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!  

Dangers of running at 2.7 ohms..

Discussion in 'Amps and Cabs [BG]' started by TJ_NM, Jul 28, 2007.


  1. TJ_NM

    TJ_NM

    Jul 21, 2007
    Ok, so if you combine an 8 ohm and a 4 ohm cabinet, you end up getting 2.7 ohms, and that is not reccomended..

    can anyone please tell me what the dangers of doing this are, and what are the possible outcomes?
     
  2. TJ_NM

    TJ_NM

    Jul 21, 2007
    Oh, and my head can handle a two ohm load, I'm just wondering what the dangers of a mismatch of levels are.
     
  3. Bettyrocker23

    Bettyrocker23

    Jun 8, 2007
    Chico, CA
    As long as it can handle 2 ohms, yeah the head will be fine.
    The 4 ohm cab will receive more watts than the 8 ohm cab though. Im not sure about how much, but I think the 4 ohm would get bout twice as much as the 8 ohm cab.
     
  4. TJ_NM

    TJ_NM

    Jul 21, 2007
    well then that's perfect, because the 4 ohm cab is rated at 400w and the 8 ohm cab is rated at 200w.
     
  5. The lower the impedance load, the more strain is put on the amplifier in the form of heat. Heat is the enemy of electronics.

    I'd be VERY careful about doing this, and take measurements before attempting it. Here's why: an 8 ohm nominal impedance cab can be less than 8 ohms at the tuning frequency (ported). The impedance can drop down to almost that of the DC resistance of the voice coil, which is around 5 ohms for a typical 8-ohm driver, and around 3.7 for a 4-ohm type. This is about a 2.31 ohm load.
     
  6. lomo

    lomo passionate hack Supporting Member

    Apr 15, 2006
    Montreal
    I love doing this. My
    rig is an Ampeg PB800 rated down to 2 Ohms. I run it through a 4 Ohm Epifani 2x10 and an 8 Ohm Epi 115. I get 2/3 of the juice via the 210. I like this because I don't want the 115 to be overbearing, just to complement the 210. Overall it's a 21012 with around 700 watts at 2.7 Ohms-works well for me and my amp never complains.
     
  7. pmaraziti

    pmaraziti Gold Supporting Member

    Feb 12, 2006
    Singapore
  8. TJ_NM

    TJ_NM

    Jul 21, 2007
    That is most certainly a wonderful tool.
    thanks for your help.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.