JBL D120Fs and Greenbacks in Same Cabinet

Discussion in 'Cabinets & Speakers' started by DavidS, Nov 24, 2020.

  1. DavidS

    DavidS New Member

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    Hello,
    I am trying to replicate Eddie Van Halen's brown sound, and I was wondering how he was able to use JBL D120Fs and Greenbacks in the same cabinet given that the JBLs are 8 ohms and Greenbacks are (usually) 16 ohms. I have a set of both speakers and an empty basketweave that I want to install them in. Here is a picture of Diamond Dave sitting on the cabinet loaded with both (you can see the metal cone caps on the JBLs):

    [​IMG]
     
  2. Gene Ballzz

    Gene Ballzz Well-Known Member

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    While 8 ohms is the most commonly seen for the JBLs, they were/are certainly available in 16 ohm as well as even occasionally in 4 ohms. And even though the majority "vintage" greenbacks tend to be 16 ohms, new ones are readily available in 8 ohms.

    Just Sayin'
    Gene
     
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  3. StingRay85

    StingRay85 Well-Known Member

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    I've seen a Fender Quad Reverb with 4x JBL D120F 16 ohms. So they indeed exist.

    Also the 8 ohms pulsonics were made. In some combos, HH, Vox
     
  4. metromutt

    metromutt Well-Known Member

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    Wasn't aware but after looking into it, you would be able to mix the 8 and 16ohms...

    To wire the 4x12" with JBLs and Greenbacks - connect each pair in series (the two JBLs make 16 ohms, the two Greenbacks make 32 ohms), then connect both the series pairs in parallel:

    Jack + to JBL1 - and GB1 +
    JBL1 + to JBL2 - and GB1 - to GB2 +
    Jack - to JBL2 + and GB2 -
    = 10.66 ohms at the jack. So set the amp to 8ohms

    Don't forget to wire the JBL's the opposite way round at the terminal posts as the phasing will be the other way round when using another brand of speaker, so red will be black etc.


    I actually liked the '70's blackback G12m's for evh, they had a bit more of a bite but warm too. Which when you listen to the clips of RWTD left and right is a mix of the sizzle of the jbl and the warm pulsonic greenback.
     
    Last edited: Nov 25, 2020
  5. StingRay85

    StingRay85 Well-Known Member

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    Or a JBL 8 next to a greenback, and then below a greenback next to an unconnected speaker. This way you can also make a good sounding 16 ohm cab
     
  6. metromutt

    metromutt Well-Known Member

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    Could you expand a bit on this set up.
     
  7. StingRay85

    StingRay85 Well-Known Member

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    It requires paralleling of the 16 ohm speakers, and connect them in series with the JBL. So you go from the jack chassis + two red wires to the + of the greenbacks, you combine the - (black) of the greenbacks, and run that towards the + of the JBL. Finally you go from - of the JBL back to jack chassis ground (black). End result is 16 ohms. The fourth speaker is just there to fill the hole.

    Paralleling all three would give you a 4 ohm load.

    Also, don't forget that on a JBL the + is the BLACK pin, and RED is the minus pin. It doesn't matter for the load, but otherwise your speakers are not in phase.
     
    Last edited: Nov 25, 2020

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