JBL 4355 Replica

[berga12]

Dear JBL lovers,
I would like to share with you my JBL4355 replica, from Italy!

first of all this is a really expensive project, and it's really difficult to find components in good condition...
I was coming from a Setup build up with JBL4560 with Altec 416-8A and 2441 in 2350 plus fostex Ft65h (i'm still owner of box and horn :D)
so...2441 was present...lets start.

I decided since beginning to avoid a FULL replica with Classic blue and classic walnut veneer, not because i don't like, but to avoid drastic mistakes and reduce a bit enclosure cost (i'm not expert in veneer and i've no skills to do it). A carpenteer friend of mine help me in the construction than i'm finishing in house the internal furniture.

we used 24mm birch (really heavy strong and dense) for full structure, at the end is something like double the weight and rigidity of a normal playwood (a 24mm thickness count something like 14-16 layers)

we decided for a removable back to help working inside, maybe later on, this back panel will be fixed and glued together with the box, let see how it sound...

I decided to try with a normal filtering without Charge coupled variant, but i will try also the equivalent schematic simulating the autotrasformer.
I Re-use some material coming from previous setup, so expense was not huge, and i'm also thinking to try a full passive variant.

for the moment I just found an UREI 5235 and I'm going to build 290hz 18db board for him.

I'll start with a couple of UCD400H&R for woofers and MC2120 alternate with Uesugi 211 tube amplifier for mid-high.

At the moment I miss 4-2235h, I found them in USA but I'm thinking about the huge expense to bring them to Italy (i just bought a mint 2202h couple from USA...sigh!) but I have 4 E140 basket empty and 4 2226h that i want to try (setting the tune to 35hz), simulation show not far away response, even if i suppose 2235 sound far much lower and better (maybe)...

so, come on and Kill me with suggestions/opinions!
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[berga12]

more...
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[berga12]

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[berga12]

7060970610706117061270613

[berga12]

I found nice 077 Alnico, so i will go with them...

2405 i've on a pair of JBL4315 original, also Alnico version but yellw diaphagram, i suppose they sound similar.


7061470615706167061770618

[Challenger604]

Very Very nice!!!

If I may, If it's not too late! I would use a bigger gauge for the wiring.
And I would make sure that the back panel is very well attached to the back of the 2202 chamber.
Vibration from the bass could give you some parasite sound.

I want to build an other pair...
C

[berga12]

Thanks!

wire is 1,3mmq teflon insulate mil spec, OFC copper silver plated.

i can duplicate the size on the woofer (up to 2,3mmq each conductor +/-)

for mid-high should be enough.


i still need to compensate 6-7mm between MID box and back panel,but i've two solution:

- Just a Neoprene gasket to avoid any kind of vibration plus 2 screw on the back of the box
- compensate the 6-7mm with solid wod panel and add 5 screw on the back of the box ( one in the center one on each corner)

you think 1,3mmq is not enough as wiring? it should easily handle 6-7Amp (not common for an house usage...)

[berga12]

Filter progress, for the moment i will use a 2,2mH Jantzen toroidal coil (i've those ones at home :)), let see, in case i will buy some Mundorf L200 air core 2,4 (i've some 3.3mH and don't want to un-wire them...)

i will also place 0.01uF bypass capacitors, 2441 attenuation i will try with Autotrasformer if needed.

All Series component are Mid-high quality, parallel one a bit less but still nice level.

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[Challenger604]

Thanks!

wire is 1,3mmq teflon insulate mil spec, OFC copper silver plated.

i can duplicate the size on the woofer (up to 2,3mmq each conductor +/-)

for mid-high should be enough.


i still need to compensate 6-7mm between MID box and back panel,but i've two solution:

- Just a Neoprene gasket to avoid any kind of vibration plus 2 screw on the back of the box
- compensate the 6-7mm with solid wod panel and add 5 screw on the back of the box ( one in the center one on each corner)

you think 1,3mmq is not enough as wiring? it should easily handle 6-7Amp (not common for an house usage...)

I would increase to 1.63 to the high and 2.06 to the bass. That's what I would do.
The conductibility quality is of course important but the quantity also.

