side , this 3way all alnico bi-amp funny system sound is so good ! l dont need 4343 anymore ??

Yes just joke lol.


control amp : marantz 7T (1967) use 1 and 2 preout
2405,2420 : sansui AU-D907X (1982) with 4343 internal crossover network for 2405.2420.
2212 : sansui AU-9500 (1972)

73797

berga12
09-28-2016, 01:05 AM
I've the same problem on my 12" out of JBL4315A, you have to Replace the spider.... :(

unfortunately to do that you have to cut the suspension....dustcap....old spider....

Re-place spider, Re-center voice coil, Re-glue spider....new suspension......new dustcap :(

Over the years could happen that the spider is broken or loose tension.

y60kuro
09-28-2016, 04:19 PM
I've the same problem on my 12" out of JBL4315A, you have to Replace the spider.... :(

unfortunately to do that you have to cut the suspension....dustcap....old spider....

Re-place spider, Re-center voice coil, Re-glue spider....new suspension......new dustcap :(

Over the years could happen that the spider is broken or loose tension.


Hi berga12

Thank you advice. I done it like this :)


7381273813738147381573816

y60kuro
10-05-2016, 03:57 PM
7391173912739137391473915

y60kuro
10-05-2016, 04:01 PM
I've applied a water-based urethane varnish inside.

7391673917

y60kuro
10-05-2016, 04:04 PM
I have a base adjustment of the surface with a file of # 240

7391873919

NWCgrad
10-05-2016, 04:41 PM
They have come a long way, great effort!

ARMED
10-05-2016, 08:00 PM
good job man....thanks for your help!!!!

y60kuro
10-06-2016, 03:50 PM
They have come a long way, great effort!

Thank you NWCgrad . I dont have special skills and tools but have mind of DIY .



good job man....thanks for your help!!!!

Thank you man . It will finish box soon .

y60kuro
10-06-2016, 04:15 PM
I was finished with WATCO oil the veneer of 4343. I'll show you how I did and if the info. Place the cushion on the 2x4 wood was placed in a state of floating from the floor to 4343 in this manner. It gave a masking to wrap on the inside. WATCO oil used was dark walnut. And paint and put in a bucket, but since very high liquidity note that the spill in this manner. :p

73925739267392773928

y60kuro
10-06-2016, 04:29 PM
Was painted using a brush of small and large. Small brush is used to small end part of the baffle side. Baffle beside was painted carefully in the first because it is very high fluidity oil. Then paint from the top to the bottom, go paint under taking into account the oil dripping down. It is very easy to paint. I think that there is no problem after it pint carefully baffle side only.

7392973930

y60kuro
10-06-2016, 05:18 PM
After leaving for about 15-30 minutes, wipe the WATCO that stand out on the surface with a dry cloth. Then paint it again one more time the WATCO 1/4 amount for the first time. And dried 24-48 hours. Currently this is the last in a dry state. Please read the notation of container for more information. Also this wipe cloth is also needed attention in this process because the flammable increases.

739317393273933

y60kuro
10-07-2016, 04:51 PM
And removing the glass wool on the upper side of the baffle, it was painted urethane varnish. Box for midbus the plate also thin, was a structure that is very resonant sound when knock box. 2121 sound is said to smell the paper, but I feel that whether there is also the effect of this box. This is it is not good. need something .Also likely to better absorb the moisture in the porous material. Although I think that the thinking of internal loss, I can not ignore the influence of moisture. In fact varnish also suction like the sand.

7394073941739427394373944


And I got sansui vintage channel divider for bi-amp , yes this need fix too now I list up internal parts capacitor ,register,solid state ,,,,,log way to 4343

y60kuro
10-11-2016, 05:18 PM
I invited the 4343 in my house from the garage because the finished major maintenance of the box. Veneer, of the rear baffle maintenance, removal of glass wool, moisture-proof measures and surface enhancement of the board due to the internal of urethane varnish, additional reinforcement. I will next to go the upper baffle maintenance, selection of sound-absorbing material, network of maintenance, replacement of the unit edge (2121,2213A),,,,

7401374014

y60kuro
10-28-2016, 06:37 PM
I got sheep wool insulation for my 4343. This is made for audio insulation (25mm thick, natural sheep wool 85% ) . Good by tired , strange smell , living germ yellow original glass wool insulation.  I calculate the required area of about 15,325 cm2 in the body on one side, mid-box back is 3,045 cm2,  total by a pair 36,740 cm2 . Mid inside 2,570 cm2 in pairs.....


