1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
     
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

4 ohms or bs?

Discussion in 'Amps and Cabs [BG]' started by olias, May 5, 2006.


  1. olias

    olias

    Mar 30, 2006
    Amarillo, Texas
    I just bought a new Legion 212 cab off the internet. It was supposed to be 4 ohms, but the label on the back says 8 ohms. When I contacted the merchant, I was told "this cabinet is 4 ohms. It is loaded with two (2) knight eight (8) ohm drivers wired in parallel, making this cabinet a four (4) ohm load. Sorry for the typo on the manufacturers label, I assure you that it is a four (4) ohm cabinet, as the knight
    drivers do not come in any other form than an eight (8) ohm driver.
    There are only two combinations they can make with two (2) eight (8) ohm drivers.
    1. wired in parallel, as these are, you would have a four (4) ohm load.
    2. wired in series, you would have a sixteen (16) ohm load."

    Does this make sense, or am I being fed a line?
     
  2. TrooperFarva

    TrooperFarva

    Nov 25, 2004
    New City, NY
    That makes sense, but if I were you, I'd open up the cab, and just see whats in there. If it's as he described, then yup, its 4 ohms.
     
  3. ibz

    ibz

    Apr 14, 2005
    Columbus, OH
    Check for yourself.

    If there both speakers say 8ohm on them, then 99.9% chance its a 4ohm cab.

    Also, that explanation makes sense too.
     
  4. LesS

    LesS

    Mar 3, 2006
    no longer a member
    I have the same Legion Sound LS 212 cabinet and it really is 4 ohms. I measured mine with a meter.
    I never noticed the sticker - but I just looked and it does say 8 ohms.
     
  5. RobertUI

    RobertUI Thumper Supporting Member

    Apr 7, 2005
    Herndon, VA - NoVa
    i called and spoke with them a while back and it's correct that madison does not make a 4 ohm bass speaker, only 8 ohm ones. i doubt that they would have wired it in series, more likely is that they're reusing old labels from another line of cabs. definitely open it up and see for yourself though. i would also consult this page http://colomar.com/Shavano/2x12wiring.html and it should give you an idea of what you're dealing with.
     
  6. olias

    olias

    Mar 30, 2006
    Amarillo, Texas
    Thanks guys! I feel much better about my purchase now. I still don't understand how 8+8=4, but I do understand that I have a 4 ohm cab and a 4 ohm head, and that is all I need. I can now speak highly of my dealings with musicsupplycenter.com--they answered my questions quickly and were very friendly and easy to deal with, and got my cab to me well packed and in short order.
     
  7. It's not 8 PLUS 8. Eight PLUS eight does equal 16, but only if the speakers (or resistors) are in SERIES. When the speakers (or resistors) are mounted in PARALLEL, then the total impedance (or resistance) is less than the resistance of one speaker alone. Check this out (it's for car audio, but it works for bass amps, too):

    http://www.bcae1.com/spkrmlti.htm
     
  8. appler

    appler Guest

    For two speakers (or resistors) with a resistance of eight ohms wired in parallel, I believe the formula goes like this:

    1/R1 + 1/R2 = 1/Req

    1/8 + 1/8 = 1/4


    The equivalent resistance is four ohms.
     
  9. woody357

    woody357 Supporting Member

    Jun 17, 2005
    I've looked at some of those cabinets how do they sound?
     
  10. I think it's pretty crappy for a company to incorrectly label something so important.
     
  11. ibz

    ibz

    Apr 14, 2005
    Columbus, OH
    Eh, you get what you pay for I guess. :meh:
     

Share This Page