Here is the conversion table: http://www.firemountaingems.com/resources/encyclobeadia/charts/6404

And I would recommend for your speaker wires, 12 guage, 2,06 mm... At least...

I would go with the wood and screws...

Cheers!
C

[srm51555]

Those are looking awesome, nice work.

[berga12]

ok let say, for woofers i will double the cable up to 2,6mmq (c.a. 10AWg)

for 2202h and 2441 & 077 i would keep 1,3 (16 Awg), i will not give them never more than 100W, way to much...

i can mybe think to double the section on 2202h... even if his cable is quite short.


Main cable will be something like 4x4mmq, so no problem.

http://www.atlanticpc.com/cable.jpg

[Challenger604]

ok let say, for woofers i will double the cable up to 2,6mmq (c.a. 10AWg)

for 2202h and 2441 & 077 i would keep 1,3 (16 Awg), i will not give them never more than 100W, way to much...

i can mybe think to double the section on 2202h... even if his cable is quite short.


Main cable will be something like 4x4mmq, so no problem.

http://www.atlanticpc.com/cable.jpg
Up to you! 16 is too small. You won't even go to 100 Watts. If you go that far, you will destroy your hearing. They are soooo efficient!
You don't need 10 guage below 50 feet. If you bring 10 to the terminal and you don't have anything to follow, whats the point??
14 for the high is what I would do...
Cheers!
C

[Challenger604]

i can mybe think to double the section on 2202h... even if his cable is quite short.


If the hose section is small, even a short hose will not give you a lot of water...
Do you see what I mean? I would do the same to the 2405 and 2441...
But it is just me...
C

[berga12]

i'm Just speaking about internal Wiring

lenght are something like:

25" for every woofer

30" for Mid 2202

35" for both 2441 & 077


External wiring from Amp to SPeakers will be something like 10-15feet, not more.

[berga12]

i can mybe think to double the section on 2202h... even if his cable is quite short.


If the hose section is small, even a short hose will not give you a lot of water...
Do you see what I mean? I would do the same to the 2405 and 2441...
But it is just me...
C


i get your point ;) and i'll take this suggestion.

those speakers can be driven in any case with Few watts for home listening.

[Challenger604]

i get your point ;) and i'll take this suggestion.

those speakers can be driven in any case with Few watts for home listening.

Good!
You may know but just in case...

All the drivers polarity are reversed. The red is the negative and the black is the positive.

For the 4355 all drivers should go forward. All positive phase.
C

[berga12]

Good!
You may know but just in case...

All the drivers polarity are reversed. The red is the negative and the black is the positive.

For the 4355 all drivers should go forward. All positive phase.
C


i will check
from schematics all polarity are reversed, but not for 2441 where minus is minus and plus is plus (dual 12db filtering gives 0 phase rotation)

for woofers, even if Active, should be like you said due to the reverse polarity on the UREI 5235 right?

good. i'll check phase before mounting the driver in box.

[Challenger604]

i will check
from schematics all polarity are reversed, but not for 2441 where minus is minus and plus is plus (dual 12db filtering gives 0 phase rotation)

for woofers, even if Active, should be like you said due to the reverse polarity on the UREI 5235 right?

good. i'll check phase before mounting the driver in box.


The 2441 is also reversed.

On your passive crossover inside the speaker. The red (output) of your crossover goes to the black of the driver and the black goes to the red. This for all the drivers.

The 2235's are in parallel to give you a 4 Ohms... Or less with JBL's. The all highs should give you about 6.5 Ohms.

The 5235 has nothing to do with the polarity of the drivers, speaker.
You will connect your amp to the speaker as a regular speaker. Red to red...

When everything will be done and connected. Check the phase with a phase checker. That could be usefull...

I know, it could be confusing sometime.
C

[berga12]

Just checked schematics, right all reversed.

also woofer? mean, ok they are in parallel, but i will also use the negative as a positive? (as i know JBL winding is reversed itself...?)

[Challenger604]

Just checked schematics, right all reversed.

also woofer? mean, ok they are in parallel, but i will also use the negative as a positive? (as i know JBL winding is reversed itself...?)


Yep! Same thing!

