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2x12 made from Bandmaster cabinet

Discussion in 'Amps and Cabs [BG]' started by rufus.K, Oct 23, 2015.


  1. rufus.K

    rufus.K

    Oct 18, 2015
    SoCal
    So Ive got this mid 70s Fender Bandmaster 2x12 vertical cabinet, empty. its in okay shape, but no speakers. I do have an Eminence Beta12a lying around, and the Aguilar GS112 ive retired could donate its speaker, both 8 ohms. Been thinking of making a 4ohm bass cab out of it, maybe find another cheap 12 instead of gutting the Aggie. ... either way... i may as well load up the empty with drivers ive got lying around.
    Then it occurs to me I could use the 6.5" Carvin leftover from a nEARful build (with a simple high pass before it), heck, if I use the Aggie's 12", then I could use the horn & Lpad as well.
    Whats everyone think of that?
    The Bandmaster cab in question is 39"tall, 29" wide, and 11.5" deep, outside dimensions.
     
  2. I'd try it with just the 12's first. If it sounds really crappy , you won't have screwed up a good cab by cutting it up for the 6.5 or a horn. If it sounds good but maybe sounds like it needs more high end , then maybe try the 6.5 or the horn. If it sounds really good with just the 12's , don't mess with success.
     
  3. rufus.K

    rufus.K

    Oct 18, 2015
    SoCal
    Valid point.
     
  4. rufus.K

    rufus.K

    Oct 18, 2015
    SoCal
    Anyone in LA wanna trade a Carvin PS15-8 for a 12" bass driver to make this project build a reality?
     
  5. rufus.K

    rufus.K

    Oct 18, 2015
    SoCal
    Ooh, here's an idea, how about cutting one of the cutouts bigger, throw the PS15-8 in as the second driver.
    Crossover the two around 500 hz... now that'd be sweet... a 1x15 1x12 in a bandmaster cab...
    How would that be in a box of those dimensions?
     
  6. Sputnik Monroe

    Sputnik Monroe

    Feb 11, 2014
    Let me first say I have never tried this ... But it's a common practice in the hi fi world. You might consider using a single active speaker (I personally would use a 15) and use a passive tunable radiator in the second hole. The passive will act as a port and also radiate sound waves. I know there is a company called Dayton that makes them and Parts Express sells them. Maybe someone with experience can chime in on this one. If I remember Mesa used this in one of their cabs?
     
  7. rufus.K

    rufus.K

    Oct 18, 2015
    SoCal
    Novel idea indeed.
    Dayton has this to say"
    Note: Adding mass to the passive radiator will decrease Fs and increase Qms.

    Tip: As a general rule the passive radiator(s) should be able to move double the volume of air as the active woofer(s)/subwoofer(s) in the system. For example: A passive radiator system for a 12" woofer/subwoofer that has 10mm of X-max would require 2-12" passive radiators with 10mm of X-max. For single passive radiator systems, it is common to use a passive that is larger than the active woofer(s)/subwoofer(s)."


    If i have a 12 already, will i just destroy the 12" radiator?
    I have to open the cab to see if it is completely sealed or not, which will affect the the radiator's performance. maybe a bit of venting will keep it from blowing out. No passive radiator experience...
     
    Last edited: Oct 23, 2015
  8. rufus.K

    rufus.K

    Oct 18, 2015
    SoCal
    So the baffle is mdf, I dated the cab from 80 or 81. As the picture shows, the baffle is toast.
    If I mount a 15" driver I have lying around to the baffle over the area where it's damaged, but not enlarging the 12" hole to a 15" cutout, so the it's choking the 15", what is the tonal effect it has on the tone or frequency response of said driver? Dampen lows in a goodbway?
    Allow highs to pass normally?
    vibrate the the baffle horribly creating unwanted resonance?
     

    Attached Files:

  9. The cones need to be able to move outward.

    Doing what you are proposing sounds like it will lead to cone damage.
     
  10. rufus.K

    rufus.K

    Oct 18, 2015
    SoCal
    I wasn't thiking of letting the cone hit the baffle.let's suppose it didn't hit.
     

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