Has anyone ever modified a 2x12 closed back cab by opening up the back a little...?

Discussion in 'Amps and Cabs' started by hottub, Apr 23, 2008.

  1. hottub

    hottub Member

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    meaning to say, have you ever modified a closed back cab with a non-removable back and opened her up? For instance, cutting a small width of say 2 - 3" the length of the cab to make it a very slightly partially open-back, but still retain some of the closed back qualities?
     
  2. StompBoxBlues

    StompBoxBlues Member

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    Excellent question that is really relavent for me too. Hope you get some answers!
     
  3. mcdyas

    mcdyas Supporting Member

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    i did it with a /13 212D cab, i cut a 7" strip out across the middle of the back panel. it sounds better now to my ear.
     
  4. Guinness Lad

    Guinness Lad Silver Supporting Member

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    I had a cb Guytron cab and rather then butcher it I decided to sell it unloaded and use the funds to buy a Avatar OB cab. Regarding the sound difference, I am much happier to have this sound as I was always fighting the excess and boomy bass with the cb cabinet.
     
  5. jlummaa

    jlummaa Member

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    Not a 2x12" but i made my Marshall 1960A 4x12" cab open back (the same way the JTM45/100 RI stack slant cab is). I made new back panels so that 1/3 of it is open. Much better to me, i prefer the slightly wider sound than the closed back bass boost.
     
  6. Third Stone

    Third Stone Member

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    Yup, I have an old '63 blond Fender 2x12. I stored the original panel and had two new back panels made....left about a 4 inch gap between them. It worked out great, and the sound is very punchy with great bass...and a little airy-ness. THD used to make (maybe they still do?) a cab that had the same thing. I think they called it a rear "port" but it was basically a 3 inch wide slit running the length of the back, side to side.
     
  7. FloridaSam

    FloridaSam Member

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    I did it to an old Kustom red tuck and roll unported 2x12. I cut about 1/3rd off the top, hinged it and let it be open or closed. Made a big difference with some amps, I am really glad I did it.
     
  8. rockon1

    rockon1 Member

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    Yep-more than once! I recently bought a LOPO large closed back 2x12 thing the bass would better than a smaller 2x12 closed cab. Well the cab sounded good but lacked a lot of low end especially at lower to medium volumes.

    The back panel of the cab is 20 inches in hieght. I cut 5 inches off the bottom so its 1/4 open on the bottom. WOW! what a difference! The cab sounds bigger fuller and has a lot more low end!

    I'd say it doesnt retain a lot of the closed back qualities but it still projects just fine. All I can say is no more closed back x12's for me! Bob
     
  9. jay42

    jay42 Member

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    The THD 2-12" looks to be roughly a 2.5" to 3" slot.
     
  10. Oldtone

    Oldtone Member

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    So, since my cab has a sealed back, I can measure the area that would exist if I had a 3"-4" gap running the length of the rear panel and cut round holes with the same area to get the same effect?
     
  11. jay42

    jay42 Member

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  12. rockon1

    rockon1 Member

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    Sure but its a lot easier to just rip 3 or 4 inches off the panel with a cicular saw. I peeled back the tolex and ripped mine. Then I reglued it. Looks like it came that way! Bob
     

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