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Thread: JBL 4311B Control Monitor Polarity Confusion

  1. #1
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    JBL 4311B Control Monitor Polarity Confusion

    Hello everyone. First post on a forum anywhere for myself here. After recently getting into 'hifi', I've finally found myself a little project.

    I recently found a pair of 4311B's at Value Village for $19.99. That's right, and I actually had to think about it for a second. They are in great shape, other than some replacement tweeters (had a pair of Audax 24010 tastefully installed), and the woofers are somewhat brownish, but at least they don't smell like smoke.

    I managed to find a pair of LE25-4 tweeters on CanuckAudioMart for $115 CDN shipped. I thought that would be the better option for a replica pair of LE25-2's that would cost me at least $250.

    First thing I noticed was that one of the woofers (2213H) was rotated 90 degrees, assuming to get a more symmetrical look, so I popped that one open first. To my surprise, the GREEN/BLACK wire was connected to the RED terminal. I found a link somewhere to the technical manual, and it showed the GREEN/BLACK goes to the '-' terminal on the woofer, and I would assume that the Black terminal is '-'. So I thought they must have hooked it up wrong when they rotated the woofer.

    I found and started reading a thread on here saying the many jbl's will have a driver out of phase. That thread had a ridiculous amount of info, but no real answers about how exactly different models should be hooked up. There was actually little talk about the 4311B for that matter also.

    So I thought to myself, well maybe that was actually hooked up correctly, and the black terminal is actually '+' (or something like that).

    BUT then I popped out the tweeter on the other one, and I saw that the GREEN/BLACK was hooked up to the BLACK terminal !!! So at this point, I'm a little confused.



    Does anyone have photos of their hookups on a re-build, or can any nice 4311B owner crack one open to look? There doesn't seem to be any schematic available regarding this.

    Looking forward to sorting this out. Thanks.

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    Administrator Robh3606's Avatar
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    Senior Member macaroonie's Avatar
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    I wouldn't rule out the Audax tweeters completely , to the best of my knowledge both L40 and L110 had an oem. Audax tweet and they were both fine sounding speakers.
    Once you get your wiring sorted out things will improve greatly.
    I did have a search for an Audax with the number you posted , nothing . Any other ID or a pic. If we can find the model it should be easy tho get the tech data on the driver.

    M

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    Quote Originally Posted by Robh3606 View Post


    Thanks for your reply. Yes, that's the technical manual I was talking about. The problem is, it doesn't tell you if the '+' is the red or the black terminal on the 2213H.

    I did the battery test, and the positive end on the battery to the red terminal, makes the driver go inwards. So I guess the 2213H drivers are 'innies'? I have yet to pop out the mids to see how they are hooked up.



    Here is the forum that I found that had everyone confused. You will see it is not as simple of a topic as you might think.

    http://www.audioheritage.org/vbullet...p/t-37337.html

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    Quote Originally Posted by macaroonie View Post
    I wouldn't rule out the Audax tweeters completely , to the best of my knowledge both L40 and L110 had an oem. Audax tweet and they were both fine sounding speakers.
    Once you get your wiring sorted out things will improve greatly.
    I did have a search for an Audax with the number you posted , nothing . Any other ID or a pic. If we can find the model it should be easy tho get the tech data on the driver.

    M

    Sorry, I was looking at the wrong number. They are the Audax TW043X0. 1.3" textile dome.

    https://www.madisoundspeakerstore.co...weeter-by-aac/

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    Senior Member macaroonie's Avatar
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    I'm pretty sure that's the same one JBL oem'd. JBL version has a different faceplate with 3 mounting holes and they used button head allen screws to hold it all together.
    Whoever did the mod has ' researched' the choice of driver here IMO.
    A look at the X/O implementation in the L110 could give some idea as to what should be going on for that driver.
    You may just be wanting to get these back to stock , I understand that but don't overlook what might be an opporchancity.

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    Administrator Robh3606's Avatar
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    RED is always the + terminal on a JBL transducer.

    Robh
    "I could be arguing in my spare time"

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    Quote Originally Posted by Robh3606 View Post
    RED is always the + terminal on a JBL transducer.

    Robh

    Excepting when positive was actually the Black Terminal ( which is the case in virtually all the legacy drivers made pre mid-1990's ).


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    Administrator Robh3606's Avatar
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    Excepting when positive was actually the Black Terminal ( which is the case in virtually all the legacy drivers made pre mid-1990's ).
    No no no! This is exactly why there is so much confusion. Forget about driver polarity. We all tend to out smart ourselves. We are talking specially about the wiring diagram that clearly shows the green goes to the + INPUT of the driver. That means RED or + if so marked.

    Sorry but when you hook up anything with 2 terminals one RED and one BLACK which one is always signal and the other ground? Any Amp or pair of speakers and so on. Its about as conventional as you can get and it doesn't matter if the amp inverts polarity Red means signal Black ground.

    Rob
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    http://www.jblproservice.com/pdf/Stu...ries/4311B.pdf

    Green to the black terminal on the woofer, green/white to the red.

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    Administrator Robh3606's Avatar
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    No it's green to the black terminal on the outside speaker terminals and green to the +++ Plus on the woofer. + on the woofer is red.

    Rob
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    Quote Originally Posted by Robh3606 View Post
    No no no! This is exactly why there is so much confusion. Forget about driver polarity. We all tend to out smart ourselves. We are talking specially about the wiring diagram that clearly shows the green goes to the + INPUT of the driver. That means RED or + if so marked.

    Sorry but when you hook up anything with 2 terminals one RED and one BLACK which one is always signal and the other ground? Any Amp or pair of speakers and so on. Its about as conventional as you can get and it doesn't matter if the amp inverts polarity Red means signal Black ground.

    Rob
    Thanks for the most straight up and confident reply I've seen on this issue. This is what I was starting to lean towards the further I dove into this. I found a JBL's 'Technical Notes, Volume 1 Number 12' document I found on Polarity (I tried to attach it). It's dumbfounding how they do not mention the 4311B monitors, or the 2213H woofers. But as I mentioned I already did the battery test, and the positive voltage made the driver go in, so it appears the 2213H woofer is a 'negative system'.

    I'm about to hook up one of the LE25-4 tweeters, and I have the woofers hooked up the same, in a conventional Green to the Red terminal, and Green/Black to the Black terminal. Really curious to hear it up against the Audax tweeter. Also to see if the bass has improved from when I first got them. Listened to them for about a week or so. Was fairly impressed, but thought the bass was a little weak from a pair of 12" woofers. Little did I know one we hooked up out of phase.




    JBL Polarity.pdf

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    I was able to find this attached schematic for the L100, Century/4311 which tells me the "Male terminal is PLUS" on a LE25/26. Fingers crossed it is the same for the LE25-4 (not too confident in that actually, but that's all I got).

    I needed to know this because the original disconnects were cut off to solder on the Audax tweeter, and I'm about to install new disconnects on the yellow wires to hook up one of the LE25-4.



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  14. #14
    Administrator Robh3606's Avatar
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    What you posted above is not from JBL uses a different crossover and is a negative system.

    From the PDF

    Control Monitors; all models are positive: 4312A L/R

    Now look at both techsheets the wiring is the same as the 4311B.


    https://manuals.harman.com/JBL/HOM/T.../4312%20ts.pdf


    The woofer is wired with the Green Black to the Negative Black on the woofer to the Red on the Outside connectors. This wiring flips the polarity of the woofer making it a Positive System.

    Rob
    "I could be arguing in my spare time"

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    Did ANYONE even look at the JBL Proservice pdf I linked? The answer is plain as day on the wiring diagram on it!

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