jbl l65 jubals with 123a-1 woofers?

[boom6342]

hi, i just bought my first pair of jbl speakers, jbl l65 jubals, after doing
some research on them i'm wondering if the woofers are original, the
woofers in my speakers are 123a-1, from what i can find those came
in the l100's, 4310 and 4311, did the jubals ever come from the factory
with the 123a-1's or has someone changed these out?

the speakers sound great the way they are, i'm just curious about the
woofers and would these sound better or worse than the originals?

thanks for any information anyone has on these...

[speakerdave]

No, they're not original. Interesting idea, though. How do they sound?

David

[boom6342]

they sound good to me but i don't know what originals would sound like,
i do like the idea that there is no surrounds to rot out, i'm guessing
that may have been why they were just changed out by someone,
the bass is good and punchy

[speakerdave]

they sound good to me but i don't know what originals would sound like,
i do like the idea that there is no surrounds to rot out, i'm guessing
that may have been why they were just changed out by someone . . . .

That's likely. I had a pair with the original 122a woofers. They were nice, designed to go a little deeper than I would guess you are getting with the 123A, but I would not say they had a lot of slam. I can't really picture what your frequency response would be like with the 123A, nor can I comment on the cabinet tuning for that woofer, but you're the one that has to like it, so if you do, then enjoy them. Be careful not to overdrive them.

David

[boputnam]

I had a pair with the original 122a woofers. ... I can't really picture what your frequency response would be like with the 123A, nor can I comment on the cabinet tuning for that woofer...

Biggest issue I see, is the 122A is a negative transducer; 123A-1 is positive.

You'll need to check the wiring in that cabinet and make sure the connections to the LF have been reversed - this will give you the crossover response as engineered by JBL.

[boom6342]

thanks david and bo,
ok i've reversed the wires on the woofers, i now have green
wire going to red terminal and black wire going to black
terminal, would that be right? i can't tell any difference in
sound quaility.

[boputnam]

You'll need to check the wiring in that cabinet and make sure the connections to the LF have been reversed - this will give you the crossover response as engineered by JBL.

...ok i've reversed the wires on the woofers, i now have green wire going to red terminal and black wire going to black terminal, would that be right? i can't tell any difference in sound quaility.

Well, it seems whomever swapped woofers knew how to do it - thus, the wording of my post.

To use the 123A-1 in the L65 you'll need the Green going to the Black terminal, and Black wire to Red terminal. So, un-do what you just done.

And no, there won't be a drastic difference in sound quality. However, there will be less/no doubling in the range of the crossover point. This range might seem a bit less muddy.

[boputnam]

However, for our gentle readers, my records show there were three variants of the N65 network (thanks, Giskard!! ), and JBL used three different woofers:
122A = N65A
126A = N65
129H = N65B

It would be best to determine which N65 variant you had.

If yours had the 122A, as David suggested, we are fine. But, we need to know your network.

[boom6342]

thank you very much bo,
well i've changed the wires back, i noticed on the crossover
it was n65 on the round cardboard filter, i can change the wires
back if i need to, just let me know

[boputnam]

If it's truly the N65, the original woofer would have been the 126A, and not the 122A as was suspected.

The 126A, like the 123A-1, was also a "positive" transducer - a rarity amongst vintage JBL.

I've lost track of how you've got things right now, but regardless: According to the N65 network (and notes on the 126A), to use the 123A-1 woofer the Green wire = woofer Red terminal, Black wire = woofer Black terminal.

Sorry for the confusions, but you can see that by JBL having three network variants it is important to know which one you had, to honor the original network design.

Now go play some music!

[boom6342]

well you've really got me laughing hard now (because you lost track)
thanks for your time for helping me get these the way they are supposed
to be!

[boputnam]

well you've really got me laughing hard now (because you lost track)

Yea, but it's a deliberate posture I've learned to employ to make sure the situation is reviewed, again, before those seeking remedy are "done". Human error is everything out here...

[Zilch]

http://manuals.harman.com/JBL/HOM/Te...ancer%20ts.pdf

I have no clue why I know this stuff. It's like a curse.

Only one person I know of here might know where/how to find the schematic.

[And it's not me.... ]

[markd51]

Interesting thread,
Once, about 8-9 years ago, a man gave me two brand new Pro JBL 12" drivers to try in my L-65 Cabs, and I have forgotten the model #, but it was I think 2206?

Was curious how they would've sounded, and due to no foam rotting might've been a alternative to use, but hence, the magnets were so much larger on these beautiful drivers, and with the L-65's L-Shaped Port Tubes interfering with proper mounting, I trashed that idea as I wasn't about to butcher the cabs in this little experiment.

Once could probably acquire the correct pair of 126A drivers without too much expense, and may be a worthy expenditure to have these back bone stock, and the way they were meant to sound. Provided you can find a pair that haven't been blown, and just need surrounds, the correct surrounds can be gotten (probably from Rick Cobb right here)

I do understand though, that the recone kit is now gone from JBL, correct? (I now gotta pray I never blow one of my four 126A's!) Can the 126A be reconed with another kit? Mark

[Fernand]

I'm new to this forum hoping this is the place to find the right info. I purchased back in the late 70' 2 Jubal L65. They have an N25 Crossover and a model 126A woofer. A woofer was punctured and I bought 2 122A-1 woofers (not knowing the ones I had were 126A)

Is this an appropriate woofer for my Jubals? I connected the black to the black and the green (network) to the red terminal on the 122A-1.