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Thoughts on replacing old Kustom 2x15 speakers w/ 12s?

Discussion in 'Amps and Cabs [BG]' started by smoothdave, May 4, 2010.

  1. smoothdave


    May 24, 2009
    I have one of these old Kustom 2x15 cabinets.


    Unfortunately, the bottom speaker, while original, is blown. The top speaker works great if you want your bass to sound like a southern fried six string telecaster. I can't understand how a speaker can make everything that comes out of it be nothing but twang, but it does it.

    Anyway, I would like to replace the 15's with something else. At the moment, I have access to some inexpensive 12's, which would surely be a step up. I'm looking for thoughts on whether I should put two 12's in it, wait until I can get 15's, although that might be a while, or do something else. One thought I had was to try to put two 12's in it with two 6's or one 12 with two 6's as sort of a poor man's/lazy man's hack of a fEarful.

    I would appreciate any thoughts or suggestions. Thank you.
  2. JMac- Wiskerface Designs

    JMac- Wiskerface Designs Terror headcase dude

    Jul 8, 2009
    Atlanta, GA
    Replace the blown 15's with new/ working 15's that are comparable to what came in the cab. The outcome of what your talking about doing is never pretty. Actually for what you would spend on replacing those speakers you would probably come out better buying another used cab.
  3. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    I'd be inclined to put a 3015LF in the bottom hole and a midrange driver above it. You should get familiar with WinISD and use it to figure out how the cab is tuned. Since the design pre-dates T/S I doubt very much that the ports were properly sized.
  4. Probably not, but if my memory serves me well (that's a laugh!!), the 2x15 sounded very good with a lot of authority in the low end.
    I'd definitely not butcher the cab, but would load it with a couple of 3015s (non LF). Many 2x15 players around here really like a pair of these in a good quality cabinet.
  5. smoothdave


    May 24, 2009
    Thank you for all of your advice. I'll forget about the idea of dropping the 12s in there since everyone was consistent with that advice.

    It's going to be a while before I can get 15s, so I'll have to come back to the question of whether to go with 2x15 or one 15 and the midrange. Maybe by that time I'll be able to do both. :)

    Thanks again. I'm glad I didn't bother with the 12s.
  6. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    It depends on your amp. One 3015LF will put out as much low end as two 3015, but with 6dB less voltage sensitivity, so you need an amp rated for at least 400w into 8 ohms to take advantage of the excursion of the 3015LF. If you do have that much power the result with one 3015LF plus a mid will be far better.
  7. smoothdave


    May 24, 2009

    My amp is a joke. It is something called a Tosh that puts out 160 watts on a good day. If I have a loud drummer, I pull the back of the cab off and play with my head inside so I can hear what I'm doing. :D

    Okay. The money is no object plan is the 3015LF with one of those 6 inch Alphas up top in some kind of enclosed frame and a new ripping power amp.

    The other plan is to keep poking around for some respectable 15s to put in there.

    Thank you.
  8. Walking


    Apr 5, 2010
    Can the speakers be re-coned? JBL D140s are pretty cool, if that's what you have. Alnico magnets, I believe.
  9. Oren Hudson

    Oren Hudson

    Dec 25, 2007
    Gastonia, NC
    Hey smooth - when you replace the speakers, I'll take the JBLs or Altecs off of your hands. I have a cab waiting for either. :cool:
  10. smoothdave


    May 24, 2009
    Only one of the 15's is original, and that's the one that sounds blown to me. I don't know if it can be re-coned since I don't know anything about that. I can't remember which model it is. I'll have to pull it apart again and check.

    The other 15, as I recall, is some kind of Jensen. That's the one with the severe twang. That speaker is not right.

    Unfortunately, I'll be running it like this for a while yet, but I'll let you know. The guy who gave me the cabinet for nothing has first dibs. :)
  11. Just remember, if you go with a 15 + 6, you'll need a crossover too. Also, I don't think Bill was suggesting a separate head case for the 6, but instead, making a baffle to cover the top 15" hole, and cutting a mounting hole in it for the mid cone.

