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2x15, 4x12, or 8x10?

Discussion in 'Amps and Cabs [BG]' started by Eric Cameron, Aug 7, 2001.


  1. I'm about to build my self a nice new cab, and I was wondering, which would be more practical to build, the 2x15, the 4x12, or the 8x10? Money is not the object right now, I'm talking more about wiring, components and construction techniques. Also, would it be and harder if I went to a 4x15, or even an 8x15? Or is there some pressing reason that this is not done. (besides volume:D)

    Advice, counsel, wisdom, radom prattlings, anything would be of use.

    Rock on
    Eric
     
  2. FalsehoodBass

    FalsehoodBass

    Jul 22, 2001
    Denver, CO
    oh my... think of how much an 8-15 would weigh.. you'd need 4 guys to carry it.. my 1-15 was of comparable weight to my 4-10... i can't imagine how much that would be.. plus all the extra wood it would take to support the speakers themselves. If you happen to own a forklift company or something, i say go for the 8-15 though... you could launch people with a nicely timed b-string thump.
     
  3. MikeyD

    MikeyD

    Sep 9, 2000
    I would think that the fewer the drivers, the easier the construction and tuning. When you get into lots of drivers, sometimes you wind up partitioning the cabinet internally as well. More work.

    A good 2x15 will be fairly large, a 4x15 - very large, and an 8x15 - huge. The latter seems impractical - even if you could move it you'd probably have difficulty getting it through a lot of doors.

    You should start by defining the sound (tonal balance), loudness, and size/weight limitations you want. An 8x10 will often sound very different than a 2x15 or 4x12, for example.
    - Mike
     
  4. gO FoR ThE 8x10 cUz iT poosHeS mOrE AIR.
     
  5. That's what I have been hearing. That more, smaller speakers gives greater volume that fewer, larger speakers.

    I think I'm gonna opt for a 4x12 or 4x15. NOW it comes down to what I can afford. The SWR Mo' bass amp is currently in the mail, so I'm not lacking for power.

    Sorry, JR, I just couldn't leave your sentance alone.:D

    Rock on
    Eric
     
  6. Parlfetch

    Parlfetch

    Aug 8, 2001
    Chicago
    I just had a 2-15 built for me. Its made of 3 ply Birtch Plywood. Its braced extremly well. It stands about 45 inch tall. So its big. Very heavy. Two people can move it. But it sounds amazing. Try it out.
     
  7. In the Eminence line, their best 10" moves 110 mL compared to the 470+ mL of their better 15" and the 1136 mL of their best 18". The Carvin PS10 moves the same 138 mL as their PS15... go figure. But the Carvin 18" moves 637 mL which is 450% more air than the PS10 10".

    By comparison, the JBL 2242 18" moves 1101 mL of air volume.

    Note this is the *amount* of air each driver can move.
     
  8. john turner

    john turner You don't want to do that. Trust me. Staff Member Administrator

    Mar 14, 2000
    atlanta ga
    i would go for building a few well designed 1x15"'s or 1x18"'s. a lot easier to move around.
     
  9. John Davis

    John Davis Guest

    Mar 27, 2001
    Houston, Texas
    I was having this SAME discussion with some of my band mates, about me making a 4x15" cabinet. They got kinda mad, because all the guitarists currently use are 2x12"s. :D

    Let us know how it goes.
     
  10. Hmmm...4x18?:D:eek:

    Rock on
    Eric
     
  11. And each one of those 18" requires 24 cubic feet for the optimum enclosure. Doing the math, the cab is about 97 cubic feet, and measures 7.44 feet high x 4.6 feet wide x 2.85 feet deep.

    The good news, this configuration is dead flat (-1 dB) to 23 Hz, or all the way down to John Turner land at Low F#. It is capable of producing 139 dB if you have 4,000 watts available.

    Rock on, indeed.

    :D
     
  12. MikeyD

    MikeyD

    Sep 9, 2000
    Which driver was this? You mentioned Eminence, but I didn't think the Kilomax would perform like this. Please clarify, and what cabinet tuning are you using? This sounds like a really mean subwoofer. If your figures are correct, you imply 103 db @ 1w, 1m sensitivity. Did you factor the mutual coupling into this figure? How would the same basic design (using same drivers) perform for a 2x18? A 1x18?
    - Mike
     
  13. john turner

    john turner You don't want to do that. Trust me. Staff Member Administrator

    Mar 14, 2000
    atlanta ga
    yikes! my back! :D
     
  14. Kilomax Pro 18"
    97 SPL 1w/1m, 127 SPL max calculated
    Driver count doubled 2x (+6dB + 6dB)
    Mutual coupling included, all drivers in one cabinet
    Optimum alignment, Vb=97 cu.ft, Fb=23, F3=19 Hz
    Minimum port diameter = 12.75"

    Eminence response chart shows falloff begins at 1700 Hz. I personally think this is overly optimistic, but hey... it's their charts.

    Cut the box in half, subtract 6 dB, and that is how it would work in 48 cubic feet. Shave it again to run a single 1x18 in 24 cubic feet. This still requires a box 21" x 35" x 56" internal size, no compensation for driver, port, or bracing displacement. The loudness goes down, but the frequency response remains unchanged.

    Or to quote JT "yikes! my back! :D"
     
  15. MikeyD

    MikeyD

    Sep 9, 2000
    Thanks for the quick and detailed reply. I will save this thread and revisit the Kilomax driver.
    - Mike
     
  16. Why??? It's.... HUGE!!!
     
  17. MikeyD

    MikeyD

    Sep 9, 2000
    It seems to be Low and Loud. You are right - large, though. A nice 1x18 would be about the size of my office desk. WinISD shows response of -1 dB at 25 Hz. and -3 dB at 23 Hz. That's a nice LF response. It would make a good stationary cabinet, I suppose, in a discotheque. I would be kind of surprised the driver could take all 1000 watts below 30 Hz. though. My interest was piqued by the good low end at reasonable dB.
    - Mike
     
  18. See, in actuallity, I'm doing contract work for the military, and we are going to use 4x18 and 2x24 cabs to knock over tanks on the battlefield.:D

    Rock on
    Eric
     
  19. boogiebass

    boogiebass

    Aug 16, 2000
    I'd go for an 8X18. Be sure and build a trailer to pull it in, too. Recommend at least 2K watts for good punch. Then go play it in a pasture somewhere, preferably not in the state of California.
     
  20. MikeyD

    MikeyD

    Sep 9, 2000
    As I recall, I think Bootsy Collins has something like this (well maybe 8 separate 18's), and drives them (and some other speakers) with three QSC Powerlight 2.0 amps (1100 w/ch each) - 6600 watts! I'm not positive of this, but it was something outrageous like that! :)
    - Mike