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DIY 1x15's w/JBL k140

Discussion in 'Amps and Cabs [BG]' started by rawuol, Mar 26, 2013.


  1. rawuol

    rawuol

    Mar 26, 2013
    This is my first post, Im kind of a noob. Basically I wanna build two Ported 1x15 Cabs.

    As far as woodworking goes I am an experienced carpenter so not much to worry about there. What I am worried about is determining the Dimensions of these cabinets. I downloaded WinISD and apparently the JBL's are lacking some stats to input. Without stats, (and proper knowledge on how to use the program, Im at a standstill.

    Suggestions? Ideas?
     
  2. Do you already own the drivers?
     
  3. Ha! you've come to the right place. Easiest way is to put them into ElectroVoice TL-606 cabs and use their 40 Hz box tuning.

    The plans are readily available on line and have been a classic in the DIY world for a long time. I still have one and just recently finished one of two 1-15s to house a couple of D140Fs. The cab(s) is/are based on the TL-606 but I used round ports instead as well as a different bracing scheme.

    If you go with the TL 606 I'd suggest using 1/2 inch plywood and lose the edge/corner bracing as that contributes nothing but weight. Instead brace using 1/2 by 1.5" plywood, maybe like this:

    BigM 7.JPG

    http://mypicsonline.net/archive/arc...es/EV/Builders Plans/TL606 Builders Plans.pdf
     
  4. rawuol

    rawuol

    Mar 26, 2013
    Yes I do already have the drivers.

    As far as the TL-606 plans go, I think you made my day.
     
  5. glad to hear it :cool:

    JBL recommends a Vb of 4 cu ft and a low Fb but the 3.2 cu ft of the TL-606 works nicely too, improved power handling.

    I had my D140Fs in a 2.2 cu ft tuned cab and that was quite satisfactory for my needs (I don't play a 5 stringer) but since it was two of those in an old Showman cab my back said "no more" :rollno:

    BTW, here's the JBL driver parameters, gives you most of what you need for WinISD modelling, albeit not everything:

    http://www.jblproservice.com/pdf/thiele small parameters/theile parameters.pdf
     
  6. rawuol

    rawuol

    Mar 26, 2013
    I would like to build this with round ports. Any chance I can trade of on height and width dimensions to allow for 2-4 round ports? If so, what kind of port dimensions would I be looking at? Specifically Diameter, and Depth.
     
  7. rawuol

    rawuol

    Mar 26, 2013
    LOL yes those would be the specs. Unfortunately, with my lack of working knowledge with WinISD I couldnt get past the missing fields stage. :(
     
  8. rawuol

    rawuol

    Mar 26, 2013
  9. you sure can, that's what I did here:

    photo (20).

    I went with a higher Fb of around 48, so it was four 3 inch diameter ports that were 6" long.

    You realize you have to make your cab a little larger than a Vb of 3.2 cu ft to accomodate the driver, port tubes, bracing, and handles? That said, I've found the JBLs quite forgiving of discrepencies of Vb vs. Fb.

    Some drivers, however, are not so forgiving..........
     
  10. JBL standard bass cab recommendation is 4ft with two 4" round ports of 6.5" length, they say it is tuned 40hz, winISD disagrees but it's known to be a bit off so I would go with the JBL.

    JBL 4625B looks to be a tad bigger going off the exterior dimensions. They say it is -10dB at 40Hz.
     
  11. If you go with ports that long make sure they're at least 3 to 4 inches from the back panel, otherwise you'll mess up the air flow and the ports won't function properly.

    Take a look at this build for some more ideas, albeit his is a 2-15:

    http://www.talkbass.com/forum/f15/diy-2x15-cabinet-build-real-deal-965308/
     
  12. rawuol

    rawuol

    Mar 26, 2013
    So ill be honest I think 2 of these baby's would be exactly what my first cab build should be. Any chance you would like to share your building specs? Id love to clone the cab. Seems like exactly what I was looking for.
     
  13. nysbob

    nysbob

    Sep 14, 2003
    Cincinnati OH
    When I had my 15" boxes built, I handed the JBL spec sheet to the builder. These are 28" W x 20"H x 16" deep...I think just a little larger than the old cabaret cabs. They've served me well for the past twenty years. These have 145s in them, but they'd work just as well for 140s.

    [​IMG]
     
  14. jnewmark

    jnewmark Just wanna play the groove. Supporting Member

    Aug 31, 2006
    Stax 1966
    Third St. Cigar Records staff musician.
    Hey Bob ! Nice to see that you're still rockin those JBL's !
     
  15. nysbob

    nysbob

    Sep 14, 2003
    Cincinnati OH
    They refuse to die...or sound bad. :D

    they're definitely not getting any lighter, though:p
     
  16. jnewmark

    jnewmark Just wanna play the groove. Supporting Member

    Aug 31, 2006
    Stax 1966
    Third St. Cigar Records staff musician.
    Yeah, every once in awhile I'll drag out that old 215 loaded with E140's, then my back tells me to put it back!
     
