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alnico
09-15-2004, 06:28 PM
Hi.

I have a pair of L-200B and I would like changed ( modified ) in L-300, I have a pair of 2405H and i whish to use them with a internal passive crossover.

anybody have done that modification if yes how was the result good or bad

ps.... Excuse me,........ I barely speak English , i use translate on net french/ english.......

tanks

Alex Lancaster
09-15-2004, 07:48 PM
Get a couple of N8000 or 3106 networks and follow the instructions elsewhere on this forum; It is as close as You can easily get to a L300.

alnico
09-16-2004, 01:09 PM
But anybody have done that modification if yes how was the result good or bad ????

boputnam
09-16-2004, 02:25 PM
Also Search under 4331 (two-way) and 4333 (three-way). These are the Pro versions of your project.

I'll search, too...

*****

http://audioheritage.csdco.com/vbulletin/showthread.php?s=&threadid=1138&highlight=4333+2405

and maybe the long stale "Entwistle" thread...
http://audioheritage.csdco.com/vbulletin/showthread.php?s=&threadid=674&highlight=entwistle

majick47
09-16-2004, 07:21 PM
I also have a pair of L200b speakers and wonder if an external active crossover could be used in place of the L300/4333b crossover? The active external crossover I have in mind is the a/d/s C2000. I used the a/d/s C2000 in a biamp setup with a/d/s 1530 monitors and it can also be used with non a/d/s speakers at selectable crossover points. From what I have read it sounds like they could be biamped if upgraded to L300/4333b. Appreciate all the excellent advice I have received so far. I came home to JBL after many years, some of my first speakers were JBL L19 and 4311b. Rich.

Ken Pachkowsky
09-16-2004, 08:29 PM
The short answer...

Adding the 2405H as described will bring these 2 ways to life. You will be very happy.

Ken

Mr. Widget
09-16-2004, 10:54 PM
Originally posted by majick47
I also have a pair of L200b speakers and wonder if an external active crossover could be used in place of the L300/4333b crossover?

From what I have read it sounds like they could be biamped if upgraded to L300/4333b.

The stock L200B crossover has a minor HF boost built in to compensate for the falling HF of the LE85. Yes you can biamp them but you will need to introduce some form of HF compensation if you want to continue using them as a two way.

The 3133A crossover (4333A/B) does have a provision for biamping at 800Hz. It requires a crossover designed to be set to that frequency.

If you decide to try to create a L300, be advised that even after you add the 077/2405 and appropriate crossover you will still have the short 1200Hz H91 horn and not the preferred 800Hz H92. Unfortunately the H92 will not fit in the L200 cabinet.

You could add the 2121 or 2122 in a .5 cu ft cab up top and a 2405 and 3143 crossover and you will have an odd looking but sonically superior speaker to the L300. It will be approximately equivalent to the 4343.

As far as the ADS C2000 is concerned, while it was specifically designed for certain ADS speakers, there is a provision for customizing it for other speakers. If you have the original documentation on how to make the modification and are knowledgeable, you could give it a try.

Widget

alnico
09-17-2004, 09:38 AM
If you decide to try to create a L300, be advised that even after you add the 077/2405 and appropriate crossover you will still have the short 1200Hz H91 horn and not the preferred 800Hz H92. Unfortunately the H92 will not fit in the L200 cabinet.



My L-200B use H91 with original spec crossover frequency 800 HZ....and L-300 use H92 with original spec crossover frequency is 800 HZ - 8500 HZ ..........and 4333 is 800 HZ - 8500 HZ .

then I can use a passif crossover 3114(L-300) or 3133 (4333) ??

L-300= 800hz-8500hz
4333= 800hz - 8500hz

4313B
09-17-2004, 09:50 AM
Here are three more passive networks you can try in addition to Alex Lancaster's suggestion.

The 3133 network as used in the 4333
The N333 network as used in the L300
The LX300 network as used in the S300 (Good luck finding one of these!)

The 3114 is used in the 4315 Studio Monitor.

Mr. Widget
09-17-2004, 09:54 AM
You can use the H91 (short horn) at 800Hz as JBL did in the L200B but it is a compromise. That horn works better at 1200Hz. In fact so does the driver. That is one of the main reasons that the 4343 and 4345 are superior to the 4333/L300. Using the LE85/2420 above 1200Hz really improves it's sound.

The original L200 crossed over at 1200Hz with the H91 horn, but the woofer was a compromise... I guess you just have to pick your compromise.