[berga12]

Thanks

Also Cork gasket is missing, do I need Cork or Neoprene is just fine?

[Challenger604]

Thanks

Also Cork gasket is missing, do I need Cork or Neoprene is just fine?

No no don't worry none are missing. i installed it later.

I would do with cork. I bought a sheet of 2x4 at a craft store that we have here and cut each of them.
you have some on ebay but it's expensive and I don't see the point to spend that much money.
A sheet is about $20 for all and more.

[berga12]

fine, i will do so :bouncy:

[Challenger604]

fine, i will do so :bouncy:

That is what I would do but of course is all up to you!

Neoprene can make a mess after awhile. They don't age well.
Cork is way better!... Like a good old bottle of wine!
Cheers!

[berga12]

here a simulation between 2 2226h and 2 2235h, first tuned to 36hz second tuned to 28hz.

Ofcourse no discussion on the fact that 2235 have a lower and more flat response, for a studio monitor should be the best solution.

in the meantime i will get some 2235h, i try also 2226h, they should have much more efficiency and a better transient Impact/response, but not so deep bass.

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[berga12]

Challenger is asking and I'm doing ahahah, Just kidding.

AWG 13, all around :bouncy:
70628

[Challenger604]

Challenger is asking and I'm doing ahahah, Just kidding.

AWG 13, all around :bouncy:
70628

Ha ha ha!! No no! I know exactly what you are doing!
Good idea!
C

[berga12]

I had some issue with One box... unfortunately the drilling for 2311 was not so precise, and fit a 1/4-20 screw was not easy, i would have to open the hole up to 9mm :blink:

so i decided to use a gasket, M5 brass screw and Self blocking nut+washer inside the box, the fitting looks nice, it takes just 15min more to dismount the driver, and i hope he will stay in place for long time.

bigger wire are also for the driver (not pictured)

here you can see my driver support copy-paste from the other 4355 thread.

I had one 2311 not so clean, and a nice H93, so decided to paint fully in black to match front panel.

maybe a bit to fashion, but front finish will be Gold/Black, elegant.... I've in my planning to substitute also tweeter screw ;)

7073470735

[Challenger604]

I had some issue with One box... unfortunately the drilling for 2311 was not so precise, and fit a 1/4-20 screw was not easy, i would have to open the hole up to 9mm :blink:

so i decided to use a gasket, M5 brass screw and Self blocking nut+washer inside the box, the fitting looks nice, it takes just 15min more to dismount the driver, and i hope he will stay in place for long time.

bigger wire are also for the driver (not pictured)

here you can see my driver support copy-paste from the other 4355 thread.

I had one 2311 not so clean, and a nice H93, so decided to paint fully in black to match front panel.

maybe a bit to fashion, but front finish will be Gold/Black, elegant.... I've in my planning to substitute also tweeter screw ;)

7073470735

Hello Luca!

You could'nt find the right screws and the gaskets for the 2311 and 2405?
I'm sure a good hardware store would have it!
Let me know! I could help you!

I painted my 2405 screws and had helen screws for the 2311's.
Anyway! You are getting closer!!
Good for you!
Cheers!
C

[berga12]

Hello Luca!

You could'nt find the right screws and the gaskets for the 2311 and 2405?
I'm sure a good hardware store would have it!
Let me know! I could help you!

I painted my 2405 screws and had helen screws for the 2311's.
Anyway! You are getting closer!!
Good for you!
Cheers!
C


HI,
unfortunately it's not so easy to find them here in my city and i can see many on e-bay but with some expensive delivery cost (25-26 USD just for shipping...)

i will try another shop here, because i would like to use Flat head 8/32 philips slot for the tweeter and re-try 1/4-20 later on for the driver...

Gasket no problem, real problem here is the UNC/UNF screw variants, here we have Metric unit.:crying:

if you have a set 8+8 screw as spare....contact me! :)

[Challenger604]

HI,
unfortunately it's not so easy to find them here in my city and i can see many on e-bay but with some expensive delivery cost (25-26 USD just for shipping...)

i will try another shop here, because i would like to use Flat head 8/32 philips slot for the tweeter and re-try 1/4-20 later on for the driver...

