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Thread: So many times, so many ways, ad nauseam.............

  1. #31
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    Quote Originally Posted by tonester View Post
    I found another 123A-3 neg polarity speaker to match my other 123A-3. Should they be connected black wire to red post to keep them in correct phase with midrange? It appears that late L100A are supposed to be black to red post looking at schematic, irregardless of polarity direction.
    I don't know what speaker(s) you have.

    Right off the top of my head I can't remember if the LE5-2 mid-range driver is a positive or negative driver............

    BUT, it makes NO difference IF you have either the L100A or L100A (late) with the N100 network working from what we have

    Both tech sheets show them to be EXACTLY the same EXCEPT for the woofer used and an "out of thin air" polarity change between models as indicated by JBL to address the "I have no fu&king idea" part

    And I say "out of thin air" because NOTHING ELSE IS SHOWN to be different.

    Is WOOFER CONE EXCURSION DIRECTION all that defines the difference between an L100A and an L100A (Late) model? Because with what data we have that would APPEAR to be the case.

    And that is why this stupid ass question which has never been answered still irritates the shit out of me.

    I can tell you this much and it coincides with how my L100A (Late) production L100s were factory wired to the LE5-2s, the owner's manual illustration above and (we assume) the tech sheet(s), UNLESS someone or some tech tampered with them:

    The WHITE WIRE coming off the L-pad #2 lug is to be attached to the RED terminal of the LE5-2, on BOTH variants, again, IF, the chart is correct AND the illustration in the one and only owner's manual there seems to be in circulation applies to all models with regards to the LE5-2 mid-range driver as BOTH tech sheets are IDENTICAL sans the woofers.

    But I reiterate, the tech sheets do not indicate TRANSDUCER terminal color code, ONLY wire colors from input terminals through the entire network until we get to the business end of things where with the exception of the tweeter's fastons, your guess is as good as mine as for original intent and we are back to relying on how JBL did it "most of the time" with anything wirewise BLACK going to BLACK terminals.

    We simply have to assume it is correct (the nice owner's manual illustration) and runs consistently true through ALL incarnations of the L100 (reflects accurately that they were all assembled this way) But I do not KNOW this to be a FACT:

    http://manuals.harman.com/JBL/HOM/Te...L100A%20ts.pdf

    http://manuals.harman.com/JBL/HOM/Te...0LATE%20ts.pdf

    And this is the part that (still) pisses me off. Why in the world are there TWO versions of the SAME speaker identical in EVERY aspect except woofer model/VC polarity?

    Actually, NOT EVEN THAT as the only FUNCTIONAL change to the system, again assuming our data to be correct, was the direction of woofer cone movement. (technical improvements/refinements between the two woofers notwithstanding)

    Was a subjective decision made that wiring the LATE L100A to be an "outie" just sounded "better" than the standard L100A, which going by those tech sheets above is absolutely the ONLY difference between the two systems.

    OR are we missing a part of this puzzle still?

    I understand that going from the 123A-1 to the 123A-3 that the VC polarity "issue" would need to be addressed, obviously, their respective behavior is different, but as your question DOES suggest, then we have in fact CHANGED the relationship between the WOOFER and the MID as everything else remains EXACTLY the same...................unless?

    I mean how fu&king hard would it have been to expend 3 more molecules of black ink and identify the actual TRANSDUCER'S TERMINALS?

    This bull shit L100 wiring hubbub has exacerbated me for too god damned long now..............I really wish I could find a manual that reflects what's ACTUALLY in MY specific pair and or a COMPLETE system schematic complete with the small detail of which fi&king TRANSDUCER terminal to use with which wire. I DON'T HAVE ANY YELLOW WIRES!

    Based on what we do know combined with what we have to assume, wire as described above because apparently JBL didn't seem to think it mattered...............or did they?

