My JBL 4355 Homecinema Soundbar build

[music2u]

Hello all!

Although I read in this forum for some time now, this is my first post. By way of introduction, I am Stefan, I live in a small city very close to Frankfurt/Germany. So, apologies for the one or the other typo or grammar mistake. I turned 50 this year and my interest in HiFi and DIY started in the eighties with a pair of Infinity Kappa 8. Lately I tried electrostats and open baffle subwoofers.

However, I have always been interested in a very lively sound experience. I have to thank Holger Barske ("hb") for the inspiration. His 4355 build is documented elsewhere in this forum. His build encouraged me to try it by myself.

On one hand, my room was not wide enough for a proper placement of a pair of 4355. On the other hand, my interest is not only music but also homecinema. Why not combining the two?


The woofers of the 4355 are actively crossed over anyhow.
The mid-high section may be better arranged in a vertical row.
The four 2235 can better be replaced by two 2245
All Drivers could be arranged in one cabinet (inspired by the Paragon)


I started with a brief coloured image to get an idea how things could tie together:

75206

I learned and profited a lot from this forum and without the documents and hints and tips herein, this would not have been possible. Therefore, the intention of this thread is, to share some of my experiences and pictures with you to say "thank you guys". From my own experience, I always enjoyed a lot to view storys and pictures of someones built.

So, I hope you enjoy it.
Stefan

[music2u]

It is hard to get all the chassis here in Europe in good condition at a reasonable price. Finally, it took about a year to collect everything. The receipt of every part was celebrated like eastern and x-mas on one day......

I expected the project to fail, if I can not get the 2441/2440 and the 2245 drivers in advance. I found 2440 with Radian dia's at an acceptable price in Germany. They were the first to come:

75207

Next thing was to get the 2245. I found them also in Germany, nearly mint and freshly refoamed. The seller did not want to send them. I planned to go to a bike rallye nearby so I decided to go there by car and pick them up (that cost a number of beers at the rallye, not to show up on my bike...):

75212

The 2202 where not easy to find and they were all in bad conditions. I got them from Germany and the UK:

75208

They have all been reconed by a small local company (at a reasonable price) who claim, that JBL Germany sends the one or the other vintage chassis to them for repair.

The 2405 were not hard to find:

75209

It turned out, that the h93/2311 are really hard to find. I got them from the US as well as the clamps. But it is impossible to find the lenses. So I ordered them at Kendrick and I think the price is also about fair. The email contact, delivery and everything was excellent:

75210

[music2u]

As my room is exactly twice as long as wide, I have some problems with room modes. So, I did not know, whether this will work in my room. And this is my first experience with JBL. As prices for good wood have gone up over the past years, I decided to start with an easy test enclosure made of particle board.

The volume was calculated based on the documentation of the subwoofer for the 2245 (2 times the 20Hz Version with 12 sqrft). The size is 2m x 0.5m x 1.1m.

First thing was to cut the holes into the baffle wall:

75213

To keep the test enclosure simple, I decided to use the mid woofer housing also as bracing for the enclosure:

75214

First look at the raw enclosure:

75215

This cannot be overseen in the living room. I decided to add some paint to see if I like a "blue wall" of 2 x 1 m in my living room:

75216

The damping was done with hemp mats:

75217

[music2u]

I decided to try the charge coupled crossovers. As a tribute to originality I buildt the original version with a lot of inductors.... Actually I am in some doubt whether that was a wise decision. However, as I would always doubt, whether the 9V battery is still in good condition I decided to go for the diode method. Again, I can not thank enough the members of this forum with their documentation and insights. There is so much to learn and to gain here. Good work!

A lot of parts had to be ordered for three crossovers:

75218

The inductor values are not common in Germany. So I had to unwind them individually:

75219

Then everything was placed properly for another test-"enclosure":

75220

And this is a completed crossover:

75221

Finally, I "produced" the gaskets by myself out of foam rubber plates:

75222

[music2u]

Everything was put together and there was a long way to go with measurements etc.

