Hi all,
I need a little help, and here is my background. I can wire a house, a car, built a Hafler DH220 kit amp once, and can design and build lots of mechanical things, but I am no JBL expert. It seems all this talk about vintage HIFI, JBL classic speakers, and watching the value of this stuff on the secondary market, makes me lust after the sound. Or at least I want a JBL experience!
I bring home stray stuff, and play with it, and try to improve restore and make it nice. Then rotate the collection after a year or two. My latest stray dog find, was a clean but tired JBL LE-15A woofer, LE85 HF driver, LX-5 crossover, all 16 ohm. I went to try the components out in a home brew cabinet, and the woofer had no action. I took it to the best local speaker guy I could find, and he did a recone on it. He used an 8 ohm recone kit numbered 2235 (maybe JBL kit?) with a DCR of 3.6-3.7 now. (old 16 ohm checked 8.9 or so)
So now that I have it home, I want to play it, without screwing up something. Reading all this stuff on old JBL components, has led me to read for hours and hours on wiring polarity, impedance, cross-overs, and lets just say I tried to answer my own questions and learn, but sometimes you need good help.
So can I run this setup with an 8 ohm LE-15A, the 16 ohm LX-5 crossover, and 16 ohm LE-85 HF driver?
This is question 1... will this mismatch cause problems that are costly?
or are the problems sonic only?
or will there be a problem?
The recone guy thought the 16 ohm, LE-85 HF driver, would be OK on the crossover network.
Polarity confusion...
Originally the LE-15A had reverse polarity, where red was actually negative, when tested with a 9 volt battery, for excursion direction. Now its still the same way as original. (Old JBL standard right)
The recone guy didn't know about this old JBL reverse polarity standard.
When asked how the HF should be wired out of the crossover, he said the polarity of the HF driver doesn't matter as its behind the network, and blind.
I see where there are people running the outer two wires, at the output lineup on the crossover, to the red terminals on the HF and LF speakers.
So should I hook up my amp's red output wire to the LX-5 crossover black input side?
I even went into the LX-5 schematic, and looked this over.
It seems like past advice on the forum is to do it this way.
I am unsure about the top row on this LX-5 crossover, as all the lugs are black?
Why would they not make this clear is beyond me.
Next step...
Reading things here, leads me to believe my mismatch of stuff might make go looking for a 8 ohm crossover, and put an 8 ohm diaphragm in the LE-85 HF setup?
If I were to run this setup, as stated above, would I hurt anything or would the woofer just play louder than before?
Can you hurt an amp, or speaker, if you have a 16 ohm C-36 on one channel and a 8 ohm C-36 on another channel of your stereo?
thanks Don from Davenport Iowa
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