Gasket no problem, real problem here is the UNC/UNF screw variants, here we have Metric unit.:crying:

if you have a set 8+8 screw as spare....contact me! :)

I could'nt find phillips screws for the 2441 but I used helen screws and it works very well. You don't even see the difference! Of course if you put your nose on... LOL!! I can go get it for you also!

For the 2405's screws, le me know if you can find it! If not, I can go to get it for you.
You just need to spray some paint on it like I did and nobody will see it!

I'm going to see my dad in spain and could send the all thing to you from there!

Let me know!

Please let me me tell you that you are building a piece of art that will bring a great joy that the real audiophile will appreciate!

Cheers to that!

[berga12]

My Grills, small modification compared to original, but I see those as an improvement! Material is MDF and solid wood for the domes.

now i need to prepare holes for support pin (i will not use the original ones that may broke,i will make some aluminium or teflon Dome and screw them on the front panel), mill insert for Magnets (i will use 8 neodinium magnets 12x2mm 1,2kg force each) and place some hidden screw on the front, exactly in the project position (hidden by the softer part of Velcro, to protect magnets from strong impact). :bouncy:

Grills are made by my carpenter on CNC machine.70749707507075170752

[Challenger604]

My Grills, small modification compared to original, but I see those as an improvement! Material is MDF and solid wood for the domes.

now i need to prepare holes for support pin (i will not use the original ones that may broke,i will make some aluminium or teflon Dome and screw them on the front panel), mill insert for Magnets (i will use 8 neodinium magnets 12x2mm 1,2kg force each) and place some hidden screw on the front, exactly in the project position (hidden by the softer part of Velcro, to protect magnets from strong impact). :bouncy:

Grills are made by my carpenter on CNC machine.70749707507075170752

Very nice! CNC makes it so easy!

[berga12]

Below one filter, not yet finish!
bypass cap are missing, Neutrik connector and IN-OUT cable,and Autotrasformer for 2441!


70870

[berga12]

grills assembly

7088570886

[ARMED]

beautiful! I wish someone could build me this here in SoCal!

[Challenger604]

grills assembly

7088570886


Very nice!
Your screws are in the envelop and ready to go!
I'll let you know when posted from Spain!
Cheers!
C

[berga12]

Thanks Christope!


Armed I'm pretty shure there is a good carpenter or wood specialist that can make a replica For you!!!! The cost should be between 650-1000 dollar (For 2 cabinet)

[Challenger604]

Thanks Christope!


Armed I'm pretty shure there is a good carpenter or wood specialist that can make a replica For you!!!! The cost should be between 650-1000 (tel:650-1000) dollar (For 2 cabinet)


For me Luca?
Those on my avatar are what I made!
you didn't know?

http://www.audioheritage.org/vbulletin/showthread.php?11166-4355-Monitor-Plans/page3

[berga12]

Was for the user ARMED

[Challenger604]

Was for the user ARMED

Oh! Sorry! Was confused...

[focalguy]

You gents could also build the JBL 4351's.....as Christophe knows I have built the 4355 too...much better stereo imaging with the 4351. I am using all active crossovers.. the new DBX 360.. it has auto room eq and makes a huge difference...Unheard spl's 122db!and clarity. Love blending the old with the improved digital age.

check out some videos on YouTube..search for channel : KangSound.


Armed I'm pretty shure there is a good carpenter or wood specialist that can make a replica For you!!!! The cost should be between 650-1000 dollar (For 2 cabinet)[/QUOTE]

[ARMED]

Thanks Christope!


Armed I'm pretty shure there is a good carpenter or wood specialist that can make a replica For you!!!! The cost should be between 650-1000 dollar (For 2 cabinet)it would be better to find a carpenter/jbl enthusiast

[Challenger604]

That is very very cheap!

[Challenger604]

Hi Luca,
Sent it from Mijas, you should get in within 4 to 5 days!
Cheers!
C

[berga12]

Hi Luca,
Sent it from Mijas, you should get in within 4 to 5 days!
Cheers!
C


Thanks!!!! that sound great!