However, while I write theses posts I listen to Gregory Porter (on Vinyl) and it all paid off. I love the sound, although I have a number of questions and ideas for improvements ;-)

75223

75224

75225

Thanks for watching. I hope you enjoyed it...

Stefan

[Challenger604]

Holy Moly!!

[Ed Zeppeli]

This is insane. I love it.

Maybe it will inspire Samsung's next soundbar. :)

[hjames]

OMG - Fantastico!

Considering it's nothing that can be easily moved,
did you build a base with wheels for it?

[Vahe Sahakian]

Thanks for watching. I hope you enjoyed it...


When I was building my DIY 4350's I considered pair of 18's instead of 15's but the 8 cu ft. enclosure for each 18 gave me a pause.
Is this just one speaker or a stereo pair?

Vahe

[srm51555]

Awesome!!! Welcome to the forum.

[Woody Banks]

Vundabar!

[Mr. Widget]

I want to say that is "out of the box" thinking, but that is one hell of a box! ;)

It it looks wonderfully crafted with great care and passion. Congratulations!


Widget

[dezmond]

Looks awesome, nice work. Are you going to build another for stereo ? I can only imagine how sweet it must sound.

[pos]

Nicely done and impressive!
Is this really only a test enclosure? It looks better than my "final" builds :p

What active crossover are you using?
How do you distribute the three channels among the two woofers?

[Ed Kreamer]

Wow!! What a neat idea! Do you have some plots?

[music2u]

Thanks for your kind words! Actually, it is not a big thing (although it is kind of huge...). However, it is a lot smaller than three 4355...

Maybe some explanations how it works:



There are three mid-high channels (left-center-right) based on the 4355 (driver and passive crossover).They act like satellite speakers.
There is one subwoofer channel comprising the two 2245. They replace the 2235 of the 4355.
Everything is combined in one cabinet. Therefore I called it "soundbar": It is kind of a "3.2 System" (left-center-right + two subwoofers).
The active crossover/bass management is currently handled by a simple AV Receiver (actually a Pioneer SC-2022 - they claim to have good and stable class-d amps included).
The crossover is around 100/120 Hz. The 2202 are corrected via DSP because their SPL already drops from around 250 Hz downwards.


Going forward, I consider to replace the digital bass management by an active crossover to have a real analog signal chain from the turntable to the speaker. But it is kind of tricky to combine the two channel stereo or 2.1-world with the 5.1 or 7.1 world.

And no, it can not be moved around but that was never the intention. My open baffle speakers had to stay about 1m away from the back wall. It was always lost and dusty space behind the speakers and a lot of cables laid around. The idea was to have a speaker like a cupboard which fits nicely against the back wall.

Actually, I do not have plots. Originally I planned a more sophisticated internal bracing like a matrix. But the test enclosure is much simpler. The midwoofer enclosures are the only bracings. A good thing is, that the heavy 2440/2441 drivers can be placed on the midwoofer enclosures. And there is a simple lath attached to the back and top wall. If you look through a 2245-hole you can see the lath, the midwoofer-enclosures left and right and the small boards on top of them which are the stands for the 2440/2441:

75231

I hope that helps.

Stefan

[toddalin]

Cool project.

My concern would be that the L/R are pretty close leading to a loss of separation. Also, the cabinet looks a bit small for all that's going on in there.

[Flodstroem]

Thanks for watching. I hope you enjoyed it... Stefan
Wow! What a huge project..... If we enjoyed it, your kidding :bouncy: :p
I liked your 2 x 2245ś, that is a huge difference compared to the "small" 2235ś :D
But Im not so impressed about your bracings in such a huge cabinet. Many large areas that can vibrate
But as you said, it was a test cabinet and then it can go for that...... ;)

[music2u]

Thanks for your concerns and recommendations.


toddalin
My concern would be that the L/R are pretty close leading to a loss of separation. Also, the cabinet looks a bit small for all that's going on in there.

