impedence questions.

Discussion in 'Amps and Cabs [BG]' started by bassist286, Apr 11, 2002.

  1. bassist286


    Nov 22, 2001
    rhode island
    hello, i own an swr jr. which is 8 ohms, and i own a S.O.B. witch is also 8 ohms, but now i found a great trade in deal on a big bertha. The only problem is that the swr jr. is 8 ohms and the bertha is 4 ohms. the mimimun load on a swr 350 is 2 ohms, could i make this work or would i have to trade my 8 ohm jr. for a 4 ohm one. to make 2 ohms? thanks a bunch
  2. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    The load of a 8 Ohm and a 4 Ohm cab in parallel is 2.67 Ohm, so you'll be ok.

    Cabs are usually connected in parallel.
    You calculate their impedance like this:

    1/Rtotal = 1/Rcab1 + 1/Rcab2

    In this case:

    1/Rtotal = 1/4 + 1/8 = 3/8

    => Rtotal = 8/3 Ohm = 2 2/3 Ohm = 2.67 Ohm

    As long as it's over 2 Ohm you're ok. Fractions don't matter, and Impedance numbers are not that accurate anyway.