    I don't know; I have mine wired with the white #2 L-pad lug wire to the red terminal on the LE5-2

    It's just incomprehensible to me that such a fundamental piece of information regarding what is possibly THE most iconic home loudspeaker system of all times is so elusive, in ANY and ALL of it's variations

    Very frustrating, especially when I can (fairly easily) find out how many times the production line workers took a piss during the 8:00 AM Klipsch Heresy piece of crap shift run, on any given day back in August 1977 if I really needed too.......................and probably, with just a little extra effort, what P.W.K had for lunch that day

  2. #32
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    Sorry for sharing my frustrations all over you......it's just I have put about 100 hours into these as well as quite a few hours in others, restoring them cosmetically to the Nth degree and have never known with absolute certainty if some of them were wired correctly.

    There IS something missing

  3. #33
    Senior Member 1audiohack's Avatar
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    I am a bit puzled by all of this.

    I don't have a pair of these and likely never will so I have done no homework on the subject but I can't help to wonder, if there is no solid schematic to go from, has no one ever set up and taken proper measurements of these and settled the polarity thing objectively? How hard could it possibly be?

    Don't get me wrong, I am not beating on anyone but one would think that long before now this would have been settled via measurement.

    I suppose that if you can't tell a difference by ear then the question remains is what does it really matter?

    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  4. #34
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    Quote Originally Posted by 1audiohack View Post
    I am a bit puzled by all of this.
    I suppose that if you can't tell a difference by ear then the question remains is what does it really matter?

    Barry.
    I kinda agree with the above , but will play DA for a bit.

    IF the L-100A was the last of that line , AND the 4311B is the last of it's line AND they are supposedly identical , then why not check the latter to see how it's wired ?
    Some kind of happiness is measured out in miles

  5. #35
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    Quote Originally Posted by SEAWOLF97 View Post
    I kinda agree with the above , but will play DA for a bit.

    IF the L-100A was the last of that line , AND the 4311B is the last of it's line AND they are supposedly identical , then why not check the latter to see how it's wired ?

    Understood, makes good common sense, and THANKS for the thought; may have figured this out using your suggestion.

    BUT, there are TWO L100As as I so arduously pointed out above and they disagree with one another based on what "we" (I) have (or don't have). And the disagreement appears (based on what we have) only to be CONE EXCURSION DIRECTION brought on by the wiring switch at the woofers?

    I have already pointed it out 5 ways now, if the 123A-3 were wired according to "the convention" then it would behave exactly as the 123A-1 L100A versions. And that would make sense too from a functional and multi-system systems (boxes) compatibility perspective too.

    I am certain that the L100A and the L100A (Late) models coexisted frequently in the inventories and show room set ups at JBL dealers in the late '70s. I know for a fact that the JBL dealer in my small hometown sold enough L100s that there would have most definitely been inventory overlap, without question.

    I would also think that to make one an "innie" and the other an "outie" when they were so close together and there were also other JBL "innie" models sharing the same space for demos that this would have posed a fairly substantial issue. Remember too that this was the era of "Quadraphonic Sound" so I can easily imagine more than a few demos being done with 4 JBL L100s and the quad receivers of the day. Other than serial #s there is nothing on the outside of an "A" or an "A" (Late) to distinguish the two. It just does not add up and is why I continue to chew on this bone.

    Been having this one for a while now:
    http://www.audioheritage.org/vbullet...r-faulty-units

    The 4311B tech sheet also seems to adhere to that illustration from the owner's manual for the L100A with the yellow tweeter wires, which contradicts the understanding of how to treat a 123A-3, but would anecdotally support the idea that that manual does apply to the final run based on those yellow wires (aka, the 123A-3/2213H equipped examples). You would think that a wire color reversal/departure from convention would be to make the current L100s "match" those that had just come before them, being as NOTHING else was changed driver compliment and networkwise. Only the technical refinements and VC polarity of the woofer.

    I mean, an awful lot of (consumer) type folks would have to be "consulting" their authorized JBL dealers as the manual does briefly suggest if memory serves. And studio/pro sound guys having to pull down systems to switch woofer wires around? Crazy! Why?

    http://www.jblproservice.com/pdf/Stu...ries/4311B.pdf
    But at least the 4311B's schematic does indicate transducer terminals with a + and -. Is a 2213H exactly the same driver as a 123A-3? Terminal colors, "innie", "outie", all of that?

    As for why it matters? I would like to know that my boxes are wired as the original design was intended, without any guess work or assumptions.