[berga12]

Grills are going to be finish soon!!!! :bouncy:

than, driver and first switch on!!!! I'm in delay with crossover card for my 5235, i will use an Alto mobile temporary untill I finish the PCB's!

713137131471315

[Challenger604]

Grills are going to be finish soon!!!! :bouncy:

than, driver and first switch on!!!! I'm in delay with crossover card for my 5235, i will use an Alto mobile temporary untill I finish the PCB's!

713137131471315


Very nice! Hang in there Luca!

[berga12]

Small progress....this weekend I should mount the drivers and make the first trial! :bouncy:

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[1audiohack]

Those look great!

Barry.

[Challenger604]

That makes me want to begin my grills!!I'm sure you will be a bit emotional when you gonna hear some sound coming out of it!They are a very big project...Congrat!Cheers!

[Mr. Widget]

Those look great!:bouncy:


Widget

[berga12]

Mid high complete, and done some cabling on crossover network.....road to the "end"

Velcro is 3M type, so sticky that I don't need to put staplets! a bit wider than the original progect, this is 1", but it looks fine and keep what he need to keep!

Gold finishing on black is nice, still need to change screw on the 2441 and paint them in black, then place the foilcal that a friend provide me, but this is just final "makeup", now I'm fighting with the Vents for the 2226h and prepare vents for 2235h!:blink:

71541

[Challenger604]

Mid high complete, and done some cabling on crossover network.....road to the "end"

Velcro is 3M type, so sticky that I don't need to put staplets! a bit wider than the original progect, this is 1", but it looks fine and keep what he need to keep!

Gold finishing on black is nice, still need to change screw on the 2441 and paint them in black, then place the foilcal that a friend provide me, but this is just final "makeup", now I'm fighting with the Vents for the 2226h and prepare vents for 2235h!:blink:

71541


Hi Luca,
Very nice!

I didn't stapled the velcro at the begining. But after awhile they gonna detached very slowly by themself and you might found your lenses on the floor broken... I would cut it to the width and staple it.
Did you place some cork gasket around the 2202?

C

[berga12]

Ciao,
I didn't found the right "rubber cork" to my need at the shop, and the only Cork I found was really instable and fragile.

For the time being I used a 1cm x 3mm Neoprene that gave me a nice fitting, I hope to do not have to dismount the driver so often, if I will find the right cork I can substitute the Neoprene.

[Challenger604]

Ciao,
I didn't found the right "rubber cork" to my need at the shop, and the only Cork I found was really instable and fragile.

For the time being I used a 1cm x 3mm Neoprene that gave me a nice fitting, I hope to do not have to dismount the driver so often, if I will find the right cork I can substitute the Neoprene.

You should be fine with that too.

[ARMED]

those are nice grills! im gonna make one myself for my barzilay box and get rid of the lattice grill!

[berga12]

My crossover is also finish, I need to cut a nice Plexyglass Panel

I left space for eventual:

- Auto transformer for 2441
- Passive high pass for 2202h
- Passive low pass for Woofers
- space for passive biamp connector and woofer exit

Just in case I would like to try something different and speriment.

Starting design will be as the project request.715877158871589

[Challenger604]

My crossover is also finish, I need to cut a nice Plexyglass Panel

I left space for eventual:

- Auto transformer for 2441
- Passive high pass for 2202h
- Passive low pass for Woofers
- space for passive biamp connector and woofer exit

Just in case I would like to try something different and speriment.

Starting design will be as the project request.715877158871589

I would use Solen components if I was you. Top of the top and very good looking...

[berga12]

Sorry, but I don't Agree, Solen are fine, but those are Mundorf (one Jantzen) and some Russian Cap, Far away better than Solen.

Just look their website and variety of product and price they have.


beside that, that could be a personal choice, I had nearly 70% of the crossover components at home, so it make no sense to spend additional 300-400€ for Solen that it's even not better.


Solen is a good component with good price/quality compromise, Mundorf,Jantzen,Obligato,Hammond etc etc etc are State of the Art.;)

[Challenger604]

Sorry, but I don't Agree, Solen are fine, but those are Mundorf (one Jantzen) and some Russian Cap, Far away better than Solen.