My previous speakers were at the same position. About 2m apart from each other and my listening position is about 3m away. You may be right but there is no more space anyhow. For music it is fine.For homecinema I would like to have the speakers closer to the side walls. However, I tried two 2445 with other horns in separate cabinets at about the same position but toed in and I think that was good idea (and for a number of other reasons they sounded so much better than the combination 2440/Radian/2311). I consider to give the final enclosure a "curved" baffle wall. But this will not be an easy woodwork...

The internal net volume (without the midwoofer cabinets and the volume displaced by the drivers) is about 24 cu ft (two times 12 cu ft like proposed in the subwoofer paper for the 2245 documented in the forum-library). I have done impendance measurements: The 2245 are tuned to about 22-24 Hz.


Flodstroem
But Im not so impressed about your bracings in such a huge cabinet. Many large areas that can vibrate
But as you said, it was a test cabinet and then it can go for that....

The midwoofer cabinets work quite good as bracings for the front, back and side wall. But there were clearly resonances at the top. That is why I included the lathes later. But you are absolutely right: The final enclosure will definitely have a "matrix bracing".

[Val]

Amazing! Thank you for documenting your project!

[tjm001]

Awesome! Classic German engineering.:)

[berga12]

Great Job!!!

Convert them into a kind of 2.1 or 3.0

I Mean, 2245+2202+2441+2405 --> Left and Right Channel

2202+2441+2405 --> Center Channel in "Small" configuration (it cuts High pass up to 100hz)

In this case you can run a great Electronic crossover for the stereo channel, and have a wonderfull stereo experience.

in case of Movie, you have available also the center channel, to be ecluded in stereo mode.

Use the AV amp for the center, and use 2 quality amplifiers for the stereo (maybe a nice Class D for the 2245 and a Nice tube amp for the Midhigh).



I was a fan of Home theater, since I'm using 2 JBL4355, I dismounted everything and I'm watching movies in 2.0. TOP! :bouncy:

[NWCgrad]

Very innovative and unique build! Thanks for sharing. When I saw soundbar and 4355 in the title I was intrigued and knew it would be something great.

[Amnes]

This thread is awesome.

[music2u]

If it is called 4355 it is always big in a certain way... ;-)

@berga12: Thanks for the compliment which I am pleased to return. I saw your built in the other thread. Great craftsmanship! And you nailed it: I plan to run L+R as "large" and have an "analog" active x-over and class a or tube amps. But then I would also like to have the DSP (in the AVR) completely out of the phono signal chain. I have to figure out a good and comfortable way to switch the sources and the bass management. BTW: I use also Hypex UCD 400 for the bass. But this is second priority.

First priority is to finish the speaker. Actually, the 2445 with a diffraction type horn (I don't know what it is) sound much better than the 2440/Radian/2311 combo. I have not yet figured out, whether the driver, the diaphragma or the horn is primarily responsible for the clearly audible difference.

So, what is the best mid-horn combo for 4355 (if we stay with vintage gear)? From reading differents posts, maybe 2446 + Beryllium + Yuichi horn?

[berga12]

Thanks to you too!!!

I turned completely analog, so removed AVR DSP, you can also put a swich and use the AVR pre-out for Audio-video purpose, and Keep 100% analog for 2ch and Vinyl listening.

with this system, a Fanless PC with "KODI", I'm very happy, with those huge system you can enjoy the Movie dynamics and effects in any case, also on DTS movie, this is my personal experience.

For the horn IMHO you have to make some distinguish, if you want to follow the monitor project you have to keep 2311 and filter between 1,2 and 10Khz....but if you run bigger horn like JBL 2350,Yuichi, IWATA, then you have to cut down to 400-500hz, changing completely the crossover point and speaker response.

I've no experience with Berylium diaphagram on 2441 or 2440 and no experience with 2445. Just consider some fact:
- 2440-2441 are Alnico
- 2445 are Ferrite
- Berylium is tipically used on TAD drivers (both alnico and ferrite) and does it sound much brilliant than Aluminum diaphagram (for my listening experience).


Have you Re-magnetized 2440-2441? In the past those drivers where used under the sun light, with large amount of power,many of them have lost much of the Magnetization, resulting with not original sound....

check this first.