    If a schematic could be found which indicated TRANSDUCER terminal ID by color and or cone movement then this one could be put to bed forever.

    But I think I may finally understand what's going on. The owner's manual illustration translates well to the one for the 4311B. They jive except for the wire colors used and what wire goes where to the woofer (the terminal ID, L100 sheets just choose to omit that as previously bitched about).

    As mentioned, the 4311B's tech sheet is more complete and DOES included terminal ID on the drivers themselves and clearly shows the "+" terminal of the woofer being fed by a SOILD GREEN wire which originates at the BLACK or NEGATIVE side of the NETWORK input. All has been revealed with that one!

    Obviously JBL got their color convention back on track with the 4311B's networks and possibly those N100s that are shown in that ubiquitous owner's manual. Yea! May have a plausible answer once and for all (except that nagging "why" part)! And what about our new design regarding the woofer/mids relationship?

    So, I am prepared to speculate that JBL was using up the hundreds or maybe even thousand of N100s that they had on hand, already assembled with the conventional colors soldered in place and simply making the wire "switch" to accommodate the new woofers (123A-3) and just never committed that change over period/cluster of boxes built and shipped, to print. All makes perfect sense and actually, an "intermediate" version of the manual could have possibly screwed up/confused things even more, especially on the consumer end (folks who don't generally receive service bulletins).

    So, I am ALMOST happy that my current pair is correct (based on the 4311B's tech sheet), except for the nagging question why?
    Why go from the "innie" to an "outie" with no other apparent changes?

    We are still changing the phase relationship with the LE5-2 as well, even if the 4311B's sheet is the final word.

    Still don't get it. If we're going to change the woofer/mid relationship like that, shouldn't there have been an adjustment made there too?

    Lot of folks say that to their ears the last incarnation sounds the best, maybe that's it? But others say it's the original verticals with a real network (I personally take that one with a grain of salt, network or not, just listen to the LE20 beside an LE25). But even from start to finish, the mid-range stands alone! Untouched baby!

    I just want to know.

  6. #36
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    I'm surprised there hasn't some input from folks who are original owners, know their pair hasn't been opened, and based on the battery test from the binding posts can report on cone movement. Perhaps a thread with a poll? List the serial number, and woofer direction with the battery test, and whether you're confident your pair hasn't been opened. Come on, help a brother out.

  7. #37
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    Quote Originally Posted by rusty jefferson View Post
    I'm surprised there hasn't some input from folks who are original owners, know their pair hasn't been opened, and based on the battery test from the binding posts can report on cone movement. Perhaps a thread with a poll? List the serial number, and woofer direction with the battery test, and whether you're confident your pair hasn't been opened. Come on, help a brother out.
    I agree and I am the one that started it all (again).
    Member "4313B" basically did that with the chart he created and presented here ages ago, but I do not know the source of the data; tech sheets or actual speakers. There are also some errors on that sheet as well that do not relate to the woofers.

    I have operated on the assumption that the woofer parts of it were accurate.

    In the process however, the question that's big in my mind and still gives rise to wonder what's "right" is the new model designation by essentially just changing the woofer's cone excursion? They could have just as easily wired the new 123A-3 in a way that would be consistent with the version that came before it.
    And leaving the mid the same throughout the line?
    What was the thought process?

    As I already said, I finally settled on the "outie" woofer convention and adhered to the WHITE wire to RED terminal on the LE5-2, a la the 4311B but without the corresponding colors to really validate things. Still lines up with the "anything with BLACK on it" rule though and then breaks it; that would validate the chart.

    So, I'll just use them like that but still won't know what's "right".................and why.

  8. #38
    Senior Member 1audiohack's Avatar
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    I have never had any of these little guys but as luck would have it, (not my good luck) a guy called me out of the blue, I mean I didn't even recognize the name of the guy who gave this guy my number, anyway, where was I, oh yeah this guy calls and tells me that he has four 4312's that he needs to get made right. He says "I have a bunch of spare parts too." Should have be a warning.

    I am a sucker to work on and listen to nearly any (real?) JBL so I end up with a project that I swore I wouldn't spend more than a half a day on and that part I actually managed.

