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Convert a 1x15 to a 2x12 or 10

Discussion in 'Amps and Cabs [BG]' started by adamaarts, May 9, 2003.


  1. adamaarts

    adamaarts Supporting Member

    Apr 19, 2001
    Corona, CA
    Beta tester Source Audio, demos/reviews of many others
    i am wanting to convert my Carvin RL115 cab into a 2x12 or maybe a 2x10. i measured it and the inner dimensions equal 6048 cubic inches. this does not include the bottom slot port. i can make this smaller if i had to (by trimming off the back or from the bottom or sides). i am going to buy a piece of ply for the front (for the new speakers)

    question, how do you compare cubic inches or feet, to liters


    From the Eminence Website - Omega 12

    Recommended Enclosure Volume - 34 - 57 liters
    (vented) 1.2 - 2.0 cu. ft


    So how do i convert this? this is not the speaker im definitely going to use, im actually looking still.

    how do i determine the size port i need?

    i know i may not know much about speaker cab building, but anything else i need to consider. any good links for some information?

    this a project i really would like to do. thanks for any help you may give.
     
  2. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    What a very weird idea.
     
  3. adamaarts

    adamaarts Supporting Member

    Apr 19, 2001
    Corona, CA
    Beta tester Source Audio, demos/reviews of many others
    yea, well i wasnt happy with the 15" speaker, i want something fuller, and i like the sound of 10's and 12's, so i just thought id save some money on materials and kill thios thing and make it a new and refreshed cab that i will actually use.
     
  4. Tsal

    Tsal

    Jan 28, 2000
    Finland, EU
    Here's my simple, three-part guide on converting cabinets:

    1) Sell the old cab.
    2) Give the cab purchase a bit of thought. Buy a new cab.
    3) Be happy with the new cab.

    I can guarantee you'll be happier this way, unless some sort of divine favour is on your side.
     
  5. Johnny BoomBoom

    Johnny BoomBoom Supporting Member

    Jun 8, 2001
    Glasgow, Scotland


    OK, there are 2.54 cm in an inch.

    So, to go from cubic inches, to cubic cm (cc) you multiply your cubic inches by 2.54 cubed (ie 2.54 x 2.54 x 2.54), whihc works out at 16.4.


    Take your cubic inches, and multiply by this gives 99109 cc. Divide this by 1000 to get litres is 99.1 litres.


    Not sure if this helps you in any way, but the maths is done!
     
  6. Ziggy

    Ziggy

    May 9, 2001
    Orange County, CA
    Stinky,

    BoomBoom has the right formula and correct answer to part of your query:
    99.109 liters... almost double your 'recomended' volume.

    Continuing the conversion: 99.109 liters = 3.5 cubic feet (again, nearly twice the recomended size)

    As for the port size??

    -This can get complicated and an error + or - will affect the cabinet's "tuning".
    My own research has found that a 'minimum port' size - covering a frequency range of 75hz < 210hz, is 34" width x 23.5" depth. Resulting in 300 sq.cms of port space. A 'longer' port, 20% to 30% deeper, will result in an increase in the upper frequency response.

    Some NOTES:

    - Adding braces to help secure the speaker magnet/s increases the solidness of the speaker mounting.

    - When determining 'interior volume', keep in mind the back of the speaker/s frame and magnet uses space.

    - Some of the resonance wave bouncing around inside the cabinet can be minimized with the addition of a few inches of "loose" fiberglas or other suitable material. ( see http://www.basslinear.com )
    Finally; some helpful sites:

    http://www.sciencemadesimple.com/2fconversions.html

    http://members.aol.com/speaker60e/speakerpro.html

    The latter is a 'shareware' "free" software program for speaker designing - scroll to the bottom of the page. (I haven't used the program, but one of the design sites suggests and recommends the program)

    Hope some of this helps you out,
    michael s.

    BTW: drop us note and tell how it turned out
     
  7. Well this means those drivers will be just fine, as he's using two of them.
     
  8. Johnny BoomBoom

    Johnny BoomBoom Supporting Member

    Jun 8, 2001
    Glasgow, Scotland


    OK, we have an internal volume for your cabinet.


    Now looking at the info on the link :-

    http://www.carvin.com/cgi-bin/Isearch.exe?CFG=2&P2=RL115&P1=BA


    I'm thinking that your 2 x 12 option is gonna be real tight!
     
  9. I've tried doing stuff like your proposing to do. It ended up being a lot of work and money with poor results. That's why "if you see me carrying a hammer, you know I'm gonna sell it cause I sure can't use it". With that said, by the time you buy the drivers and the other materials needed to get this project right, you could have sold the 1x15 cab and bought a Avatar 212 or 410 and had money left over. Even if it sounds OK it probably won't be cost effective. jmho
     
  10. adamaarts

    adamaarts Supporting Member

    Apr 19, 2001
    Corona, CA
    Beta tester Source Audio, demos/reviews of many others
    1. thanks for converting liters to feet. that heps.

    2. i want the avatar 2x12, but i cant sell this old cab.

    3. i know the 2 12s wont fit on the cab's front, i have to take out the bottom slot port and make tube ports on the sides of the 12s.

    4. i know it may not be cost effective, but i am a project taking kind of guy. i like to plan out and put my talents to use.

    5. thanks for that link to the shareware program, i already downloaded one like it but this one is much better, thanks.

    6. thanks for all your help. i am still trying to find some 12s though.
     
  11. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    This is exactly what I would have said if I hadn't been so weirded out.
     
  12. Johnny BoomBoom

    Johnny BoomBoom Supporting Member

    Jun 8, 2001
    Glasgow, Scotland



    Your welcome for the conversion!


    Good luck with your project - I hope it works out!

    Let us know how you get on!:)
     
  13. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    I started out wanting to convert an old 15 I had lying arount into a 2x10. I soon realised it was only a little bit more work to build the entire cab from stratch. In a lot of ways it's easier because you integrating the purpose built porting is easier than modifying existing porting - especially the shelf kind.

    Having said that, I've still got that 15 lying around and I still get the itch to turn it into something useful. Who knows, maybe one day I'll need a 6th speaker cab????
     
  14. BruceWane

    BruceWane

    Oct 31, 2002
    Houston, TX
    I got a piece of glass cut to just the right size and now my old Sunn 1x15 cabinet is serving as an end table.

    Of course, your wife or girlfriend may not appreciate this kind of decorative creativity.
     
  15. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    My newly ex g/f operates a PA. We could have turned her spares into wardrobes.........

    Seriously, it's a big old Fender BXR with a single 15 in it. It sounds like sheeet. But the cab is really big for a 15, big enough that I could probably plonk in some carefully chosen speakers - a 15 with 2x8's maybe. Maybe an 18" with a 10". I could easily build seperate chambers for the smaller speakers......

    Stop it you guys, you're making me think about it too much..... I don't need any more gear!