Connecting cabs of different Ohm ratings?

Discussion in 'Amps and Cabs [BG]' started by TCollins, Feb 5, 2002.


  1. TCollins

    TCollins

    Apr 4, 2000
    I have a 2x15 (4 Ohms) and will be getting a
    2x10 rated at 8 Ohms. I have a Basis M-2000 that
    has speaker outputs for 2, 4, & 8 ohm connections.
    My question is which speaker output on the amp should
    I connect to if I use both of these cabs?

    Thanks!
     
  2. Christopher

    Christopher

    Apr 28, 2000
    New York, NY
    Amps typically are endangered when they face a load that is lower than the one that they are rated for. The combined load of the two cabs in parallel is 2.67 ohms.

    I don't know the specifics of the amp that you have, but my guess is that it would be safer to connect to the 2 ohm posts.
     
  3. Showdown

    Showdown Supporting Member

    Jan 21, 2002
    Honolulu, Hawaii
    The formula for caculating total Ohms, with X being the first cab and Y being the second is:

    1/(1/X)+(1/Y)

    Christopher is right that a 4 Ohm and a 8 Ohm cab in parallel = 2.67 Ohms. And I agree the 2 Ohm input is the one you should use.
     
  4. Matthias

    Matthias

    May 30, 2000
    Vienna, Austria
    1/((1/X)+(1/Y))
    to be correct... ;)

    you can also use (X*Y)/(X+Y)

    Matthias