    A quick plug in with pink noise and none of them fully work. I just shelled out all the drivers and swept them individually and ended up with just enough to make a pair, kinda, if you don't mind mixing AlNiCo and Ferrite drivers.

    So we get to the polarity question and boy does the frequency response look like hell if you get the woofer wrong. Well, you better measure because one of these boxes is green/black to red and the other is green to red.

    I will post sweep pics tomorrow in hopes to help, add to the confusion haha.

    These sound better than I thought they would. Suprize.

    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  9. #39
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    Quote Originally Posted by 1audiohack View Post
    I have never had any of these little guys but as luck would have it, (not my good luck) a guy called me out of the blue, I mean I didn't even recognize the name of the guy who gave this guy my number, anyway, where was I, oh yeah this guy calls and tells me that he has four 4312's that he needs to get made right. He says "I have a bunch of spare parts too." Should have be a warning.

    I am a sucker to work on and listen to nearly any (real?) JBL so I end up with a project that I swore I wouldn't spend more than a half a day on and that part I actually managed.

    A quick plug in with pink noise and none of them fully work. I just shelled out all the drivers and swept them individually and ended up with just enough to make a pair, kinda, if you don't mind mixing AlNiCo and Ferrite drivers.

    So we get to the polarity question and boy does the frequency response look like hell if you get the woofer wrong. Well, you better measure because one of these boxes is green/black to red and the other is green to red.

    I will post sweep pics tomorrow in hopes to help, add to the confusion haha.

    These sound better than I thought they would. Suprize.

    Barry.
    Sounds good!
    But here we go again; no ambiguity with the 4312 tech sheet, they identify the terminals clearly:
    http://www.jblproservice.com/pdf/Stu...ies/4312LR.pdf
    As with the 4311B, you can see that even though they (the woofers) were wired in "reverse" from the INPUT, JBL did get back on track with the wiring color code convention. I think now for sure that the L100A hubbub was due to the fact that they were using up already assembled N100s that HAD BEEN going into boxes that didn't need the switch.

    From a JBL Technical Service Bulletin:
    "Control Contractor Series Studio Monitors: All 4300-Series models (except models 4311 and 4312L, R) are negative. The following models are negative: 4406, 4408L, R, 4410L, R 4412L, R, 4425L, R 4430L, R, 435L, R. The following models are positive: 4206, 4208, 4311, 4312L, R, 4408A-L, R 4410A-L, R, 4412A-L, R 6208, DMS-1 LSR4300-Series, LSR-Series LSR6300-Series"

    Like the fact too that they finally addressed the mirrored image dealio with this incarnation as well. Sure built and sold a whole lot of these sucky, two cap crossover speakers for a really long time, din't they?!:


  10. #40
    Senior Member 1audiohack's Avatar
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    Here is a couple of measurement pics. The first is the sophisticated crossover driven with a D45 and measured with an 8.2 Ohm resistor on the individual outputs and the voltage measured at the load.

    The second is the complete speaker measured on it's back on a corner of the bench with the mic 2 feet strait above the port in between the mid and tweet. Both presence / absence knobs at 12: O'clock or centered on #5.

    The white line is with all the drivers wired for forward motion with positive voltage applied and validated via impulse measurement. Not bad huh?

    The yellow line is with only the woofer wired reverse polarity, the tweet and mid left forward, yuck.

    I would seem that if there was a definitive wiring schematic for all of these in their variations it would have shown up by now no?

    I submit that if you don't have a way to measure that you just will never know for sure what you have. Looking at the Reverse Polarity magnitude measurement you would sure think that one could hear that.

    Hope this helps,
    Barry.
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    If we knew what the hell we were doing, we wouldn't call it research would we.

  11. #41
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    Quote Originally Posted by 1audiohack View Post
    The yellow line is with only the woofer wired reverse polarity, the tweet and mid left forward, yuck.
    Wow, thanks Barry!

    I do not understand what the sentence above means, or just exactly what you have going on when you're taking your measurements

    How about just posting the wiring scheme used on the whole system that gave you the best results?

    Thanks for the extraordinary efforts!

  12. #42
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    Hi;

    The wires in this box are all terminated with male and female spade connectors in the mid's and tweets and the drivers are not polarity marked.

