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Mike F
06-29-2014, 10:59 PM
So I picked up a pair this morning only to find the relative and absolute polarities all over the place :(
Some previous owner decide to "upgrade" the internal wiring as well as capacitors with little regard to the phasing of the system.
The male and female fast on connectors on one LE25 of one cabinet and LE5-6 of the other were reversed as well as one of the 2213.
I have no idea which is right or wrong. I have been able to determine the following:
Positive voltage applied to the female terminals of the tweeter and mid yields a inward cone movement as well as a positive voltage to the red terminal of the 2213.
Unfortunately the 3112 schematics only deal with wire color and not polarities which is not of much good to me as the original wiring has be replaced.
Needless to say, the pair sounds like total crap, hoping to get some help here.
TIA

DavidF
07-01-2014, 12:27 PM
So I picked up a pair this morning only to find the relative and absolute polarities all over the place :(
Some previous owner decide to "upgrade" the internal wiring as well as capacitors with little regard to the phasing of the system.
The male and female fast on connectors on one LE25 of one cabinet and LE5-6 of the other were reversed as well as one of the 2213.
I have no idea which is right or wrong. I have been able to determine the following:
Positive voltage applied to the female terminals of the tweeter and mid yields a inward cone movement as well as a positive voltage to the red terminal of the 2213.
Unfortunately the 3112 schematics only deal with wire color and not polarities which is not of much good to me as the original wiring has be replaced.
Needless to say, the pair sounds like total crap, hoping to get some help here.
TIA

Have you been able to sort things out yet? I don't see a 4311A schematic but the "B" is attached showing all polarities.


http://manuals.harman.com/JBL/HOM/Technical%20Sheet/4311B%20ts.pdf

Mike F
07-01-2014, 01:26 PM
That link definitely helps, thanks David. If the wiring wasn't enough of a headache, I discovered that my test amplifier inverts the signal, just to add to the confusion.
I think I`ll be OK from here. I`ve focused my attention on the aesthetics in the meantime. I can post some pictures and notes if anyone is interested.

hjames
07-01-2014, 02:18 PM
That link definitely helps, thanks David. If the wiring wasn't enough of a headache, I discovered that my test amplifier inverts the signal, just to add to the confusion.
I think I`ll be OK from here. I`ve focused my attention on the aesthetics in the meantime. I can post some pictures and notes if anyone is interested.

Of course an amp that inverts signals when there are only 2 speakers in the room is no real problem -
its when you add another pair on another amp or two that it matters ...

DavidF
07-02-2014, 06:55 AM
That link definitely helps, thanks David. If the wiring wasn't enough of a headache, I discovered that my test amplifier inverts the signal, just to add to the confusion.
I think I`ll be OK from here. I`ve focused my attention on the aesthetics in the meantime. I can post some pictures and notes if anyone is interested.

Doing good work often inspires others. Post away.