Widget

alnico
09-17-2004, 10:15 AM
which internal passive crossover with a frequency of 1200HZ and 8500hz ????

tanks

4313B
09-17-2004, 10:24 AM
The one you already have plus the ones Alex suggested above.

N200B HF output goes to N8000/3106 input
N8000/3106 LF output goes to the LE85 and the HF output goes to the 2405


Originally posted by alnico
I barely speak English , i use translate on net french/ english.......

tanks I don't know how well these posts translate using software, maybe our French/English speakers can translate for you.

Infredible
09-17-2004, 11:25 AM
He Alnico, if you need some translation help I can help you because I'm French from Paris living in California.

Si tu as besoin d'aide en anglais je peux t'aider a traduire car j'habite en Californie.

Fred.

4313B
09-17-2004, 11:27 AM
Excellent! Thank you! :)

alnico
09-17-2004, 11:43 AM
Tanks

majick47
09-17-2004, 02:53 PM
I read all the expert replies and admit I'm a novice re modifications to speakers/crossovers so please be patient. If I understand correctly I can install the 077 tweeters/horns and add on the N8000 to my N200b crossovers. Is the N8000 a crossover or what is it? What would be the ballpark price for adding two N8000 and where would I locate them? I have seen the 077 tweeters selling on Ebay in the $500 range. I realize that this upgrade will be a compromize, not a true L300, but reasonably close. Rich.

Mr. Widget
09-17-2004, 03:37 PM
Adding the 077/2405 and N8000 to your system will get you very close to a L300.

To save money you can use 2405Hs. they are acoustically identical to the 077 and are typically about half the price.

For the N8000 here is the schematic:

http://www.jblproservice.com/pdf/Network%20Schematics/3106%20Network.pdf

Yes you to can build it. It is so simple all you need are two low DCR .3mH inductors, a pair of 1.5uF mylar caps, a pair of 20 ohm resistors and an 8 ohm L-pad. The total cost would be about $15 each.

Have fun!

Widget

majick47
09-17-2004, 07:04 PM
Mr Widget thank you for clarifing the upgrade of L200b and I now have a much clearer picture of whats involved. Also appreciate your recommending the 2405H horn as a less expensive substitute for the 077. I have been thrilled with the performance of the L200b speakers and I'm certain that with a few "tweaks" they will be even more impressive. Rich.

alnico
09-17-2004, 08:41 PM
Mr Widget thank you for information and precision.

Yes you to can build it. It is so simple all you need are two low DCR .3mH inductors, a pair of 1.5uF mylar caps, a pair of 20 ohm resistors and an 8 ohm L-pad.

But what take? inductor wired in 20, 18, 16 , or 14awg.....the DCR is important .

tanks

http://www.solen.ca/

alnico
09-17-2004, 08:44 PM
..

4313B
09-19-2004, 08:41 AM
The 18 or 20 AWG should be just fine.

alnico
09-20-2004, 06:41 AM
Tanks Giskard

majick47
10-07-2004, 12:27 PM
Re my L200b speakers being upgraded with 2405 tweeters and 3106 crossovers I went back and read Mr. Widgets reply re that this would still be a compromise due to H91 (short horn) crossing over at 800hz and that the H91 horn works better at 1200hz as in the L200. I'm aware of the shortcomings of the L200, especially the boomy bass. My question boils down to the possibility of useing a L200 crossover (1200hz) in a L200b cabinet with my 136a woofers, H91 horns and 2405 tweeters with the added 3106 crossovers? Another question was the major problem with the L200 the woofers or both the woofers and crossovers that created the boom? Also I'm afraid I'll run into trouble with the 3106 crossovers for the 2405 tweeters and they will not be compatiable with the L200 crossover. As you said maybe I'll have to pick my compromises. Again I appreciate any advice from the experts, Rich.

Mr. Widget
10-07-2004, 09:04 PM
There will be no problem adding the 3106 to the N200B from the L200B.

The LX16 from the L200 is designed for 4-6 ohm woofer so it really shouldn't be used with the "8 ohm" 136A. Besides, using the 136A up to 1200HZ is at least as big of a compromise as the horn... JBL did sell a number of L200Bs and they all had the short horn crossed over at 800Hz.

This quote below from Giskard comes from an earlier thread discussing this subject.

http://audioheritage.csdco.com/vbulletin/showthread.php?s=&threadid=1465

"This might be of help. The 1.0 uF, 0.16 mH, and 5 ohm circuit in the N200B provides a bump around 13 kHz. You'll want to remove that when you add the 077/2405. You can reuse the 1.0 uF and the 0.16 mH for the high pass on the 077/2405 if you want. I'd personally be inclined to start from scratch and keep the stock N200B networks you have stock. Additionally, you may want to see if the HL92/2312 horn will fit in your enclosure. You can find the increase in length of that horn in the library on this site."