  17. Happy to share, they ain't rocket surgery nor proprietary :D

    I use 1/2" arauco plywood from Home Despot. Apparently you can get it easily here on the West Coast but not in other parts of the country so I've been told. It's significantly lighter than birch, which is a very good choice. As Jnewmark and NYSbob stated, these drivers ain't light so I'll take every pound off that I can (I'm over 50....). A good substitute you can get in most parts of the country is poplar ply. But if you're young don't sweat it, use what you like, birch finished naturally is beautiful ;)

    The outer dimensions are 24" high, 20 inches wide, and 16" deep. The front baffle is recessed 1.5". I made the handles but you don't have to do that, just get 'em from the usual suspects (Parts Express, Speaker Hardware, etc) and be done with it. I also make the jack plate, again just buy one. Since those drivers can't take more than a couple hundred watts and will likely be used with more vintage-y amps just go with 1/4" jacks, not speakons.

    The internal bracing is key so here's what I did using 1/2" thick by 1.5" ply and 1" diameter dowels, this was copped from the fEARFUL design and Bill Fitzmaurice:

    BigM 7.JPG

    I use good old Elmer's Carpenter's glue. A lot of folks like the urethanes, it's up to you. I screw in the braces but dowel the panels together so I don't have to worry about nicking my router blade when I round over.

    I reinforce the rim where the speaker mounts with pieces of 1/2" ply, but you can cut a ring of the stuff out. I also add a little bracing midline on the front baffle above and below the speaker opening. The port tubes are glued in and add a lot of stiffness like bracing already.

    Since arauco (and poplar) are rather soft compared to birch, one assembled, I painted on 3 coats of diluted (1:1 with water) carpenters glue all over the outside of the cab. Really hardens the surface nicely. This is after I do final sanding (down to 180 grit). Then I use Rustoleum semi-gloss black spray paint. I will, however, apply an epoxy coating to both the cabs later this year so the glue coating is kinda moot in this case. Just experimenting.....

    The ports are 3" diameter cardboard tubes 1/4" thick, just cast off shipping tubes. Painted inside, of course. They're 6" deep each for a Fb around 45. Note that those handle boxes take up more cab volume than standard metal handles so the gross box volume takes those into account. If you're going to go with the metal ones and you're duplicating this design, just add a couple of pieces of styrofoam (maybe 2" thick by 6" by 6" or so?). Probably over doing it but why not? I've found the JBLs pretty forgiving of Vb and Fb unlike other drivers.

    Line the entire interior (but not the front baffle) with 1" thick polyfill, the stuff used for comforters and pillows, available at any craft or sewing store. Stapling works nicely. Make sure you completely seal the interior, and I also make sure there's a nice filet of glue everywhere a piece of wood glues to another.

    Note I front mount the driver, those were designed for rear mounting. Just use weather stripping tape for a gasket. I use wood screws to mount the driver because it's easier and I don't plan on swapping out the driver.

    For casters or any hardware other than corners (I don't use them) I double up the plywood underneath where it's going to be mounted.

    My best guess is that this thing weighs just under 40lbs, probably close to 35.

    That's it, pretty basic, really.
     
  18. rawuol

    rawuol

    Mar 26, 2013
    Thanks alot for the info!

    My apologies for not replying sooner. Had a death in the family, and have been quite busy making arrangements and such.

    Ill be sketching up some plans tonight. If all goes well Ill post picks of my plans by tomorrow.

    Im a little OCD when it comes to projects, so I like to build entirely on paper first. Allows me to work out any kinks before I get too far.
     
  19. rawuol

    rawuol

    Mar 26, 2013
    Whipped up my front. All sides even was my goal. Gonna use 1/2" Plywood for this build. No mdf for this guy. Most likely the cheapest unless something really catches my eye. A depth of 16" for these cabs as suggested. I may go rear mount for the JBL's, and not recess the Baffle. That all depends on if I can find some decent flush mount speaker cover/grills. 3" ABS pipe for porting. Im still indecisive about stain/paint/vinyl/carpet. Vinyl will be my first choice but it depends on what kind of options our local fabricland has.

    Ill try and whip up the bracing pic tomorrow. I wanna get handle dimensions first so I can see how offset the braces have to be.

    Think thats it for now.
     

    Attached Files:

  20. rawuol

    rawuol

    Mar 26, 2013
    So I found some links to parts and stuff last night. Thought Id post em for anyone looking for stuff.

    Handles and Corners. http://www.tchweb.com/
    Speaker Grills and Casters. http://www.parts-express.com/
    Jack Plates. 1/4" Inputs http://www.allparts.com/

    Looks like a little over $100 plus shipping for all of the parts I need. Im gonna price out my Plywood and ABS tomorrow.

    Ive decided to go with a simple sand/paint/shellac. Although I havent decided on a color yet. Vinyl and carpet seemed a little too expensive for this project. Stain was just a little too woody for me.

    Im getting excited now. I traded for the JBL's (some junker guitar I found). Material and parts looks to be under $300. Things are looking good for this project!
     

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