Just look their website and variety of product and price they have.


beside that, that could be a personal choice, I had nearly 70% of the crossover components at home, so it make no sense to spend additional 300-400€ for Solen that it's even not better.


Solen is a good component with good price/quality compromise, Mundorf,Jantzen,Obligato,Hammond etc etc etc are State of the Art.;)


Oh Sorry Luca!
We don't usualy deal with Russia in North America! That's the way it goes around here...

[ivica]

My crossover is also finish, I need to cut a nice Plexyglass Panel

I left space for eventual:

- Auto transformer for 2441
- Passive high pass for 2202h
- Passive low pass for Woofers
- space for passive biamp connector and woofer exit

Just in case I would like to try something different and speriment.


Hi

using toroidal core for LF section (without air gap), hmmmm ???? very unusual decision...

regards
ivica

[berga12]

This toroidal jantzen was at home already.

my plan is to change with an air core flat wire in the near future, but for a 2.4mH is quite expensive.


I have some 3.3mH L200 mundorf at home in cAse i want to remove some wiring and Bring them to the right value....but not Now

[berga12]

And finally assembled! Now I've to switch them On!

in the meantime I'm preparing 2235h woofer, but final simulation shorws not that less with 2226, for sure faster and with more punch, but less below 35hz compared to 2235 and less flat response (but they sound good)

716977169871699

[Challenger604]

And finally assembled! Now I've to switch them On!

in the meantime I'm preparing 2235h woofer, but final simulation shorws not that less with 2226, for sure faster and with more punch, but less below 35hz compared to 2235 and less flat response (but they sound good)

716977169871699


Hi Luca!
Very nice work!
You really need to put your bass reflex ports to make the measurement. Those will help you to tune up your speakers.
On a simulator, the length of the port should be 12" + 1 eventually to lower the frequency.
You could use the 2226 but the 2235 are way better... They have ring at the base of the dust cap to increase the weight and so lower the speed of the cone. I'm sure you knew that...
Cheers!

[berga12]

12" lenght for 2235? 30cm! Oh God! from the simulation is 240mm (c.a 9,8")

Now I've 85mm that's good to tune 2 2226h to 35hz (not 27-28hz like expected from a 2235).


I will make a Real measurmen on the box and Post it here.

Yes I know the abou the ring, but I read often that as a compromise 2234 (so 2235 without ring) is way better, but tuning about 30hz...:blink:

[Challenger604]

12" lenght for 2235? 30cm! Oh God! from the simulation is 240mm (c.a 9,8")

Now I've 85mm that's good to tune 2 2226h to 35hz (not 27-28hz like expected from a 2235).


I will make a Real measurmen on the box and Post it here.

Yes I know the abou the ring, but I read often that as a compromise 2234 (so 2235 without ring) is way better, but tuning about 30hz...:blink:

Better too long than too short! The angle at 4" is 21.5 degrees. Pretty easy to make...

[berga12]

If the woofer can go so low is better yes, if not is just causing problem, fine for 2235h.


Not difficult? :crying: I'm not a master in cutting tubes, and I found only plastic ones not carton....

what did you use for the cut? the Saw blade? the blade can go up to 14cm?

[Challenger604]

If the woofer can go so low is better yes, if not is just causing problem, fine for 2235h.


Not difficult? :crying: I'm not a master in cutting tubes, and I found only plastic ones not carton....

what did you use for the cut? the Saw blade? the blade can go up to 14cm?

I used my miter saw as far as possible then I used a fine hand saw to the end. You flip it 180 degrees then you glue it with wood glue and when it's dry, you cover with construction glue.

I used cardboard tupe. I'm sure you can find it in Italy. They tube that are used for shipping...
the inner is 5".

http://www.audioheritage.org/vbulletin/showthread.php?11166-4355-Monitor-Plans/page7

Check those pages...

I didn't want to use PVC tubes...

[berga12]

Ok, I will search fror them in Italy, I also don't like PVC tubes, especially for this kind of angular needs...

Mine are Just pressed on the front of the box, so I can easily change with Longer ones as soon as I will buy 2235h's.

I will prepare the carton tube ones!

