2,66 ohms is that loadable?

Discussion in 'Amps and Cabs [BG]' started by Yvette, Nov 25, 2001.

  1. Hi all,

    If an amp says the minimum load is 2 ohm (in fact it says 2-8 ohm, so 2 to 8 ohm can be loaded without switches), can this amp (a EBS Fafner) handle 0ne 8 ohm and 0ne 4 ohm cab (combining to 2,66 ohm). Point is the amp comes, cheap (under 1000 dollar second hand) with a two 10" EBS 4 ohm cab and I have a 15" 8 ohm Marshall cab. I would like to use them both on bigger gigs, and I sure like the Fafner amp.
    Well I hope to get some answers (one actually) thanks in advance,

  2. MikeyD


    Sep 9, 2000
    Yes, it should be okay if the amplifier can handle loads down to 2 ohms. You are correct that a 4-ohm in parallel with 8-ohm cabinet will be equivalent to 2.7 ohms. Note that your 2x10 will receive twice the power from the amp as the 1x15.
    - Mike
  3. Thanks for the reply!
    Won't that be a problem if both cabs can handle it that one get double from the other, like one can only be heard so the 15" can't add much bottom?
    Or is it something you don't really hear?

  4. MikeyD


    Sep 9, 2000
    You're welcome. You're asking good questions. There are so many variables, it would be hard to predict what it will sound like. It depends mostly on the respective sensitivity of each cabinet and how you EQ the sound. I'd say give it a try. Ultimate flexibility would be obtained if it were a stereo head - that way you could adjust the volume to each cabinet. Barring that, if both cabinets have nearly the same sensitivity (sound level for a given wattage input), then the 4-ohm cabinet might be only 3 dB louder than the other cabinet with the set-up you're asking about - which isn't that much. If you have sensitivity and frequency response specs for each cabinet, it might be easier to guess how they might work together.
    - Mike
  5. geshel


    Oct 2, 2001
    It depends on the sensitivity of the cabs. When mixing cabs it's a good idea to use ones that have similar sensetivities (rated in dB per watt, typically between 95 and 105), otherwise you'll mostly only hear the one.

    If the 15 has a 3dB higher sensitivity than the 2x10, then you're in luck: that's the difference that twice the power makes. If it is somewhere between 2 and 4 dB more efficient this would probably work fine. If it is more than that, or the 15 is less efficient than the 2x10, then I wouldn't mix the two, one will be much louder than the other.
  6. Thanks again,

    I have one more thought, does it make a difference that the connection to the second cab comes from the first cab, since the Fafner has only one speaker out and the speakers are meant to be linkt?

  7. I think that makes a big difference if you are talking about them being wired in series...

    if it is in series then it would = 12ohms
    if it is still in parallel then it would be 2.66 ohms and not make any difference at all.


  8. gordotone


    Nov 22, 2001
    I'm not a speaker expert; but my understanding is that it doesn't work that way.
    When you "daisy chain" speaker cabs together, the speaker load (ohms) still goes lower.
  9. cassanova


    Sep 4, 2000
    as long as your amp is rated 2 ohms, you can run a 2.66 load. because your still above the minimum rating
  10. geshel


    Oct 2, 2001
    99.9% chance that the two inputs on any cab are wired in parallel. So the daisy-chaining results in parallel.

    Only caveat about this is that the first speaker cable carries twice the juice, so make sure it is a good one!
  11. MikeyD


    Sep 9, 2000
    Unless stated otherwise on the cabinet, if there are multiple jacks, they are usually wired in parallel. You can "daisy chain" multiple cabinets this way, but the net impedance will be the parallel figure (2.7 ohms, in your case).
    - Mike
  12. arfur


    Nov 26, 2001
    London, UK
    Easy to tell if the daisy chain jack in the back of your cab is wired in series. If it is then the cab won't work unless another cab is plugged in.
  13. No worries guys... just something to check.