avt4x12 + jbl d120f +greenback

Discussion in 'Cabinets & Speakers' started by Exotic, Sep 30, 2019.

  1. Exotic

    Exotic Active Member

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    how is this thing hooked up when it has the bayonet type connector seemingly inserted into the jbl's posts? c1814fkqftysrjozyoh6 (Mobile).jpg plus how would u do it if u needed to connect 2 bayonets ,like when there is a wire going to another speaker and one wire also going to the jack,out of a single post?
     
    Last edited: Oct 5, 2019
  2. metromutt

    metromutt Well-Known Member

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    You'll have to cut both bayonets off and strip the plastic wire covering back by quarter of an inch (carefull not to cut the individual wire strands) then twist the strands to stop the fraying then press the post down and aim the wire through the visible hole as far as you can go and release the post spring. Give the wire a slight tug to make sure it's firmly gripped.
    Also when you do put your speakers back in the cab don't over tighten the spk bolts, just nip them up equally alround.
     
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  3. Kinkless Tetrode

    Kinkless Tetrode Well-Known Member

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    Beat to draw,

    What I would do is just snip those off. Then bare back the wire a bit. Then twist the exposed wire tight. What you do i believe in this case, is just push the red or black buttons which opens a slot to insert the bare wire into. Done. On Altecs which might be the same, those are thumb screws doing the same thing.

    A word about polarity. There's a chance that the GB and/or the JBL speakers will not be the same polarity as the stock speakers. To verify which terminals are + and which are -, use a 9 volt battery. What you want is to assign + to the terminal on each speaker that makes the cone go out instead of in when connected to the positive side of the battery. Then make sure that the wires are connected accordingly.
     
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  4. Exotic

    Exotic Active Member

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    i did it, i saw it ,plus to plus moves the cone out ,and it made a sound too . plus to minus moves the cone in, got it .very helpfull thanks .
    now in the future if i wanted to use those bayonets again i could just press it back together with pliers right?
    the greenback should be ok plus/minus ,and hopefully the jbl will have red for plus right?
     
  5. Kinkless Tetrode

    Kinkless Tetrode Well-Known Member

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    Don't worry about saving or reusing the bayonets. You can buy them for 5 cents a piece at any hardware store.

    Make sure the other speakers react the same to avoid any phase issues.
     
  6. Metroman

    Metroman Well-Known Member

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    IMHO, its a bad idea for the life of the GB. They use 8 x 25w speakers with a 100w amp for a reason.

    Also don't forget JBLs are reverse +-.. Red is Negative. Black Positive.
     
  7. Exotic

    Exotic Active Member

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    ok cool ,then how about a power brake or an attenuator ,but i don't plan on cranking up for the time being just using it for practice .
     
  8. Exotic

    Exotic Active Member

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    please elaborate on why it is exactly they use 8x25 watt speakers ?
     
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  9. metromutt

    metromutt Well-Known Member

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    The only thing you need to take from that it the Red post is negative and Black positive when wiring up.
    If you're not cranking your amp everything should be fine with that set up.

    Worth a note, have you checked for the 21032 code printed white on the back of the paper cone. The will tell you if the cone is original. Sometimes some recones can be the conventional wiring way, red pos etc.
     
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  10. Metroman

    Metroman Well-Known Member

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    Because a 100w amp with only 100w worth of speakers is a disaster waiting to happen. Thermally speaking.

    All watts are for the amp is the ability to create heat. The wattage rating for speakers is how much they can take before meltdown.
    A 100w amp cranked can easily put out 150w+, so with 100w worth of speakers the speakers never get a break.

    Hendrix regularly blew 240w worth of speakers with a 100w amp. That's 8 x 30w speakers. 240w worth.

    In comparison the late 60s early 70 Hiwatts came with 300w worth of speakers Per Cabinet. DR103 came with 8 x 75w Fane, and if you got an upgrade to the 100w Cresendo, that's 800w worth of speakers for a 100w RMS amp.
     
  11. metromutt

    metromutt Well-Known Member

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    I understand and most do... but this only applies if you are running the amp at high volumes. There will be the 'odd' few that can stand in front of a fully cranked marshall either at home!!!! or with a VERY understanding front of house guy mixing your band. SO... I'd have to say most people could run a 100w cab with a head 'without disaster' but I do understand your warning.
     
  12. Metroman

    Metroman Well-Known Member

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    For me, I HATE any kind of speaker funny business. Its also hard to determine just how many watts youre cranking through the amp just by looking at the V control. I don't like to guess, and if you use any kind of drive pedals ect, its just an extra burden.
     
  13. Exotic

    Exotic Active Member

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  14. Exotic

    Exotic Active Member

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  15. Exotic

    Exotic Active Member

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    well there it is ,seems like it would be a cake walk ,maybe for a young whipper snapper ,but for me i broke a sweat ,and my legs are all rubbery . IMG_1729 (Custom).JPG
     
  16. Matthews Guitars

    Matthews Guitars Well-Known Member

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    The difference between 100 watts and 50 watts to the speakers is just 3 dB of sound level. To the ear that's just a small difference in output.

    If you crank the amp up all the way and then back it off by "a little" to the ear then you've backed it off to half power, pretty much guaranteed. Back it off just a little more and you're sure to be in the safe range for your speakers.

    If you don't run your master volume above 8, you're not going to put more than half of the amp's full rated power into the speakers. And that's punishingly loud.
     
  17. Exotic

    Exotic Active Member

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    i'm only using the amp on from 0 to 2 at the most ,but yeah hopefully it won't blow up . not much difference in sound with one greenback running with 3 other avt's ,but it's not as loud as the 16 ohm cabs and we'll see what happens on monday when i add the jbl to the mix ,and hopefully in the future it will be 2 jbls and 2 greenbacks .
     
  18. Kinkless Tetrode

    Kinkless Tetrode Well-Known Member

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  19. Exotic

    Exotic Active Member

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    make that 2 jbl's d120f .i have a grey one (scheduled for monday)that has been reconed and i just bought a orange one that has the original cone ,so those will be both on top with the greenback and the avt on bottom till i get one last greenback . 1 (Custom).jpg but yeah at first i was panicking like no ,he sent the wrong one ,but there was a greenback in there . now if all goes well i will be able to see how much difference in sound there is in a grey one and a orange one and i guess also how much difference in a recone and an original ?
     
  20. johnfv

    johnfv Well-Known Member

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    The vintage JBLs look nice, congrats! I wouldn't be too worried about a recone. My K series got reconed back in the early '80s and sounded the same to me. One more reminder about reversing the polarity on the JBLs relative to the greenbacks. I think I would do an X pattern (put one JBL on bottom). The JBLs will be louder (more efficient) so you're gonna hear them more even if they're on bottom.
     

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