[Challenger604]

Ok, I will search fror them in Italy, I also don't like PVC tubes, especially for this kind of angular needs...

Mine are Just pressed on the front of the box, so I can easily change with Longer ones as soon as I will buy 2235h's.

I will prepare the carton tube ones!


I still have bunch of tubes but the shipping would be expensive I suppose...

[berga12]

Yes...way to expensive....

I've to find out a 140mm Outer diameter (I've pre milled front....)

PVC is 140mm outher and 136,6mm inside like project.


it's 5-3/8" not 5" :)

Let me search around there...

[Challenger604]

Yes...way to expensive....

I've to find out a 140mm Outer diameter (I've pre milled front....)

PVC is 140mm outher and 136,6mm inside like project.


it's 5-3/8" not 5" :)

Let me search around there...

5 1/4 outer but 5" inner. Thats what you gonna find...

[berga12]

I understand, mine have the interior Milled Like in the project drawing, so my front panel is Milled to have the Gap between inner and Outher diameter (I've 1/2" insertion in the front panel, or 12mm if you prefer).

Not a big problem going from a 136,6mm (5-3/8") Outher to a 140mm (5-1/2") Just a matter of fine tuning of the box,I've the tool to measure Tuning.

Mine are build as follow.
71702

[Challenger604]

I understand, mine have the interior Milled Like in the project drawing, so my front panel is Milled to have the Gap between inner and Outher diameter (I've 1/2" insertion in the front panel, or 12mm if you prefer).

Not a big problem going from a 136,6mm (5-3/8") Outher to a 140mm (5-1/2") Just a matter of fine tuning of the box,I've the tool to measure Tuning.

Mine are build as follow.
71702

I understand Luca but I doubt you will find the right diameter size tube now adays!
You will tune it with lenght of it... Believe me, I did a lot of research for those tubes...

[berga12]

I find out something that could fit...:D

71703

[Challenger604]

I find out something that could fit...:D

71703


Good!

[berga12]

If someone has the same issue than me, having a JBL 5235 with a 18db card with Eq for high freq...

here the modification that you have to do to bring this card with Eq into a normal 18db without EQ! I'm going to buy some capacitors and Resistors! :bouncy:
71832

[Doctor_Electron]

Sick !

[berga12]

Today I will try my cardboard on my 5235, I received some Allen bradley Carbon resistance and Holco too, capacitors are Sprague Orange MKP and Wima one.

I find out only HI-Voltage components and 1W resistor, so not much space left on the board, additionally soldering on a 30years old board will cause some issue :blink:

but then, I succeed! let see if it will explode or not!
7247372474

[berga12]

Everything is working! Incredible how natural the sound is, so dynamic and precise, warm and realistic!!!

I was not expecting that from the Crossover JBL5235, I was thinking it's just a piece of crap! For sure there is something better on the market.

I would like to try Bryston 10B, maybe a Dbx venu 360 or even an RME sound board to have a nice DAC and full DSP to work with!

for the moment I keep this setup with the MC2120 (that sometime fails on some Relais, i've to check), today evening I will try also this bad guy with 211 on mid high!!! :D

7266072661

[Lee in Montreal]

Oh Sorry Luca!
We don't usualy deal with Russia in North America! That's the way it goes around here...

Why do you say that?

[berga12]

12W tube amp (211 tube,uesugi project) on mid high and Hypex UCD400HR on Low bass is something superb :bouncy: more than enough power need to drive those monsters in home application.


72800

[laszlo]

amazing picture. congratulation with the project.


12W tube amp (211 tube,uesugi project) on mid high and Hypex UCD400HR on Low bass is something superb :bouncy: more than enough power need to drive those monsters in home application.


72800

[laszlo]

Hello

Can you tell me what the original purpose of the metal internal support bracket?

thanks




again7060470605706067060770608

[berga12]

If I remember Well was For cieling mount using chains

[dn92]

If someone has the same issue than me, having a JBL 5235 with a 18db card with Eq for high freq...

here the modification that you have to do to bring this card with Eq into a normal 18db without EQ! I'm going to buy some capacitors and Resistors! :bouncy:
71832

Dear berga12,

Nice to see that my work around JBL UREI 5235 (and some of my pictures) is usefull to you ( http://vintage-jbl.forumpro.fr/t3066-filtre-actif-jbl-urei-5235 ). In this topic (In French, but I had the intention to translate it for Lansing Heritage, this is in my big to do list), there is all what I know and found about THE 5235 and its boards.