*4343 body :15,325 (cm2/one side)-----30,650(cm2/pair)
*mid box outer:3,045 (cm2/one side)-----6,090(cm2/pair)
*mid box inside: 2,570 (cm2/one side)-----5,140(cm2/pair)
-----------------------------------------------------------
total 41,880(cm2/pair)

This box inside 30,000(cm2). Shortfall there is no dealer stock will be at a later date.


74269

ARMED
10-28-2016, 11:16 PM
keep up the good work man!

y60kuro
11-03-2016, 04:00 PM
I was fixed with a staple of the insulation.

7440174402

pyonc
11-08-2016, 12:39 PM
I was fixed with a staple of the insulation.

7440174402

Nice!

y60kuro
01-31-2017, 04:26 PM
A little time passed since last post.

My 4343 repair is ongoing.


7575575756

y60kuro
01-31-2017, 05:08 PM
Remove ripe urethane edges 2121 

7576475765757667576775768

x2

JeffW
01-31-2017, 05:13 PM
Good to see you are making progress, nice work!

y60kuro
01-31-2017, 05:39 PM
Good to see you are making progress, nice work!

Thank you JeffW  :)

y60kuro
01-31-2017, 05:48 PM
7576975770757717577275773

y60kuro
01-31-2017, 05:51 PM
75774757757577675777

X2

Need twice times as 2121 :)

hansenni
01-31-2017, 08:31 PM
Well done:hurray:

laszlo
02-01-2017, 01:22 PM
amazing job!!!

Flodstroem
02-01-2017, 02:42 PM
Compression drivers including UHF drivers does normally not need any re-charging of the magnet because Alnico V is very stable
when used with those small electrical induction levels in the HF and UHF frequencies
But those 2231A could have loosen some of the magnetic charge due to large electrical inductions from the voice coil so a re-charging of the magnet could probably be beneficially. It can be done with voice coil and cone mounted in the basket. No need for to take it out. ;)

Btw, A hell of a restoration work for you, and it looks very very good so far :)

y60kuro
02-01-2017, 07:54 PM
Well done:hurray:

Thank you hansenn :)


amazing job!!!

Thank you laszlo :)


Compression drivers including UHF drivers does normally not need any re-charging of the magnet because Alnico V is very stable
when used with those small electrical induction levels in the HF and UHF frequencies
But those 2231A could have loosen some of the magnetic charge due to large electrical inductions from the voice coil so a re-charging of the magnet could probably be beneficially. It can be done with voice coil and cone mounted in the basket. No need for to take it out. ;)

Btw, A hell of a restoration work for you, and it looks very very good so far :)

Thank you good knowledge Flodstroem
I will do re-magnetize 2231A or change LE-5A . it is first time to do this job for me , remove and clean up unit frame was so hard to my finger ;)

y60kuro
02-01-2017, 08:04 PM
Fix edge and cone first .

75789757907579175792


Leave overnight my 2121

y60kuro
02-01-2017, 08:07 PM
Next to 2231A

757937579475795

Good night guys see you next morning ;)

Flodstroem
02-03-2017, 05:55 PM
Me to put the glue on both parts, the foam surround and the cone before putting them together. The benefit for doing that is that no part of the cone and foam will lack any glue and it also making it possible to "move" the foam surround on the cone for a short time for to get it exactly placed even and centered all around the
circumference of the cone :)

Take care of your finger tips and dont use to much of solvents....... ;)

y60kuro
02-03-2017, 07:18 PM
Me to put the glue on both parts, the foam surround and the cone before putting them together. The benefit for doing that is that no part of the cone and foam will lack any glue and it also making it possible to "move" the foam surround on the cone for a short time for to get it exactly placed even and centered all around the
circumference of the cone :)

Take care of your finger tips and dont use to much of solvents....... ;)

Thank you Flodstroem .

I used a slow drying type vinyl acetate adhesive. Since the damper was not weakened, centering was also possible without problems. I removed the old urethane with the power of my fingers, so it took quite a while and my fingers were very tired. :)

y60kuro
02-03-2017, 07:24 PM
Morning guys !

7584975850758517585275853

Leave half a day :)

srm51555
02-03-2017, 08:41 PM
Nice progress

Flodstroem
02-04-2017, 02:46 PM
Yea Nice progress ;)