Ofcourse you are free to put a bigger horn on the top of your cabinet to lower the driver crossover point.

ciao
Luca

[badman]

Nice work- good effort on the "test" enclosure, while the material/thickness/bracing are lacking for a final build, your build skill sure isn't! I do think a wider enclosure for a little more separation might be worthwhile if you can make it work, and perhaps a little shorter so it's not quite so close to the display.

[music2u]

Thanks for your kind words. I always wanted the speaker higher and the screen lower.... The sound is predominantely generated by the 2440/2441. I think they have to be at least at ear level. It's always a compromise.

@Luca: Yes, I had the 2440/2441 remagnetized. I do also enjoy the dynamics in movies and the bass that the two 2245 can generate. The dynamics in music are more and more compressed (aka "loudness war") and I am sometimes surprised when there is music in the background of a film.

Actually, the x-mas tree is gone and there is again time and space for experiments. I tried the other horn again with 2445 and they sound better (but it may also be the different dia's). Does anyone know which horn this is? It has a diffraction slot and a JBL badge but who knows. It is about 25 cm wide and 28 cm high.

75351

[Wardsweb]

Wow that is a spectacular build. Really something to be proud of.

[bldozier]

Yeah I can't take my eyes of your crossovers great build

[toddalin]

I assume that the intention is to put a monitor on top of this cabinet (you too bldozer).

Have you checked to see if your monitor is suseptable to stray magnetic fields?

Don't belive the crap that AlNiCo JBLs do not affect CRTs. This is why when you look at my center channel speaker, all of the components were originally mounted at the bottom with the ports at the top.

But even just with a couple 130As, a 175/potato masher, and an 075 mounted low in the cabinet, the Mitsubishi 40" table top (CRT) would be subject to distortion/purpling toward the bottom of the screen. When I went to front projection with a Stewert screen, this was no longer a problem and the horn was raised in the cabinet to replace the center port and this port was put at the bottom. This also allowed me to put a tweeter on top of the cabinet.

http://www.audioheritage.org/photopost/data//525/medium/Stereo_007.JPG

[dezmond]

Who still uses crt's ? I don't know anyone .

[toddalin]

Who still uses crt's ? I don't know anyone .





So are you saying that NONE of the modern monitors can be affected by a stray magnetic field in any way? I don't know that I would take that bet, which is why I cautioned the OP to check it out.

[bldozier]

Thanks um I will remember that for a future build

[mech986]

Excellent build thread and design. Although in a space limited area, have you had the opportunity to "stretch its legs" with say 200+ watts of power and some great music? The compression drivers being extremely efficient will always dominate the sound field without padding them down considerably.

Do do you have a crossover schematic that you worked from?

eventually, you may want to review again the 4345 commentary from Greg Timbers and consider going fully active tri-amp or quad-amping with less passive crossover components, but that is a huge proposition unless using a lot of DSP correction and compensation.

very nice build effort, and if this is your test box, love to see what you have in mind for a final design.

I'd suggest a model number of 4358-C, the 435x following the double woofer systems, the 8 referring to 18" woofers,Mandy the C for a center channel "soundbar".

[music2u]

Thank you so much "mech986". After "a long journey" it is nice to see, that you guys understand why one is doing these things and understand the rationale behind it. I will experiment with amps (also tubes) and as this is in my own house, I have "some flexibility" to listen to "higher volumes" ;-)

I took the crossover schematic from GT as documented in this forum, charge coupled (diode method). If I look at all the inductors, my first idea was to go fully active. I consider to go in a two way design per satellite speaker and add the 2405 with a simple 6db highpass filter as a super tweeter (the center will remain passive). I plan to do that in the analog domain, i.e. without any DSP.

Before I settle on the final enclosure and crossover, I plan to try alternatives to the compression driver section. The 2440 and the Radian dia's sound somewhat "soft" in my opinion. The 2245 and 2202 section will stay. And the concept with 2" compression drivers. Although I like the tribute to the 4355, I would love to compare the setup with larger horns like Yuichi's.

