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Question about daisy chaining cabs...

Discussion in 'Amps and Cabs [BG]' started by McHack, Jan 3, 2006.


  1. McHack

    McHack

    Jul 29, 2003
    Central Ohio!
    This is a stupid question, & I should already know the answer... But, i'm I cant remember the net effect on impedence, when adding cabs to a given line.

    I ask, because I've got a Crown XLS 402... For those not familiar with the model, here's the basic power output specs...

    2ohm (per channel) 570W
    4ohm (per channel) 400W
    8ohm (per channel) 260W

    8ohm (mono bridged) 800W
    4ohm (mono bridged) 1140W

    I bought this power amp, w/ the mindset, that I'd simply run 2 4ohm cabs, one per channel.

    But, I am wonder what happens to impedence, if you daisy chain two 4 ohm cabs, running in bridged mode...
     
  2. cheezewiz

    cheezewiz Supporting Member

    Mar 27, 2002
    Ohio

    I could very well be wrong, but I believe running two 4 ohm cabs chained together would give you a 2 ohm load, which apparently your amp won't do bridged, so that's a no no.
     
  3. Thor

    Thor Moderator Staff Member Gold Supporting Member

    Seconded.

    If your are going to run it bridged, mimimum load
    based on the specs is 4 ohms.

    The load is calculated thus
    Code:
    
    1
    ----
    (1/R1 + 1/R2 + ... 1/Rn)
    
    
    or in this example
    
    1                 1
    ----         =  ---- = 2 Ohms
    (1/4+1/4)        1/2
    
    
     
  4. Jeff A

    Jeff A

    Oct 22, 2005
    CT
    Thirded

    In other words, it is the reciprocal of the sum of the reciprocals. This applies to parallel circuits only.
    1/R(total) = 1/R1 + 1/R2 + 1/R3



    In a series circuit, resistance is simply additive.
    R(total) = R1 + R2 + R3 + ...



    So yes, you will need to run it in the two channel mode and settle for just 400 watts per side.

    :hyper: :bassist: