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What to DO?

Discussion in 'Amps and Cabs [BG]' started by bluesbass1972, Apr 30, 2009.


  1. I am building a 212 Subwoofer cabinet to use as my gigging bass rig. I am using two Eminence 250 watt Neo Subs both 8 ohms. I am also wanting to use a Peavey Triflex Horn. It is rated at 150 watts, and is 8 ohms.
    I want to run the subwoofers direct, and use a high pass on the horn, to keep it sounding smooth. I built the rig from scratch, installing all of my own hardware, having it sprqayed with a truck bed liner, and hand-picking the components. I hit a snag when I fired it up, and the horn distorted. The minimum ohm load is 4 ohms. My Genz Benz Shuttle 6.0 operates at the level I desire at 4 ohms. 600 watts.

    Can somebody help me with finding the right crossover, or high pass filter?
    I am stumped.
    Thanks!
    Dan​
    :help:
     
  2. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    I would love to help but I'm not that smart. But let me be the first to say.....

    no pics, no rig.


    P.S. Welcome to the forum!!!!
     
  3. so you have 3 8ohm speakers? if you wired the subs together you would get either 4 or 16 ohms and if you wired it at 4 if you add the 8ohm horn you get 2.6 ohms which you head cannot handle. At what freq did you have the cross over, mybe to much lows going to the horn.
     
  4. Thor

    Thor Gold Supporting Member In Memoriam

    There is a lot of DIY info in the FAQ's.

    Parts Express has a crossover page here:
    http://www.parts-express.com/crossovers.cfm

    and a page on crossover design here:
    http://www.parts-express.com/resources/building-a-crossover.cfm

    That should answer most of your questions.

    Also, once you install the crossover, the impedance of the horn
    becomes irrelevant in the Ohms calculation of the cab, only the
    ohmage of the sub-woofers is important. (Source: Bill FM)

    I forgot to ask, is this horn a piezo horn? If so, it requires
    no crossover. IIRC in the piezo the resistance tends to infinity
    at low frequencies If it has a silk tweeter dome or something like that,
    it does need an x-over. 800 hertz is a commonly suggested
    crossover point.
     
  5. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    You would probably be better off with a midrange instead of a tweeter. Subs don't tend to go too high.

    Paul
     
  6. rbonner

    rbonner

    Sep 25, 2008
    See the post anti- tweeters that has got about 4 pages in one day.
     
  7. gerryjazzman

    gerryjazzman

    Dec 31, 2006
    New Jersey
    What exactly are the Eminence drivers you are using? It sounds like you don't have any crossover on the tweeter. If so that's why it's distorting. Don't run it like that until you get a crossover installed or you'll blow the tweeter.

    Can't tell you much more unless we know the type of drivers. If they are truly subwoofers (3012LF's? not exactly subs, but almost) then Paul is right, a tweeter would not be appropriate since you won't be able to cross it over low enough. A midrange would be better in that case. If they are actually S2012's or Deltalite II 2512's you could get away with a tweeter that can be crossed over around 1.5 - 2 Khz.
     
  8. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    The Peavey Triflex isn't a horn, it's a self-powered PA system.
     
  9. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Whoa... stop what you are doing before you possible damage something.

    The current TriFlex is a powered sub with passive satellite speakers (powered by an amp in the sub). Is this what you are using? Are you trying to add a passive 2 way satellite speaker to your 212 "sub"? If that's the case, don't do it, as the impedance is falling well below 4 ohms. Even if you are using a high pass filter at say 100Hz, most of the system's bandwidth is still well under 4 ohms.

    There was also a very old system (Tri-something I can't remember since it was 25years old) that consisted of seperates that had a big ol' honking horn flair on a 22 driver and that's IMO a totally inappropriate product for bass guitar regardless of crossover.

    When rolling your own, it's essential that you understand the details of what you are doing before hooking it up to a perfectly good amp (by any manufacturer). Protection circuits are not 100% infailable and it would be a shame to damage your amp this way.
     
  10. greenboy

    greenboy

    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
  11. greenboy

    greenboy

    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
    250 watt Em neo subs? Guess I missed those.

    Please, when you want help on these kinds of things, LIST MODEL NUMBERS - even provide URLs. Because usually the problem only gets worse with the Manglement of Major Misinformation.
     
  12. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    I don't think it's rated for 150 watts ;) in fact, 15 watts would be a heck of a stretch.
     
  13. greenboy

    greenboy

    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
    Well, since everything else is suspect in the original post too...
     
  14. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Good point ;)
     

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