@bldozier: Crossover build is only technical. With some discipline and patience you will make it. Development of a crossover is more like an art.
@toddalin: I don't have any probs with my Sony LCD screen.

[JuniorJBL]

HA!!

Soundbar!! :rotfl:

That's just plain cool!! Definitely a one-off. :)


Excellent job Stefan. :banana:

[berga12]

Forget about running the 2405 at 6db slope.... ;) it will be destroyed.
minimum 12khz above 7-8khz is the minimum (some say 12db at 6khz....I still consider only 18db above 8khz...)

yuichi is a wonderful chioce if you decrease crossover point of 2440, then you'll not listen anymore to a studio monitor,but something different.

[music2u]

Thanks "Junior"... I see you enjoy it :)

@Luca: OK, I will take care of my 2405. Currently, I try different setups for the mid-high section.


eventually, you may want to review again the 4345 commentary from Greg Timbers and consider going fully active tri-amp or quad-amping with less passive crossover components, but that is a huge proposition unless using a lot of DSP correction and compensation.


I am very interested but I couldn't find it. Does anyone remember where it is?

[bubbleboy76]

Soundbar, LOL :)
Respect!
What is the weight of this thing?

[Betiuxs]

78669Hello! can someone help me on this ? I have 2 JBL 5739 dual 15" cabinets that I would like to use with 2235H's
can someone tell me if they can be tuned to match the JBL 4355 Low frequency? these are the enclosure dimensions
PHYSICAL SPECIFICATIONS:
• Enclosure Dimensions: 1219 x 762 x 450 mm D(48.0 x 30.0 x 17.8 in. D)




Thanks

[ivica]

Hello! can someone help me on this ? I have 2 JBL 5739 dual 15" cabinets that I would like to use with 2235H's
can someone tell me if they can be tuned to match the JBL 4355 Low frequency? these are the enclosure dimensions
PHYSICAL SPECIFICATIONS:
• Enclosure Dimensions: 1219 x 762 x 450 mm D(48.0 x 30.0 x 17.8 in. D)




Thanks

Hi Betiuxs,

About 95mm each if port diameter about 105mm
or 157mm if diameter is about 125mm.
ivica

[Betiuxs]

Hi Betiuxs,

About 95mm each if port diameter about 105mm
or 157mm if diameter is about 125mm.
ivica
sorry but still don't get it can you explain a little more Thank you so much

[mech986]

sorry but still don't get it can you explain a little more Thank you so much

Ivica gave you the port lengths for a given port inner diameter. These dimensions give the volume and mass of air contained in the port which affects the port tuning that defines how the cabinet interacts with a given woofer.

since your cabinet is a lot smaller than the 4355 cabinet, the internal volume is also a lot smaller, and requires tuning with the ports to achieve the same relative tuning with the much larger 4355 cabinet. One can also tune lower or higher and introduce artificial electronic EQ to extend the response lower if needed at the expense of power, a bit more complexity, and potential overexcursion of woofers in question.

[Betiuxs]

Ivica gave you the port lengths for a given port inner diameter. These dimensions give the volume and mass of air contained in the port which affects the port tuning that defines how the cabinet interacts with a given woofer.

since your cabinet is a lot smaller than the 4355 cabinet, the internal volume is also a lot smaller, and requires tuning with the ports to achieve the same relative tuning with the much larger 4355 cabinet. One can also tune lower or higher and introduce artificial electronic EQ to extend the response lower if needed at the expense of power, a bit more complexity, and potential overexcursion of woofers in question.
got it guys thank you very much

[Betiuxs]

Hi Betiuxs,

About 95mm each if port diameter about 105mm
or 157mm if diameter is about 125mm.
ivica
Hello again Ivica, I went and got the cabinets today just to find out that in reality the cabinet size is 35x30x17 the plywood is 3/4 thick with the front plywood being 1" with double port of 5" 1/4 diameter each.
can you give me an exact tuning tube lenght ?
or anyone else can help me on this? I want to use this as a bass cab and I want it to sound very close to the 4355