JBL LX4-2 crossover, what is this missing?

[432HzBob]

Hey y'all, I want to know what is missing from this crossover in my C56 cabinets?
Someone pulled the "potato masher" horns out years ago and probably something in the XO as well?
There is currently a good shape LE12C coaxial JBL woofer in the cabinet and I put in a Fountek ribbon "horn" tweeter in the old tweeter hole, crosses over at 3,500Hz with a 4.7uF Vishnay resistor.
It seems to mesh well with the 2 inch LE20 cone tweeter and extends the high end.
The LE20 tweeter on the coax has its own XO mounted to the woofer basket so it is already independent of the XO on the back of the cabinet.
I want to know if something is missing in here like a choke coil or something?
Any advice?
We plan to keep these speakers running for another 45 years or at least long enough to afford the stock potato masher horns for them again.
Thanks!!

 

[EarlK]

Here's the schematic;

Looks like you are missing both the 6uF capacitor and the .4mH coil .

 

[432HzBob]

Ah ok so all I need do is order a .4mH copper coil and wire it between the woofer ground and the tweeter hot and it won't act wonky?

 

[EarlK]

Ah ok so all I need do is order a .4mH copper coil and wire it between the woofer ground and the tweeter hot and it won't act wonky?

As per your thread title, I have showed you the parts needed to restore the LX4-2 back to it's original form ( there's no other inference intended ).

Since what you currently have in place seems to be working fine, I'd leave well enough alone.

Additionally, I don't think you understand the consequences of a mis-located coil within a 2-pole Hi-Pass circuit .

 

[432HzBob]

Yes thanks, I am somewhat confused what purpose a coil has wired between the hot and ground legs of two different drivers.
Some sort of an inductiver resistor or buffer is my guess though I certaintly don;t want to fry anything.
This LX4-2 XO stuck me as very simple compared to the other XO's I have which all have vaious copper coils in addition to various resistors in the layout,
...except my Dynaco A-25's which are simply 5 resistors on the pad and 0ne single resistor (which I replaced).
Since it seems to work fine as I have it without a copper coil perhaps I will just leave it as is.
Just wanted to know what was missing and if it was important.
Thanks, I'm sort of new to this copper coil in the XO thing!!