15/6 cab project (non fearful/nearful)

Discussion in 'Amps and Cabs [BG]' started by rogypop, Nov 10, 2012.

  1. rogypop


    Jan 10, 2009
    The eminence kappa 15lfa and alpha 6cbmra have just arrived, got a pretty good deal on them.
    I´m going to build relatively compact/low/loud cab, I´will have to make quite a few compromises but still sure the cab will end up superior to most wide avilable, mid priced 1x15 or 2x10´s.

    Winisd says (2.83cuft tuned at 47 hz): f3@50 hz, f10@36 hz, mech. limit 293W@80hz with slight (1.6db) upper bass bump centered around 100hz. I tend to add some eq in that region anyway so its not much of a problem.

    I´m planing to cross it over somewhere in 1-1.2 khz region, just before the beaming on 15 kicks in to get more of a ´bass cab´ voicing, 2nd order butterworth, both lpf and hpf.

    These days I´m gonna be hunting some decent 1/2 plywood, wish me luck!
  2. ::::BASSIST::::

    ::::BASSIST:::: Progress Not Perfection.

    Sep 2, 2004
    Vancouver, BC Canada
    Good luck.

    You can get away with using light 1/2 inch ply if you brace it very well.
  3. How the heck you gonna have room for a 15, and a 6, and ports, in a box that small?? Box must have no depth at all! I built a 4.0cuft box with just a single 15 plus ports, and I have little wood left in the baffle. Just askin'.
  4. rogypop


    Jan 10, 2009
    thanks! i will be using panel to panel bracing.
  5. rogypop


    Jan 10, 2009
    have done the math, 2.83 cuft is what remains after volume of all components is substracted.
  6. ::::BASSIST::::

    ::::BASSIST:::: Progress Not Perfection.

    Sep 2, 2004
    Vancouver, BC Canada
    Wood is cheap so if it doesnt work out he can always re-do it.
  7. rogypop


    Jan 10, 2009

    im talking about internal volume here
  8. 4-stringB


    Jun 10, 2010
    I had to search around. The best I could find locally was 1/2" AC grade ply, not usually available at the big box stores...
  9. rogypop


    Jan 10, 2009
    3/4 ply will work too but I´m hoping to find 12mm birch or marine grade okume.
  10. rogypop


    Jan 10, 2009
    Ok, let's bring the zombie thread back to life. It's been a while since I posted last time cause my job and other projects kept me busy.
    Anyway, the cab is finished and tested so i can give you a little review and will try to stay unbiased as much as I can.
    I will post a crappy cellphone pic as soon as I find out how to do so.
    As it was previously said cab is 15/6, ceramic magnet eminence drivers. Kappa 15 lfa and closed back alpha 6 cbmra mid, 80 liter volume tuned to 47 hz via single 6.3'' front tube port, crossover is 2nd order butterworth set to 1.1khz,
    Mechanically limited at 300W/80hz with little 1.5db bumpitty bump centered around 100 hz with f3 point at 50 hz.

    I made the cab out of 3/4 marine grade meranti ply which i had left from my boatbuilding project (heavy),
    the front grille is custom ordered stamped steel sheet grille,
    heavy and expensive stuff but virtually indestructible.
    If i wanted to make cab heavier it could be done only if i poured lead into it. :meh: Anyway, I'm young and fit
    and whats more important, this cab will do most of its work in our practice room.

    The amp used: hartke lh 500- absolutely best bang for the buck out there, loud loud and loud. It's simple pre and passive
    a'la bassman eq gives it nice, warm but clean and clear SS punch with just a tad of the 'tubey' warmth.
    The bass: Fender jazz bass marcus miller upgraded with
    duncan's antiquity 2 pickups and aguilar obp-1 preamp. The ultimate 70's monster jazz.

    The apartment low volume test. The first thing I have noticed is how low, clear and even the cab sounds BUT there was some of that hideous 1-2khz 'gank' which made string clack and fret buzz even more present and annoying. Time for playing technique improvement
    Anyway, except for bit of the gank the cab sounded very polite and even, may I even say hi-fi. The closed back midrange does a nice job and isn't as harsh sounding as some blokes claim, but loud it is, i think it could cope even with two 15's.
    I know that eminence ceramic magnet drivers have been long outdated by kappalite 3xxx series but trust me, kappa 15 lfa is no wussy, at least in this cab. It literally blew out of water any 1x15 cab i have ever played through. Combined with the mid driver it's in the 2x12 territory but without built-in low midrange punch.

    Usually any cab that sounds nice and even when played in living room at low volume levels gets eaten in the loud rock mix, this is such a cab.
    As i don't have enough eq power (passive tone stack and boost only onboard pre) I hardwired my Marcus in series to get more punch. My boatbuilding project ate through my budget
    so 31 band graphic eq will have to wait. :-(
    About MM jazz wired in series: while in passive it's nothing but
    undefined, mushy, cloudy mud punch, with a flip of a switch it turns into a monster. Huge, fat, punchy, snarly jazz bass. The
    type of tone people in nordstrand big singles marketing department write about.

    Reharshal test. The place we practice at is an old classroom, huge room with tall ceiling. Before the band came
    I fired it up and tossed a few lines. I immediatelly noticed
    how bad the sound in the room is, single pluck or one 16th note leaves two to three seconds of overhang but while standing in front of the cab it punched so loud that it masked most of the room echo.
    When the band joined me and started playing the most of the punch was eaten up and what was left was deep and penetrating 60-150hz bass content and midrange zing. While it sounded so good with ballads and slower songs, filling up the room with deep, meaty bass it sucked with loud fast rock. The loud lows and snarly mids were still there but body was missing. 300-600 hz content that can't be retrieved without good eq. I need an eq!! After the practice my drummer told my that my cab, which stood behind my back, was punchnig the air out of his lungs so after all it is possible that the room is eating up all of my low mids.

    Some comparisons: Compared to my cab, mark bass Jeff Berlin combo sounds like a muted fart while the other mark bass cab i have tested is quite an opposite, the standard 102HF 2x10 cab, it's very loud, punchy and articulate, GREAT small, light bass stage monitor, a lot louder and present in the mix than my cab, but for gigs without PA support i wouldn't
    trade it for my lil 15/6 frankencab :)