I would just add the 3106 and 2405 and see if you are happy.

Widget

majick47
10-07-2004, 09:50 PM
Mr. Widget I had a feeling their would be a catch to useing the L200 crossover (LX16) in the L200b. I'll stick with your original recommendation re useing the 2405 tweeters and 3106 crossovers to get as close as possible to the L300/4333. I'm sure all the options were long ago explored and this is the best way to do an upgrade. I'll keep the board advised as to my progress, thanks for the info, Rich.

4313B
10-08-2004, 07:36 AM
You guys have me confused with the networks.
Are we talking about the N200B or the LX16/LX16A?

4313B
10-08-2004, 07:36 AM
L200 / L200A

4313B
10-08-2004, 07:37 AM
L200B

4313B
10-08-2004, 07:43 AM
Originally posted by Mr. Widget
I would just add the 3106 and 2405 and see if you are happy.Yeah, I agree. I posted the graphic how to wire it in another thread but I can't remember where. I submitted the wiring documents in January. They'll show up in the Library some day.

Zilch
10-08-2004, 09:41 AM
Of note are the driver replacements recommended in the Tech Manual for the L200B there: 4430 drivers. This suggests the possibility of doing a complete conversion to 4430, perhaps a project worthy of consideration, i.e., the "vintage" look with more modern driver technology. Saw some empty L200 cabinets on eBay recently.

Lessee, my L200's have the switch level adjustment, so they're not "B's." I HATE them, actually. I have a pair of 4430 crossovers, and some 2344A horns. Maybe try the LE85's with them first, and dump the LE15B's. Hmmm.... :p

Mr. Widget
10-08-2004, 09:43 AM
Originally posted by Giskard
You guys have me confused with the networks.
Are we talking about the N200B or the LX16/LX16A?

He has the N200B and was considering the LX16, but I believe he has decided to stay with the N200B and simply add the 3106 and 2405.

Widget

4313B
10-08-2004, 10:02 AM
Oh, good idea :D

Thanks :p

4313B
10-08-2004, 10:07 AM
Originally posted by Zilch
Maybe try the LE85's with them Change the diaphragms to D8R2421's or D8R2425's and let 'em rip.

4313B
10-09-2004, 06:37 AM
Originally posted by Giskard
I posted the graphic how to wire it in another thread but I can't remember where.

4313B
10-09-2004, 06:39 AM
K

4313B
10-09-2004, 06:41 AM
J

alnico
10-14-2004, 08:08 AM
what think for transformed passive crossover N200B for my L-200B ?

alnico
10-14-2004, 08:10 AM
N200B and N333 original crossover

alnico
10-14-2004, 08:16 AM
With modification the mid ( Le-85 ) works of 800HZ at 8500HZ, 12DB oct. exactly similar like the L-300.....and the 2405 8500HZ at 20KHZ....

4313B
10-14-2004, 08:56 AM
Yes, that's what I meant in another post about using the 1.0 uF and 0.16 mH from the N200B EQ circuit to build the HP for the 077/2405 instead.

In any case, you can leave the EQ in the original N200B and see if it will be any trouble once you add the 077/2405 in. I suspect you will want to remove it though.

Zilch
10-14-2004, 10:18 AM
It's interesting to observe the evolution of somebody's little spark of inspiration to augment the HF response of a compression driver by bypassing it around the MF attenuation.

That clever little innovation distinguishing the L200B from the L200 later came to full flower in the 4430 and 4435, where it sufficiently extended the HF response without an additional VHF driver to produce practical two-way systems with surprisingly good performance.

In today's lexicon, the 4430 is actually a "Quasi-three-way," and with it's analogous approach to the VLF, the 4435 a "Quasi-four-way."

The extended range is perfectly voiced and coherent. A big HUZZAH! to whoever came up with it.... :thmbsup:

majick47
12-26-2004, 07:36 AM
Giskard I need your HELP. I just installed 3106 crossovers and 2405 tweeters in my L200b speakers and I'm having trouble with the wiring. I have the 3106 LF output going to the LE85 horns and the 3106 HF output going to the 2405 tweeters. Both work but I'm unable to adjust the output of both L pads (LE85/2405). I have the 136a woofers running off the N200b crossovers as they were originally in L200b form. I have red and black wires from the 3106 crossovers going to the corresponding red/black wires of the N200b. The two wires that went from the N200b crossover to the LE85 are not hooked up to anything. Where should they go? I suspect that it might have something to do with the "N200b HF output going to the 3106 input". I tried to follow the wiring diagrams but I got lost. Note: The 136a woofers, LE85 horns and 2405 tweeters are "working" as its wired now. Any assistance would be greatly appreciated.