I made these 4345/4355 boards for a friend who intend to build his own DIY JBL 4355, and I had some difficulties to find the appropriate capacitors with enough precision (try the Panasonic capacitors, see the pictures of the finished board). I made some measurement of these 4345/4355 boards showing the importance of the components precision, see this page: http://vintage-jbl.forumpro.fr/t3066p125-filtre-actif-jbl-urei-5235.

This board was made from a 18dB board as the original board for 4345/4355:
72952

If you need further help with 5235 (I did some imrovements also) do not hesitate to contact me. The linked topic is in French and if interest I can translate some parts for you.
If you dont have the necessary 18dB board (I've seen that you used a 18dB xxBREQ board, I have made a PCB Eagle file for it ( as well as for the two other cards models).
72953

dn92

[berga12]

Dn92 that looks great!

yes I Would like to build new pcb and try different components with better precision(0,5-1%)

I can manage a bit French Thanks!
I will be contacting you by private message! Thanks

[berga12]

And finally,after 10 months.........thanks to many person of the forum (one in particular), I find out 6 JBL2235h, now time to select 4 of them, and Refoam, still have to decide if it's better to re-sell 2 of them or keep as spareparts.

delivered today to me!
7421374214


now I can say I've (as I'll refoam them... :) ) 4355 Replica!

[Lee in Montreal]

Choice is easy. Refoam and keep as spares or build a third 4355 ;-)

[berga12]

maybe 4343 or 4333 :p

[berga12]

I'm always working slow....due to missing time...

Port are done, reinforced with fiberglass (2 layer) in the conjunction and just Resin around.

The fitting on the box is not like I was expecting, so I can't use Wood glue as there was already some paint....So I had to use another sintetic glue to compensate the minimal gap then use an Hot Glue gun on the back of the speakers between front panel and tube...

ok, strong enough....it works fine, I just have to forget and back to listening...

also the 2235h are re-foam by an expert repair shop in Italy called "Mausound" he did a great Job, in the next 2 days I'll finalize the speakers! 74966749677496874969

[Lee in Montreal]

The bead of glue around the domes is indeed pretty good looking. It shows the expertise of the technician.

[berga12]

I don't know if this was coming from an old refoaming or this one, but for sure I was not able to do something better.... so bere we are,I can't complain so much...

[ivica]

The bead of glue around the domes is indeed pretty good looking. It shows the expertise of the technician.

Hi Lee,
But the color of the foam and its size is something unexpected for me.
Interesting can be seen if T/S parameters would be measured, and compared to the JBL declared.

regards
ivica

[berga12]

I'll perform measurement and post them

[berga12]

Hi Lee,
But the color of the foam and its size is something unexpected for me.
Interesting can be seen if T/S parameters would be measured, and compared to the JBL declared.

regards
ivica

In the meantime that I'm performing few hours of suspension brake-up before measuring T&S parameters, what's looks strange ore unexpected for you? I compared my re-foam and suspension with many pictures of originals..........and I can't see the difference :blink:

dustcap and black glue is original, the technician did not remove the dustcap and center the cone with a low frequency tone.

two pictures with Flash and without Flash.......maybe the light was causing "coloring issue".

7498674987


and a couple of example from Japan......I can't find any difference.
let see the measures.

749887498974990

[berga12]

So, I performed A first shot of measures but It seems that the cone itself was too "cold" (in the garage at -4°) so spider and suspension were still not at RT 20° so I got slightly different measurments.

Fs around 22hz, Qms around 3, QES and QTS around 0,3 , VAS a bit below the 460L and efficiency around 93db, Mms shows bigger than 155g

there must be and error due to temperature factor, and some breaking up time that need to make the suspension running for more than 50hours.

I place the cone in the box and I'll be running now 25hz for a couple of days and I'll dismount one cone for measurments later on.
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