    One box has a 2213H and the other a 2212 and they are polarity different from each other so I don't have an answer for the tracer positive or negative question.

    The second measurement screen shot is the near field on axis frequency response of the aggregate 4312 system.

    The white trace is with all drivers wired where positive voltage gives positive / forward cone motion. +++

    The yellow trace is with the woofer wired where positive voltage gives negative / inward cone motion while the mid and tweet remain. -++

    Side note: I have a dozen 2227's, all have JBL cones in them, one of them is polarity inverse to the other 11. A check with a compass tells me the magnet is flipped. This shit will drive you nuts! You just can't assume anything is correct. Measure, test and validate is all you can do.

    ~If I have misunderstood your question and or completely failed to answer it, try me again.

    All the best,
    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  13. #43
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    Quote Originally Posted by 1audiohack View Post
    Hi;

    The wires in this box are all terminated with male and female spade connectors in the mid's and tweets and the drivers are not polarity marked.

    One box has a 2213H and the other a 2212 and they are polarity different from each other so I don't have an answer for the tracer positive or negative question.

    The second measurement screen shot is the near field on axis frequency response of the aggregate 4312 system.

    The white trace is with all drivers wired where positive voltage gives positive / forward cone motion. +++

    The yellow trace is with the woofer wired where positive voltage gives negative / inward cone motion while the mid and tweet remain. -++

    Side note: I have a dozen 2227's, all have JBL cones in them, one of them is polarity inverse to the other 11. A check with a compass tells me the magnet is flipped. This shit will drive you nuts! You just can't assume anything is correct. Measure, test and validate is all you can do.

    ~If I have misunderstood your question and or completely failed to answer it, try me again.

    All the best,
    Barry.
    Hi Barry,
    I want to know the correct way, without ANY doubt, confusion, assumptions, extrapolations, deductive reasoning or misunderstandings, how to wire my pair of LATE production JBL L100As with the driver compliment that I possess in mine.

    The way the designer(s) of the system INTENDED for it to be wired when it left the JBL factory back in the 1970s, regardless of how things measure or sound for you or anyone today.

    Secondarily, I would also like to know, is it indeed a fact that the only difference between the L100A and the L100A (Late) is cone woofer excursion and is in fact the wiring to the mid driver (LE5-2) supposed to be the same throughout the entire line up (all incarnations) of the JBL L100, for both "innie" and "outie" wired cabinets?

    Those are my questions but the first one is the MOST important (the one I really care about).

    Thank you for your help and interest, very kind and thoughtful of you!
    Thomas

  14. #44
    Senior Member 1audiohack's Avatar
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    Hi Thomas;

    I get that and truly wish that I could find that for you, but I can not.

    I do know that the guys at JBL do / did in fact measure and I am certain that they would opt for the white line.

    I wish you all the best in your quest, It would sure as hell be nice to put this to bed once and for all.

    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

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    Quote Originally Posted by 1audiohack View Post
    Hi Thomas;

    I get that and truly wish that I could find that for you, but I can not.

    I do know that the guys at JBL do / did in fact measure and I am certain that they would opt for the white line.

    I wish you all the best in your quest, It would sure as hell be nice to put this to bed once and for all.

    Barry.
    Agreed
    So, tell me each wire color I need to attach to which terminal color on each transducer (because I will admit I can't understand what it is you are telling me that you did)
    My L100A (Late) have N100 networks with the RED and Black network input wires to the network
    My driver compliment is:
    123A-3
    LE5-2
    LE25
    Here is an accurate schematic, sans terminal ID:
    http://manuals.harman.com/JBL/HOM/Te...0LATE%20ts.pdf
    Everything is correct that is shown, obviously you can see with your eyes that they don't indicate traducer hook up polarity (terminal ID)

    Now, tell me EXACTLY how to hook it up, which wire goes where and which COLOR goes where for BOTH the wires AND the transducer terminals.
    Also, please provide exact 1.5V battery test results for verification so that we're both talking the same thing when we say "positive" and "negative" for example
    Then I might take these apart again and try it (to get your response curve) and see if they sound any better

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