4313B
12-26-2004, 07:43 AM
Yes, the HF output of the L200B that used to go to the LE85 now goes to the input of the 3106.

Figure K is for the normal LX200B hookup.
LF transducer = 124, 2203, LE14, 136, 2231
HF transducer = LE175, 2410, LE85, 2420
HF horn & lens = HL91, 2307/2308

Figure J is for adding the 075 or 077 using a N7000, 3105, N8000, 3106

majick47
12-26-2004, 01:55 PM
Giskard many thanks for again posting the info and diagrams re the LE85 wires going to the 3106 inputs. I worked last evening and started installing the components after work at midnight and the sun was coming up when I called it quits, by morning it was confusing. One final question, what happens to the two original L200b input wires (red +/black -) from the terminal/post board on the back of the L200b cabinet that went into the LX200b crossover? All the other wires have been accounted for (136a, LE85 and 2405).

majick47
12-27-2004, 11:08 AM
Giskard I need your help again. I followed your instructions and ran the the LE85/LX200b crossover wires to the 3106 input. My problem now is that the woofer isn't working when connected to the LX200b woofer outputs. I also still have the LX200b power (+/- red/black) unconnected to anything. Bottom line is the woofer isn't working.

4313B
12-27-2004, 11:28 AM
Let's try to get all your wire colors sorted out.

L200B network:
There should be six wires coming out of a strain relief gromet in the L200B crossover network, what colors are they?

*********************************************

For reference here is a wiring diagram of an L200B on the left:

All you do is take the wires going from the L200B to the LE85, disconnect them from the LE85 and plug them into the inputs of the 3106 instead. Run wires from the LE85 to the LF outputs of the 3106 and wires from the 077 to the HF outputs of the 3106.

Another reference graphic on the right:

majick47
12-29-2004, 02:57 PM
Giskard I followed the wiring instructions and now both L pads and horns (LE85 and 2405) work. The color of the wires in my L200b speakers is not consistant with the L200b diagram you posted. The LX200b crossovers could of been rewired at some point or came like that from the factory, who knows! This morning I had just enough time to rewire one of the L200b speakers. A quick listening test with the 2405 L pad wide open and the LE85 L pad set fairly low produced the sound i was expecting from these speakers. The bass, mid and high were very close to perfectly balanced. When I get home tonight I will tackle the second speaker and I'm sure I will be delighted with the final results.

4313B
12-29-2004, 03:12 PM
The color of the wires in my L200b speakers is not consistant with the L200b diagram you posted.Not surprising. JBL used other colors before settling on the "typical" green for LF, white for MF, yellow for HF, and orange for UHF we have today.

Zilch
12-31-2004, 04:07 PM
O.K., we want the FULL report on the results now, preferably with pics....:)

majick47
12-31-2004, 08:58 PM
First off I have to thank Giskard, Zilch and all the other members of the Audio Heritage board who provided all the technical info and insperation. I also want to thank John and the staff of Pro Sound in Braintree MA (781-849-1285) for their expert work in rebuilding all the components. Now to the L200b speakers, all the original components, 136a woofers, LE85 horns, L pads and LX200b crossovers have been completly rebuilt and updated with all new oem/JBL diaphrams, cones etc. I have added 2405 tweeters and oem JBL 3106 crossovers that have also been updated with new diaphrams, crossover parts and L pads. After listening to the speakers I have to play a little more with the L pads and get a better balance between the woofers and horns/tweeters. The best way for me to describe the sound is in one word, RICH. The speakers are as clear and clean as a bell even at the highest volume which borders on painful in my large listening room. I played a live concert DVD, Rod Stewart At the Royal Albert Hall, the JBL horns, tweeters and woofers were having one hell of a workout and it sounded like you were seated in the audience. Zero distortion even at the highest volume. A very noticable difference from the original components with 30 year old parts. It wasn't cheap to do but the sonic results are worth every penny and I'll be enjoying the L200b "modified" for many years to come.

4313B
01-01-2005, 03:56 AM
It wasn't cheap to do but the sonic results are worth every penny and I'll be enjoying the L200b "modified" for many years to come.That's the kind of thing we like to hear! :cheers: