JBL L200 restoration and crossover upgrade . Need advice

[mesudman]

Hi Everybody

I recently bought a pair of L200 from UK for 600 pounds (1100$). I think they are L200A model.

They were in a theatre for about 40 years. The boxes are painted in black but the general condition is good. One of the woofers has a small damage. I sent the speaker for repair.

The drivers look good and have the original JBL diaphrams. The harness inside was changed due to a bad upgrade with Motorola tweeters.

I have decided to completly restore them , so I have removed the drivers . I scrached of the paint with a heat gun, the Motorola drivers went to trash and in their place I will put some wood

to fill the holes. I ordered veneer and I will try to restore them exactly like they looked back in the 70's.

The crossovers look original inside , but I'am a little bit worried about them.

Here is were I will need your help guys:

1. What kind of upgrade for the crossover do you recomend so I can add a 077(2405) tweeters on top of them separately ? I can not afford upgrade to 2235h so original woofers will remain
2 I want to change the harness inside because the wires looks to be a bad quality. I tought QED silver so what do you think ?


Here are some pics with them .

I will keep you posted with the upgrade.

Thanks

Alex.

[hjames]

Sounds like an Interesting project ...

How technical are you - can you solder up your own crossover if we give you a schematic?

Hi Everybody

I recently bought a pair of L200 from UK for 600 pounds (1100$). I think they are L200A model.

They were in a theatre for about 40 years. The boxes are painted in black but the general condition is good. One of the woofers has a small damage. I sent the speaker for repair.

The drivers look good and have the original JBL diaphrams. The harness inside was changed due to a bad upgrade with Motorola tweeters.

I have decided to completely restore them , so I have removed the drivers . I scratched of the paint with a heat gun, the Motorola drivers went to trash and in their place I will put some wood to fill the holes. I ordered veneer and I will try to restore them exactly like they looked back in the 70's.

The crossovers look original inside , but I'm a little bit worried about them.

Here is where I will need your help guys:

1. What kind of upgrade for the crossover do you recommend so I can add a 077(2405) tweeters on top of them separately ? I can not afford upgrade to 2235h so original woofers will remain

2 I want to change the harness inside because the wires looks to be a bad quality. I thought QED silver so what do you think ?


Here are some pics with them .

I will keep you posted with the upgrade.

Thanks

Alex.

[mesudman]

I completly removed the paint of them with the heat gun.

The removed the crossovers. I filled with car body filler the bases that were in bad shape. I did not want to replace them.

In the pictures you can see the harness. I think it is not original because on my 4333a the wires are not so easy to bend like theese .

The next stept will be to clean the boxes and venner them. I thought to repaint the front in black because in some places the paint is missing.

Thanks for watching

[mesudman]

I will manage to build a crossover but I will need some schematic

Did some research and found some schematics here on the forum but I want to be sure what I am doing.

Thanks

[hjames]

I will manage to build a crossover but I will need some schematic

Did some research and found some schematics here on the forum but I want to be sure what I am doing.

Thanks

The "original 3133 Equivalent Circuit" member 4313B posted in 2007 is here:

http://www.audioheritage.org/vbullet...l=1#post140919

I built a pair and run them in my L200B cabinet 3-ways ...


I have a couple of long threads here that detail all the changes I went through with my pair ...
still have them, running them with a 60w/ch tube amp these days,
I swappd the old woofer out for 2234s, and later bypassed the internal LE85s and ran the midrange
out to some walnut smith horns (with 2445J drivers) on top

[mesudman]

I will search for your posts for better knowlegde ...

Also in your pics see that you have horns placed on top. Nice

I thought also to place an Altec 511B horn from Model 19 instead of 077 but I am not sure yet. I saw the schematic posted by 4313B on 3133 crossover. Thanks a lot.

In case that I decide to mount horns I will need another crossover . Also here I need some advice too. I had Altec 19 and in my opinion are better than my 4333A , so 511B horns are an

interesting combination with L200 .

Thanks

Alex

[audiomagnate]

You don't need to do anything complicated to add a 2405. Nelson Pass uses a simple first order at 8K and it sounds quite nice. I think it's just a 2 uf cap and an Lpad IIRC.

[Odd]

You refer to this

[audiomagnate]

You refer to this

Yes I do sir. It's just a lonely 1 uf cap (and the original L-Pad). It doesn't get much simpler than that. I hear GT recommended an electronic crossover for the 2405 as ideal. I've tried that as well. All three solutions (stock, NP's and GT's) sound excellent to me. I love that tweeter.