    As much as I love a 15/6, I still think I'd rather have a pair of great Neo fifteens in this particular cab though.
  12. Am I really the going to be the first to point out that 12s won't fit? :eyebrow:
  13. smoothdave


    May 24, 2009
    Thank you. I got that, but I think I wasn't clear. I was looking at some pictures of the insides of the fEarfuls and gb has a little enclosure that holds the six inch speaker within the main cab. I was thinking that I would build one of those little enclosures like in this picture and then mount it in the Kustom. In other words, I would do everything you suggest, but I would build an enclosure for the 6 inch mounting hole.

  14. smoothdave


    May 24, 2009
    I've got power tools. :hyper::hyper::hyper:

    Actually, I was thinking that it would be possible to make a plywood mount between the 15 inch hole and the 12 inch speaker, but that plan has been shelved based upon the sound:ninja: advice of the collective.
  15. Korladis

    Korladis Banned Supporting Member

    Why don't you just get two 3015's and call it done?
  16. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Because one 3015LF will put out as much as two 3015s, a midrange driver has twice the range and dispersion as a 3015, and the cab volume is too small to get the best result from a pair of fifteens.
  17. Foz


    Jul 26, 2008
    Jax FL USA
    Lottsa work for an old box... but someone need to preserve that tuck and roll look for posterity.

    So I elect you. Cut the old baffle out and replace - add a pillar or two to keep it stiff. Then load a pair of 3012lf's in the bottom and add a small mid box and a rack case "air head" to the top where the Top 15 used to go. If you planned it just right the displacement of the mid box and airhead would reduce the balance of the cab to the right size for the 3012LF's... then add a shelf port at the bottom. See the fearful wiki on the 1212/6 to calc if you have enough volume to pull it off.



    Would weigh a ton - but be loud as hell, thick as a brick, and probably blow some minds when you fired it up.

    see diagram below:

    * Contact Kustom and see if they can hook you up with a good deal on the head - send lots of pics so they have a chance to get interested in your project.

    ** add a horn if you really want to go nuts

    *** fold out ash tray & beer holder?

    Attached Files:

  18. Korladis

    Korladis Banned Supporting Member

    I admit to not reading the thread before replying. My bad. I was responding to the notion of putting in 12"s instead.
  19. SanDiegoHarry

    SanDiegoHarry Banned Supporting Member

    Aug 11, 2008
    San Diego, CA
    Given that those old Kustom cabs looked VERY cool but had really mediocre hardware, it seems to me that you could improve the devil out of it buy getting some *nice* 15s - Speaker technology has improved a great deal since the days of Kustom...
  20. smoothdave


    May 24, 2009
    Well, I'm an idiot, but thank you to all of you for your help.

    I was in church yesterday with some time to kill, and I decided to take a closer look at my 2x15. As I was studying it, it suddenly seemed to me that the cab wasn't quite tall enough to accommodate two 15's, although it was plenty wide enough. Then I looked at the woofers in our 12 inch mains, and then I looked at the woofers in our 15 inch subs, and then I looked at my 2x15 Kustom again, and after repeating that process about ten more times, I knelt down in front of my Kustom and started feeling the speakers through the mesh.

    Um, it's a 12. :meh:

    It's got two 12's in it.

    The guy who gave it to me told me it was a 2x15, and I just took him at his word, but they do make these things called rulers that can be used to distinguish between a 15 inch woofer and a 12 inch woofer.

    So, since Carvin is blowing out PS-12's on ebay for twenty bucks a pop right now, it's getting those. I really like the idea of going with a nice lf woofer, 6 inch mid range and a crossover, but for $53 including shipping, this is the way to go for right now.

    Please note that I have updated my signature to reflect my new status in the talkbass community. :rollno:

    Thank you again to all of you.

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